a

README.md

@@ -31,6 +31,9 @@ steps:
       annotation:
         org.opencontainers.image.title: My Image
         org.opencontainers.image.description: A description.
+      build-args:
+        NPM_CONFIG_REGISTRY: # reused from ci env
+        FOO: bar
       platform: [linux/amd64, linux/arm64]
       auth:
         registry.example.org:
@@ -75,6 +78,7 @@ docker run --rm --user=$(id -u) --volume=$HOME:$HOME:ro --workdir=$PWD --env=PLU
 | `frontend`          | PLUGIN_FRONTEND          | `dockerfile.v0`  | Only dockerfile frontend supported right now                                                    |
 | `context`           | PLUGIN_CONTEXT           | `$PWD`           | Context directory to use for build                                                              |
 | `dockerfile`        | PLUGIN_DOCKERFILE        | `Dockerfile`     | Dockerfile to use.                                                                              |
+| `build-args`        | PLUGIN_BUILD_ARGS        | `none`           | Build args to pass to build                                                                     |
 | `platform`          | PLUGIN_PLATFORM          | `none`           | Target platform for container image.                                                            |
 | `source-epoch-date` | PLUGIN_SOURCE_DATE_EPOCH | `0`              | Timestamp to use for reproduceable builds.                                                      |
 | `name`              | PLUGIN_NAME              | `none`           | Images names where to push the image.                                                           |

entrypoint.sh

@@ -37,6 +37,10 @@ fi
 COMMAND+=" --frontend=$BUILDCTL_FRONTEND"
 COMMAND+=" --local=context=$BUILDCTL_CONTEXT"
 COMMAND+=" --local=dockerfile=$BUILDCTL_DOCKERFILE"
+if [[ -n "${PLUGIN_BUILD_ARGS:-}" ]]; then
+	env|sort
+	OUTPUT+="$(echo "$PLUGIN_BUILD_ARGS" | jq --join-output 'keys[] as $k|",annotation.\($k)=\(.[$k])"')"
+fi
 if [[ -n  "${PLUGIN_PLATFORM:-}" ]]; then
 	COMMAND+=" --opt=platform=$PLUGIN_PLATFORM"
 fi