Use a common python build/install role

In order to radically simplify how we prepare the service
venvs, we use a common role to do the wheel builds and the
venv preparation. This makes the process far simpler to
understand, because the role does its own building and
installing. It also reduces the code maintenance burden,
because instead of duplicating the build processes in the
repo_build role and the service role - we only have it all
done in a single place.

We also change the role venv tag var to use the integrated
build's common venv tag so that we can remove the role's
venv tag in group_vars in the integrated build. This reduces
memory consumption and also reduces the duplication.

This is by no means the final stop in the simplification
process, but it is a step forward. The will be work to follow
which:

1. Replaces 'developer mode' with an equivalent mechanism
   that uses the common role and is simpler to understand.
   We will also simplify the provisioning of pip install
   arguments when doing this.

Depends-On: https://review.openstack.org/598957
Change-Id: I97a614422490e7bff3bbe5f651387fbeb092aeda
Implements: blueprint python-build-install-simplification
Signed-off-by: Jesse Pretorius <jesse.pretorius@rackspace.co.uk>

defaults/main.yml

@@ -36,8 +36,19 @@ searchlight_developer_mode: false
 searchlight_developer_constraints:
   - "git+{{ searchlight_git_repo }}@{{ searchlight_git_install_branch }}#egg=searchlight"
 
+# TODO(odyssey4me):
+# This can be simplified once all the roles are using
+# python_venv_build. We can then switch to using a
+# set of constraints in pip.conf inside the venv,
+# perhaps prepared by giving a giving a list of
+# constraints to the role.
+searchlight_pip_install_args: >-
+  {{ searchlight_developer_mode | ternary(pip_install_developer_constraints | default('--constraint /opt/developer-pip-constraints.txt'), '') }}
+  {{ (pip_install_upper_constraints is defined) | ternary('--constraint ' + pip_install_upper_constraints | default(''), '') }}
+  {{ pip_install_options | default('') }}
+
 #: Name of the virtual env to deploy into
-searchlight_venv_tag: untagged
+searchlight_venv_tag: "{{ venv_tag | default('untagged') }}"
 searchlight_bin: "/openstack/venvs/searchlight-{{ searchlight_venv_tag }}/bin"
 # searchlight_venv_pkgs: "/openstack/venvs/searchlight-{{ searchlight_venv_tag }}/lib/python2.7/site-packages"
 

handlers/main.yml

@@ -23,3 +23,5 @@
   with_items:
     - "{{ searchlight_listener_program_name }}"
     - "{{ searchlight_api_program_name }}"
+  listen:
+    - "venv changed"

tasks/searchlight_install.yml

@@ -13,10 +13,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-- include_tasks: searchlight_install_apt.yml
-  when:
-    - ansible_pkg_mgr == 'apt'
-
+# TODO(odyssey4me):
+# This can be simplified once all the roles are using
+# python_venv_build. We can then switch to using a
+# set of constraints in pip.conf inside the venv,
+# perhaps prepared by giving a giving a list of
+# constraints to the role.
 - name: Create developer mode constraint file
   copy:
     dest: "/opt/developer-pip-constraints.txt"
@@ -27,73 +29,22 @@
   when:
     - searchlight_developer_mode | bool
 
-- name: Attempt venv download
-  get_url:
-    url: "{{ searchlight_venv_download_url }}"
-    dest: "/var/cache/{{ searchlight_venv_download_url | basename }}"
-    checksum: "sha1:{{ lookup('url', searchlight_venv_download_url | replace('tgz', 'checksum')) }}"
-  register: searchlight_get_venv
+- name: Ensure remote wheel building is disabled in developer mode
+  set_fact:
+    venv_build_host: "{{ ansible_hostname }}"
   when:
-    - searchlight_venv_download | bool
+    - searchlight_developer_mode | bool
 
-- name: Remove existing venv
-  file:
-    path: "{{ searchlight_bin | dirname }}"
-    state: absent
-  when: searchlight_get_venv  is changed
-
-- name: Create searchlight venv dir
-  file:
-    path: "{{ searchlight_bin | dirname }}"
-    state: directory
-  register: searchlight_venv_dir
-  when: searchlight_get_venv  is changed
-
-- name: Unarchive pre-built venv
-  unarchive:
-    src: "/var/cache/{{ searchlight_venv_download_url | basename }}"
-    dest: "{{ searchlight_bin | dirname }}"
-    copy: "no"
-  when: searchlight_get_venv  is changed
-  notify:
-    - Restart Searchlight services
-
-- name: Install pip packages
-  pip:
-    name: "{{ searchlight_pip_packages }}"
-    state: "{{ searchlight_pip_package_state }}"
-    virtualenv: "{{ searchlight_bin | dirname }}"
-    virtualenv_site_packages: "no"
-    extra_args: >-
-      {{ searchlight_developer_mode | ternary(pip_install_developer_constraints | default('--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 is success
-  retries: 5
-  delay: 2
-  when: searchlight_get_venv | failed or searchlight_get_venv | skipped
-  notify:
-    - Restart Searchlight services
-
-# NOTE(odyssey4me):
-# We reinitialize the venv to ensure that the right
-# version of python is in the venv, but we do not
-# want virtualenv to also replace pip, setuptools
-# and wheel so we tell it not to.
-# We do not use --always-copy for CentOS/SuSE due
-# to https://github.com/pypa/virtualenv/issues/565
-- name: Update virtualenv path
-  shell: |
-    find {{ searchlight_bin }} -name \*.pyc -delete
-    sed -si '1s/^.*python.*$/#!{{ searchlight_bin | replace ('/','\/') }}\/python/' {{ searchlight_bin }}/*
-    virtualenv {{ searchlight_bin | dirname }} \
-        {{ (ansible_pkg_mgr == 'apt') | ternary('--always-copy', '') }} \
-        --no-pip \
-        --no-setuptools \
-        --no-wheel
-  when:
-    - not searchlight_developer_mode | bool
-    - searchlight_get_venv is success
-  tags:
-    - skip_ansible_lint
+- name: Install the python venv
+  include_role:
+    name: "python_venv_build"
+    private: yes
+  vars:
+    venv_install_destination_path: "{{ searchlight_bin | dirname }}"
+    venv_install_distro_package_list: "{{ searchlight_distro_packages }}"
+    venv_pip_install_args: "{{ searchlight_pip_install_args }}"
+    venv_pip_packages: "{{ searchlight_pip_packages }}"
+    venv_facts_when_changed:
+      - section: "searchlight"
+        option: "venv_tag"
+        value: "{{ searchlight_venv_tag }}"

tasks/searchlight_install_apt.yml

@@ -1,38 +0,0 @@
----
-# Copyright 2015, Rackspace US, Inc.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-#TODO(evrardjp): Replace the next 2 tasks by a standard apt with cache
-#when https://github.com/ansible/ansible-modules-core/pull/1517 is merged
-#in 1.9.x or we move to 2.0 (if tested working)
-
-- name: Check apt last update file
-  stat:
-    path: /var/cache/apt
-  register: apt_cache_stat
-
-- name: Update apt if needed
-  apt:
-    update_cache: yes
-  when: "ansible_date_time.epoch|float - apt_cache_stat.stat.mtime > {{cache_timeout}}"
-
-- name: Install apt packages
-  apt:
-    pkg: "{{ item }}"
-    state: "{{ searchlight_package_state }}"
-  register: install_packages
-  until: install_packages is success
-  retries: 5
-  delay: 2
-  with_items: "{{ searchlight_apt_packages }}"