{"id":1177,"date":"2020-12-21T20:35:04","date_gmt":"2020-12-21T20:35:04","guid":{"rendered":"https:\/\/www.nicktailor.com\/?p=1177"},"modified":"2023-05-12T02:52:44","modified_gmt":"2023-05-12T02:52:44","slug":"how-to-generate-new-network-uuids-with-ansible","status":"publish","type":"post","link":"https:\/\/nicktailor.com\/tech-blog\/how-to-generate-new-network-uuids-with-ansible\/","title":{"rendered":"How to generate new Network UUID\u2019s with Ansible"},"content":{"rendered":"

Okay some of you might have deployed linux vm\u2019s from clone templates using ansible by way of the vmware_guest module<\/strong>.<\/p>\n

Now everybody goes about it differently, and from what I read online…. It would seem that lots of people over complicate the generation of the UUID with over complicated code to generate the UUID.<\/p>\n

.<\/span><\/span><\/p>\n

At the end of the day all a UUID is….is JUST A “UNIQUE IDENTIFIER”<\/strong>. It serves no other function other than being another form of labelling the network interface on the vm. There is no need to over complicate the creation of a UUID. This is also provided you defined UUID\u2019s on your deployments.<\/p>\n

.<\/span><\/span><\/p>\n

Why\u2026would you want to do this? Well if you cloned from a template. The new clone with have the same network UUID on every new machine you create. Now this wont impact your infrastructure in anyway, other than you *might* get duplicate UUID warning at some point. However, it can be problematic when doing backups, restores, migrations, and monitoring in some cases.<\/p>\n

.<\/span><\/span><\/p>\n

Ansible Setup:<\/strong><\/p>\n

\n
\n
\u2022<\/span> <\/span>This post assumes that you have ansible setup and running<\/div>\n<\/div>\n<\/div>\n

Role :<\/p>\n

\n
\n
\u2022<\/span> <\/span>Create a role called CreateNewNetworkUUID in \/etc\/ansible\/roles<\/div>\n
\n
\n
\uf0fc<\/span>mkdir<\/em><\/span> -p \/etc\/ansible\/roles\/<\/em><\/span>CreateNewNetworkUUID<\/em><\/span>\/tasks<\/em><\/span><\/div>\n<\/div>\n<\/div>\n
\n
\n
\u2022<\/span> <\/span>Create a main.yml inside \/etc\/ansible\/roles\/<\/span>CreateNewNetworkUUID<\/span>\/tasks<\/span>\/<\/span><\/div>\n
\n
\n
\uf0fc<\/span>v<\/em><\/span>i <\/em><\/span>\/etc\/ansible\/roles\/<\/em><\/span>CreateNewNetworkUUID<\/em><\/span>\/tasks\/<\/em><\/span>main.yml<\/em><\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n

.<\/span><\/span><\/p>\n

\n
\n
\u2022<\/span> <\/span>Now add the following <\/span>yaml<\/span> code.<\/span><\/div>\n<\/div>\n<\/div>\n

–<\/span><\/p>\n

.<\/span><\/span><\/p>\n

Note: This just runs the \u2018uuidgen\u2019 command on the linux vm and then registers the result into a variable that is passed to the next task.<\/strong><\/em><\/p>\n

.<\/span><\/span><\/p>\n

–<\/span> name: Generate new UUID<\/span><\/p>\n

shell: <\/span>uuidgen<\/span><\/p>\n

register: <\/span>new_uuid_result<\/span><\/p>\n

.<\/span><\/span><\/p>\n

– debug:<\/span><\/p>\n

var: <\/span>new_uuid_result<\/span><\/p>\n

.<\/span><\/span><\/p>\n

Note: This updates the network file on redhat and adds the UUID line with the newly generated UUID and shows a log of the new UUID that was added. This section will also be outlined in the file as managed by ansible<\/strong><\/em><\/p>\n

.<\/span><\/span><\/p>\n

– name: Add New UUID to network config<\/span><\/p>\n

  <\/span>blockinfile<\/span>:<\/span><\/p>\n

    <\/span>dest<\/span>: \/etc\/<\/span>sysconfig<\/span>\/network-scripts\/ifcfg-ens192<\/span><\/p>\n

    <\/span>insertafter<\/span>: NAME=”ens192″<\/span><\/p>\n

block: |<\/span><\/p>\n

UUID=”<\/span>{{ <\/span>new<\/span>_uuid_result<\/span>[‘<\/span>stdout<\/span>‘] }}”<\/span><\/p>\n

register: <\/span>filecontents<\/span><\/p>\n

.<\/span><\/span><\/p>\n

– debug: <\/span>msg<\/span>=”<\/span>{{ <\/span>filecontents<\/span> }}”<\/span><\/p>\n

.<\/span><\/span><\/p>\n

\n
\n
\u2022<\/span> <\/span>Save the file<\/div>\n<\/div>\n<\/div>\n

.<\/span><\/span><\/p>\n

Ansible playbook run: <\/strong><\/p>\n

.<\/span><\/span><\/p>\n

\n
\n
\u2022<\/span> <\/span>From inside \/etc\/ansible directory call your role inside your playbook or create a new playbook calling the role<\/div>\n<\/div>\n<\/div>\n

.<\/span><\/span><\/p>\n

\n
\n
\n

\uf0fc<\/span> vi <\/em><\/span>createnewUUID.yml<\/span><\/em><\/p>\n<\/div>\n<\/div>\n<\/div>\n

\n
\n
\u2022<\/span> <\/span>Add the following to your playbook.<\/div>\n<\/div>\n<\/div>\n

.<\/span><\/span>.<\/span><\/span><\/p>\n

– hosts: all<\/span><\/p>\n

  <\/span>gather_facts<\/span>: no<\/span><\/p>\n

roles: <\/span><\/p>\n

– role: <\/span>CreateNewNetworkUUID<\/span><\/p>\n

.<\/span><\/span><\/p>\n

\n
\n
\u2022<\/span> <\/span>Save the file<\/span><\/div>\n<\/div>\n<\/div>\n

.<\/span><\/span><\/p>\n

Ansible playbook run:<\/span><\/strong><\/p>\n

\n
\n
\u2022<\/span> <\/span>Run your new role against your hosts <\/span>
\n
\nNote: this <\/strong><\/em><\/span>run<\/span> the role against all your hosts <\/span>defined in inventory\/DEV\/hosts via <\/span>ssh<\/span>. You will need to know the root\/pass for your <\/span>ssh<\/span> connection to be able to carry out the <\/span><\/strong><\/em>tasks.<\/strong><\/em><\/span><\/span><\/div>\n
\n
\n
\uf0fc<\/span>ansible-playbook –<\/span>i<\/span> inventory\/DEV\/hosts <\/span>createnewUUID.yml<\/span> -k<\/span><\/em><\/div>\n

.<\/span><\/span><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n

Ansible playbook log:<\/span><\/strong><\/p>\n

SSH password:<\/span><\/p>\n

.<\/span><\/span><\/p>\n

PLAY [all] ****************************************************************************************************************************************************************************************************<\/span><\/p>\n

.<\/span><\/span><\/p>\n

TASK [<\/span>CreateNewUUID<\/span> : Generate new UUID] **********************************************************************************************************************************************************************<\/span><\/p>\n

changed: [<\/span>nicktestvm<\/span>]<\/span><\/p>\n

.<\/span><\/span><\/p>\n

TASK [<\/span>CreateNewUUID<\/span> : debug] **********************************************************************************************************************************************************************************<\/span><\/p>\n

ok: [<\/span>nicktestvm<\/span>] => {<\/span><\/p>\n

“<\/span>new_uuid_result<\/span>“: {<\/span><\/p>\n

“<\/span>ansible_facts<\/span>“: {<\/span><\/p>\n

“<\/span>discovered_interpreter_python<\/span>“: “\/<\/span>usr<\/span>\/bin\/python”<\/span><\/p>\n

},<\/span><\/p>\n

“changed”: true,<\/span><\/p>\n

“<\/span>cmd<\/span>“: “<\/span>uuidgen<\/span>“,<\/span><\/p>\n

“delta”: “0:00:00.010810”,<\/span><\/p>\n

“end”: “2020-12-21 20:13:36.614154”,<\/span><\/p>\n

“failed”: false,<\/span><\/p>\n

“<\/span>rc<\/span>“: 0,<\/span><\/p>\n

“start”: “2020-12-21 20:13:36.603344”,<\/span><\/p>\n

“stderr”: “”,<\/span><\/p>\n

“<\/span>stderr_lines<\/span>“: [],<\/span><\/p>\n

“<\/span>stdout<\/span>“: “49242349-5168-4713-bcb6-a53840b2e1d6”,<\/span><\/p>\n

“<\/span>stdout_lines<\/span>“: [<\/span><\/p>\n

“49242349-5168-4713-bcb6-a53840b2e1d6”<\/span><\/p>\n

]<\/span><\/p>\n

}<\/span><\/p>\n

}<\/span><\/p>\n

.<\/span><\/span><\/p>\n

TASK [<\/span>CreateNewUUID<\/span> : Add New UUID to network config] *********************************************************************************************************************************************************<\/span><\/p>\n

changed: [<\/span>nicktestvm<\/span>]<\/span><\/p>\n

.<\/span><\/span><\/p>\n

TASK [<\/span>CreateNewUUID<\/span> : debug] **********************************************************************************************************************************************************************************<\/span><\/p>\n

ok: [<\/span>nicktestvm<\/span>] => {<\/span><\/p>\n

“<\/span>new_uuid_<\/span>result.stdout<\/span>“: “49242349-5168-4713-bcb6-a53840b2e1d6”<\/span><\/p>\n

}<\/span><\/p>\n

.<\/span><\/span><\/p>\n

PLAY RECAP ****************************************************************************************************************************************************************************************************<\/span><\/p>\n

nicktestvm<\/span>             <\/span> :<\/span> ok=4 changed=2 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0<\/span><\/p>\n

.<\/span><\/span><\/p>\n

Nicktestvm:<\/strong><\/p>\n

.<\/span><\/span><\/p>\n

[root@nicktestvm ~]$ cat \/etc\/sysconfig\/network-scripts\/ifcfg-ens192<\/p>\n

TYPE=”Ethernet”<\/p>\n

PROXY_METHOD=”none”<\/p>\n

BROWSER_ONLY=”no”<\/p>\n

BOOTPROTO=”none”<\/p>\n

DEFROUTE=”yes”<\/p>\n

IPV4_FAILURE_FATAL=”no”<\/p>\n

IPV6INIT=”yes”<\/p>\n

IPV6_AUTOCONF=”yes”<\/p>\n

IPV6_DEFROUTE=”yes”<\/p>\n

IPV6_FAILURE_FATAL=”no”<\/p>\n

IPV6_ADDR_GEN_MODE=”stable-privacy”<\/p>\n

NAME=”ens192″<\/p>\n

# BEGIN ANSIBLE MANAGED BLOCK<\/span><\/strong><\/p>\n

UUID=”49242349-5168-4713-bcb6-a53840b2e1d6″<\/span><\/strong><\/p>\n

# END ANSIBLE MANAGED BLOCK<\/span><\/strong><\/p>\n

DEVICE=”ens192″<\/p>\n

ONBOOT=”yes”<\/p>\n

IPADDR=”192.168.1.69″<\/p>\n

PREFIX=”24″<\/p>\n

GATEWAY=”192.168.1.254″<\/p>\n

DNS1=”8.8.8.1″<\/p>\n

DNS2=”8.8.8.2″<\/p>\n

DOMAIN=”nicktailor.co.uk”<\/p>\n

IPV6_PRIVACY=”no”<\/p>\n

.<\/span><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Okay some of you might have deployed linux vm\u2019s from clone templates using ansible by way of the vmware_guest module. Now everybody goes about it differently, and from what I read online…. It would seem that lots of people over complicate the generation of the UUID with over complicated code to generate the UUID. . At the end of theRead More …<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":true,"template":"","format":"standard","meta":{"footnotes":""},"categories":[51,124],"tags":[],"class_list":["post-1177","post","type-post","status-publish","format-standard","hentry","category-ansible","category-network-stuff"],"_links":{"self":[{"href":"https:\/\/nicktailor.com\/tech-blog\/wp-json\/wp\/v2\/posts\/1177","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nicktailor.com\/tech-blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nicktailor.com\/tech-blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nicktailor.com\/tech-blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/nicktailor.com\/tech-blog\/wp-json\/wp\/v2\/comments?post=1177"}],"version-history":[{"count":15,"href":"https:\/\/nicktailor.com\/tech-blog\/wp-json\/wp\/v2\/posts\/1177\/revisions"}],"predecessor-version":[{"id":1640,"href":"https:\/\/nicktailor.com\/tech-blog\/wp-json\/wp\/v2\/posts\/1177\/revisions\/1640"}],"wp:attachment":[{"href":"https:\/\/nicktailor.com\/tech-blog\/wp-json\/wp\/v2\/media?parent=1177"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nicktailor.com\/tech-blog\/wp-json\/wp\/v2\/categories?post=1177"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nicktailor.com\/tech-blog\/wp-json\/wp\/v2\/tags?post=1177"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}