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: Iaff49b75b03635fb07260c9a96f6459d270aed83
Implements: blueprint python-build-install-simplification
Signed-off-by: Jesse Pretorius <jesse.pretorius@rackspace.co.uk>

defaults/main.yml

@@ -74,8 +74,19 @@ trove_api_workers: "{{ [[ansible_processor_vcpus|default(2) // 2, 1] | max, trov
 trove_conductor_workers_max: 16
 trove_conductor_workers: "{{ [[ansible_processor_vcpus|default(2) // 2, 1] | max, trove_conductor_workers_max] | min }}"
 
+# 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.
+trove_pip_install_args: >-
+  {{ trove_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
-trove_venv_tag: untagged
+trove_venv_tag: "{{ venv_tag | default('untagged') }}"
 trove_bin: "/openstack/venvs/trove-{{ trove_venv_tag }}/bin"
 
 # venv_download, even when true, will use the fallback method of building the

handlers/main.yml

@@ -21,16 +21,25 @@
     state: "restarted"
   when:
     - not trove_use_mod_wsgi | bool
+  listen:
+    - "Restart trove services"
+    - "venv changed"
 
 - name: Restart trove conductor service
   systemd:
     name: "{{ trove_services['trove-conductor']['service_name'] }}"
     state: "restarted"
+  listen:
+    - "Restart trove services"
+    - "venv changed"
 
 - name: Restart trove taskmanager service
   systemd:
     name: "{{ trove_services['trove-conductor']['service_name'] }}"
     state: "restarted"
+  listen:
+    - "Restart trove services"
+    - "venv changed"
 
 - name: Restart Apache
   service:
@@ -41,3 +50,6 @@
   until: apache_restart is success
   retries: 5
   delay: 2
+  listen:
+    - "Restart trove services"
+    - "venv changed"

tasks/trove_install.yml

@@ -16,18 +16,12 @@
 # (c) 2016 Donovan Francesco <donovan.francesco@is.co.za>
 # (c) 2016 Paul Stevens <paul.stevens@is.co.za>
 
-- name: Install distro packages
-  package:
-    name: "{{ item }}"
-    state: "{{ trove_package_state }}"
-    update_cache: "{{ (ansible_pkg_mgr == 'apt') | ternary('yes', omit) }}"
-    cache_valid_time: "{{ (ansible_pkg_mgr == 'apt') | ternary(cache_timeout, omit) }}"
-  register: install_packages
-  until: install_packages is success
-  retries: 5
-  delay: 2
-  with_items: "{{ trove_distro_packages }}"
-
+# 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"
@@ -38,116 +32,22 @@
   when:
     - trove_developer_mode | bool
 
-- name: Retrieve checksum for venv download
-  uri:
-    url: "{{ trove_venv_download_url | replace('tgz', 'checksum') }}"
-    return_content: yes
-  register: trove_venv_checksum
-  when: trove_venv_download | bool
-
-- name: Attempt venv download
-  get_url:
-    url: "{{ trove_venv_download_url }}"
-    dest: "/var/cache/{{ trove_venv_download_url | basename }}"
-    checksum: "sha1:{{ trove_venv_checksum.content | trim }}"
-  register: trove_get_venv
-  when: trove_venv_download | bool
-
-- name: Remove existing venv
-  file:
-    path: "{{ trove_bin | dirname }}"
-    state: absent
-  when: trove_get_venv  is changed
-
-- name: Create trove venv dir
-  file:
-    path: "{{ trove_bin | dirname }}"
-    state: directory
-    mode: "0755"
-  register: trove_venv_dir
-  when: trove_get_venv  is changed
-
-- name: Unarchive pre-built venv
-  unarchive:
-    src: "/var/cache/{{ trove_venv_download_url | basename }}"
-    dest: "{{ trove_bin | dirname }}"
-    copy: "no"
-  when: trove_get_venv  is changed
-  notify:
-    - Restart trove API services
-    - Restart trove conductor service
-    - Restart trove taskmanager service
-    - Restart Apache
-
-- name: Install pip packages
-  pip:
-    name: "{{ trove_pip_packages }}"
-    state: "{{ trove_pip_package_state }}"
-    virtualenv: "{{ trove_bin | dirname }}"
-    virtualenv_site_packages: "no"
-    extra_args: >-
-      {{ trove_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: trove_get_venv | failed or trove_get_venv | skipped
-  notify:
-    - Restart trove API services
-    - Restart trove conductor service
-    - Restart trove taskmanager service
-    - Restart Apache
-
-- name: Remove python from path first (CentOS, openSUSE)
-  file:
-    path:  "{{ trove_bin | dirname }}/bin/python2.7"
-    state: "absent"
+- name: Ensure remote wheel building is disabled in developer mode
+  set_fact:
+    venv_build_host: "{{ ansible_hostname }}"
   when:
-    - ansible_pkg_mgr in ['yum', 'dnf', 'zypper']
-    - trove_get_venv  is changed
+    - trove_developer_mode | bool
 
-# 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 {{ trove_bin }} -name \*.pyc -delete
-    sed -si '1s/^.*python.*$/#!{{ trove_bin | replace ('/','\/') }}\/python/' {{ trove_bin }}/*
-    virtualenv {{ trove_bin | dirname }} \
-        {{ (ansible_pkg_mgr == 'apt') | ternary('--always-copy', '') }} \
-        --no-pip \
-        --no-setuptools \
-        --no-wheel
-  when: trove_get_venv  is changed
-  tags:
-    - skip_ansible_lint
-
-- name: Install optional pip packages
-  pip:
-    name: "{{ trove_optional_oslomsg_amqp1_pip_packages }}"
-    state: "{{ trove_pip_package_state }}"
-    virtualenv: "{{ trove_bin | dirname }}"
-    virtualenv_site_packages: "no"
-  when: trove_oslomsg_amqp1_enabled
-  register: install_optional_packages
-  until: install_optional_packages is success
-  retries: 5
-  delay: 2
-  notify:
-    - Restart trove API services
-    - Restart trove conductor service
-    - Restart trove taskmanager service
-    - Restart Apache
-
-- name: Record the venv tag deployed
-  ini_file:
-    dest: "/etc/ansible/facts.d/openstack_ansible.fact"
-    section: trove
-    option: venv_tag
-    value: "{{ trove_venv_tag }}"
+- name: Install the python venv
+  include_role:
+    name: "python_venv_build"
+    private: yes
+  vars:
+    venv_install_destination_path: "{{ trove_bin | dirname }}"
+    venv_install_distro_package_list: "{{ trove_distro_packages }}"
+    venv_pip_install_args: "{{ trove_pip_install_args }}"
+    venv_pip_packages: "{{ (trove_oslomsg_amqp1_enabled | bool) | ternary(trove_pip_packages + trove_optional_oslomsg_amqp1_pip_packages, trove_pip_packages) }}"
+    venv_facts_when_changed:
+      - section: "trove"
+        option: "venv_tag"
+        value: "{{ trove_venv_tag }}"