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/blog/ansible/_index.md                |  5 ++
 content/blog/ansible/ansible-vault-example.md | 36 +++++++++++
 content/blog/ansible/custom-fact.md           | 89 +++++++++++++++++++++++++++
 content/blog/ansible/dump-all-vars.md         | 38 ++++++++++++
 4 files changed, 168 insertions(+)
 create mode 100644 content/blog/ansible/_index.md
 create mode 100644 content/blog/ansible/ansible-vault-example.md
 create mode 100644 content/blog/ansible/custom-fact.md
 create mode 100644 content/blog/ansible/dump-all-vars.md

(limited to 'content/blog/ansible')

diff --git a/content/blog/ansible/_index.md b/content/blog/ansible/_index.md
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+---
+title: "Ansible"
+linkTitle: "Ansible"
+weight: 30
+---
diff --git a/content/blog/ansible/ansible-vault-example.md b/content/blog/ansible/ansible-vault-example.md
new file mode 100644
index 0000000..fb6ef45
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+++ b/content/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/blog/ansible/custom-fact.md b/content/blog/ansible/custom-fact.md
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+---
+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/blog/ansible/dump-all-vars.md b/content/blog/ansible/dump-all-vars.md
new file mode 100644
index 0000000..d5991a3
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+++ b/content/blog/ansible/dump-all-vars.md
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+---
+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 >}}
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