From 7755f58a47011cd8db7a16e2b681fd2b6809e57b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Milan=20Felix=20=C5=A0ulc?= <rkfelix@gmail.com>
Date: Tue, 29 Sep 2026 20:21:44 +0000
Subject: [PATCH] Docker: add optional test input

The new "test" input is a shell command that tests the image before the
push. When it is set, the workflow builds the image for linux/amd64,
loads it into Docker and runs the command with IMAGE=image:tag. The
multi-arch build that follows uses the same builder cache.

Callers without "test" are not changed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VSKw7jY45nUJWQxWpvjm82
---
 .github/workflows/docker.yml | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/.github/workflows/docker.yml b/.github/workflows/docker.yml
index 3f5b0d1..9e42437 100644
--- a/.github/workflows/docker.yml
+++ b/.github/workflows/docker.yml
@@ -30,6 +30,13 @@ on:
         required: false
         type: string
 
+      # Shell command to test the image before the push. The workflow first
+      # builds the image for linux/amd64 and loads it into Docker as
+      # IMAGE (image:tag). The command runs from the repository root.
+      test:
+        required: false
+        type: string
+
 jobs:
   docker-workflow:
     name: "${{ inputs.image }}:${{ inputs.tag }}"
@@ -54,6 +61,23 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v4
 
+      - name: Build test image
+        if: inputs.test
+        uses: docker/build-push-action@v7
+        with:
+          context: ${{ inputs.context }}
+          file: ${{ inputs.dockerfile || format('{0}/Dockerfile', inputs.context) }}
+          tags: ${{ inputs.image }}:${{ inputs.tag }}
+          platforms: linux/amd64
+          load: true
+          cache-from: type=gha
+
+      - name: Test
+        if: inputs.test
+        env:
+          IMAGE: ${{ inputs.image }}:${{ inputs.tag }}
+        run: ${{ inputs.test }}
+
       - name: Build and push
         uses: docker/build-push-action@v7
         with: