Merge PR #6: Simplify entrypoint script a little bit

entrypoint.sh

@@ -1,136 +1,106 @@
 #!/usr/bin/env bash
 set -e
 
-DATA_DIR="/data"
+readonly DATA_DIR="/data"
-BARE_BONES_CONFIG_FILE="/etc/mumble/bare_config.ini"
+readonly BARE_BONES_CONFIG_FILE="/etc/mumble/bare_config.ini"
-CONFIG_FILE="${DATA_DIR}/mumble_server_config.ini"
+readonly CONFIG_FILE="${DATA_DIR}/mumble_server_config.ini"
+readonly CONFIG_REGEX="^(\;|\#)?\ *([a-zA-Z_0-9]+)=.*"
+
+# Compile list of configuration options from the bare-bones config
+readarray -t existing_config_options < <(sed -En "s/$CONFIG_REGEX/\2/p" "$BARE_BONES_CONFIG_FILE")
 
 # Grab the original command line that is supposed to start the Mumble server
-server_invocation=( "${@}" )
+declare -a server_invocation=("${@}")
+declare -a used_configs
 
-array_contains () { 
+normalize_name() {
-	local array="$1[@]"
+	local uppercase="${1^^}"
-	local seeking=$2
+	echo "${uppercase//_/}"
-	local contained=false
+}
-	for element in "${!array}"; do
+
-		if [[ $element == "$seeking" ]]; then
+# Create an associative array for faster config option lookup
-			contained=true
+declare -A option_for
-			break
+
-		fi
+for config in "${existing_config_options[@]}"; do
+	option_for["$(normalize_name "$config")"]="$config"
+done
+
+array_contains() {
+	local array_expansion="$1[@]" seeking="$2"
+	for element in "${!array_expansion}"; do
+		[[ "$element" = "$seeking" ]] && return 0
 	done
-
+	return 1
-	echo "$contained"
 }
 
 set_config() {
-	local config_name="$1"
+	local config_name="$1" config_value="$2" is_default="$3"
-	local config_value="$2"
-	local is_default="$3"
 	local apply_value=true
 
-	# Don't use default value if the user already set one
+	[[ "$is_default" = true ]] && array_contains "used_configs" "$config_name" && \
-	if [ "$is_default" = "true" ]; then
+		apply_value=false # Don't use default value if the user already set one!
-		contained=$( array_contains used_configs "$config_name" )
+
-		if [[ "$contained" = "true" ]]; then
+	[[ "$apply_value" != true ]] && return 0
-			apply_value=false
+
-		fi
+	echo "Setting config \"$config_name\" to: '$config_value'"
-	fi
+	used_configs+=("$config_name")
-    
+
-    if [ "$apply_value" = "true" ]; then
+	# Append config to our on-the-fly-built config file
-        echo "Setting config \"$config_name\" to: '$config_value'"
+	echo "${config_name}=${config_value}" >> "$CONFIG_FILE"
-        used_configs+=("$config_name")
-        
-        # Append config to our on-the-fly-built config file
-        echo "${config_name}=${config_value}" >> "$CONFIG_FILE"
-    fi
 }
-    
+
 # Drop the user into a shell, if they so wish
-if [ "$1" = "bash" ] || [ "$1" = "sh" ]; then
+if [[ "$1" = "bash" ||  "$1" = "sh" ]]; then
     echo "Dropping into interactive BASH session"
     exec "${@}"
 fi
 
-if [ -f "$MUMBLE_CUSTOM_CONFIG_FILE" ]; then
+if [[ -f "$MUMBLE_CUSTOM_CONFIG_FILE" ]]; then
-	# Just use the config file specified by the user and don't bother assembling our own
 	echo "Using manually specified config file at $MUMBLE_CUSTOM_CONFIG_FILE"
 	echo "All MUMBLE_CONFIG variables will be ignored"
 	CONFIG_FILE="$MUMBLE_CUSTOM_CONFIG_FILE"
 else
-	# As a first step, we ensure that the config file is empty, so we can always start from a clean slate
+	# Ensures the config file is empty, starting from a clean slate
 	echo -e "# Config file automatically generated from the MUMBLE_CONFIG_* environment variables\n" > "${CONFIG_FILE}"
 
-	used_configs=()
+	# Process settings through variables of format MUMBLE_CONFIG_*
-	existing_config_options=()
+
-    
-	####
-	# Check what kind of configurations there exist in the bare bones config file
-	####
-	while read -r line; do
-		if [[ "$line" =~ ^(\;|\#)?\ *([a-zA-Z_0-9]+)=.* ]]; then
-			existing_config_options+=("${BASH_REMATCH[2]}")
-		fi
-	done < "$BARE_BONES_CONFIG_FILE"
-	####
-	# Process settings following environments variables starting with "MUMBLE_CONFIG_"
-	# Iterate over all environment variable key, value pairs and check if they match our naming scheme
-	####
 	while IFS='=' read -d '' -r var value; do
-		if [[ "$var" == "MUMBLE_CONFIG_"* ]]; then
+		config_option="${option_for[$(normalize_name "$var")]}"
-			uppercase_variable=${var/MUMBLE_CONFIG_/}
 
-			# Remove underscores (to ensure that it doesn't matter whether the user
+		if [[ -z "$config_option" ]]; then
-			# uses e.g. MUMBLE_CONFIG_DB_BLA or MUMBLE_CONFIG_DBBLA)
+			>&2 echo "[ERROR]: Unable to find config corresponding to variable \"$var\""
-			uppercase_variable_no_underscores="${uppercase_variable//_/}"
+			exit 1
-			found=false
-
-			for current_config in "${existing_config_options[@]}"; do
-				# convert to uppercase
-				upper_current_config=${current_config^^}
-				
-				if [ "$upper_current_config" = "$uppercase_variable" ] || [ "$upper_current_config" = "$uppercase_variable_no_underscores" ]; then
-					set_config "$current_config" "$value"
-					found=true
-					break
-				fi
-			done
-
-			if [ "$found" = "false" ]; then
-				>&2 echo "[ERROR]: Unable to find config corresponding to variable \"$var\""
-				exit 1
-			fi
 		fi
-	done < <( printenv --null ) # Feeding it in like this, prevents the creation of a subshell for the while-loop
 
-	####
+		set_config "$config_option" "$value"
-	# Default settings (will apply only, if user hasn't specified the respective config options themselves)
+	done < <( printenv --null | sed -zn 's/^MUMBLE_CONFIG_//p' )
-	####
+	# ^ Feeding it in like this, prevents the creation of a subshell for the while-loop
+
+	# Apply default settings if they're missing
+
 	set_config "database" "${DATA_DIR}/murmur.sqlite" true
 	set_config "ice" "\"tcp -h 127.0.0.1 -p 6502\"" true
 	set_config "welcometext" "\"<br />Welcome to this server, running the official Mumble Docker image.<br />Enjoy your stay!<br />\"" true
 	set_config "port" 64738 true
 	set_config "users" 100 true
 
-	# Add ICE section
+	{ # Add ICE section
-	echo -e "\n[Ice]" >> "$CONFIG_FILE"
+		echo -e "\n[Ice]"
-	echo "Ice.Warn.UnknownProperties=1" >> "$CONFIG_FILE"
+		echo "Ice.Warn.UnknownProperties=1"
-	echo "Ice.MessageSizeMax=65536" >> "$CONFIG_FILE"
+		echo "Ice.MessageSizeMax=65536"
+	} >> "$CONFIG_FILE"
 fi
 
-####
+# Additional environment variables
-# Additionnal environement variables
-####
-if [ -n "$MUMBLE_VERBOSE" ] && [ "$MUMBLE_VERBOSE" = true ]; then
-    server_invocation+=( "-v" )
-fi
 
-# Make sure the correct config file will be used
+[[ "$MUMBLE_VERBOSE" = true ]] && server_invocation+=( "-v" )
+
+# Make sure the correct configuration file is used
 server_invocation+=( "-ini" "${CONFIG_FILE}")
 
-####
 # Variable to change the superuser password
-####
+if [[ -n "${MUMBLE_SUPERUSER_PASSWORD}" ]]; then
-if [ -n "${MUMBLE_SUPERUSER_PASSWORD}" ]; then
     "${server_invocation[@]}" -supw "$MUMBLE_SUPERUSER_PASSWORD"
     echo "Successfully configured superuser password"
 fi
@@ -140,7 +110,7 @@ echo "Running Mumble server as uid=$(id -u) gid=$(id -g)"
 echo "\"${DATA_DIR}\" has the following permissions set:"
 echo "  $( stat ${DATA_DIR} --printf='%A, owner: \"%U\" (UID: %u), group: \"%G\" (GID: %g)' )"
 
-echo "Command run to start the service : ${server_invocation[@]}"
+echo "Command run to start the service : ${server_invocation[*]}"
 echo "Starting..."
 
 exec "${server_invocation[@]}"