GUACAMOLE-374: Support absolutely all properties and extensions.

Dockerfile

@@ -61,6 +61,9 @@ ENV \
 
 # Add configuration scripts
 COPY guacamole-docker/bin/ /opt/guacamole/bin/
+COPY guacamole-docker/build.d/ /opt/guacamole/build.d/
+COPY guacamole-docker/entrypoint.d/ /opt/guacamole/entrypoint.d/
+COPY guacamole-docker/environment/ /opt/guacamole/environment/
 
 # Copy source to container for sake of build
 COPY . "$BUILD_DIR"
@@ -68,6 +71,8 @@ COPY . "$BUILD_DIR"
 # Run the build itself
 RUN /opt/guacamole/bin/build-guacamole.sh "$BUILD_DIR" /opt/guacamole
 
+RUN rm -rf /opt/guacamole/build.d /opt/guacamole/bin/build-guacamole.sh
+
 # For the runtime image, we start with the official Tomcat distribution
 FROM tomcat:${TOMCAT_VERSION}-${TOMCAT_JRE}
 
@@ -91,6 +96,9 @@ RUN useradd --system --create-home --shell /usr/sbin/nologin --uid $UID --gid $G
 # Run with user guacamole
 USER guacamole
 
+# Environment variable defaults
+ENV GUACAMOLE_HOME=/etc/guacamole
+
 # Start Guacamole under Tomcat, listening on 0.0.0.0:8080
 EXPOSE 8080
-CMD ["/opt/guacamole/bin/start.sh" ]
+CMD ["/opt/guacamole/bin/entrypoint.sh" ]

guacamole-docker/bin/build-guacamole.sh

@@ -1,4 +1,4 @@
-#!/bin/sh -e
+#!/bin/bash -e
 #
 # Licensed to the Apache Software Foundation (ASF) under one
 # or more contributor license agreements.  See the NOTICE file
@@ -23,10 +23,15 @@
 ##
 ## Builds Guacamole, saving "guacamole.war" and all applicable extension .jars
 ## using the guacamole-client source contained within the given directory.
-## Extension files will be grouped by their associated type, with all MySQL
+## Extension files will be grouped by their associated type, identical to
-## files being placed within the "mysql/" subdirectory of the destination, all
+## extracting the .tar.gz files included with each Guacamole release except
-## PostgreSQL files being placed within the "postgresql/" subdirectory of the
+## that version numbers are stripped from directory and .jar file names.
-## destination, etc.
+##
+## The build process is split across multiple scripts within the
+## /opt/guacamole/build.d directory. Additional steps may be added to the
+## build process by adding .sh scripts to this directory. Any such scripts MUST
+## be shell scripts ending with a ".sh" extension and MUST be written for bash
+## (the shell used by this entrypoint).
 ##
 ## @param BUILD_DIR
 ##     The directory which currently contains the guacamole-client source and
@@ -39,164 +44,21 @@
 ##     extension type.
 ##
 
+##
+## The directory which currently contains the guacamole-client source and in
+## which the build should be performed.
+##
 BUILD_DIR="$1"
+
+##
+## The directory to save guacamole.war within, along with all extension .jars.
+## Note that this script will create extension-specific subdirectories within
+## this directory, and files will thus be grouped by extension type.
+##
 DESTINATION="$2"
 
-#
+# Run all scripts within the "build.d" directory
-# Create destination, if it does not yet exist
+for SCRIPT in /opt/guacamole/build.d/*.sh; do
-#
+    source "$SCRIPT"
+done
 
-mkdir -p "$DESTINATION"
-
-#
-# Build guacamole.war and all extensions
-#
-
-cd "$BUILD_DIR"
-
-#
-# Run the maven build, applying any arbitrary provided maven arguments.
-#
-
-mvn $MAVEN_ARGUMENTS package
-
-#
-# Copy guacamole.war to destination
-#
-
-cp guacamole/target/*.war "$DESTINATION/guacamole.war"
-
-#
-# Copy JDBC auth extensions and SQL scripts
-#
-
-tar -xzf extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-dist/target/*.tar.gz \
-    -C "$DESTINATION"                                   \
-    --wildcards                                         \
-    --no-anchored                                       \
-    --strip-components=1                                \
-    "*.jar"                                             \
-    "*.sql"
-
-#
-# Download MySQL JDBC driver
-#
-
-echo "Downloading MySQL Connector/J ..."
-curl -L "https://dev.mysql.com/get/Downloads/Connector-J/mysql-connector-j-$MYSQL_JDBC_VERSION.tar.gz" | \
-tar -xz                        \
-    -C "$DESTINATION/mysql/"   \
-    --wildcards                \
-    --no-anchored              \
-    --no-wildcards-match-slash \
-    --strip-components=1       \
-    "mysql-connector-*.jar"
-
-#
-# Download PostgreSQL JDBC driver
-#
-
-echo "Downloading PostgreSQL JDBC driver ..."
-curl -L "https://jdbc.postgresql.org/download/postgresql-$PGSQL_JDBC_VERSION.jar" \
-    > "$DESTINATION/postgresql/postgresql-$PGSQL_JDBC_VERSION.jar"
-
-#
-# Copy SSO auth extensions
-#
-
-tar -xzf extensions/guacamole-auth-sso/modules/guacamole-auth-sso-dist/target/*.tar.gz \
-    -C "$DESTINATION"                                   \
-    --wildcards                                         \
-    --no-anchored                                       \
-    --strip-components=1                                \
-    "*.jar"
-
-#
-# Download SQL Server JDBC driver
-#
-
-echo "Downloading SQL Server JDBC driver ..."
-curl -L "https://github.com/microsoft/mssql-jdbc/releases/download/v$MSSQL_JDBC_VERSION/mssql-jdbc-$MSSQL_JDBC_VERSION.jre8.jar" \
-    > "$DESTINATION/sqlserver/mssql-jdbc-$MSSQL_JDBC_VERSION.jre8.jar"   \
-
-#
-# Copy LDAP auth extension and schema modifications
-#
-
-mkdir -p "$DESTINATION/ldap"
-tar -xzf extensions/guacamole-auth-ldap/target/*.tar.gz \
-    -C "$DESTINATION/ldap"                              \
-    --wildcards                                         \
-    --no-anchored                                       \
-    --xform="s#.*/##"                                   \
-    "*.jar"                                             \
-    "*.ldif"
-
-#
-# Copy Radius auth extension if it was build
-#
-
-if [ -f extensions/guacamole-auth-radius/target/guacamole-auth-radius*.jar ]; then
-    mkdir -p "$DESTINATION/radius"
-    cp extensions/guacamole-auth-radius/target/guacamole-auth-radius*.jar "$DESTINATION/radius"
-fi
-
-#
-# Copy TOTP auth extension if it was built
-#
-
-if [ -f extensions/guacamole-auth-totp/target/guacamole-auth-totp*.jar ]; then
-    mkdir -p "$DESTINATION/totp"
-    cp extensions/guacamole-auth-totp/target/guacamole-auth-totp*.jar "$DESTINATION/totp"
-fi
-
-#
-# Copy Duo auth extension if it was built
-#
-
-if [ -f extensions/guacamole-auth-duo/target/*.tar.gz ]; then
-    mkdir -p "$DESTINATION/duo"
-    tar -xzf extensions/guacamole-auth-duo/target/*.tar.gz \
-        -C "$DESTINATION/duo/"                             \
-        --wildcards                                        \
-        --no-anchored                                      \
-        --no-wildcards-match-slash                         \
-        --strip-components=1                               \
-        "*.jar"
-fi
-
-#
-# Copy header auth extension if it was built
-#
-
-if [ -f extensions/guacamole-auth-header/target/guacamole-auth-header*.jar ]; then
-    mkdir -p "$DESTINATION/header"
-    cp extensions/guacamole-auth-header/target/guacamole-auth-header*.jar "$DESTINATION/header"
-fi
-
-#
-# Copy json auth extension if it was built
-#
-
-if [ -f extensions/guacamole-auth-json/target/guacamole-auth-json*.jar ]; then
-    mkdir -p "$DESTINATION/json"
-    cp extensions/guacamole-auth-json/target/guacamole-auth-json*.jar "$DESTINATION/json"
-fi
-
-#
-# Copy automatic brute-force banning auth extension if it was built
-#
-
-if [ -f extensions/guacamole-auth-ban/target/guacamole-auth-ban*.jar ]; then
-    mkdir -p "$DESTINATION/ban"
-    cp extensions/guacamole-auth-ban/target/guacamole-auth-ban*.jar "$DESTINATION/ban"
-fi
-
-#
-# Copy history recording storage extension if it was built
-#
-
-if [ -f extensions/guacamole-history-recording-storage/target/guacamole-history-recording-storage*.jar ]; then
-    mkdir -p "$DESTINATION/recordings"
-    cp extensions/guacamole-history-recording-storage/target/guacamole-history-recording-storage*.jar "$DESTINATION/recordings"
-fi

guacamole-docker/bin/entrypoint.sh

@@ -0,0 +1,39 @@
+#!/bin/bash -e
+#
+# 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 entrypoint.sh
+##
+## (Re-)configures the Apache Guacamole web application based on the values of
+## environment variables, deploys the web application beneath a bundled copy of
+## Apache Tomcat, and starts Tomcat.
+##
+## The startup process is split across multiple scripts within the
+## /opt/guacamole/entrypoint.d directory. Additional steps may be added to the
+## startup process by adding .sh scripts to this directory. Any such scripts
+## MUST be shell scripts ending with a ".sh" extension and MUST be written for
+## bash (the shell used by this entrypoint).
+##
+
+# Run all scripts within the "entrypoint.d" directory
+for SCRIPT in /opt/guacamole/entrypoint.d/*.sh; do
+    source "$SCRIPT"
+done
+

guacamole-docker/build.d/000-build-and-install-guacamole.sh

@@ -0,0 +1,62 @@
+#
+# 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 010-build-and-install-guacamole.sh
+##
+## Builds the Guacamole web application and all main extensions, installing the
+## resulting binaries to standard locations within the Docker image. After the
+## build and install process, the resulting binaries can be found beneath:
+##
+## /opt/guacamole/webapp:
+##   The web application, "guacamole.war".
+##
+## /opt/guacamole/extensions:
+##   All extensions, each within their own subdirectory and identical to the
+##   result of extracting a released .tar.gz except that version numbers of been
+##   stripped.
+##
+
+#
+# Build guacamole.war and all extensions, applying any provided Maven build
+# arguments
+#
+
+cd "$BUILD_DIR"
+mvn $MAVEN_ARGUMENTS package
+
+#
+# Copy built web application (guacamole.war) to destination location
+#
+
+mkdir -p "$DESTINATION/webapp"
+cp guacamole/target/*.war "$DESTINATION/webapp/guacamole.war"
+
+#
+# Extract all extensions to destination location, stripping version number
+# suffix from .jar files and top-level directory name
+#
+
+mkdir -p "$DESTINATION/extensions"
+find extensions/ -path "**/target/*.tar.gz" -exec tar -xzf "{}" \
+    -C "$DESTINATION/extensions"                                \
+    --xform='s#^\([^/]*\)-[0-9]\+\.[0-9]\+\.[0-9]\+#\1#g'       \
+    --xform='s#-[0-9]\+\.[0-9]\+\.[0-9]\+\(\.jar$\)#\1#g'       \
+    ";"
+

guacamole-docker/build.d/010-map-guacamole-extensions.sh

@@ -0,0 +1,118 @@
+#
+# 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 020-map-guacamole-extensions.sh
+##
+## Maps all installed Guacamole extensions (built in a previous step) to their
+## corresponding environment variable prefixes, adding symbolic links so that
+## the changes to the contents of GUACAMOLE_HOME can be easily made by the
+## container's entrypoint based on which environment variables are set, without
+## requiring that the entrypoint be specifically aware of all supported
+## environment variables.
+##
+
+##
+## Reads a mapping of Guacamole extension to environment variable prefix from
+## STDIN, creating a hierarchy of directories and symbolic links on the
+## filesystem that can be easily consumed by the container's entrypoint later.
+##
+## Each mapping consists of a single line with two values separated by
+## whitespace, where the first (leftmost) value is the path to the directory
+## containing the extension .jar file (relative to /opt/guacamole/extensions)
+## and the second (rightmost) value is the environment variable prefix used by
+## that extension. For readability, periods may be used in lieu of spaces.
+##
+## After mapping has occurred, the resulting mappings are located beneath
+## /opt/guacamole/environment. They consist of directories named after the
+## provided environment variable prefixes, where the contents of those
+## directories are subsets of the contents of GUACAMOLE_HOME that would need to
+## be added to the actual GUACAMOLE_HOME to enable that extension.
+##
+map_extensions() {
+
+    # Read through each provided path/prefix mapping pair
+    mkdir -p "$DESTINATION/environment"
+    tr . ' ' | while read -r EXT_PATH VAR_PREFIX; do
+
+        # Add mappings only for extensions that were actually built as part of
+        # the build process (some extensions, like the RADIUS support, will
+        # only be built if specific build arguments are provided)
+        if [ -d "$DESTINATION/extensions/$EXT_PATH/" ]; then
+            echo "Mapped: $EXT_PATH -> $VAR_PREFIX"
+            mkdir -p "$DESTINATION/environment/$VAR_PREFIX/extensions"
+            ln -s "$DESTINATION/extensions/$EXT_PATH"/*.jar "$DESTINATION/environment/$VAR_PREFIX/extensions/"
+        else
+            echo "Skipped: $EXT_PATH (not built)"
+        fi
+
+    done
+
+}
+
+#
+# This section is a mapping of all bundled extensions to their corresponding
+# variable prefixes. Each line consists of a whitespace-separated pair of
+# extension path (the relative directory containing the .jar file) to that
+# extension's variable prefix. For readability, a period may be used in lieu of
+# a space.
+#
+# NOTES:
+#
+# (1) The actual variables used by each extension are not determined here, but
+# rather by the transformation of their configuration properties to variables
+# ("lowercase-with-dashes" to "UPPERCASE_WITH_UNDERSCORES"). The variable
+# prefixes listed here should be chosen to match the prefixes resulting from
+# that transformation of the extensions' properties.
+#
+# (2) The paths on the left side of this mapping are the paths of the extension
+# .jar files relative to the "/opt/guacamole/extensions" directory used by the
+# container to store extensions prior to use. They are identical to the paths
+# used by the distribution .tar.gz files provided with each Guacamole release,
+# except that the version numbers have been stripped from the top-level path.
+#
+# (3) The script processing this file uses these prefixes to define and process
+# an additional "ENABLED" variable (ie: "BAN_ENABLED", "TOTP_ENABLED", etc.)
+# that can be used to enable/disable an extension entirely regardless of the
+# presence/absence of other variables with the prefix. This allows extensions
+# that need no configuration to be easily enabled. It also allows extensions
+# that already have configuration present to be easily disabled without
+# requiring that all other configuration be removed.
+#
+map_extensions <<'EOF'
+    guacamole-auth-ban..........................BAN_
+    guacamole-auth-duo..........................DUO_
+    guacamole-auth-header.......................HTTP_AUTH_
+    guacamole-auth-jdbc/mysql...................MYSQL_
+    guacamole-auth-jdbc/postgresql..............POSTGRESQL_
+    guacamole-auth-jdbc/sqlserver...............SQLSERVER_
+    guacamole-auth-json.........................JSON_
+    guacamole-auth-ldap.........................LDAP_
+    guacamole-auth-quickconnect.................QUICKCONNECT_
+    guacamole-auth-radius.......................RADIUS_
+    guacamole-auth-sso/cas......................CAS_
+    guacamole-auth-sso/openid...................OPENID_
+    guacamole-auth-sso/saml.....................SAML_
+    guacamole-auth-sso/ssl......................SSL_
+    guacamole-auth-totp.........................TOTP_
+    guacamole-display-statistics................DISPLAY_STATISTICS_
+    guacamole-history-recording-storage.........RECORDING_
+    guacamole-vault/ksm.........................KSM_
+EOF
+

guacamole-docker/build.d/020-download-drivers.sh

@@ -0,0 +1,99 @@
+#
+# 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 030-download-drivers.sh
+##
+## Downloads all JDBC drivers required by the various supported databases. Each
+## downloaded driver is stored beneath /opt/guacamole/drivers, with symbolic
+## links added to the mappings beneath /opt/guacamole/environment to ensure any
+## required drivers are added to GUACAMOLE_HOME if necessary to support a
+## requested database.
+##
+
+##
+## Downloads the JDBC driver at the given URL, storing the driver's .jar file
+## under the given name and environment variable prefix. The downloaded .jar
+## file is stored such that it is pulled into GUACAMOLE_HOME automatically if
+## environment variables with that prefix are used.
+##
+## If the URL is for a .tar.gz file and not a .jar file, the .jar will be
+## automatically extracted from the .tar.gz as it is downloaded.
+##
+## @param VAR_PREFIX
+##     The environment variable prefix used by the extension that requires the
+##     driver.
+##
+## @param URL
+##     The URL that the driver should be downloaded from.
+##
+## @param DEST_JAR
+##     The filename to assign to the downloaded .jar file. This is mainly
+##     needed to ensure that the drivers bundled with the image have names that
+##     are predictable and reliable enough that they can be consumed by
+##     third-party use of this image.
+##
+download_driver() {
+
+    local VAR_PREFIX="$1"
+    local URL="$2"
+    local DEST_JAR="$3"
+
+    # Ensure primary destination path for .jar file exists
+    local DEST_PATH="$DESTINATION/drivers/"
+    mkdir -p "$DEST_PATH"
+
+    # Download requested .jar file, extracting from .tar.gz if necessary
+    if [[ "$URL" == *.tar.gz ]]; then
+        curl -L "$URL" | tar -xz       \
+            --wildcards                \
+            --no-anchored              \
+            --no-wildcards-match-slash \
+            --to-stdout                \
+            "*.jar" > "$DEST_PATH/$DEST_JAR"
+    else
+        curl -L "$URL" > "$DEST_PATH/$DEST_JAR"
+    fi
+
+    # Add any required link to ensure the .jar file is loaded along with the
+    # extension that requires it
+    mkdir -p "$DESTINATION/environment/$VAR_PREFIX/lib"
+    ln -s "$DEST_PATH/$DEST_JAR" "$DESTINATION/environment/$VAR_PREFIX/lib/"
+
+}
+
+#
+# Download and link any required JDBC drivers
+#
+
+# MySQL JDBC driver
+download_driver "MYSQL_" \
+    "https://dev.mysql.com/get/Downloads/Connector-J/mysql-connector-j-$MYSQL_JDBC_VERSION.tar.gz" \
+    "mysql-jdbc.jar"
+
+# PostgreSQL JDBC driver
+download_driver "POSTGRESQL_" \
+    "https://jdbc.postgresql.org/download/postgresql-$PGSQL_JDBC_VERSION.jar" \
+    "postgresql-jdbc.jar"
+
+# SQL Server JDBC driver
+download_driver "SQLSERVER_" \
+    "https://github.com/microsoft/mssql-jdbc/releases/download/v$MSSQL_JDBC_VERSION/mssql-jdbc-$MSSQL_JDBC_VERSION.jre8.jar" \
+    "mssql-jdbc.jar"
+

guacamole-docker/build.d/999-verify-sanity.sh

@@ -0,0 +1,47 @@
+#
+# 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 999-verify-sanity.sh
+##
+## Performs sanity checks on the results of the build that verify the image
+## contains everything it is expected to contain, including all built
+## extensions. If symbolic links were not correctly constructed, or some built
+## extensions were not mapped to environment variable prefixes, this script
+## will log errors and fail the build.
+##
+
+# Perform basic sanity checks that the symbolic links used to associated
+# environment variables with extensions/libraries have been correctly created,
+# bailing out if any problems are found.
+(
+
+    # Search for any broken symbolic links intended to map files for
+    # environment variables
+    find "$DESTINATION/environment/" -xtype l | sed 's/^/Broken link: /'
+
+    # Search for extensions that have not been mapped to any environment
+    # variables at all
+    comm -23 \
+        <(find "$DESTINATION/extensions/" -name "*.jar" -exec realpath "{}" ";" | sort -u) \
+        <(find "$DESTINATION/environment/" -path "**/extensions/*.jar" -exec realpath "{}" ";" | sort -u) \
+        | sed 's/^/Unmapped extension: /'
+
+) | sed 's/^/ERROR: /' | (! grep .) >&2 || exit 1
+

guacamole-docker/entrypoint.d/000-migrate-legacy-variables.sh

@@ -0,0 +1,105 @@
+#
+# 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 000-migrate-legacy-variables.sh
+##
+## Checks for usage of any environment variables that were formerly supported
+## but are now deprecated, warning when any deprecated variables are
+## encountered.  Until support for a deprecated variable is entirely removed,
+## the value provided for the deprecated variable is automatically assigned to
+## the currently-supported variable.
+##
+
+##
+## Checks for usage of the given deprecated environment variable, automatically
+## assigning its value to the given currently-supported environment variable.
+## If usage of the deprecated variable is found, a warning is printed to
+## STDERR.
+##
+## @param LEGACY_VAR_NAME
+##     The name of the environment variable that's deprecated.
+##
+## @param CURRENT_VAR_NAME
+##     The name of the environment variable that is currently supported and
+##     replaces the deprecated variable.
+##
+deprecate_variable() {
+
+    local LEGACY_VAR_NAME="$1"
+    local CURRENT_VAR_NAME="$2"
+
+    if [ -n "${!LEGACY_VAR_NAME}" ]; then
+        echo "WARNING: The \"$LEGACY_VAR_NAME\" environment variable has been deprecated in favor of \"$CURRENT_VAR_NAME\". Please migrate your configuration when possible, as support for the older name may be removed in future releases." >&2
+        export "$CURRENT_VAR_NAME"="${!LEGACY_VAR_NAME}"
+    fi
+
+}
+
+##
+## Checks for usage of any environment variables using the given deprecated
+## prefix, automatically assigning their values to corresponding environment
+## variables having the given currently-supported prefix. If usage of the
+## deprecated prefix is found, a warning is printed to STDERR.
+##
+## @param LEGACY_VAR_PREFIX
+##     The environment variable prefix that's deprecated.
+##
+## @param CURRENT_VAR_PREFIX
+##     The environment variable prefix that is currently supported and
+##     replaces the deprecated variable prefix.
+##
+deprecate_variable_prefix() {
+
+    local LEGACY_VAR_PREFIX="$1"
+    local CURRENT_VAR_PREFIX="$2"
+
+    local LEGACY_VAR_NAME
+    local CURRENT_VAR_NAME
+    local HAS_LEGACY_VARIABLES=0
+
+    # Automatically reassign all "POSTGRES_*" variables to "POSTGRESQL_*"
+    while read -r LEGACY_VAR_NAME; do
+        HAS_LEGACY_VARIABLES=1
+        CURRENT_VAR_NAME="$CURRENT_VAR_PREFIX${LEGACY_VAR_NAME#$LEGACY_VAR_PREFIX}"
+        export "$CURRENT_VAR_NAME"="${!LEGACY_VAR_NAME}"
+        unset "$LEGACY_VAR_NAME"
+    done < <(awk 'BEGIN{for(v in ENVIRON) print v}' | grep "^$LEGACY_VAR_PREFIX")
+
+    if [ "$HAS_LEGACY_VARIABLES" = "1" ]; then
+        echo "WARNING: The \"$LEGACY_VAR_PREFIX\" prefix for environment variables has been deprecated in favor of the \"$CURRENT_VAR_PREFIX\" prefix. Please migrate your configuration when possible, as support for the older prefix may be removed in future releases." >&2
+        export "$CURRENT_VAR_NAME"="$LEGACY_VAR_NAME"
+    fi
+
+}
+
+# The old "*_USER" style for configuring the user account to be used to access
+# the database is being replaced with "*_USERNAME" such that all environment
+# variables exactly correspond to the names of configuration properties from
+# guacamole.properties.
+deprecate_variable "MYSQL_USER"     "MYSQL_USERNAME"
+deprecate_variable "POSTGRES_USER"  "POSTGRESQL_USERNAME"
+deprecate_variable "SQLSERVER_USER" "SQLSERVER_USERNAME"
+
+# The old "POSTGRES_" prefix for configuring usage of PostgreSQL is being
+# replaced with "POSTGRESQL_" such that all environment variables exactly
+# correspond to the names of configuration properties from
+# guacamole.properties.
+deprecate_variable_prefix "POSTGRES_" "POSTGRESQL_"
+

guacamole-docker/entrypoint.d/100-generate-guacamole-home.sh

@@ -0,0 +1,111 @@
+#
+# 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 010-generate-guacamole-home.sh
+##
+## Automatically generates a temporary, skeleton GUACAMOLE_HOME to be used for
+## this run of the container. GUACAMOLE_HOMEs from previous runs are
+## automatically deleted prior to creating the new skeleton. A
+## randomly-generated temporary directory is used instead of a standard
+## directory like "/etc/guacamole" to allow users to use "/etc/guacamole" as a
+## basis for their own configuration.
+##
+
+##
+## The directory to copy/link over as a basis for the GUACAMOLE_HOME actually
+## used by the Guacamole web application. Any configuration generated by this
+## container will be overlaid on top of this configuration. To achieve the
+## overlay, symbolic links will be created for all files inside and beneath
+## this directory. Only the guacamole.properties file will be copied instead of
+## using symbolic links (to ensure property generation performed by the
+## container does not potentially modify an external file).
+##
+GUACAMOLE_HOME_TEMPLATE="$GUACAMOLE_HOME"
+
+##
+## Tests whether a given property is set within the guacamole.properties file
+## in GUACAMOLE_HOME.
+##
+## @param PROPERTY_NAME
+##     The name of the property to check.
+##
+## @returns
+##     Zero if the given property is set to any value within
+##     guacamole.properties, non-zero otherwise.
+##
+is_property_set() {
+    local PROPERTY_NAME="$1"
+    grep "^[[:space:]]*$PROPERTY_NAME\>" "$GUACAMOLE_HOME/guacamole.properties" &> /dev/null
+}
+
+#
+# Start with a fresh GUACAMOLE_HOME
+#
+
+rm -rf /tmp/guacamole-home.*
+GUACAMOLE_HOME="`mktemp -p /tmp -d guacamole-home.XXXXXXXXXX`"
+mkdir -p "$GUACAMOLE_HOME/"{lib,extensions}
+
+cat > "$GUACAMOLE_HOME/guacamole.properties" <<EOF
+# guacamole.properties - generated `date`
+EOF
+
+#
+# Copy contents of provided GUACAMOLE_HOME template, if any
+#
+
+if [ -e "$GUACAMOLE_HOME_TEMPLATE" ]; then
+
+    # Create links for any libraries provided in the template GUACAMOLE_HOME
+    find "$GUACAMOLE_HOME_TEMPLATE/lib" -mindepth 1 -maxdepth 1 \
+        -exec ln -sv "{}" "$GUACAMOLE_HOME/lib/" ";"
+
+    # Create links for any extensions provided in the template GUACAMOLE_HOME
+    find "$GUACAMOLE_HOME_TEMPLATE/extensions" -mindepth 1 -maxdepth 1 \
+        -exec ln -sv "{}" "$GUACAMOLE_HOME/extensions/" ";"
+
+    # Create links for all other files directly within the template
+    # GUACAMOLE_HOME
+    find "$GUACAMOLE_HOME_TEMPLATE" -mindepth 1 -maxdepth 1 \
+        -name guacamole.properties -o -name lib -o -name extensions -prune \
+        -o -exec ln -sv "{}" "$GUACAMOLE_HOME/" ";"
+
+    # Add any properties provided within template GUACAMOLE_HOME
+    if [ -e "$GUACAMOLE_HOME_TEMPLATE/guacamole.properties" ]; then
+        cat "$GUACAMOLE_HOME_TEMPLATE/guacamole.properties" >> "$GUACAMOLE_HOME/guacamole.properties"
+    fi
+
+fi
+
+# Enable reading of properties directly from environment variables unless
+# overridden
+if ! is_property_set "enable-environment-properties"; then
+    cat >> "$GUACAMOLE_HOME/guacamole.properties" <<'EOF'
+#
+# NOTE: The following was automatically added by the container entrypoint to
+# allow all Guacamole configuration properties to be automatically read from
+# environment variables. If this is not desired, you can override this behavior
+# by specifying the "enable-environment-properties" variable yourself in your
+# own guacamole.properties file.
+#
+enable-environment-properties: true
+EOF
+fi
+

guacamole-docker/entrypoint.d/110-configure-guacamole-logging.sh

@@ -0,0 +1,33 @@
+#
+# 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 030-configure-guacamole-logging.sh
+##
+## Checks the value of the LOGBACK_LEVEL environment variable, producing a
+## corresponding logback.xml file within GUACAMOLE_HOME if a log level has been
+## explicitly specified.
+##
+
+# Set logback level if specified
+if [ -n "$LOGBACK_LEVEL" ]; then
+    unzip -o -j /opt/guacamole/guacamole.war WEB-INF/classes/logback.xml -d $GUACAMOLE_HOME
+    sed -i "s/level=\"info\"/level=\"$LOGBACK_LEVEL\"/" $GUACAMOLE_HOME/logback.xml
+fi
+

guacamole-docker/entrypoint.d/500-generate-tomcat-catalina-base.sh

@@ -0,0 +1,50 @@
+#
+# 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.
+#
+
+##
+## 500-generate-tomcat-catalina-base.sh
+##
+## Automcatically generates a fresh, temporary CATALINA_BASE for Apache Tomcat.
+## This allows Tomcat to run as a reduced-privilege user, and allows its
+## configuration to be dynamically generated by the container entrypoint at
+## startup.
+##
+
+#
+# Start with a fresh CATALINA_BASE
+#
+
+rm -rf /tmp/catalina-base.*
+export CATALINA_BASE="`mktemp -p /tmp -d catalina-base.XXXXXXXXXX`"
+
+# User-only writable CATALINA_BASE
+for dir in logs temp webapps work; do
+    mkdir -p $CATALINA_BASE/$dir
+done
+cp -R /usr/local/tomcat/conf $CATALINA_BASE
+
+cat >> "$CATALINA_BASE/conf/catalina.properties" <<EOF
+
+# Point Guacamole at automatically-generated, temporary GUACAMOLE_HOME
+guacamole.home=$GUACAMOLE_HOME
+EOF
+
+# Install webapp
+ln -sf /opt/guacamole/webapp/guacamole.war $CATALINA_BASE/webapps/${WEBAPP_CONTEXT:-guacamole}.war
+

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
+

guacamole-docker/entrypoint.d/999-start-tomcat.sh

@@ -0,0 +1,30 @@
+#
+# 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 999-start-tomcat.sh
+##
+## Starts Tomcat. This script replaces the current process with the Tomcat
+## process and does not exit.
+##
+
+# Start tomcat
+cd /usr/local/tomcat
+exec catalina.sh run
+

guacamole-docker/environment/REMOTE_IP_VALVE_/configure.sh

@@ -0,0 +1,72 @@
+#
+# 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 REMOTE_IP_VALVE_/configure.sh
+##
+## Configures Tomcat to forward the IP addresses of clients behind a proxy if
+## the REMOTE_IP_VALVE_ENABLED environment variable is set to "true".
+##
+
+# Add <Valve> element
+xmlstarlet edit --inplace \
+    --insert '/Server/Service/Engine/Host/*' --type elem -n Valve \
+    --insert '/Server/Service/Engine/Host/Valve[not(@className)]' --type attr -n className -v org.apache.catalina.valves.RemoteIpValve \
+    $CATALINA_BASE/conf/server.xml
+
+# Allowed IPs
+if [ -z "$PROXY_ALLOWED_IPS_REGEX" ]; then
+    echo "Using default Tomcat allowed IPs regex"
+else
+    xmlstarlet edit --inplace \
+        --insert '/Server/Service/Engine/Host/Valve[@className="org.apache.catalina.valves.RemoteIpValve"]' \
+        --type attr -n internalProxies -v "$PROXY_ALLOWED_IPS_REGEX" \
+        $CATALINA_BASE/conf/server.xml
+fi
+
+# X-Forwarded-For
+if [ -z "$PROXY_IP_HEADER" ]; then
+    echo "Using default Tomcat proxy IP header"
+else
+    xmlstarlet edit --inplace \
+        --insert "/Server/Service/Engine/Host/Valve[@className='org.apache.catalina.valves.RemoteIpValve']" \
+        --type attr -n remoteIpHeader -v "$PROXY_IP_HEADER" \
+        $CATALINA_BASE/conf/server.xml
+fi
+
+# X-Forwarded-Proto
+if [ -z "$PROXY_PROTOCOL_HEADER" ]; then
+    echo "Using default Tomcat proxy protocol header"
+else
+    xmlstarlet edit --inplace \
+        --insert "/Server/Service/Engine/Host/Valve[@className='org.apache.catalina.valves.RemoteIpValve']" \
+        --type attr -n protocolHeader -v "$PROXY_PROTOCOL_HEADER" \
+        $CATALINA_BASE/conf/server.xml
+fi
+
+# X-Forwarded-By
+if [ -z "$PROXY_BY_HEADER" ]; then
+    echo "Using default Tomcat proxy forwarded by header"
+else
+    xmlstarlet edit --inplace \
+        --insert "/Server/Service/Engine/Host/Valve[@className='org.apache.catalina.valves.RemoteIpValve']" \
+        --type attr -n remoteIpProxiesHeader -v "$PROXY_BY_HEADER" \
+        $CATALINA_BASE/conf/server.xml
+fi
+