[Enhancement] Add config file prefix variable #249 (#251)

README.md

@@ -117,6 +117,7 @@ SQUEEZELITE_LOG_CATEGORY_STREAM|-d|Support for log level on category `stream`
 SQUEEZELITE_LOG_CATEGORY_DECODE|-d|Support for log level on category `decode`
 SQUEEZELITE_LOG_CATEGORY_OUTPUT|-d|Support for log level on category `output`
 SQUEEZELITE_LOG_CATEGORY_IR|-d|Support for log level on category `ir`
+CONFIG_FILE_PREFIX||Prefix for files in volume `/config`
 STARTUP_DELAY_SEC||Delay before starting the application, defaults to `0`
 
 It is possible to add and additional preset configuration file using the volume `/app/assets/additional-presets.conf`.
@@ -127,7 +128,7 @@ Possible values for variables `SQUEEZELITE_LOG_CATEGORY_*` are `info`, `debug` o
 
 ### Automatic MAC address creation
 
-If you don't provide a value to `SQUEEZELITE_MAC_ADDRESS`, a random mac address will be generated and stored (if possible) under `/config/mac-address.txt`, so it will be reloaded on next restart.  
+If you don't provide a value to `SQUEEZELITE_MAC_ADDRESS`, a random mac address will be generated and stored (if possible) under `/config/mac-address.txt`, so it will be reloaded on next restart. The file name can be prepended by the optional `CONFIG_FILE_PREFIX`.  
 Use a persistent volume in order to preserve the functionality in the event of container recreation (such as when you update to a newer image).  
 
 ## Volumes

app/bin/cmd-line-builder.sh

@@ -154,10 +154,16 @@ function cmdline-rates() {
 
 function handle_mac_address() {
     if [[ -z "${SQUEEZELITE_MAC_ADDRESS}" ]]; then
+        FILE_NAME=mac-address.txt
+        if [[ -n "${CONFIG_FILE_PREFIX}" ]]; then
+            FILE_NAME=${CONFIG_FILE_PREFIX}-${FILE_NAME}
+        fi
+        FILE_PATH="/config/${FILE_NAME}"
+        echo "File name for mac-address is [$FILE_PATH]"
         echo "No mac address, specified, try loading ..."
-        if [ -f "/config/mac-address.txt" ]; then
+        if [ -f $FILE_PATH ]; then
             echo "Found file with mac address ..."
-            mac=`cat /config/mac-address.txt`
+            mac=`cat $FILE_PATH`
             echo "Mac address is ${mac}"
             SQUEEZELITE_MAC_ADDRESS="${mac}"
         else
@@ -174,7 +180,7 @@ function handle_mac_address() {
             SQUEEZELITE_MAC_ADDRESS="${mac}"
             # write if possible
             if [ -w /config ]; then
-                echo "${mac}" > /config/mac-address.txt
+                echo "${mac}" > $FILE_PATH
                 echo "Written generated [${mac}] mac address."
             else
                 echo "Config directory is not writable"

doc/release.md

@@ -10,6 +10,7 @@ Older build might be dropped in order to save space on docker-hub and incur in l
 
 Date|Type|Description
 :---|:---|:---
+2023-12-18|Improvement|Support for a config file prefix (see [#249](https://github.com/GioF71/squeezelite-docker/issues/249))
 2023-12-18|Improvement|Autogen mac address (see [#247](https://github.com/GioF71/squeezelite-docker/issues/247))
 2023-12-18|Improvement|Arguments in quotes (see [#245](https://github.com/GioF71/squeezelite-docker/issues/245))
 2023-12-17|Improvement|Support output device `-o` also with PulseAudio (see [#243](https://github.com/GioF71/squeezelite-docker/issues/243))