From c2071e5038e422e595e53a85c7885bc765416abe Mon Sep 17 00:00:00 2001
From: Geoff Bourne <itzgeoff@gmail.com>
Date: Sat, 2 Aug 2025 19:01:49 -0500
Subject: [PATCH] Add VERSION_FROM_MODRINTH_PROJECTS (#3580)

---
 Dockerfile                                    |  2 +-
 docs/mods-and-plugins/modrinth.md             | 20 +++++++++++++++++++
 .../compose.yml                               | 15 ++++++++++++++
 scripts/start-configuration                   |  9 +++++++++
 4 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 examples/modrinth/version-from-modrinth-projects/compose.yml

diff --git a/Dockerfile b/Dockerfile
index d336fa24..47d7b87e 100644
--- a/Dockerfile
+++ b/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=1.47.3
+ARG MC_HELPER_VERSION=1.48.0
 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
diff --git a/docs/mods-and-plugins/modrinth.md b/docs/mods-and-plugins/modrinth.md
index d34acfbf..1e499ea2 100644
--- a/docs/mods-and-plugins/modrinth.md
+++ b/docs/mods-and-plugins/modrinth.md
@@ -42,6 +42,25 @@
     datapack:terralith
     ```
 
+## Version from Projects
+
+When the environment variable `VERSION_FROM_MODRINTH_PROJECTS` is set to "true" the Minecraft [`VERSION`](../versions/minecraft.md) will be automatically determined by looking at the most recent version of Minecraft that is supported by all the projects provided in `MODRINTH_PROJECTS`.
+
+!!! example
+
+    Given the environment variables
+    
+    ```yaml
+        MODRINTH_PROJECTS: |
+          viaversion
+          viabackwards
+          griefprevention
+          discordsrv
+        VERSION_FROM_MODRINTH_PROJECTS: true
+    ```
+    
+    Let's say all are supported on Minecraft up to 1.21.8 except griefprevention, which is only supported up to 1.21.7. In that case, `VERSION` will be automatically set to 1.21.7.
+
 ## Extra options
 
 `MODRINTH_DOWNLOAD_DEPENDENCIES`
@@ -52,3 +71,4 @@
 
 `MODRINTH_LOADER`
 : When using a custom server, set this to specify which loader type will be requested during lookups
+
diff --git a/examples/modrinth/version-from-modrinth-projects/compose.yml b/examples/modrinth/version-from-modrinth-projects/compose.yml
new file mode 100644
index 00000000..59815fcc
--- /dev/null
+++ b/examples/modrinth/version-from-modrinth-projects/compose.yml
@@ -0,0 +1,15 @@
+services:
+  mc:
+    image: itzg/minecraft-server
+    environment:
+      EULA: true
+      TYPE: paper
+      MODRINTH_PROJECTS: |
+        viaversion
+        viabackwards
+        griefprevention
+        discordsrv
+      VERSION_FROM_MODRINTH_PROJECTS: true
+      SETUP_ONLY: true
+    ports:
+      - "25565:25565"
\ No newline at end of file
diff --git a/scripts/start-configuration b/scripts/start-configuration
index b1df96c3..031614b5 100755
--- a/scripts/start-configuration
+++ b/scripts/start-configuration
@@ -139,6 +139,15 @@ cd /data || exit 1
 export DECLARED_TYPE=${TYPE^^}
 export DECLARED_VERSION="$VERSION"
 
+if isTrue "${VERSION_FROM_MODRINTH_PROJECTS:-}" && [[ ${MODRINTH_PROJECTS:-} ]]; then
+  if ! VERSION=$(mc-image-helper version-from-modrinth-projects --projects "${MODRINTH_PROJECTS}"); then
+    logError "failed to resolve version from MODRINTH_PROJECTS: ${MODRINTH_PROJECTS}"
+    exit 1
+  fi
+  log "Resolved Minecraft version $VERSION from Modrinth projects"
+  export VERSION
+fi
+
 if isTrue "${ENABLE_AUTOPAUSE}"; then
   "${SCRIPTS:-/}start-autopause"
 fi