[buildbot] ci: add container version tag to BUILDWORKER_DESCRIPTION

[LEDE Commits]

ynezz pushed a commit to buildbot.git, branch main:
https://git.openwrt.org/5cc2a73331ccd72b5d7acf8581cdc2a5fab06863

commit 5cc2a73331ccd72b5d7acf8581cdc2a5fab06863
Author: Petr Štetiar <ynezz at true.cz>
AuthorDate: Sun Jan 11 14:26:09 2026 +0100

    ci: add container version tag to BUILDWORKER_DESCRIPTION
    
    Add CONTAINER_TAG build argument to indicate whether the container
    was built from a tag (v25), PR (pr-73), or branch (main). This makes
    it easier to identify which version of the container is running.
    
    While at it, drop Docker prefix to make it shorter.
    
    Signed-off-by: Petr Štetiar <ynezz at true.cz>
---
 .github/workflows/build-push.yml | 20 ++++++++++++++++++--
 docker/buildworker/Dockerfile    |  3 ++-
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/build-push.yml b/.github/workflows/build-push.yml
index 84004b9..2c5a717 100644
--- a/.github/workflows/build-push.yml
+++ b/.github/workflows/build-push.yml
@@ -77,7 +77,14 @@ jobs:
       - name: Environment variables
         run: |
           echo "BUILDBOT_VERSION=$(cat .github/buildbot-version)" >> $GITHUB_ENV
-          echo "GIT_SHA_SHORT=${GITHUB_SHA::${{ env.GITHUB_SHA_LEN }}}" >> $GITHUB_ENV
+          echo "GIT_SHA_SHORT=$(git rev-parse --short=${{ env.GITHUB_SHA_LEN }} HEAD)" >> $GITHUB_ENV
+          if [ "${{ github.event_name }}" = "workflow_dispatch" ]; then
+            echo "CONTAINER_TAG=pr-${{ inputs.pr_number }}" >> $GITHUB_ENV
+          elif [ "${{ startsWith(github.ref, 'refs/tags/') }}" = "true" ]; then
+            echo "CONTAINER_TAG=${{ github.ref_name }}" >> $GITHUB_ENV
+          else
+            echo "CONTAINER_TAG=${{ github.ref_name }}" >> $GITHUB_ENV
+          fi
 
       - name: Build container and export it to local Docker
         uses: docker/build-push-action at v6
@@ -88,6 +95,7 @@ jobs:
           build-args: |
             BUILDBOT_VERSION=${{ env.BUILDBOT_VERSION }}
             OPENWRT_VERSION=${{ env.GIT_SHA_SHORT }}
+            CONTAINER_TAG=${{ env.CONTAINER_TAG }}
 
       - name: Test ${{ matrix.container_flavor }} Docker container
         run: |
@@ -122,7 +130,14 @@ jobs:
       - name: Environment variables
         run: |
           echo "BUILDBOT_VERSION=$(cat .github/buildbot-version)" >> $GITHUB_ENV
-          echo "GIT_SHA_SHORT=${GITHUB_SHA::${{ env.GITHUB_SHA_LEN }}}" >> $GITHUB_ENV
+          echo "GIT_SHA_SHORT=$(git rev-parse --short=${{ env.GITHUB_SHA_LEN }} HEAD)" >> $GITHUB_ENV
+          if [ "${{ github.event_name }}" = "workflow_dispatch" ]; then
+            echo "CONTAINER_TAG=pr-${{ inputs.pr_number }}" >> $GITHUB_ENV
+          elif [ "${{ startsWith(github.ref, 'refs/tags/') }}" = "true" ]; then
+            echo "CONTAINER_TAG=${{ github.ref_name }}" >> $GITHUB_ENV
+          else
+            echo "CONTAINER_TAG=${{ github.ref_name }}" >> $GITHUB_ENV
+          fi
 
       - name: Docker meta
         id: meta
@@ -152,3 +167,4 @@ jobs:
           build-args: |
             BUILDBOT_VERSION=${{ env.BUILDBOT_VERSION }}
             OPENWRT_VERSION=${{ env.GIT_SHA_SHORT }}
+            CONTAINER_TAG=${{ env.CONTAINER_TAG }}
diff --git a/docker/buildworker/Dockerfile b/docker/buildworker/Dockerfile
index 1637a6b..3929170 100644
--- a/docker/buildworker/Dockerfile
+++ b/docker/buildworker/Dockerfile
@@ -4,10 +4,11 @@ LABEL       maintainer="OpenWrt Maintainers"
 ARG         DEBIAN_FRONTEND=noninteractive
 ARG         BUILDBOT_VERSION=2.10.1
 ARG         OPENWRT_VERSION=unknown
+ARG         CONTAINER_TAG=unknown
 
 ENV         BUILDWORKER_MASTER=builds.openwrt.org:9990
 ENV         BUILDWORKER_ADMIN=contact at openwrt.org
-ENV         BUILDWORKER_DESCRIPTION="Docker Container https://git.openwrt.org/$OPENWRT_VERSION"
+ENV         BUILDWORKER_DESCRIPTION="Container ($CONTAINER_TAG) https://git.openwrt.org/$OPENWRT_VERSION"
 
 USER root