ci: Preparing for java16 image tag

#864

.github/dependabot.yml

@@ -0,0 +1,7 @@
+version: 2
+updates:
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"

.github/workflows/build-multiarch.yml

@@ -3,15 +3,13 @@ on:
   push:
     branches:
       - multiarch
-      - java8-multiarch
       - multiarch-latest
-      - java15
-      - java15-openj9
+      - java*
       - test/multiarch/*
     tags:
       - "[0-9]+.[0-9]+.[0-9]+-multiarch"
       - "[0-9]+.[0-9]+.[0-9]+-multiarch-latest"
-      - "[0-9]+.[0-9]+.[0-9]+-java15"
+      - "[0-9]+.[0-9]+.[0-9]+-java*"
     paths-ignore:
       - "*.md"
       - "docs/**"

README.md

@@ -266,6 +266,8 @@ the server jar remain in the `/data` directory. It is safe to remove those._
 
 ## Running Minecraft server on different Java version
 
+> **NOTE** [as of snapshot 21W19A](https://www.minecraft.net/en-us/article/minecraft-snapshot-21w19a), Java 16 is now required. Please use `itzg/minecraft-server:java16` for that version and newer. Consideration of changing the `latest` will be made after 1.17 releases.
+
 To use a different version of Java, please use a docker tag to run your Minecraft server.
 
 | Tag name       | Java version | Linux  | JVM Type | Architecture      |
@@ -275,6 +277,7 @@ To use a different version of Java, please use a docker tag to run your Minecraf
 | java8-multiarch | 8           | Debian | Hotspot  | amd64,arm64,armv7 |
 | java15         | 15           | Debian | Hotspot  | amd64,arm64,armv7 |
 | java15-openj9  | 15           | Debian | OpenJ9   | amd64,arm64       |
+| java16         | 16           | Debian | Hotspot  | amd64,arm64,armv7 |
 | adopt11        | 11           | Alpine | Hotspot  | amd64             |
 | openj9         | 8            | Alpine | OpenJ9   | amd64             |
 | openj9-11      | 11           | Alpine | OpenJ9   | amd64             |

docker-versions-create.sh

@@ -9,6 +9,7 @@ branches_list=(
   'adopt11'
   'java15'
   'java15-openj9'
+  'java16'
   'multiarch'
   'multiarch-latest'
   )