GUACAMOLE-374: Support absolutely all properties and extensions.

guacamole-docker/entrypoint.d/700-configure-features.sh

@@ -0,0 +1,88 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+#
+#
+
+##
+## @fn 800-configure-features.sh
+##
+## Automatically checks all environment variables currently set and performs
+## configuration tasks related to those variabels, including installing any
+## extensions and external libraries associated with those variables to
+## GUACAMOLE_HOME.  Only environment variable prefixes are considered; this
+## script is not aware of whether an extension actually uses an environment
+## variable.
+##
+
+##
+## Returns whether the feature associated with a particular environment
+## variable prefix has configuration values set. Only the presence of
+## environment variables having that prefix is checked. Features can also be
+## entirely enabled/disabled through setting the [PREFIX_]ENABLED variable to
+## true/false respectively, where "[PREFIX_]" is the specified environment
+## variable prefix (including trailing underscore).
+##
+## @param VAR_BASE
+##     The environment variable prefix to check, including trailing underscore.
+##
+## @returns
+##     Zero if the feature associated with the given environment variable
+##     prefix is enabled, non-zero otherwise.
+##
+is_feature_enabled() {
+
+    local VAR_BASE="$1"
+
+    # Allow any feature to be explicitly enabled/disabled using a
+    # [PREFIX_]ENABLED variable
+    local ENABLED_VAR="${VAR_BASE}ENABLED"
+    if [ "${!ENABLED_VAR}" = "true" ]; then
+        return 0
+    elif [ "${!ENABLED_VAR}" = "false" ]; then
+        return 1
+    fi
+
+    # Lacking an explicit request to enable/disable the feature, rely on
+    # implicit enable/disable via presence of any other variables having the
+    # given prefix
+    awk 'BEGIN{for(v in ENVIRON) print v}' | grep "^${VAR_BASE}" > /dev/null
+
+}
+
+# Search environment for enabled extensions/features based on environment
+# variable prefixes
+for VAR_BASE in /opt/guacamole/environment/*; do
+
+    # Skip any directories without at least one corresponding environment
+    # variable set
+    is_feature_enabled "$(basename "$VAR_BASE")" || continue
+
+    # Execute any associated configuration script
+    [ ! -e "$VAR_BASE/configure.sh" ] || source "$VAR_BASE/configure.sh"
+
+    # Add any required links for extensions/libraries associated with the
+    # configured extension
+    for SUBDIR in lib extensions; do
+        if [ -d "$VAR_BASE/$SUBDIR" ]; then
+            mkdir -p "$GUACAMOLE_HOME/$SUBDIR/"
+            ln -s "$VAR_BASE/$SUBDIR"/* "$GUACAMOLE_HOME/$SUBDIR/"
+        fi
+    done
+
+done
+