Category: Centos

SMTP auth relay with postfix

In case that your SMTP server has authentication (like Gmail), For this purpose we will use Postfix. I

Install the needed packages:

Ubuntu

apt-get install postfix mailutils libsasl2-2 ca-certificates libsasl2-modules

CentOS

yum update && yum install postfix mailx cyrus-sasl cyrus-sasl-plain
  • Set Postfix config file /etc/postfix/main.cf. Add this lines to the end of the file:
  1. Set Postfix config file /etc/postfix/main.cf. Add this lines to the end of the file:

    Ubuntu

    relayhost = [smtp.gmail.com]:587
    smtp_sasl_auth_enable = yes
    smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
    smtp_sasl_security_options = noanonymous
    smtp_tls_CAfile = /etc/ssl/certs/thawte_Primary_Root_CA.pem
    smtp_use_tls = yes
    

    CentOS

    relayhost = [smtp.gmail.com]:587
    smtp_sasl_auth_enable = yes
    smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
    smtp_sasl_security_options = noanonymous
    smtp_tls_CAfile = /etc/ssl/certs/ca-bundle.crt
    smtp_use_tls = yes
    
  2. Configure email address and password:

    echo [smtp.gmail.com]:587 USERNAME@gmail.com:PASSWORD > /etc/postfix/sasl_passwd
    postmap /etc/postfix/sasl_passwd
    chmod 400 /etc/postfix/sasl_passwd
    
  3. Secure DB password

    chown root:root /etc/postfix/sasl_passwd /etc/postfix/sasl_passwd.db
    chmod 0600 /etc/postfix/sasl_passwd /etc/postfix/sasl_passwd.db
    
  4. Reload Postfix

    systemctl reload postfix
  • Test you configuration with:

    echo "Test mail from postfix" | mail -s "Test Postfix" you@example.com
    echo "Test mail from postfix" | mail -s "Test Postfix" -r someone@whatever.com you@example.com (this is if your reply address has to come from a specific sender)
    

    You should receive an email on you@example.com

You should receive an email on you@example.com

Note: If you are using centos 7, which uses systemD. You will find that postfix doesn’t send maillogs to /var/log/maillog. Someone decided it would be a great idea to send it to the journaler instead.

In order to find your mail logs and or tail the logs for postfix.

  • Journalctl -u postfix (view all logs)
  • Journalctl -u postfix -f (to tail the mail logs)

How to properly upgrade wazuh with a major update (standalone setup)

Upgrade from the same major version (3.x)

The following steps show how to upgrade to the latest available version of Wazuh 3.x (which implies upgrading to the latest version of Elastic Stack 6.x).

Starting the upgrade

If you followed our manager or agents installation guides, probably you disabled the repository in order to avoid undesired upgrades. It’s necessary to enable them again to get the last packages.

  • For CentOS/RHEL/Fedora:

#sedi“s/^enabled=0/enabled=1/” /etc/yum.repos.d/wazuh.repo

Upgrade the Wazuh manager

Note

Since Wazuh v3.7.0 the File Integrity Monitoring database is not used anymore. In order to add to Wazuh DB the file and registry entries stored from previous versions it’s necessary to run the FIM migration tool.

  • Upgrade the wazuh-manager package:
  • For CentOS/RHEL/Fedora:

# yum upgrade wazuh-manager

 

  • Upgrade the wazuh-api package:
  • For CentOS/RHEL/Fedora:

# yum upgrade wazuh-api

Note

The installation of the updated packages will automatically restart the services for the Wazuh manager, API and agents. Your Wazuh config file will keep unmodified, so you’ll need to manually add the settings for the new capabilities. Check the User Manual for more information.

 

Finishing the Wazuh upgrade

You’ve finished upgrading your Wazuh installation to the latest version. Now you can disable again the Wazuh repositories in order to avoid undesired upgrades and compatibility issues.

  • For CentOS/RHEL/Fedora:

#sedi“s/^enabled=1/enabled=0/” /etc/yum.repos.d/wazuh.repo

Upgrade to the latest Elastic Stack version

Since the release of Wazuh 3.0.0, there’s been several updates to the 6.x version of the Elastic Stack, introducing several bugfixes and important changes. In order to use the latest version of Wazuh, it’s necessary to install the latest compatible Elastic Stack packages.

  • Stop the services:

#systemctl stop filebeat (This you do not need to stop in a standalone setup, because it should not be installed. Filebeat is only used when you have a clustered setup. It sends logs back to the manager when clustered)

#systemctl stop logstash

#systemctl stop kibana

#systemctl stop elasticsearch

  • Enable the Elastic repository:

If you followed our Elastic Stack Installation Guide, probably you disabled the repository in order to avoid undesired upgrades for the Elastic Stack. It’s necessary to enable them again to get the last packages.

  • For CentOS/RHEL/Fedora:

#sedi“s/^enabled=0/enabled=1/” /etc/yum.repos.d/elastic.repo

Upgrade Elasticsearch

  • Upgrade the elasticsearch package:
  • For CentOS/RHEL/Fedora:

# yum install elasticsearch-6.5.1

 

  • Start the Elasticsearch service:

#systemctl daemon-reload

#systemctlenableelasticsearch.service

#systemctl start elasticsearch.service

It’s important to wait until the Elasticsearch server finishes starting. Check the current status with the following command, which should give you a response like the shown below:

# curl "http://localhost:9200/?pretty"

{
  "name" : "Zr2Shu_",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "M-W_RznZRA-CXykh_oJsCQ",
  "version" : {
    "number" : "6.5.1",
    "build_flavor" : "default",
    "build_type" : "rpm",
    "build_hash" : "053779d",
    "build_date" : "2018-07-20T05:20:23.451332Z",
    "build_snapshot" : false,
    "lucene_version" : "7.3.1",
    "minimum_wire_compatibility_version" : "5.6.0",
    "minimum_index_compatibility_version" : "5.0.0"
  },
  "tagline" : "You Know, for Search"
}

Updating the Elasticsearch template to the latest version is mandatory in order to avoid compatibility issues with the latest versions of Wazuh and the Elastic Stack.

# curl https://raw.githubusercontent.com/wazuh/wazuh/3.7/extensions/elasticsearch/wazuh-elastic6-template-alerts.json | curl -X PUT "http://localhost:9200/_template/wazuh" -H 'Content-Type: application/json' -d @-

Upgrade Logstash

  • Upgrade the logstash package:
  • For CentOS/RHEL/Fedora:

# yum install logstash-6.5.1

  • Download and set the Wazuh configuration for Logstash:
  1. Local configuration:
# cp /etc/logstash/conf.d/01-wazuh.conf /backup_directory/01-wazuh.conf.bak
# curl -so /etc/logstash/conf.d/01-wazuh.conf https://raw.githubusercontent.com/wazuh/wazuh/3.7/extensions/logstash/01-wazuh-local.conf
# usermod -a -G ossec logstash
  1. Remote configuration: (We are not using this in our standalone setup and therefore do not need to run this)
# cp /etc/logstash/conf.d/01-wazuh.conf /backup_directory/01-wazuh.conf.bak
# curl -so /etc/logstash/conf.d/01-wazuh.conf https://raw.githubusercontent.com/wazuh/wazuh/3.7/extensions/logstash/01-wazuh-remote.conf
  • Start the Logstash service:

#systemctl daemon-reload

#systemctlenablelogstash.service

#systemctl start logstash.service

Note

The Logstash configuration file has been replaced for an updated one. If you already configured the encryption between Filebeat and Logstash, don’t forget to check again Setting up SSL for Filebeat and Logstash if you’re using a distributed architecture.

Upgrade Kibana

  • Upgrade the kibana package:
  • For CentOS/RHEL/Fedora:

# yum install kibana-6.5.1

  • Uninstall the Wazuh app from Kibana:
  • Update file permissions. This will avoid several errors prior to updating the app:

#chown -R kibana:kibana /usr/share/kibana/optimize

#chown -R kibana:kibana /usr/share/kibana/plugins

  • Remove the Wazuh app:

#sudo -u kibana /usr/share/kibana/bin/kibana-plugin remove wazuh

  • Upgrade the Wazuh app:

# rm -rf /usr/share/kibana/optimize/bundles

#sudo -u kibanaNODE_OPTIONS=“–max-old-space-size=3072” /usr/share/kibana/bin/kibana-plugin install https://packages.wazuh.com/wazuhapp/wazuhapp-3.7.1_6.5.1.zip

Warning

The Wazuh app installation process may take several minutes. Please wait patiently.

  • Start the Kibana service:

#systemctl daemon-reload

#systemctlenablekibana.service

#systemctl start kibana.service

This section only applies if you have clustered/distributed setup

Upgrade Filebeat

  • Upgrade the filebeat package:
  • For CentOS/RHEL/Fedora:

# yum install filebeat-6.5.1

  • Start the Filebeat service:

#systemctl daemon-reload

#systemctlenablefilebeat.service

#systemctl start filebeat.service

Finishing the Elastic Stack upgrade

You’ve finished upgrading your Wazuh installation to the latest version. Now you can disable again the Elastic Stack repositories in order to avoid undesired upgrades and compatibility issues with the Wazuh app.

  • For CentOS/RHEL/Fedora:

#sedi“s/^enabled=1/enabled=0/” /etc/yum.repos.d/elastic.repo

Things you will need to fix after the upgrade

1. Running migration tool for versions before 3.7 for that have upgraded recently: 

  • If you upgraded from wazuh 3.6 or newer you will need to run the following migration tool, which migrate the database into a new format for wazuh 3.7......When they first introduced the tool it had some fail to exit code if it couldn’t decode a line and it would halt the migration. They have since fixed that, however it look something like this.

    2018-11-12 15:45:38 [INFO]   [32/239] Added 3339 file entries in agent ‘033’ database.

    2018-11-12 15:45:38 [INFO]   Setting FIM database for agent ‘033’ as completed…

    2018-11-12 15:45:38 [INFO]   [33/239] Upgrading FIM database for agent ‘034’…

    2018-11-12 15:45:38 [INFO]   [33/239] Added 61 file entries in agent ‘034’ database.

    2018-11-12 15:45:38 [INFO]   [33/239] Upgrading FIM database (syscheck-registry) for agent ‘034’…

    2018-11-12 15:45:38 [ERROR]  Couldn’t decode line at syscheck database.

    Traceback (most recent call last):

      File “./fim_migrate“, line 320, in <module>

        if not check_file_entry(agt[0], decoded[2], s):

      File “./fim_migrate“, line 91, in check_file_entry

        msg = msg + cfile + b”‘;”

    TypeError: cannot concatenate ‘str’ and ‘NoneType‘ objects 


    working
    migration tool below
    https://raw.githubusercontent.com/wazuh/wazuh/3.7/tools/migration/fim_migrate.py

2. error “api version type mismatch 3.6.1′‘ :

 

  • Next run this on the server side to confirm they match
  • cat /usr/share/kibana/plugins/wazuh/package.json | grep –i -E “version|revision

“version”: “3.7.0”,

        “revision”: “0413”,

       “version”: “6.4.3”

 

If all those match then you simply need to do the following to fix it.

  • Delete the .wazuh-version index:

curl -XDELETE http://elastic_ip:9200/.wazuh-version

  • Restart Kibana:

systemctl restart kibana

Wait for about 30 s – 1 min and now open a new window in your browser, then you should navigate without any more troubles regarding the version mismatching.

Notes: The Wazuh app creates that index when you restart Kibana if it’s not present. If your standalone setup is using localhost then the curl command should be localhost and not the elastic ip.

3. Items listed per screen when listing agents will default back to 17 items for screen and is extremely annoying. You will need to fix this in the following manner.:

# systemctl stop kibana

Let’s open the file under /usr/share/kibana/plugins/wazuh/public/templates/agents-prev/agents-prev.html and look for lines 103-109:

 

<wz-table flex path=“‘/agents'” keys=“[‘id’,{value:’name’,size:2},’ip’,’status’,’group’,’os.name‘,’os.version’,’version’]” allow-click=“true” row-sizes=“[17,15,13]”></wz-table>

The wz-table tag is related to a Wazuh custom directive which has parameters to easy change that limit.

Replace [17,15,13] by your desired size [50,50,50], where each value refers to different screen sizes. Use 50 for all screen sizes,

and you’ll see 50 agents per page regardless your screen size. Use your desired value, it can be 100 or 150…

My suggestion is to don’t increase more than 50 (Angular performance reasons).

Once you are done save and close the file. Now remove old bundles and check the permissions again:

rm rf /usr/share/kibana/optimize/bundleschown R kibana:kibana /usr/share/kibana/optimizechown R kibana:kibana /usr/share/kibana/plugins

Restart Kibana:

# systemctl restart kibana

It takes a few of minutes until it’s completed, you can check the status using the next command:

# systemctl status kibana -l

 

You’ll see “Optimizing…”, once you see “App ready to be used” you can remove cache/cookies from your browser and type your App address for accessing it.

 4. Errors in wazuh log after upgrade [FORBIDDEN/12/index read-only / allow delete (api)];”}: 

 

  • If you see the following your wazuh.log
  • tail -n500 /usr/share/kibana/optimize/wazuh-logs/wazuhapp.log

{“date”:”2018-11-22T14:24:15.613Z”,”level”:”info”,”location”:”[monitoring][init]”,”message”:”Checking if wazuh-monitoring pattern exists…”}

{“date”:”2018-11-22T14:24:15.625Z”,”level”:”error”,”location”:”[initialize][checkKnownFields]”,”message”:”[cluster_block_exception] blocked by: [FORBIDDEN/12/index read-only / allow delete (api)];”}

{“date”:”2018-11-22T14:24:15.632Z”,”level”:”info”,”location”:”[monitoring][init]”,”message”:”Updating known fields for wazuh-monitoring pattern…”}

{“date”:”2018-11-22T14:24:15.646Z”,”level”:”info”,”location”:”[monitoring][init]”,”message”:”Didn’t find wazuh-monitoring pattern for Kibana v6.x. Proceeding to create it…”}

{“date”:”2018-11-22T14:24:15.650Z”,”level”:”info”,”location”:”[monitoring][createWazuhMonitoring]”,”message”:”No need to delete old wazuh-monitoring pattern.”}

{“date”:”2018-11-22T14:24:15.650Z”,”level”:”info”,”location”:”[monitoring][configureKibana]”,”message”:”Creating index pattern: wazuh-monitoring-3.x-*”}

{“date”:”2018-11-22T14:24:15.658Z”,”level”:”info”,”location”:”[initialize][checkAPIEntriesExtensions]”,”message”:”Successfully updated API entry extensions with ID: 1535484412304″}

{“date”:”2018-11-22T14:24:15.660Z”,”level”:”error”,”location”:”[monitoring][configureKibana]”,”message”:”[cluster_block_exception] blocked by: [FORBIDDEN/12/index read-only / allow delete (api)];”

    • This usually means that one of your partitions is near full and wazuh goes into read only mode because of this, super annoying…..

To fix this you must :

    • first add diskspace to your lvm, if you don’t know how to do this look it up…haha 😛
    • The you must go into the kibana interface and under under dev tools run the following
    • PUT wazuhmonitoring-*/_settings{    “index”: {        “blocks”: {            read_only_allow_delete: “false”        }    }}

    • Make sure to restart kibana:
      • systemctl restart kibana

Once kibana is restarted the log should look show something like this.

  • tail -n500 /usr/share/kibana/optimize/wazuh-logs/wazuhapp.log

   {“date”:”2018-11-23T00:00:02.464Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

Note: Initially you might only see on entry for that day, however after a few days the logs will look like this.

   {“date”:”2018-11-22T14:25:09.166Z”,”level”:”error”,”location”:”[monitoring][configureKibana]”,”message”:”[cluster_block_exception] blocked by: [FORBIDDEN/12/index read-only / allow delete (api)];”}

{“date”:”2018-11-23T00:00:02.464Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

{“date”:”2018-11-24T00:00:01.894Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

{“date”:”2018-11-25T00:00:02.055Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

{“date”:”2018-11-26T00:00:01.983Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

{“date”:”2018-11-27T00:00:02.785Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

{“date”:”2018-11-28T00:00:02.458Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

{“date”:”2018-11-29T00:00:02.163Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

{“date”:”2018-11-29T14:41:46.871Z”,”level”:”info”,”location”:”[initialize]”,”message”:”Kibana index: .kibana“}

{“date”:”2018-11-29T14:41:46.874Z”,”level”:”info”,”location”:”[initialize]”,”message”:”App revision: 0413″}

{“date”:”2018-11-29T14:41:46.874Z”,”level”:”info”,”location”:”[monitoring][configuration]”,”message”:”wazuh.monitoring.enabled: true”}

{“date”:”2018-11-29T14:41:46.874Z”,”level”:”info”,”location”:”[monitoring][configuration]”,”message”:”wazuh.monitoring.frequency: 3600 (0 */60 * * * *) “}

{“date”:”2018-11-29T14:41:46.874Z”,”level”:”info”,”location”:”[monitoring][checkKibanaStatus]”,”message”:”Waiting for Kibana and Elasticsearch servers to be ready…”}

{“date”:”2018-11-29T14:41:48.241Z”,”level”:”info”,”location”:”[initialize][checkWazuhIndex]”,”message”:”Checking .wazuh index.”}

{“date”:”2018-11-29T14:41:48.241Z”,”level”:”info”,”location”:”[initialize][checkWazuhVersionIndex]”,”message”:”Checking .wazuh-version index.”}

{“date”:”2018-11-29T14:41:48.246Z”,”level”:”info”,”location”:”[monitoring][init]”,”message”:”Creating/Updating wazuh-agent template…”}

{“date”:”2018-11-29T14:41:48.246Z”,”level”:”info”,”location”:”[monitoring][checkTemplate]”,”message”:”Updating wazuh-monitoring template…”}

{“date”:”2018-11-29T14:41:48.945Z”,”level”:”info”,”location”:”[initialize][checkKnownFields]”,”message”:”x-pack enabled: no”}

{“date”:”2018-11-29T14:41:48.999Z”,”level”:”info”,”location”:”[initialize][checkKnownFields]”,”message”:”Found 2 index patterns”}

{“date”:”2018-11-29T14:41:48.999Z”,”level”:”info”,”location”:”[initialize][checkKnownFields]”,”message”:”Found 1 valid index patterns for Wazuh alerts”}

{“date”:”2018-11-29T14:41:48.999Z”,”level”:”info”,”location”:”[initialize][checkKnownFields]”,”message”:”Default index pattern found”}

{“date”:”2018-11-29T14:41:48.999Z”,”level”:”info”,”location”:”[initialize][checkKnownFields]”,”message”:”Refreshing known fields for \”index-pattern:wazuh-alerts-3.x-*\””}

{“date”:”2018-11-29T14:41:49.092Z”,”level”:”info”,”location”:”[initialize][checkKnownFields]”,”message”:”App ready to be used.”}

{“date”:”2018-11-29T14:41:49.181Z”,”level”:”info”,”location”:”[initialize][checkAPIEntriesExtensions]”,”message”:”Checking extensions consistency for all API entries”}

{“date”:”2018-11-29T14:41:49.188Z”,”level”:”info”,”location”:”[initialize][checkAPIEntriesExtensions]”,”message”:”Successfully updated API entry extensions with ID: 1535484412304″}

{“date”:”2018-11-29T14:41:49.266Z”,”level”:”info”,”location”:”[monitoring][init]”,”message”:”Creating today index…”}

{“date”:”2018-11-29T14:41:49.295Z”,”level”:”info”,”location”:”[monitoring][init]”,”message”:”Checking if wazuh-monitoring pattern exists…”}

{“date”:”2018-11-29T14:41:49.314Z”,”level”:”info”,”location”:”[monitoring][init]”,”message”:”Updating known fields for wazuh-monitoring pattern…”}

{“date”:”2018-11-29T14:41:49.320Z”,”level”:”info”,”location”:”[monitoring][init]”,”message”:”Skipping wazuh-monitoring pattern creation. Already exists.”}

{“date”:”2018-11-30T00:00:01.567Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

{“date”:”2018-12-01T00:00:02.368Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

{“date”:”2018-12-02T00:00:01.297Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

{“date”:”2018-12-03T00:00:02.052Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

{“date”:”2018-12-04T00:00:01.602Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

{“date”:”2018-12-05T00:00:01.886Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

{“date”:”2018-12-06T00:00:02.870Z”,”level”:”info”,”location”:”[monitoring][createIndex]”,”message”:”Successfully created today index.”}

 5. Setup DiskSpaceWatch Cron:

    • I was getting annoyed with having to deal with the diskspace issues which leads to loss of logs and therefore setup a little bash script called “/usr/bin/diskspacewatchThe script runs as root cron every 30 mins, to get to the cron type ‘crontab -e’

#!/bin/sh

df -h | grep –vE ‘^Filesystem|tmpfs|cdrom‘ | awk‘{ print $5 ” ” $1 }’ | while read output;

do

echo $output

usep=$(echo $output | awk‘{ print $1}’ | cut -d’%’ -f1 )

partition=$(echo $output | awk‘{ print $2 }’ )

if [ $usepge75 ]; then

echo “Running out of space!! on wazuh production server. Add space or wazuh will go into read only mode. \”$partition ($usep%)\” on $(hostname) as on $(date)” |

mail -s “Alert: Almost out of disk space, add diskspace to wazuhprod server. $usep%” nick@nicktailor.com

fi

done

 

    • If any of the partitions reach 75 percent it will send out an email alert to nick@nicktailor.com
    • This is to help avoid log loss from wazuh going into read only mode because of diskspace.

 

    • Upgrading wazuh agents to 3.7

Note: Lastly They say in wazuh documentation that the agent is backwards compatible however this is not true in my opinion. Reason being features stop working and now require you to update all the agents. This is not a simple as simply updating the agent….

 

    • If you attempt to update the agent simply by yum or apt. It will result in the agent loosing the manager ip and key created.
    • This particular piece of the upgrade is something that you should test in a test environment by cloning your entire system to a dev one and running simulations. I learned this the hard way and how to be inventive to get it working.
    • There is an agent_upgrade tool they provide which is supposed to download the new agent, install, and recopy the manager ip and key to the agent all in one go

 

    • List out the agents that need to be upgraded
    • /var/ossec/bin/agent_upgrade -l

 Example.

Example.

waz01 ~]# /var/ossec/bin/agent_upgrade -l

ID    Name                                Version

003   centosnewtemp                       Wazuh v3.6.0

165   test1                     Wazuh v3.6.1

192   test2                       Wazuh v3.6.1

271   test3                        Wazuh v3.3.1

277   test4                           Wazuh v3.3.1

280   test5                           Wazuh v3.3.1

306   test6                           Wazuh v3.3.1

313   test6                           Wazuh v3.3.1

    • Manual update of agent(Successful)

# /var/ossec/bin/agent_upgrade -d -a 003

 

Manager version: v3.7.0

Agent version: v3.3.1

Agent new version: v3.7.0

WPK file already downloaded: /var/ossec/var/upgrade/wazuh_agent_v3.7.0_windows.wpk – SHA1SUM: 79678fd4ab800879aacd4451a64e799c62688b64

Upgrade PKG: wazuh_agent_v3.7.0_windows.wpk (2108 KB)

MSG SENT: 271 com open wb wazuh_agent_v3.7.0_windows.wpk

RESPONSE: ok

MSG SENT: 271 com lock_restart -1

RESPONSE: ok

Chunk size: 512 bytes

Sending: /var/ossec/var/upgrade/wazuh_agent_v3.7.0_windows.wpk

MSG SENT: 271 com close wazuh_agent_v3.7.0_windows.wpk

RESPONSE: ok

MSG SENT: 271 com sha1 wazuh_agent_v3.7.0_windows.wpk

RESPONSE: ok 79678fd4ab800879aacd4451a64e799c62688b64

WPK file sent

MSG SENT: 271 com upgrade wazuh_agent_v3.7.0_windows.wpk upgrade.bat

RESPONSE: ok 0

Upgrade procedure started

MSG SENT: 271 com upgrade_result

RESPONSE: err Maximum attempts exceeded

MSG SENT: 271 com upgrade_result

RESPONSE: err Cannot read upgrade_result file.

MSG SENT: 271 com upgrade_result

RESPONSE: ok 0

 

Agent upgraded successfully

 

    • Using the list provided by agent_upgrade you can copy the agent id’s to a txt file like
    • vi agentupgrade.txt   

003

165

192

271

Etc

    • You can then use a for loop like so to cycle through the list
    • for name in `cat agentupgrade.txt`; do /var/ossec/bin/agent_upgrade -a $name; echo $name; done

 Notes: Exiting the script once its running as it may cause issues as I didn’t put in any error fail to exit obviously.. The other issue I did notice that windows 2016 and windows 7 machines had issues updating the agent I saw the following errors as indicated below. This would update the agent, and then timeout without reinputting the manager ip and key. I had to manually update the failed machines as Wazuh was unable to provide me with answer as to why it was failing. I was able to replicate the issue on 50 machines. So in short if your going to upgrade and have 1000 machines. I highly recommend doing lots of simulations before you upgrade as this is one the most important parts of the upgrade. If they fail to mention in their documentation.

 

Errors:

                  # /var/ossec/bin/agent_upgrade -d -a 298 

Manager version: v3.7.0

Agent version: v3.3.1

Agent new version: v3.7.0

WPK file already downloaded: /var/ossec/var/upgrade/wazuh_agent_v3.7.0_windows.wpk – SHA1SUM: 79678fd4ab800879aacd4451a64e799c62688b64

Upgrade PKG: wazuh_agent_v3.7.0_windows.wpk (2108 KB)

MSG SENT: 298 com open wb wazuh_agent_v3.7.0_windows.wpk

RESPONSE: err Maximum attempts exceeded

MSG SENT: 298 com open wb wazuh_agent_v3.7.0_windows.wpk

RESPONSE: err Maximum attempts exceeded

MSG SENT: 298 com open wb wazuh_agent_v3.7.0_windows.wpk

RESPONSE: err Maximum attempts exceeded

MSG SENT: 298 com open wb wazuh_agent_v3.7.0_windows.wpk

RESPONSE: err Maximum attempts exceeded

MSG SENT: 298 com open wb wazuh_agent_v3.7.0_windows.wpk

RESPONSE: err Maximum attempts exceeded

MSG SENT: 298 com open wb wazuh_agent_v3.7.0_windows.wpk

RESPONSE: err Maximum attempts exceeded

MSG SENT: 298 com open wb wazuh_agent_v3.7.0_windows.wpk

RESPONSE: err Maximum attempts exceeded

MSG SENT: 298 com open wb wazuh_agent_v3.7.0_windows.wpk

RESPONSE: err Maximum attempts exceeded

MSG SENT: 298 com open wb wazuh_agent_v3.7.0_windows.wpk

RESPONSE: err Maximum attempts exceeded

MSG SENT: 298 com open wb wazuh_agent_v3.7.0_windows.wpk

RESPONSE: err Maximum attempts exceeded

MSG SENT: 298 com open wb wazuh_agent_v3.7.0_windows.wpk

RESPONSE: err Maximum attempts exceeded

Error 1715: Error sending WPK file: Maximum attempts exceeded

Traceback (most recent call last):

File “/var/ossec/bin/agent_upgrade”, line 165, in <module>

main()

File “/var/ossec/bin/agent_upgrade”, line 119, in main

rl_timeout=-1 if args.timeout == None else args.timeout, use_http=use_http)

File “/var/ossec/bin/../framework/wazuh/agent.py”, line 2206, in upgrade

show_progress=show_progress, chunk_size=chunk_size, rl_timeout=rl_timeout, use_http=use_http)

File “/var/ossec/bin/../framework/wazuh/agent.py”, line 2102, in _send_wpk_file

raise WazuhException(1715, data.replace(“err “,””))

wazuh.exception.WazuhException: Error 1715 – Error sending WPK file: Maximum attempts exceeded

 

 

 

 

 

 

 

 

 

 

 

 

How to survive a log flood – wazuh

This is directly from wazuh documentation, but I thought it would good to have here for people browsing through. I guess the main section to take notice of is how to augment the agent buffer via the ossec.conf on the client side for troubleshooting purposes

Survive a log flood

A centralized logging system needs to be able to process many events per second (eps) from many different log sources at the same time, but sometimes things just get completely out of hand. A variety of problems like infinite loop conditions, poorly written software, and misconfigured applications can cause one or a few individual devices to suddenly start producing a huge and unstopping stream of log messages rushing at your logging system at a rate of hundreds or even thousands of events per second. When such a device or devices suddenly take up vastly more than their fair share of network and log processing resources, it can become widely disruptive. Log flooding can saturate your network bandwidth and/or overtax your Wazuh and Elastic system components while one gigabyte after another of likely the same repeated log messages are being reanalyzed and churned to disk.

Thankfully the Wazuh agent has a flood protection mechanism to prevent out of control log production on one system from creating disruptions to your network or to your Wazuh/Elastic services. In this lab we will create a small log flood and observe how it is gracefully contained by the Wazuh agent before it departs the system where the logs are produced. We will also take a look at the leaky bucket queue that Wazuh uses to accomplish this. Lastly we will note the alerts that are produced to keep us informed about the onset of, escalation of, and recovery from log flooding events.

Configure the Wazuh agent client buffer on linux-agent

  • In this lab, we will limit agent log production to 20 events per second (eps). By default, this limit is prevented from being set to lower than 50, so we will override that by changing the relevant internal options setting. This does not actually set an eps limit. Rather, it is a strictly agent-side setting that protects the agent from being inadvertently subjected to overly restrictive eps limits pushed to it via Wazuh manager centralized configuration. Here we make it possible to enforce an eps as low as 10.
  • #echoagent.min_eps=10″ >> /var/ossec/etc/local_internal_options.conf
  • Open /var/ossec/etc/ossec.conf and find the <client_buffer> section, which looks like this:
  • <client_buffer>
  • <!– Agent buffer options –>
  • <disabled>no</disabled>
  • <queue_size>5000</queue_size>
  • <events_per_second>500</events_per_second>
  • </client_buffer>
  • Restart the Wazuh agent
  • #ossec-control restart

Note

The client buffer is explained in detail in the Wazuh User manual. Search for “Anti-flooding mechanism”. In brief, it allows a Wazuh agent to limit the rate at which it sends log events to the Wazuh Manager. If events are produced at a rate in excess of the configured eps limit, then they are stored in a leaky bucket queue until the eps rate slows down enough that the queue contents can be sent along to the Wazuh Manager. If the queue gets full, then any new events are droped, i.e the bucket leaks. Various alerts are sent to the Wazuh Manager about all of this.

  • To ensure our flood simulation causes queueing and ultimately overflows the queue, change <queue_size> to 500 and <events_per_second> to 20. Save and close ossec.conf. The new section should look like this:
  • <client_buffer>
  • <!– Agent buffer options –>
  • <disabled>no</disabled>
  • <queue_size>500</queue_size>
  • <events_per_second>20</events_per_second>
  • </client_buffer>

Warning

These settings are small for simulation purposes. You would not want to make them this low in production.

Make Wazuh manager record alerts for each flooded event record

Because we will intentionally include the word “fatal” in the flooding log records we generate, they each will trigger generic Wazuh rule 1002 which has a low severity level of 2. By default, Wazuh Manager does not record alerts on rules of severity levels less than 3, so for this lab we will lower the threshold.

  • Edit /var/ossec/etc/ossec.conf and change <log_alert_level> from 3 to 1 so that the <alerts> section looks like below. Now alerts of all severity levels will show up in Kibana.
  • <alerts>
  • <log_alert_level>1</log_alert_level>
  • <email_alert_level>12</email_alert_level>
  • </alerts>
  • Restart Wazuh Manager.
  • #ossec-control restart

Generate a log flood on linux-agent

  • Create a script called /usr/local/bin/makeflood, with this content:
  • #!/bin/bash
  • for i in {1..10000}
  • do
  • echo -n “1:floodtest:Feb 3 03:08:47 linux-agent centos: fatal firehose $i” | ncatUu /var/ossec/queue/ossec/queue
  • echo -n “.”
  • done

Note

While we could write records to a log file monitored by Wazuh agent, this script takes an even faster approach of writing records directly to the Wazuh agent’s internal socket where, for example, ossec-logcollector streams new log lines from log files. The script uses netcat to do this, but any tool that can write datagrams to a Unix socket will do the job. Sometimes it is desirable to have a script on a Wazuh agent send results directly back to the Wazuh manager while completely bypassing the agent’s filesystem. The quoted log line that is piped to netcat consists of three colon-separated parts. First, the “1” corresponds to the syslog log type. The second field causes the location metadata value to be set to “floodtest”. After that is a log line just like you might see in /var/log/messages.

  • Make the script executable and then run it to generate a rapid flood of 10,000 log entries.
  • #chmod700 /usr/local/bin/makeflood
  • #makeflood
  • Notice that the periods representing log messages are scrolling acrosss the screen at a rate well above our 20 eps limit.

See what happened according to Kibana

  • Query Kibana for “firehose”. Click [Add] next to “full_log” for readability. Change the scale from “Auto” to “Second”.

Wazuh Agent Client Buffer

  • Notice that the flooding events only arrived at the Wazuh Manager at a rate of 20 eps, our intended limit. The client buffer eps limit worked!
  • Notice that only 1,269 hits are reported for a flood. It appears many of the flooded events were lost.
  • Expand one of the “firehose” records and compare the field values to the script you used to produce these records.

  • Query Kibana for “agent_flooding”. Click [Add] additionally next to “rule.description” and “data.level” for readability.

  • Observe how Wazuh alerts us at various stages of a flooding event so that we can know when we need to intervene with an over-logging system that is not recovering to a normal state on its own.

Return linux-agent to normal client buffer settings

  • In the <client_buffer> section of /var/ossec/etc/ossec.conf file, change it back to this:
  • <client_buffer>
  • <!– Agent buffer options –>
  • <disabled>no</disabled>
  • <queue_size>5000</queue_size>
  • <events_per_second>500</events_per_second>
  • </client_buffer>
  • Restart the Wazuh agent
  • #ossec-control restart

Congratulations on completing this lab. You survived the log flood!

How to update java on centos

First of all, check your current Java version with this command:

java -version

Example:

$ java -version
java version "1.8.0_181"
Java(TM) SE Runtime Environment (build 1.8.0_181-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed mode)

If your installed version is not Java 8 update 181, then you could follow the step in order to download the latest Java version and install it:

  1. Download the Java JRE package for RPM-based distributions:
    curl -Lo jre-8-linux-x64.rpm --header "Cookie: oraclelicense=accept-securebackup-cookie" "https://download.oracle.com/otn-pub/java/jdk/8u181-b13/96a7b8442fe848ef90c96a2fad6ed6d1/jre-8u181-linux-x64.rpm"
    
  2. Check that the package was successfully downloaded:
    rpm -qlp jre-8-linux-x64.rpm > /dev/null 2>&1 && echo "Java package downloaded successfully" || echo "Java package did not download successfully"
    
  3. Install the package using yum:
    yum -y install jre-8-linux-x64.rpm
    rm -f jre-8-linux-x64.rpm
    

How to diagnose a kernel panic caused by a killed process

You should install atop on your server as this is top on steroids and can help diagnose all kinds of server issues such as.

https://lwn.net/Articles/387202/ – Atop usage

  • CPU load
  • IO load
  • Memory usage
  • Process utilization of resources
  • Paging/swaping
  • etc…
  • How you install atop on ubuntu/debian
    • ‘apt-get install atop’
  • Then you want to start the atop logging
    • ‘/etc/init.d/atop start

Note : by default the atop logs every 10mins

Now lets say you console your VM or blade server. You see a message that states the server killed a process or ran out of memory or something.

Example:

  • Out of memory: Kill process 11970 (php) score 80 or sacrifice child
    Killed process 11970 (php) total-vm:1957108kB

When you reboot the server you will want to find out exactly how it happened.  How you do this is by checking the kernel log. Now if you have kdump installed you can use that to get a dump of the kernel log and if not you can do this.

  • dmesg | egrep -i ‘killed process’
    • this will provide a log as indicated below

Kernel log

  • [Wed July 10 13:27:30 2018] Out of memory: Kill process 11970 (php) score 80 or sacrifice child]
  • [Wed July 10 13:27:30 2018] Killed process 11970 (php) total-vm:123412108kB, anon-rss:1213410764kB, file-rss:2420k]

Now once you have this log you can see the time stamp of when it occurred and you can use atop logs to drill down and find the process id, and see if you can see which daemon and or script caused the issue.

From the log ‘July 10 13:27:30 2018’ we can see the time stamp. Inside /var/log/atop you can do the following.

Run the following:

  • ‘atop -r atop_20180710’
    this will bring up a screen and you can toggle through the time intervals by using lowercase ‘T’ to move forward in time or Capital ‘T’ to go backward in time.
  • Once you find the time stamp you can
    press –
    ‘c’ – full command-line per process to see which processes were running at that time stamp and you should be able to locate the id process from the kernel log

    atop -r atop_20180710’

     

Example

  • 3082  27% php
  • 15338  27% php
  • 26639  25% php
  • 8520   8% php
  • 8796   8% php
  • 2157   8% /usr/sbin/apache2 -k start
  • 11970   1% php – This is the process ID from the kernel log above and what appears to what was running. So we know it was a php script. Atop doesn’t always provide the exact script. However from the kernel log and this we can determine what was some type of rss feed. From this you can also see that it wasnt using very much CPU. This helps us determine that the php code is causing a memory leak and needs to be updated and or disabled.
  • 10493   1% php
  • 10942   1% php
  • 5335   1% php
  • 9964   0% php

Written by Nick Tailor

 

How to setup ansible on centos 7

Prerequisites

To follow this tutorial, you will need:

Step 1 — Installing Ansible

To begin exploring Ansible as a means of managing our various servers, we need to install the Ansible software on at least one machine.

To get Ansible for CentOS 7, first ensure that the CentOS 7 EPEL repository is installed:

 sudo yum install epel-release
 

Once the repository is installed, install Ansible with yum:

 sudo yum install ansible
 

We now have all of the software required to administer our servers through Ansible.

Step 2 — Configuring Ansible Hosts

Ansible keeps track of all of the servers that it knows about through a “hosts” file. We need to set up this file first before we can begin to communicate with our other computers.

Open the file with root privileges like this:

 sudo vi /etc/ansible/hosts
 

You will see a file that has a lot of example configurations commented out. Keep these examples in the file to help you learn Ansible’s configuration if you want to implement more complex scenarios in the future.

The hosts file is fairly flexible and can be configured in a few different ways. The syntax we are going to use though looks something like this:

Example hosts file

[group_name]

alias ansible_ssh_host=your_server_ip

The group_name is an organizational tag that lets you refer to any servers listed under it with one word. The alias is just a name to refer to that server.

Imagine you have three servers you want to control with Ansible. Ansible communicates with client computers through SSH, so each server you want to manage should be accessible from the Ansible server by typing:

 ssh root@your_server_ip
 

You should not be prompted for a password. While Ansible certainly has the ability to handle password-based SSH authentication, SSH keys help keep things simple. 

We will assume that our servers’ IP addresses are 192.168.0.1192.168.0.2, and 192.168.0.3. Let’s set this up so that we can refer to these individually as host1host2, and host3, or as a group as servers. To configure this, you would add this block to your hosts file:

/etc/ansible/hosts

[servers]

host1 ansible_ssh_host=192.168.0.1

host2 ansible_ssh_host=192.168.0.2

host3 ansible_ssh_host=192.168.0.3

 

Hosts can be in multiple groups and groups can configure parameters for all of their members. Let’s try this out now.

Ansible will, by default, try to connect to remote hosts using your current username. If that user doesn’t exist on the remote system, a connection attempt will result in this error:

Ansible connection error

host1 | UNREACHABLE! => {

“changed”: false,

msg“: “Failed to connect to the host via ssh.”,

“unreachable”: true

}

Let’s specifically tell Ansible that it should connect to servers in the “servers” group with the nick user. Create a directory in the Ansible configuration structure called group_vars.

 sudo mkdir /etc/ansible/group_vars
 

Within this folder, we can create YAML-formatted files for each group we want to configure:

 sudo nano /etc/ansible/group_vars/servers
 

Add this code to the file:

/etc/ansible/group_vars/servers

ansible_ssh_user: ansiblenick

YAML files start with “—“, so make sure you don’t forget that part.

Save and close this file when you are finished. Now Ansible will always use the ansiblenick user for the servers group, regardless of the current user.

If you want to specify configuration details for every server, regardless of group association, you can put those details in a file at /etc/ansible/group_vars/all. Individual hosts can be configured by creating files under a directory at /etc/ansible/host_vars.

Step 3 — Using Simple Ansible Commands

Now that we have our hosts set up and enough configuration details to allow us to successfully connect to our hosts, we can try out our very first command.

Ping all of the servers you configured by typing:

 ansible -m ping all
 

Ansible will return output like this:

Output

host1 | SUCCESS => {

“changed”: false,

“ping”: “pong”

}

.

host3 | SUCCESS => {

“changed”: false,

“ping”: “pong”

}

.

host2 | SUCCESS => {

“changed”: false,

“ping”: “pong”

}

This is a basic test to make sure that Ansible has a connection to all of its hosts.

The -m ping portion of the command is an instruction to Ansible to use the “ping” module. These are basically commands that you can run on your remote hosts. The ping module operates in many ways like the normal ping utility in Linux, but instead it checks for Ansible connectivity.

The all portion means “all hosts.” You could just as easily specify a group:

 ansible -m ping servers
 

You can also specify an individual host:

 ansible -m ping host1
 

You can specify multiple hosts by separating them with colons:

 ansible -m ping host1:host2
 

The shell module lets us send a terminal command to the remote host and retrieve the results. For instance, to find out the memory usage on our host1 machine, we could use:

 ansible -m shell -a ‘free -m’ host1
 

As you can see, you pass arguments into a script by using the -a switch. Here’s what the output might look like:

Output

host1 | SUCCESS | rc=0 >>

total used free shared buffers cached

Mem: 3954 227 3726 0 14 93

-/+ buffers/cache: 119 3834

Swap: 0 0 0

.

How to recover file system corruption on 4T LVM using DDrescue on a VM

How to recover file system corruption on 4T LVM on ubuntu using a VM

In this example we will be fixing a xfs filesystem that failed initial xfs_repair

If this happens don’t panic. We can fix most likely fix it.

Steps to do

 Increase vm memory to 32Gig of ram
 Add another disk that is the same size or even slightly larger as the lvm with the corrupted.
 Make sure you use a complete new datastore and that’s not being managed by DRS if your using vmware as this will be temporary.
 reboot the VM

.

Create new physical volume, volume group and logical volume

 Create a new physical volume so that it can be added to a new volume group
 Fdisk -l (to find the disk)
 Pvcreate /dev/sdx  <- replace x with drive designation
 Create volume group
 Vgcreate recovery /dev/sdx < – use whatever drive designation was used in above step
 Create logical volume
 lvcreate -l 100%FREE -n data1 $VGNAME
 lvcreate -l 100%free -n data1 recovery <- example
 mkfs.xfs /dev/recovery/data1
 Mount the new lvm
 Mount /dev/recovery/data1 /mnt/recovery

Now install ddrescue and make image of the corrupted file system on the new logical volume

 sudo add-apt-repository universe
 sudo apt update
 sudo apt install gddrescue

.

Make swap size 30gigs – this is needed so when we repair the filesystem it doesn’t time out because it runs out of memory. Which tends to be the problem when trying to repair such large filesystems.

 sudo dd if=/dev/zero of=/swapfile bs=30G count=2 <- move the /swapfile to a location where there enough room
 chmod 0600 /swapfile
 mkswap /swapfile
 swapon /swapfile
 swapon -s (should show the new swapfile)
Sample outputs
 Filename        Type    Size  Used  Priority
 /dev/sda5 partition  3998716  704  -1
 /swapfile file    2097148  0

Create rescue image on new logical volume

 ddrescue -d -r3 $oldfilesyetem imagefile.img loglocationpath.logfile

ddrescue -d -r3 /dev/recovery/data /mnt/recovery/recovery.img /mnt/recovery/recoverylog.logfile

 this will take awhile to run, probably hours

Once the file is created we want to repair it using xfs_repair

 xfs_repair -m 30000 /mnt/recovery/recovery.img
 this will also take awhile to run:

– agno = 29

– agno = 9

– agno = 10

– agno = 11

– agno = 12

– agno = 13

– agno = 14

– 20:02:48: check for inodes claiming duplicate blocks – 88951488 of 88951488 inodes done

Phase 5 – rebuild AG headers and trees…

– 20:02:57: rebuild AG headers and trees – 41 of 41 allocation groups done

– reset superblock…

Phase 6 – check inode connectivity…

– resetting contents of realtime bitmap and summary inodes

– traversing filesystem …

– traversal finished …

– moving disconnected inodes to lost+found …

Phase 7 – verify and correct link counts…

Done

 once complete you should be able to mount the image
 mount recovery.img /mnt/recovery/data1
 if successful it should mount under when you do df -h
 /dev/loop0 3.0T 1.2T 1.9T 38% /mnt/recovery/data1

.

Written By Nick Tailor

.

.

.

How to automate your RedHat Satellite 5.x Channel Cloning

  • In order for the scripts to work without sending your password to “ps” you will need to setup a config for spacecmd

Credential FileEdit section

Spacecmd can be configured with a credentials file so you are not prompted for a username/password each time. This allows for easier scripting.

  1. Create a hidden spacecmd directory in your home. Lock down permissions.
    mkdir ~/.spacecmd
    chmod 700 ~/.spacecmd
    
  1. Create a config file in the directory and give proper permissions.
    touch ~/.spacecmd/config
    chmod 600 ~/.spacecmd/config
    
  1. Edit the config file and fill in the header, Spacewalk server fqdn, username, and password.
    vim ~/.spacecmd/config
    
    [spacecmd]
    server=spacewalk.nicktailor.com
    username=usernamehere
    password=passwordhere

Clone scripts
http://www.nicktailor.com/files/clonechannel.redhat7.sh
http://www.nicktailor.com/files/clonechannel.redhat6.sh
http://www.nicktailor.com/files/clonechannel.redhat5.sh

REDHAT 7 (EXAMPLE)
#!/bin/bash
spacewalkServer=spacewalk.nicktailor.com
defaultOrgAdmin=USER

read -p “Enter to Continue”

BASE_CHANNEL=”rhel-x86_64-server-7″
CHILD_CHANNELS=”rhel-x86_64-server-7-thirdparty-oracle-java rhel-x86_64-server-7-rhscl-1 rhel-x86_64-server-optional-7 rhel-x86_64-server-supplementary-7 rhn-tools-rhel-x86_64-server-7 epel_rhel7_x86_64 nginx.org-packages”
SPECIAL=”rhel-tools-rhel-x86_64-server-6″
DATESTRING=`date +20%y-%B-%d`
echo Run on $DATESTRING >> clonechannels-$DATESTRING.log
UNDO_FILE=clonechannels-$DATESTRING.undo
rm -f $UNDO_FILE
rm -f clonechannels-$DATESTRING.log
echo Undo file is $UNDO_FILE
echo DATESTRING = $DATESTRING
BASE_CHANNEL_NAME=$BASE_CHANNEL-$DATESTRING
echo BASE_CHANNEL_NAME = $BASE_CHANNEL_NAME
echo spacecmd -u $defaultOrgAdmin -s $spacewalkServer — softwarechannel_clone -n $BASE_CHANNEL_NAME -l $BASE_CHANNEL_NAME -s $BASE_CHANNEL -g >> clonechannels-$DATESTRING.log
spacecmd -u $defaultOrgAdmin -s $spacewalkServer — softwarechannel_clone -n $BASE_CHANNEL_NAME -l $BASE_CHANNEL_NAME -s $BASE_CHANNEL -g
echo spacecmd -u $defaultOrgAdmin -s $spacewalkServer — softwarechannel_setorgaccess $BASE_CHANNEL_NAME -e >> clonechannels-$DATESTRING.log
spacecmd -u $defaultOrgAdmin -s $spacewalkServer — softwarechannel_setorgaccess $BASE_CHANNEL_NAME -e
for CHILD_CHANNEL in ${CHILD_CHANNELS}
do
CHILD_CHANNEL_NAME=$CHILD_CHANNEL-$DATESTRING
echo CHILD_CHANNEL_NAME = $CHILD_CHANNEL_NAME
echo spacecmd -u $defaultOrgAdmin -s $spacewalkServer — softwarechannel_clone -n $CHILD_CHANNEL_NAME -l $CHILD_CHANNEL_NAME -p $BASE_CHANNEL_NAME -s $CHILD_CHANNEL -g >> clonechannels-$DATESTRING.log
spacecmd -u $defaultOrgAdmin -s $spacewalkServer — softwarechannel_clone -n $CHILD_CHANNEL_NAME -l $CHILD_CHANNEL_NAME -p $BASE_CHANNEL_NAME -s $CHILD_CHANNEL -g
if [ $CHILD_CHANNEL == “rhn-tools-rhel-x86_64-server-7” ]
then spacecmd -u $defaultOrgAdmin -s $spacewalkServer — softwarechannel_clone -n $SPECIAL -l $SPECIAL -p $BASE_CHANNEL_NAME -s $CHILD_CHANNEL -g
fi
echo spacecmd -u $defaultOrgAdmin -s $spacewalkServer — softwarechannel_setorgaccess $CHILD_CHANNEL_NAME -e >> clonechannels-$DATESTRING.log
spacecmd -u $defaultOrgAdmin -s $spacewalkServer — softwarechannel_setorgaccess $CHILD_CHANNEL_NAME -e
echo spacecmd -u $defaultOrgAdmin -s $spacewalkServer -y — softwarechannel_delete $CHILD_CHANNEL_NAME >> $UNDO_FILE
done

How to add Redhat Server 6.0 to Active Directory

.We will be using sssd/kerberos/ldap to join the server to a domain in Active directory for SSO(Single Sign On Authentication)

.

Note: After you have successfully deployed a server using kickstart or manually registered a redhat server to satellite, next we need to join the server to domain controller aka Active Directory

.

1.Login via ssh to the server via putty or similar ssh client.
2.Next we will need to install some packages, type the following below.

.

 yum install -y sssd krb5-workstation samba-common authconfig oddjob-mkhomedir
 If you do not have your server registered to satellite. You will need to manually setup the following files for this to work. I have at the bottom of this document provided example files of what they should contain. Which you will need to adjust to your specific environments.

.

· /etc/krb5.conf
· /etc/oddjobd.conf.d/oddjobd-mkhomedir.conf
· /etc/pam.d/password-auth-ac
· /etc/pam.d/su
· /etc/pam.d/system-auth-ac
· /etc/samba/smb.conf
· /etc/sudoers

.

.

3.Now since the server is already registered to satellite. You can deploy the configuration files necessary to join the server to the domain from satellite server as follows.
1.Log into the red hat satellite server into the corresponding organization you wish to manage.
2.Click one systems top left corner
3.Next filter the server by name click go.
4.Click on the host name of the server
5.Now click on configuration
6.On the far right you should see “Deploy all managed config files” click that.
7.At the bottom right select “Schedule deploy”

.

4.Login via ssh to the server and pull down the configuration files by typing the following
8.rhn_check (this will pull down all the configuration files from satellite server)

.

5.Now you want to enabled authconfig so users home directories get created if they aren’t. Type the following at the ssh prompt.
9.Authconfig –emablemkhomedir –update

.

6.Now edit the file /etc/security/limits.conf and add the following line below.
 * – nofile 16384

.

7.Now you want to load configuration from samba by running “testparm”

..

.

The output will look like something this:

.

Load smb config files from /etc/samba/smb.conf

Loaded services file OK.

Server role: ROLE_DOMAIN_MEMBER

Press enter to see a dump of your service definitions

.

[global]

  workgroup = NICKSTG

  realm = NICKSTG.NICKTAILOR.COM

  security = ADS

  kerberos method = secrets and keytab

  log file = /var/log/

  client signing = Yes

  idmap config * : backend = tdb

.

8.Next you want to pull the admin credentials by running the following.
10.Kinit <DC Admin Username >
11.Net ads join k (this will add the server to the domain using above AD Credentials)

.

Note: If the nets join fails. It will be due to most likely three reasons.

 DNS not setup in Active directory for the host
 NTP server time is out more by more then 5 mins.
 Your dns is not pointed to active directory in /etc/resolv.conf

.

I ran into the NTP issue. Here is how you fix it.

 Yum install ntp
 Edit the etc/ntp.conf
 Add the following lines and save the file

.

 restrict default ignore
 restrict 127.0.0.1
 
 restrict ntp01.nicktailor.com mask 255.255.255.255 nomodify notrap noquery
 server ntp01.nicktailor.com iburst
 
 driftfile /var/lib/ntp/drift
 
 Now you want to manually update the NTP server by doing the following
 ntpdate -u 192.168.1.56(ntp01.nicktailor.com)
 and the rerun net ads join k

.

12.enable the following services to boot on reboot.
1.Chkconfig sssd on
2.Chkconfig oddjobd on
3.Chkconfig sshd
4.
13.Start the above services
5.service start sshd
6.service start oddjobd on
7.service start sssd

.

14.Lastly you will need file sharing installed
8.Yum install –y cifs-utils

.

15.Now you should be able reboot your server and login via active directory credentials via ssh.

.

.

If your server is not registered to satellite

.

You will need to have the following files configured as such

.

/etc/krb5.conf

[logging]

default = FILE:/var/log/krb5libs.log

kdc = FILE:/var/log/krb5kdc.log

admin_server = FILE:/var/log/kadmind.log

[libdefaults]

default_realm = NICKSTG.NICKTAILOR.COM

dns_lookup_realm = false

dns_lookup_kdc = false

ticket_lifetime = 24h

renew_lifetime = 7d

forwardable = true

[realms]

NICKSTG.NICKTAILOR.COM = {

kdc = DC1.NICKTAILOR.COM

admin_server = DC1.NICKTAILOR.COM

}

[domain_realm]

.nickstg.nicktailor.com = = NICKSTG.NICKTAILOR.COM

nickstg.nicktailor.com = = NICKSTG.NICKTAILOR.COM

.

/etc/oddjobd.conf.d/oddjobd-mkhomedir.conf

<?xml version=”1.0″?>

.

<!– This configuration file snippet controls the oddjob daemon. It

     provides access to mkhomedir functionality via a service named

“com.redhat.oddjob_mkhomedir”, which exposes a single object

(“/”).

The object allows the root user to call any of the standard D-Bus

     introspection interface’s methods (these are implemented by

     oddjobd itself), and also defines an interface named

     “com.redhat.oddjob_mkhomedir”, which provides two methods. –>

.

<oddjobconfig>

.

<service name=”com.redhat.oddjob_mkhomedir”>

.

<object name=”/”>

.

<interface name=”org.freedesktop.DBus.Introspectable”>

.

<allow min_uid=”0″ max_uid=”0″/>

        <!– <method name=”Introspect”/> –>

.

</interface>

.

<interface name=”com.redhat.oddjob_mkhomedir”>

.

<method name=”mkmyhomedir”>

<helper exec=”/usr/libexec/oddjob/mkhomedir -u 0077″

                  arguments=”0″

                  prepend_user_name=”yes”/>

          <!– no acl entries -> not allowed for anyone –>

</method>

.

<method name=”mkhomedirfor”>

<helper exec=”/usr/libexec/oddjob/mkhomedir -u 0077″

                  arguments=”1″/>

<allow user=”root”/>

</method>

.

</interface>

.

</object>

.

</service>

.

</oddjobconfig>
================================================================================

.

/etc/pam.d/password-auth-ac

#%PAM-1.0

# This file is auto-generated.

# User changes will be destroyed the next time authconfig is run.

auth required pam_env.so

auth sufficient pam_unix.so nullok try_first_pass

auth requisite pam_succeed_if.so uid >= 500 quiet

auth sufficient pam_sss.so use_first_pass

auth required pam_deny.so

.

account required pam_unix.so

account sufficient pam_localuser.so

account sufficient pam_succeed_if.so uid < 500 quiet

account [default=bad success=ok user_unknown=ignore] pam_sss.so

account required pam_permit.so

.

password requisite pam_cracklib.so try_first_pass retry=3

password sufficient pam_unix.so md5 shadow nullok try_first_pass use_authtok

password sufficient pam_sss.so use_authtok

password required pam_deny.so

.

session optional pam_keyinit.so revoke

session required pam_limits.so

session optional pam_oddjob_mkhomedir.so skel=/etc/skel

session [success=1 default=ignore] pam_succeed_if.so service in crond quiet use_uid

session required pam_unix.so

session optional pam_sss.so

.

/etc/pam.d/su

#%PAM-1.0

auth sufficient pam_rootok.so

.

auth [success=2 default=ignore] pam_succeed_if.so use_uid user ingroup grp_technology_integration_servertech_all

auth [success=1 default=ignore] pam_succeed_if.so use_uid user ingroup wheel

auth required pam_deny.so

.

auth include system-auth

.

account sufficient pam_succeed_if.so uid = 0 use_uid quiet

account include system-auth

.

password include system-auth

.

session include system-auth

session optional pam_xauth.so

.

.

#This line is the last line

.

/etc/pam.d/system-auth-ac

#%PAM-1.0

# This file is auto-generated.

# User changes will be destroyed the next time authconfig is run.

auth required pam_env.so

auth sufficient pam_fprintd.so

auth sufficient pam_unix.so nullok try_first_pass

auth requisite pam_succeed_if.so uid >= 500 quiet

auth sufficient pam_sss.so use_first_pass

auth required pam_deny.so

.

account required pam_unix.so

account sufficient pam_localuser.so

account sufficient pam_succeed_if.so uid < 500 quiet

account [default=bad success=ok user_unknown=ignore] pam_sss.so

account required pam_permit.so

.

password requisite pam_cracklib.so try_first_pass retry=3

password sufficient pam_unix.so md5 shadow nullok try_first_pass use_authtok

password sufficient pam_sss.so use_authtok

password required pam_deny.so

.

session optional pam_keyinit.so revoke

session required pam_limits.so

session optional pam_oddjob_mkhomedir.so skel=/etc/skel

session [success=1 default=ignore] pam_succeed_if.so service in crond quiet use_uid

session required pam_unix.so

session optional pam_sss.so

.

/etc/samba/smb.conf

[global]

workgroup = NICKSTG

client signing = yes

client use spnego = yes

kerberos method = secrets and keytab

realm = NICKSTG.NICKTAILOR.COM

.

security = ads

log file = /var/log/

.

/etc/sssd/sssd.conf

[sssd]

config_file_version = 2

reconnection_retries = 3

sbus_timeout = 30

services = nss, pam

domains = default, nickstg.nicktailor.com

.

[nss]

filter_groups = root

filter_users = root,bin,daemon,adm,lp,sync,shutdown,halt,mail,news,uucp,operator,games,gopher,ftp,nobody,vcsa,pcap,ntp,dbus,avahi,rpc,sshd,xfs,rpcuser,nfsnobody,haldaemon,avahi-autoipd,gdm,nscd,oracle, ,deploy,tomcat,jboss,apache,ejabberd,cds,distcache,squid,mailnull,smmsp,backup,bb,clam,obdba,postgres,named,mysql,quova, reconnection_retries = 3

.

[pam]

reconnection_retries = 3

.

[domain/nickstg.nicktailor.com]

id_provider = ad

access_provider = simple

cache_credentials = true

#ldap_search_base = OU=NICKSTG-Users,DC=NICKSTG,DC=nicktailor,DC=com

override_homedir = /home/%u

default_shell = /bin/bash

simple_allow_groups = ServerTech_All,Server_Systems_Integration

.

/etc/sudoers

## /etc/sudoers

## nicktailor sudoers configuration

.

## Include all configuration from /etc/sudoers.d

## Note: the single # is needed in the line below and is NOT a comment!

.

#includedir /etc/sudoers.d

##%NICKSTG\\domain\ users ALL = NOPASSWD: ALL

% ServerTech_All ALL = NOPASSWD: ALL

% Server_Systems_Integration ALL = NOPASSWD: ALL

.

How to do a full restore if you wiped all your LVM’s

I’m sure some of you have had the wonderful opportunity to experience loosing all your LVM info in error. Well all is not lost and there is hope. I will show ya how to restore it.

The beauty of LVM is that is naturally creates a backup of the Logical Volumes in the following location.

  • /etc/lvm/archive/

Now If you had just wiped out your LVM and it was simply using one physical disk for all your LVM’s you could simply do a full restore doing the following.

      • vgcfgrestore -f /etc/lvm/archive/(volumegroup to restore) (destination volumegroup)
        o    (ie.)vgcfgrestore -f /etc/lvm/archive/vg_dev1_006.000001.vg vg_dev

If you had multiple disks attached to your volume group then you need to do a couple more things to be able to do a restore.

  • Cat the file /etc/lvm/archive/whatevervolumgroup.vg file you should see something like below
  • physical_volumes {

                        pv0 {

                                    id = “ecFWSM-OH8b-uuBB-NVcN-h97f-su1y-nX7jA9”
                                    device = “/dev/sdj”         # Hint only
                                    status = [“ALLOCATABLE”]
                                    flags = []
                                    dev_size = 524288000    # 250 Gigabytes
                                    pe_start = 2048
                                    pe_count = 63999          # 249.996 Gigabytes
                        }

 

You will need to recreate all the physical volume UUID inside that .vg file for volume group to be able to restore.

    • pvcreate –restore /etc/lvm/archive/vgfilename.vg –uuid <UUID> <DEVICE>

      (IE) pvcreate –restorefile /etc/lvm/archive/vg_data_00122-1284284804.vg –uuid ecFWSM-OH8b-uuBB-NVcN-h97f-su1y-nX7jA9 /dev/sdj
  • Repeat this step for all the physical volumes in the archive vg file until they have all been created.

Once you have completed the above step you should now be able to restore your voluegroups that were wiped

    • vgcfgrestore -f /etc/lvm/archive/(volumegroup to restore) (destination volumegroup)

      o (ie.)vgcfgrestore -f /etc/lvm/archive/vg_dev1_006.000001.vg vg_dev
  • Running the command vgdisplay and pvdisplay should show you that everything is back the way it should be

If you have questions email nick@nicktailor.com

Cheers

 

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