Implement uWSGI for sahara-api

As part of the Pike goals we are moving api services to run as WSGI
apps. sahara-api service is set up as a wsgi app, and this patch
moves it over.

Since this is just a drop in replacement for the existing eventlet
service, operators an deployers should notice no difference.

Change-Id: Ie4826358d5ee1686ad9ea7fa9eb0441acff565f2
Implements: blueprint goal-deploy-api-in-wsgi

defaults/main.yml

@@ -161,6 +161,7 @@ sahara_pip_packages:
   - python-keystoneclient
   - sahara
   - warlock
+  - uwsgi
 
 sahara_engine_init_overrides: {}
 sahara_api_init_overrides: {}
@@ -171,11 +172,24 @@ sahara_services:
     group: sahara_api
     service_name: sahara-api
     init_config_overrides: "{{ sahara_api_init_overrides }}"
+    wsgi_overrides: "{{ sahara_api_uwsgi_ini_overrides }}"
+    wsgi_app: True
+    log_string: "--logto "
+    wsgi_name: sahara-wsgi-api
+    uwsgi_port: "{{ sahara_api_service_port }}"
+    uwsgi_bind_address: "{{ sahara_api_bind_address }}"
+    program_override: "{{ sahara_bin }}/uwsgi --ini /etc/uwsgi/sahara-api.ini"
   sahara-engine:
     group: sahara_engine
     service_name: sahara-engine
     init_config_overrides: "{{ sahara_engine_init_overrides }}"
 
+## Sahara uWSGI settings
+sahara_wsgi_processes_max: 16
+sahara_wsgi_processes: "{{ [[ansible_processor_vcpus|default(1), 1] | max * 2, sahara_wsgi_processes_max] | min }}"
+sahara_wsgi_threads: 1
+sahara_wsgi_buffer_size: 65535
+
 # This variable is used by the repo_build process to determine
 # which host group to check for members of before building the
 # pip packages required by this role. The value is picked up
@@ -187,3 +201,4 @@ sahara_api_paste_ini_overrides: {}
 sahara_conf_overrides: {}
 sahara_rootwrap_conf_overrides: {}
 sahara_policy_overrides: {}
+sahara_api_uwsgi_ini_overrides: {}

releasenotes/notes/sahara_uwsgi-41e7e0a91a3f8c33.yaml

@@ -0,0 +1,15 @@
+---
+features:
+  - The ``sahara-api`` service has moved to run as a
+    uWSGI application. You can set the max number of
+    WSGI processes, the number of processes, threads,
+    and buffer size utilizing the
+    ``sahara_wsgi_processes_max``,
+    ``sahara_wsgi_processes``, ``sahara_wsgi_threads``,
+    and ``sahara_wsgi_buffer_size``.
+    Additionally, you can override any settings in the
+    uWSGI ini configuration file using the
+    ``sahara_api_uwsgi_ini_overrides`` setting.
+    The uWSGI application will listen on the address
+    specified by ``sahara_uwsgi_bind_address`` which
+    defaults to ``0.0.0.0``.

tasks/main.yml

@@ -35,6 +35,10 @@
   tags:
     - sahara-config
 
+- include: sahara_uwsgi.yml
+  tags:
+    - sahara-config
+
 - include: sahara_init_common.yml
   tags:
     - sahara-config

tasks/sahara_uwsgi.yml

@@ -0,0 +1,32 @@
+---
+# Copyright 2017, 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.
+
+- name: Ensure uWSGI directory exists
+  file:
+    path: "/etc/uwsgi/"
+    state: directory
+    mode: "0711"
+
+- name: Apply uWSGI configuration
+  config_template:
+    src: "sahara-uwsgi.ini.j2"
+    dest: "/etc/uwsgi/{{ item.value.service_name }}.ini"
+    mode: "0744"
+    config_overrides: "{{ item.value.wsgi_overrides }}"
+    config_type: ini
+  with_dict: "{{ sahara_services }}"
+  when: item.value.wsgi_app | default(False)
+  notify:
+    - Restart sahara services

templates/sahara-systemd-init.j2

@@ -10,10 +10,10 @@ Type=simple
 User={{ sahara_system_user_name }}
 Group={{ sahara_system_group_name }}
 
-{% if program_override is defined %}
-ExecStart={{ program_override }} {{ program_config_options|default('') }} --log-file=/var/log/sahara/{{ item.value.service_name }}.log
+{% if item.value.program_override is defined %}
+ExecStart={{ item.value.program_override }} {{ item.value.program_config_options|default('') }} {{ item.value.log_string | default('--log-file=') }}/var/log/sahara/{{ item.value.service_name }}.log
 {% else %}
-ExecStart={{ sahara_bin }}/{{ item.value.service_name }} {{ program_config_options|default('') }} --log-file=/var/log/sahara/{{ item.value.service_name }}.log
+ExecStart={{ sahara_bin }}/{{ item.value.service_name }} {{ item.value.program_config_options|default('') }} --log-file=/var/log/sahara/{{ item.value.service_name }}.log
 {% endif %}
 
 # Give a reasonable amount of time for the server to start up/shut down

templates/sahara-uwsgi.ini.j2

@@ -0,0 +1,19 @@
+[uwsgi]
+uid = {{ sahara_system_user_name }}
+gid = {{ sahara_system_group_name }}
+
+virtualenv = /openstack/venvs/sahara-{{ sahara_venv_tag }}
+wsgi-file = {{ sahara_bin }}/{{ item.value.wsgi_name }}
+http-socket = {{ item.value.uwsgi_bind_address }}:{{ item.value.uwsgi_port }}
+
+master = true
+enable-threads = true
+processes = {{ sahara_wsgi_processes }}
+threads = {{ sahara_wsgi_threads }}
+exit-on-reload = true
+die-on-term = true
+lazy-apps = true
+add-header = Connection: close
+buffer-size = {{ sahara_wsgi_buffer_size }}
+thunder-lock = true
+logfile-chmod = 644

vars/redhat-7.yml

@@ -16,3 +16,4 @@ sahara_distro_packages:
   - rpcbind
   - git
   - which
+  - libxml2-devel

vars/ubuntu-16.04.yml

@@ -20,3 +20,4 @@ sahara_distro_packages:
   - rpcbind
   - rsync
   - git
+  - libxml2-dev