Simplify pip options/constraints mechanism

The current constraints generation for the
installation involves multiple tasks and multiple
variables.

Using multiple tasks extends the installation time
unnecessarily and the additional variables are
unnecessary.

This patch aims to simplify the mechanism and
hopes to speed it up a little.

Change-Id: I483d1eae983a8ff7211bcbe51158eb78a859ed3a

defaults/main.yml

@@ -28,10 +28,6 @@ ceilometer_developer_mode: false
 ceilometer_git_repo: https://git.openstack.org/openstack/ceilometer
 ceilometer_git_install_branch: master
 
-## The git source/branch for the upper-constraints (used in developer mode)
-ceilometer_requirements_git_repo: https://git.openstack.org/openstack/requirements
-ceilometer_requirements_git_install_branch: master
-
 ## The packages to build from source (used in developer mode)
 ceilometer_developer_constraints:
   - "git+{{ ceilometer_git_repo }}@{{ ceilometer_git_install_branch }}#egg=ceilometer"

releasenotes/notes/remove-requirements-git-eb90b906a4ad4642.yaml

@@ -0,0 +1,7 @@
+---
+upgrade:
+  - The variables ``ceilometer_requirements_git_repo`` and
+    ``ceilometer_requirements_git_install_branch`` have been
+    removed in favour of using the URL/path to the
+    upper-constraints file using the
+    variable ``pip_install_upper_constraints`` instead.

tasks/ceilometer_install.yml

@@ -27,33 +27,14 @@
   when:
     - ceilometer_developer_mode | bool
 
-- name: Clone requirements git repository
-  git:
-    repo: "{{ ceilometer_requirements_git_repo }}"
-    dest: "/opt/requirements"
-    clone: yes
-    update: yes
-    version: "{{ ceilometer_requirements_git_install_branch }}"
-  when:
-    - ceilometer_developer_mode | bool
-
-- name: Add constraints to pip_install_options fact for developer mode
-  set_fact:
-    pip_install_options_fact: "{{ pip_install_options|default('') }} --constraint /opt/developer-pip-constraints.txt --constraint /opt/requirements/upper-constraints.txt"
-  when:
-    - ceilometer_developer_mode | bool
-
-- name: Set pip_install_options_fact when not in developer mode
-  set_fact:
-    pip_install_options_fact: "{{ pip_install_options|default('') }}"
-  when:
-    - not ceilometer_developer_mode | bool
-
 - name: Install requires pip packages
   pip:
     name: "{{ ceilometer_requires_pip_packages | join(' ') }}"
     state: "{{ ceilometer_pip_package_state }}"
     extra_args: "{{ pip_install_options_fact }}"
+    extra_args: >-
+      {{ (pip_install_upper_constraints is defined) | ternary('--constraint ' + pip_install_upper_constraints | default(''),'') }}
+      {{ pip_install_options | default('') }}
   register: install_packages
   until: install_packages|success
   retries: 5
@@ -129,7 +110,10 @@
     state: "{{ ceilometer_pip_package_state }}"
     virtualenv: "{{ ceilometer_bin | dirname }}"
     virtualenv_site_packages: "no"
-    extra_args: "{{ pip_install_options_fact }}"
+    extra_args: >-
+      {{ ceilometer_developer_mode | ternary('--constraint /opt/developer-pip-constraints.txt', '') }}
+      {{ (pip_install_upper_constraints is defined) | ternary('--constraint ' + pip_install_upper_constraints | default(''),'') }}
+      {{ pip_install_options | default('') }}
   register: install_packages
   until: install_packages|success
   retries: 5