enable trove-api behind mod-wsgi

This change enables behind mod-wsgi as part of the community pike goal
goal-deploy-api-in-wsgi.

The change includes:

    - the wsgi script files to run trove api under apache
    - updates to the devstack plugin
    - a basic deploy doc which explains this change

Change-Id: Icdd39b47a1be426e87a5d09f9e9d567af1974a9c
Depends-On: I3d6f6649430ee40879de15fee0b215dc32e8b666
Closes-Bug: #1681478

3 files changed, 113 insertions, 2 deletions

diff --git a/devstack/files/apache-trove-api.template b/devstack/files/apache-trove-api.template
new file mode 100644
index 00000000..06c88b26
--- /dev/null
+++ b/devstack/files/apache-trove-api.template
@@ -0,0 +1,45 @@
+# Copyright 2017 Amrith Kumar.
+# All Rights Reserved.
+#
+# 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.
+
+# This is an example Apache2 configuration file for using the
+# Watcher API through mod_wsgi.  This version assumes you are
+# running devstack to configure the software.
+
+Listen %TROVE_SERVICE_PORT%
+
+<VirtualHost *:%TROVE_SERVICE_PORT%>
+    WSGIDaemonProcess trove-api user=%USER% processes=%APIWORKERS% threads=1 display-name=%{GROUP}
+    WSGIScriptAlias / %TROVE_WSGI_DIR%/app.wsgi
+    WSGIApplicationGroup %{GLOBAL}
+    WSGIProcessGroup trove-api
+    WSGIPassAuthorization On
+
+    ErrorLogFormat "%M"
+    ErrorLog /var/log/%APACHE_NAME%/trove-api.log
+    CustomLog /var/log/%APACHE_NAME%/trove-api-access.log combined
+
+
+    <Directory %TROVE_WSGI_DIR%>
+        WSGIProcessGroup trove-api
+        WSGIApplicationGroup %{GLOBAL}
+        <IfVersion >= 2.4>
+            Require all granted
+        </IfVersion>
+        <IfVersion < 2.4>
+            Order allow,deny
+            Allow from all
+        </IfVersion>
+    </Directory>
+</VirtualHost>
diff --git a/devstack/plugin.sh b/devstack/plugin.sh
index b423ff27..e64e8b0d 100644
--- a/devstack/plugin.sh
+++ b/devstack/plugin.sh
@@ -64,6 +64,14 @@ function create_trove_accounts {
     fi
 }
 
+# _cleanup_trove_apache_wsgi - Removes all the WSGI related files and
+# restart apache.
+function _cleanup_trove_apache_wsgi {
+    sudo rm -rf $TROVE_WSGI_DIR
+    sudo rm -f ${apache_site_config_for trove-api}
+    restart_apache_server
+}
+
 # stack.sh entry points
 # ---------------------
 
@@ -77,6 +85,11 @@ function cleanup_trove {
     if is_service_enabled horizon; then
         cleanup_trove_dashboard
     fi
+
+    if [[ "${TROVE_USE_MOD_WSGI}" == "TRUE" ]]; then
+        echo "Cleaning up Trove's WSGI setup"
+        _cleanup_trove_apache_wsgi
+    fi
 }
 
 
@@ -139,6 +152,27 @@ function configure_nova_kvm {
     echo "configure_nova_kvm: using virt_type: ${virt_type} for cpu: ${cpu}."
 }
 
+# _config_trove_apache_wsgi() - Setup WSGI config files for Trove and
+# enable the site
+function _config_trove_apache_wsgi {
+    local trove_apache_conf
+
+    sudo mkdir -p ${TROVE_WSGI_DIR}
+    sudo cp $TROVE_DIR/trove/cmd/app.wsgi $TROVE_WSGI_DIR/app.wsgi
+    trove_apache_conf=$(apache_site_config_for trove-api)
+    sudo cp $TROVE_DEVSTACK_FILES/apache-trove-api.template ${trove_apache_conf}
+    sudo sed -e "
+        s|%TROVE_SERVICE_PORT%|${TROVE_SERVICE_PORT}|g;
+        s|%TROVE_WSGI_DIR%|${TROVE_WSGI_DIR}|g;
+        s|%USER%|${STACK_USER}|g;
+        s|%APACHE_NAME%|${APACHE_NAME}|g;
+        s|%APIWORKERS%|${API_WORKERS}|g;
+    " -i ${trove_apache_conf}
+    enable_apache_site trove-api
+    tail_log trove-access /var/log/${APACHE_NAME}/trove-api-access.log
+    tail_log trove-api /var/log/${APACHE_NAME}/trove-api.log
+}
+
 # configure_trove() - Set config files, create data dirs, etc
 function configure_trove {
     setup_develop $TROVE_DIR
@@ -185,6 +219,12 @@ function configure_trove {
         iniset $TROVE_CONF DEFAULT trove_auth_url $TROVE_AUTH_ENDPOINT
     fi
 
+    # configure apache related files
+    if [[ "${TROVE_USE_MOD_WSGI}" == "TRUE" ]]; then
+        echo "Configuring Trove to use mod-wsgi and Apache"
+        _config_trove_apache_wsgi
+    fi
+
     # (Re)create trove taskmanager conf file if needed
     if is_service_enabled tr-tmgr; then
         # Use these values only if they're set
@@ -265,6 +305,11 @@ function configure_trove {
 function install_trove {
     setup_develop $TROVE_DIR
 
+    if [[ "${TROVE_USE_MOD_WSGI}" == "TRUE" ]]; then
+        echo "Installing apache wsgi"
+        install_apache_wsgi
+    fi
+
     if is_service_enabled horizon; then
         install_trove_dashboard
     fi
@@ -491,7 +536,13 @@ function finalize_trove_network {
 
 # start_trove() - Start running processes, including screen
 function start_trove {
-    run_process tr-api "$TROVE_BIN_DIR/trove-api --config-file=$TROVE_CONF --debug"
+    if [[ ${TROVE_USE_MOD_WSGI}" == TRUE" ]]; then
+        echo "Restarting Apache server ..."
+        enable_apache_site trove-api
+        restart_apache_server
+    else
+        run_process tr-api "$TROVE_BIN_DIR/trove-api --config-file=$TROVE_CONF --debug"
+    fi
     run_process tr-tmgr "$TROVE_BIN_DIR/trove-taskmanager --config-file=$TROVE_TASKMANAGER_CONF --debug"
     run_process tr-cond "$TROVE_BIN_DIR/trove-conductor --config-file=$TROVE_CONDUCTOR_CONF --debug"
 }
@@ -500,7 +551,13 @@ function start_trove {
 function stop_trove {
     # Kill the trove screen windows
     local serv
-    for serv in tr-api tr-tmgr tr-cond; do
+    if [[ ${TROVE_USE_MOD_WSGI} == "TRUE" ]]; then
+        echo "Disabling Trove API in Apache"
+        disable_apache_site trove-api
+    else
+        stop_process tr-api
+    fi
+    for serv in tr-tmgr tr-cond; do
         stop_process $serv
     done
 }
diff --git a/devstack/settings b/devstack/settings
index be3074f4..2dff5fb3 100644
--- a/devstack/settings
+++ b/devstack/settings
@@ -61,4 +61,13 @@ TROVE_MANAGE=$TROVE_BIN_DIR/trove-manage
 # Tell Tempest this project is present
 TEMPEST_SERVICES+=,trove
 
+# By default enable Trove API behind mod-wsgi. Change this to FALSE
+# if you don't want Apache/mod-wsgi
+TROVE_USE_MOD_WSGI=$(trueorfalse TRUE TROVE_USE_MOD_WSGI)
+
+TROVE_SERVICE_PORT=${TROVE_SERVICE_PORT:-8779}
+TROVE_DEVSTACK_DIR=${TROVE_DIR}/devstack
+TROVE_DEVSTACK_FILES=${TROVE_DEVSTACK_DIR}/files
+TROVE_WSGI_DIR=${TROVE_WSGI_DIR:-/var/www/trove}
+
 enable_service trove tr-api tr-tmgr tr-cond