Support for s3 backend of glance

This commit introduces support for s3 backend for glance.
You can enabled it in your deployment by adding below options in
your local.conf file.

For single store support:
enable_service s3api s-proxy s-account s-container
disable_service tls-proxy
GLANCE_USE_S3 = True

For multistore support:
enable_service s3api s-proxy s-account s-container
disable_service tls-proxy
GLANCE_USE_S3 = True
GLANCE_ENABLE_MULTIPLE_STORES: True

NOTE: At the moment devstack does not support tls with s3, this
support will be added soon.

Needed-By: https://review.opendev.org/c/openstack/glance/+/934311
Change-Id: Ic7264dc7faccb5e68c8df3b929eaa6d04149c6a2

Author: konan-abhi

lib/glance

@@ -41,6 +41,12 @@ else
     GLANCE_BIN_DIR=$(get_python_exec_prefix)
 fi
 
+#S3 for Glance
+GLANCE_USE_S3=$(trueorfalse False GLANCE_USE_S3)
+GLANCE_S3_DEFAULT_BACKEND=${GLANCE_S3_DEFAULT_BACKEND:-s3_fast}
+GLANCE_S3_BUCKET_ON_PUT=$(trueorfalse True GLANCE_S3_BUCKET_ON_PUT)
+GLANCE_S3_BUCKET_NAME=${GLANCE_S3_BUCKET_NAME:-images}
+
 # Cinder for Glance
 USE_CINDER_FOR_GLANCE=$(trueorfalse False USE_CINDER_FOR_GLANCE)
 # GLANCE_CINDER_DEFAULT_BACKEND should be one of the values
@@ -174,6 +180,34 @@ function cleanup_glance {
     remove_uwsgi_config "$GLANCE_UWSGI_CONF" "glance-wsgi-api"
 }
 
+# Set multiple s3 store related config options
+#
+function configure_multiple_s3_stores {
+    enabled_backends="${GLANCE_S3_DEFAULT_BACKEND}:s3"
+
+    iniset $GLANCE_API_CONF DEFAULT enabled_backends ${enabled_backends}
+    iniset $GLANCE_API_CONF glance_store default_backend $GLANCE_S3_DEFAULT_BACKEND
+}
+
+# Set common S3 store options to given config section
+#
+# Arguments:
+# config_section
+#
+function set_common_s3_store_params {
+    local config_section="$1"
+    openstack ec2 credential create
+    iniset $GLANCE_API_CONF $config_section s3_store_host "$SWIFT_SERVICE_PROTOCOL://$SERVICE_HOST:$S3_SERVICE_PORT"
+    iniset $GLANCE_API_CONF $config_section s3_store_access_key "$(openstack ec2 credential list -c Access -f value)"
+    iniset $GLANCE_API_CONF $config_section s3_store_secret_key "$(openstack ec2 credential list -c Secret -f value)"
+    iniset $GLANCE_API_CONF $config_section s3_store_create_bucket_on_put $GLANCE_S3_BUCKET_ON_PUT
+    iniset $GLANCE_API_CONF $config_section s3_store_bucket $GLANCE_S3_BUCKET_NAME
+    iniset $GLANCE_API_CONF $config_section s3_store_bucket_url_format "path"
+    if is_service_enabled tls-proxy; then
+        iniset $GLANCE_API_CONF $config_section s3_store_cacert $SSL_BUNDLE_FILE
+    fi
+}
+
 # Set multiple cinder store related config options for each of the cinder store
 #
 function configure_multiple_cinder_stores {
@@ -258,7 +292,6 @@ function configure_glance_store {
     local be
 
     if [[ "$glance_enable_multiple_stores" == "False" ]]; then
-        # Configure traditional glance_store
         if [[ "$use_cinder_for_glance" == "True" ]]; then
             # set common glance_store parameters
             iniset $GLANCE_API_CONF glance_store stores "cinder,file,http"
@@ -281,7 +314,7 @@ function configure_glance_store {
         if [[ "$use_cinder_for_glance" == "True" ]]; then
             # Configure multiple cinder stores for glance
             configure_multiple_cinder_stores
-        else
+        elif ! is_service_enabled s-proxy && [[ "$GLANCE_USE_S3" == "False" ]]; then
             # Configure multiple file stores for glance
             configure_multiple_file_stores
         fi
@@ -360,8 +393,15 @@ function configure_glance {
 
     # No multiple stores for swift yet
     if [[ "$GLANCE_ENABLE_MULTIPLE_STORES" == "False" ]]; then
-        # Store the images in swift if enabled.
-        if is_service_enabled s-proxy; then
+        # Return if s3api is enabled for glance
+        if [[ "$GLANCE_USE_S3" == "True" ]]; then
+            if is_service_enabled s3api; then
+                # set common glance_store parameters
+                iniset $GLANCE_API_CONF glance_store stores "s3,file,http"
+                iniset $GLANCE_API_CONF glance_store default_store s3
+            fi
+        elif is_service_enabled s-proxy; then
+            # Store the images in swift if enabled.
             iniset $GLANCE_API_CONF glance_store default_store swift
             iniset $GLANCE_API_CONF glance_store swift_store_create_container_on_put True
 
@@ -379,6 +419,12 @@ function configure_glance {
             iniset $GLANCE_SWIFT_STORE_CONF ref1 auth_address $KEYSTONE_SERVICE_URI/v3
             iniset $GLANCE_SWIFT_STORE_CONF ref1 auth_version 3
         fi
+    else
+        if [[ "$GLANCE_USE_S3" == "True" ]]; then
+            if is_service_enabled s3api; then
+                configure_multiple_s3_stores
+            fi
+        fi
     fi
 
     # We need to tell glance what it's public endpoint is so that the version
@@ -484,6 +530,13 @@ function create_glance_accounts {
             configure_glance_quotas
         fi
 
+        if is_service_enabled s3api && [[ "$GLANCE_USE_S3" == "True" ]]; then
+            if [[ "$GLANCE_ENABLE_MULTIPLE_STORES" == "False" ]]; then
+                set_common_s3_store_params glance_store
+            else
+                set_common_s3_store_params $GLANCE_S3_DEFAULT_BACKEND
+            fi
+        fi
     fi
 }