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-rw-r--r-- | content/en/blog/ansible/_index.md | 5 | ||||
-rw-r--r-- | content/en/blog/ansible/ansible-vault-example.md | 36 | ||||
-rwxr-xr-x | content/en/blog/ansible/custom-fact.md | 89 | ||||
-rw-r--r-- | content/en/blog/ansible/dump-all-vars.md | 38 |
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diff --git a/content/en/blog/ansible/_index.md b/content/en/blog/ansible/_index.md new file mode 100644 index 0000000..3730fd7 --- /dev/null +++ b/content/en/blog/ansible/_index.md @@ -0,0 +1,5 @@ +--- +title: "Ansible" +linkTitle: "Ansible" +weight: 30 +--- diff --git a/content/en/blog/ansible/ansible-vault-example.md b/content/en/blog/ansible/ansible-vault-example.md new file mode 100644 index 0000000..fb6ef45 --- /dev/null +++ b/content/en/blog/ansible/ansible-vault-example.md @@ -0,0 +1,36 @@ +--- +title: "Ansible vault example" +linkTitle: "Ansible vault example" +date: 2018-02-21 +description: > + Ansible vault example +--- + +Here is how to edit a vault protected file : +{{< highlight sh >}} +ansible-vault edit hostvars/blah.yml +{{< / highlight >}} + +Here is how to put a multiline entry like a private key in vault (for a simple value, just don't use a `|`): + +{{< highlight yaml >}} +ssl_key : | + ----- BEGIN PRIVATE KEY ----- + blahblahblah + blahblahblah + ----- END PRIVATE KEY ----- +{{< /highlight >}} + +And here is how to use it in a task : +{{< highlight yaml >}} +- copy: + path: /etc/ssl/private.key + mode: 0400 + content: '{{ ssl_key }}' +{{< / highlight >}} + +To run a playbook, you will need to pass the `--ask-vault` argument or to export a `ANSIBLE_VAULT_PASSWORD_FILE=/home/julien/.vault_pass.txt` variable (the file needs to contain a single line with your vault password here). + +## Ressources + + * how to break long lines in ansible : https://watson-wilson.ca/blog/2018/07/11/ansible-tips/ diff --git a/content/en/blog/ansible/custom-fact.md b/content/en/blog/ansible/custom-fact.md new file mode 100755 index 0000000..21e3300 --- /dev/null +++ b/content/en/blog/ansible/custom-fact.md @@ -0,0 +1,89 @@ +--- +title: "Ansible custom facts" +linkTitle: "Ansible custom facts" +date: 2018-09-25 +description: > + How to write custom facte with ansible +--- + +Custom facts are actually quite easy to implement despite the lack of documentation about it. + +## How they work + +On any Ansible controlled host — that is, the remote machine that is being controlled and not the machine on which the playbook is run — you just need to create a directory at +`/etc/ansible/facts.d`. Inside this directory, you can place one or more `*.fact` files. These are files that return JSON data, which will then be included in the raft of facts that +Ansible gathers. + +The facts will be available to ansible at `hostvars.host.ansible_local.<fact_name>`. + +## A simple example + +Here is the simplest example of a fact, let's suppose we make it `/etc/ansible/facts.d/mysql.fact` : +{{< highlight sh >}} +#!/bin/sh +set -eu + +echo '{"password": "xxxxxx"}' +{{< /highlight >}} + +This will give you the fact `hostvars.host.ansible_local.mysql.password` for this machine. + +## A more complex example + +A more interesting example is something I use with small webapps. In the container that hosts the frontent I use a small ansible role to generate a mysql password on its first run, and +provision a database with a user that has access to it on a mysql server. This fact ensures that on subsequent runs we will stay idempotents. Here is how it works. + +First the fact from before, only slightly modified : +{{< highlight sh >}} +#!/bin/sh +set -eu + +echo '{"password": "{{mysql_password}}"}' +{{< /highlight >}} + +This fact is deployed with the following tasks : +{{< highlight yaml >}} +- name: Generate a password for mysql database connections if there is none + set_fact: mysql_password="{{ lookup('password', '/dev/null length=15 chars=ascii_letters') }}" + when: (ansible_local.mysql_client|default({})).password is undefined + +- name: Deploy mysql client ansible fact to handle the password + template: + src: ../templates/mysql_client.fact + dest: /etc/ansible/facts.d/ + owner: root + mode: 0500 + when: (ansible_local.mysql_client|default({})).password is undefined + +- name: reload ansible_local + setup: filter=ansible_local + when: (ansible_local.mysql_client|default({})).password is undefined + +- name: Ensures mysql database exists + mysql_db: + name: '{{ansible_hostname}}' + state: present + delegate_to: "{{mysql_server}}" + +- name: Ensures mysql user exists + mysql_user: + name: '{{ansible_hostname}}' + host: '{{ansible_hostname}}' + priv: '{{ansible_hostname}}.*:ALL' + password: '{{ansible_local.mysql_client.password}}' + state: present + delegate_to: '{{mysql_server}}' +{{< /highlight >}} + +## Caveat : a fact you deploy is not immediately available + +Note that installing a fact does not make it exist before the next inventory run on the host. This can be problematic especially if you rely on facts caching to speed up ansible. Here +is how to make ansible reload facts using the setup tasks (If you paid attention you already saw me use it above). +{{< highlight yaml >}} +- name: reload ansible_local + setup: filter=ansible_local +{{< /highlight >}} + +## References + +- https://medium.com/@jezhalford/ansible-custom-facts-1e1d1bf65db8 diff --git a/content/en/blog/ansible/dump-all-vars.md b/content/en/blog/ansible/dump-all-vars.md new file mode 100644 index 0000000..d5991a3 --- /dev/null +++ b/content/en/blog/ansible/dump-all-vars.md @@ -0,0 +1,38 @@ +--- +title: "Dump all ansible variables" +linkTitle: "Dump all ansible variables" +date: 2019-10-15 +description: > + How to dump all variables used by ansible +--- + +Here is the task to use in order to achieve that : + +{{< highlight yaml >}} +- name: Dump all vars + action: template src=dumpall.j2 dest=ansible.all +{{< /highlight >}} + +And here is the template to use with it : + +{{< highlight jinja >}} +Module Variables ("vars"): +-------------------------------- +{{ vars | to_nice_json }} + +Environment Variables ("environment"): +-------------------------------- +{{ environment | to_nice_json }} + +GROUP NAMES Variables ("group_names"): +-------------------------------- +{{ group_names | to_nice_json }} + +GROUPS Variables ("groups"): +-------------------------------- +{{ groups | to_nice_json }} + +HOST Variables ("hostvars"): +-------------------------------- +{{ hostvars | to_nice_json }} +{{< /highlight >}} |