Add Loop Over A List Of Dictionaries as an Ansible TIL

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1277 TILs and counting..._
+_1278 TILs and counting..._
 
 ---
 
@@ -18,6 +18,7 @@ _1277 TILs and counting..._
 
 * [Ack](#ack)
 * [Amplify](#amplify)
+* [Ansible](#ansible)
 * [Chrome](#chrome)
 * [Clojure](#clojure)
 * [CSS](#css)
@@ -85,6 +86,10 @@ _1277 TILs and counting..._
 
 - [Sign Up User With Email And Password](amplify/sign-up-user-with-email-and-password.md)
 
+### Ansible
+
+- [Loop Over A List Of Dictionaries](ansible/loop-over-a-list-of-dictionaries.md)
+
 ### Chrome
 
 - [Access A Value Logged To The Console](chrome/access-a-value-logged-to-the-console.md)

ansible/loop-over-a-list-of-dictionaries.md

@@ -0,0 +1,33 @@
+# Loop Over A List Of Dictionaries
+
+Ansible's `loop` can iterate over a list of dictionaries in a task. That task
+will be evaluated for each `item` in that list. Since each `item` is a
+dictonary, we can access the fields on the `item` directory with dot notation —
+`item.name`.
+
+Here is what this would look like for a task that is setting up authorized SSH
+keys.
+
+```yaml
+---
+- hosts: all
+  vars:
+    dev_users:
+      - name: alice
+        ssh_key_url: https://github.com/dev1.keys
+      - name: bob
+        ssh_key_url: https://github.com/dev2.keys
+  tasks:
+    - name: Set authorized keys taken from url
+      ansible.posix.authorized_key:
+        user: "{{ item.name }}"
+        state: present
+        key: "{{ item.ssh_key_url }}"
+      loop: "{{ dev_users }}"
+```
+
+Notice the `loop` over the `dev_users` variable gives us access to an `item` in
+the task. Because each `item` has a `name` and an `ssh_key_url`, we can access
+those fields in the task.
+
+[source](https://docs.ansible.com/ansible/latest/playbook_guide/playbooks_loops.html#standard-loops)