From 60d3abc6ecdc21b4ab921d34a55b4af48690f55a Mon Sep 17 00:00:00 2001 From: Julien Dessaux Date: Thu, 11 Mar 2021 18:53:14 +0100 Subject: Rewrote the whole website to get rid on a heavy theme --- content/en/blog/ansible/custom-fact.md | 89 ---------------------------------- 1 file changed, 89 deletions(-) delete mode 100644 content/en/blog/ansible/custom-fact.md (limited to 'content/en/blog/ansible/custom-fact.md') diff --git a/content/en/blog/ansible/custom-fact.md b/content/en/blog/ansible/custom-fact.md deleted file mode 100644 index 21e3300..0000000 --- a/content/en/blog/ansible/custom-fact.md +++ /dev/null @@ -1,89 +0,0 @@ ---- -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.`. - -## 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 -- cgit v1.2.3