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.
2. Simplifies the installation of optional pip packages.
   Right now it's more complicated than it needs to be due
   to us needing to keep the py_pkgs plugin working in the
   integrated build.

Depends-On: https://review.openstack.org/598957
Change-Id: I676ddbb7028ad203e4ca3f3e1cee7ff1435d23a2
Implements: blueprint python-build-install-simplification
Signed-off-by: Jesse Pretorius <jesse.pretorius@rackspace.co.uk>

defaults/main.yml

@@ -52,8 +52,19 @@ masakari_galera_ssl_ca_cert: "{{ galera_ssl_ca_cert | default('/etc/ssl/certs/ga
 masakari_venv_download: "{{ not masakari_developer_mode | bool }}"
 masakari_venv_download_url: http://127.0.0.1/venvs/untagged/ubuntu/masakari.tgz
 
+# 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.
+masakari_pip_install_args: >-
+  {{ masakari_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
-masakari_venv_tag: untagged
+masakari_venv_tag: "{{ venv_tag | default('untagged') }}"
 masakari_bin: "/openstack/venvs/masakari-{{ masakari_venv_tag }}/bin"
 
 # Common pip packages

handlers/main.yml

@@ -20,7 +20,9 @@
     daemon_reload: yes
   with_dict: "{{ masakari_services }}"
   when: inventory_hostname in groups[item.value.group]
+  listen:
+    - "venv changed"
 
 - meta: noop
   listen: Manage LB
-  when: false
+  when: false

tasks/masakari_install.yml

@@ -13,17 +13,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-- name: Install distro packages
+# TODO(odyssey4me):
-  package:
+# This can be simplified once all the roles are using
-    name: "{{ masakari_distro_packages }}"
+# python_venv_build. We can then switch to using a
-    state: "{{ masakari_package_state }}"
+# set of constraints in pip.conf inside the venv,
-    update_cache: "{{ (ansible_pkg_mgr in ['apt', 'zypper']) | ternary('yes', omit) }}"
+# perhaps prepared by giving a giving a list of
-    cache_valid_time: "{{ (ansible_pkg_mgr == 'apt') | ternary(cache_timeout, omit) }}"
+# constraints to the role.
-  register: install_packages
-  until: install_packages is success
-  retries: 5
-  delay: 2
-
 - name: Create developer mode constraint file
   copy:
     dest: "/opt/developer-pip-constraints.txt"
@@ -33,123 +28,22 @@
       {% endfor %}
   when: masakari_developer_mode | bool
 
-- name: Retrieve checksum for venv download
+- name: Ensure remote wheel building is disabled in developer mode
-  uri:
+  set_fact:
-    url: "{{ masakari_venv_download_url | replace('tgz', 'checksum') }}"
+    venv_build_host: "{{ ansible_hostname }}"
-    return_content: yes
-  register: masakari_venv_checksum
-  when: masakari_venv_download | bool
-
-- name: Attempt venv download
-  get_url:
-    url: "{{ masakari_venv_download_url }}"
-    dest: "/var/cache/{{ masakari_venv_download_url | basename }}"
-    checksum: "sha1:{{ masakari_venv_checksum.content | trim }}"
-  register: masakari_get_venv
-  when: masakari_venv_download | bool
-
-- name: Remove existing venv
-  file:
-    path: "{{ masakari_bin | dirname }}"
-    state: absent
-  when: masakari_get_venv is changed
-
-- name: Create masakari venv dir
-  file:
-    path: "{{ masakari_bin | dirname }}"
-    state: directory
-  register: masakari_venv_dir
-  when: masakari_get_venv is changed
-
-- name: Unarchive pre-built venv
-  unarchive:
-    src: "/var/cache/{{ masakari_venv_download_url | basename }}"
-    dest: "{{ masakari_bin | dirname }}"
-    copy: "no"
-  when: masakari_get_venv is changed
-  notify:
-    - Manage LB
-    - Restart masakari services
-
-- name: Install pip packages
-  pip:
-    name: "{{ masakari_pip_packages }}"
-    state: "{{ masakari_pip_package_state }}"
-    virtualenv: "{{ masakari_bin | dirname }}"
-    virtualenv_site_packages: "no"
-    extra_args: >-
-      {{ masakari_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: masakari_get_venv | failed or masakari_get_venv | skipped
-  notify:
-    - Manage LB
-    - Restart masakari services
-
-- name: Remove python from path first (CentOS, openSUSE)
-  file:
-    path:  "{{ masakari_bin | dirname }}/bin/python2.7"
-    state: "absent"
   when:
-    - ansible_pkg_mgr in ['yum', 'dnf', 'zypper']
+    - masakari_developer_mode | bool
-    - masakari_get_venv is changed
 
-# NOTE(odyssey4me):
+- name: Install the python venv
-# We reinitialize the venv to ensure that the right
+  include_role:
-# version of python is in the venv, but we do not
+    name: "python_venv_build"
-# want virtualenv to also replace pip, setuptools
+    private: yes
-# and wheel so we tell it not to.
+  vars:
-# We do not use --always-copy for CentOS/SuSE due
+    venv_install_destination_path: "{{ masakari_bin | dirname }}"
-# to https://github.com/pypa/virtualenv/issues/565
+    venv_install_distro_package_list: "{{ masakari_distro_packages }}"
-- name: Update virtualenv path
+    venv_pip_install_args: "{{ masakari_pip_install_args }}"
-  shell: |
+    venv_pip_packages: "{{ (masakari_oslomsg_amqp1_enabled | bool) | ternary(masakari_pip_packages + masakari_optional_oslomsg_amqp1_pip_packages, masakari_pip_packages) }}"
-    find {{ masakari_bin }} -name \*.pyc -delete
+    venv_facts_when_changed:
-    sed -si '1s/^.*python.*$/#!{{ masakari_bin | replace ('/','\/') }}\/python/' {{ masakari_bin }}/*
+      - section: "masakari"
-    virtualenv {{ masakari_bin | dirname }} \
+        option: "venv_tag"
-        {{ (ansible_pkg_mgr == 'apt') | ternary('--always-copy', '') }} \
+        value: "{{ masakari_venv_tag }}"
-        --no-pip \
-        --no-setuptools \
-        --no-wheel
-  when: masakari_get_venv is changed
-  tags:
-    - skip_ansible_lint
-
-- name: Install optional pip packages
-  pip:
-    name: "{{ masakari_optional_oslomsg_amqp1_pip_packages }}"
-    state: "{{ masakari_pip_package_state }}"
-    virtualenv: "{{ masakari_bin | dirname }}"
-    virtualenv_site_packages: "no"
-  when: masakari_oslomsg_amqp1_enabled
-  register: install_optional_packages
-  until: install_optional_packages is success
-  retries: 5
-  delay: 2
-  notify:
-    - Manage LB
-    - Restart masakari services
-
-- name: Record the need for a service restart
-  ini_file:
-    dest: "/etc/ansible/facts.d/openstack_ansible.fact"
-    section: masakari
-    option: need_service_restart
-    value: True
-  when: (masakari_get_venv is changed) or
-        (masakari_venv_dir is changed) or
-        (install_packages is changed) or
-        (ansible_local is not defined) or
-        ('openstack_ansible' not in ansible_local) or
-        ('masakari' not in ansible_local['openstack_ansible']) or
-        ('need_service_restart' not in ansible_local['openstack_ansible']['masakari'])
-
-- name: Record the venv tag deployed
-  ini_file:
-    dest: "/etc/ansible/facts.d/openstack_ansible.fact"
-    section: masakari
-    option: venv_tag
-    value: "{{ masakari_venv_tag }}"