Generalize DOWNLOAD_EXTRA_CONFIGS into APPLY_EXTRA_FILES

Dockerfile

@@ -48,7 +48,7 @@ RUN easy-add --var os=${TARGETOS} --var arch=${TARGETARCH}${TARGETVARIANT} \
   --var version=${MC_SERVER_RUNNER_VERSION} --var app=mc-server-runner --file {{.app}} \
   --from ${GITHUB_BASEURL}/itzg/{{.app}}/releases/download/{{.version}}/{{.app}}_{{.version}}_{{.os}}_{{.arch}}.tar.gz
 
-ARG MC_HELPER_VERSION=1.50.0
+ARG MC_HELPER_VERSION=1.50.1
 ARG MC_HELPER_BASE_URL=${GITHUB_BASEURL}/itzg/mc-image-helper/releases/download/${MC_HELPER_VERSION}
 # used for cache busting local copy of mc-image-helper
 ARG MC_HELPER_REV=1

docs/configuration/misc-options.md

@@ -143,16 +143,6 @@ To enable support for optimized SIMD operations, the JVM flag can be set with th
 
 SIMD optimized operations are supported by Pufferfish and Purpur.
 
-## Downloading extra configuration files
-
-You can download additional configuration files or other resources before the server starts by using the `DOWNLOAD_EXTRA_CONFIGS` environment variable. This is useful for downloading configs that you want to patch or modify during the startup process.
-
-The format uses a `<` separator between the destination path and the source URL:
-
-```
-DOWNLOAD_EXTRA_CONFIGS=destination<source_url[,destination2<source_url2,...]
-```
-
 For example, to download configuration files for plugins:
 
 ```yaml

docs/mods-and-plugins/index.md

@@ -65,7 +65,31 @@ These paths work well if you want to have a common set of modules in a separate
 
     Alternatively, you can declare other directories along with files and URLs to use in [the `MODS` / `PLUGINS` variables](#modsplugins-list).
 
+## Applying extra configuration files
 
+You can download/copy additional configuration files or other resources before the server starts by using the `APPLY_EXTRA_FILES` environment variable. This is useful for downloading configs that you want to patch or modify during the startup process.
+
+The format uses a `<` separator between the destination path and the source URL/path. The destination path is relative to the `/data` directory. If specifying a source path, it needs to be path mounted within the container.
+
+!!! example
+
+    With `docker run`
+
+    ```
+    -e APPLY_EXTRA_FILES=destination<source_url[,destination2<source_url2,...]
+    ```
+
+    With a compose file:
+    ```yaml
+    environment:
+      APPLY_EXTRA_FILES: |
+        destination<source1_url
+        destination2<source2_path
+    ```
+
+!!! tip "Patch-able"
+
+The `APPLY_EXTRA_FILES` feature is processed prior to [patch processing](../configuration/interpolating.md#patching-existing-files), so this can be used as for baseline files to be patched further at runtime.
 
 ## Zip file modpack
 

examples/apply-extra-configs/compose.yml

@@ -0,0 +1,19 @@
+services:
+  mc:
+    image: itzg/minecraft-server
+    environment:
+      EULA: "TRUE"
+      TYPE: PAPER
+      MAX_MEMORY: 4G
+      MODRINTH_PROJECTS: |
+        luckperms
+      APPLY_EXTRA_FILES: |
+        plugins/LuckPerms</shared-configs/LuckPerms/
+      DEBUG: true
+    volumes:
+      - data:/data
+      - ./shared-configs:/shared-configs:ro
+    ports:
+      - "25565:25565"
+volumes:
+  data: