Performance: refactor pip configuration

Currently we perform pip configuration for a list of users, including
pip_conf.yml in a loop for each user. It is slightly more efficient to
loop over each task, since individual tasks have a higher overhead than
loops.

This change refactors the code into multiple loops, with a single
include. We keep the include to allow skipping the tasks when pip
configuration is not required.

Change-Id: I698d38613f45bd03a2e51572f6e6fb69e934f614
Story: 2007993
Task: 40719

ansible/roles/pip/tasks/main.yml

@@ -1,6 +1,4 @@
 ---
-- include_tasks: pip_conf.yml
-  loop: "{{ pip_applicable_users }}"
-  loop_control:
-    loop_var: user
+- name: Ensure pip is configured
+  include_tasks: pip_conf.yml
   when: (pip_local_mirror | bool) or (pip_proxy | length > 0)

ansible/roles/pip/tasks/pip_conf.yml

@@ -1,12 +1,13 @@
 ---
-- name: Create local .pip directory for {{ user }}
+- name: Create local .pip directory
   file:
-    path: "~{{ user }}/.pip"
+    path: "~{{ item }}/.pip"
     state: directory
   become: True
-  become_user: "{{ user }}"
+  become_user: "{{ item }}"
+  loop: "{{ pip_applicable_users }}"
 
-- name: Create pip.conf for {{ user }}
+- name: Create pip.conf
   copy:
     content: |
       [global]
@@ -22,16 +23,18 @@
       {% if pip_proxy | length > 0 -%}
       proxy = {{ pip_proxy }}
       {% endif -%}
-    dest: "~{{ user}}/.pip/pip.conf"
+    dest: "~{{ item }}/.pip/pip.conf"
   become: True
-  become_user: "{{ user }}"
+  become_user: "{{ item }}"
+  loop: "{{ pip_applicable_users }}"
 
-- name: Create .pydistutils.cfg for {{ user }}
+- name: Create .pydistutils.cfg
   copy:
     content: |
       [easy_install]
       index-url = {{ pip_index_url }}
-    dest: "~{{ user}}/.pydistutils.cfg"
+    dest: "~{{ item }}/.pydistutils.cfg"
   when: pip_index_url | length > 0
   become: True
-  become_user: "{{ user }}"
+  become_user: "{{ item }}"
+  loop: "{{ pip_applicable_users }}"