Merge pull request #123 from chronotc/support-build-args

support build args

README.md

@@ -105,6 +105,24 @@ steps:
 
 Note how the values in the list can either be just a key (so the value is sourced from the environment) or a KEY=VALUE pair.
 
+## Build Arguments
+
+You can use the [build args key in docker-compose.yml](https://docs.docker.com/compose/compose-file/#args) to set specific build arguments when building an image.
+
+Alternatively, if you want to set build arguments when pre-building an image, this plugin offers an `args` block of it's own:
+
+```yml
+steps:
+  - command: generate-dist.sh
+    plugins:
+      docker-compose#v2.0.0:
+        build: app
+        args:
+          - MY_CUSTOM_ARG=panda
+```
+
+Note that the values in the list must be a KEY=VALUE pair.
+
 ## Pre-building the image
 
 To speed up run parallel steps you can add a pre-building step to your pipeline, allowing all the `run` steps to skip image building:
@@ -252,6 +270,10 @@ The default is `${BUILDKITE_PIPELINE_SLUG}-${BUILDKITE_PLUGIN_DOCKER_COMPOSE_BUI
 
 Note: this option can only be specified on a `build` step.
 
+### `args` (optional, build only)
+
+A list of KEY=VALUE that are passed through as build arguments when image is being built.
+
 ### `env` or `environment` (optional, run only)
 
 A list of either KEY or KEY=VALUE that are passed through as environment variables to the container.

hooks/commands/build.sh

@@ -48,14 +48,18 @@ while read -r line ; do
   [[ -n "$line" ]] && services+=("$line")
 done <<< "$(plugin_read_list BUILD)"
 
-build_args=(--pull)
+build_params=(--pull)
 
 if [[ "$(plugin_read_config NO_CACHE "false")" == "true" ]] ; then
-  build_args+=(--no-cache)
+  build_params+=(--no-cache)
 fi
 
+while read -r arg ; do
+  [[ -n "${arg:-}" ]] && build_params+=("--build-arg" "${arg}")
+done <<< "$(plugin_read_list ARGS)"
+
 echo "+++ :docker: Building services ${services[*]}"
-run_docker_compose -f "$override_file" build "${build_args[@]}" "${services[@]}"
+run_docker_compose -f "$override_file" build "${build_params[@]}" "${services[@]}"
 
 if [[ -n "$image_repository" ]]; then
   echo "~~~ :docker: Pushing built images to $image_repository"

tests/build.bats

@@ -40,6 +40,24 @@ load '../lib/shared'
   unstub docker-compose
 }
 
+@test "Build with build args" {
+  export BUILDKITE_JOB_ID=1111
+  export BUILDKITE_PLUGIN_DOCKER_COMPOSE_BUILD=myservice
+  export BUILDKITE_PIPELINE_SLUG=test
+  export BUILDKITE_BUILD_NUMBER=1
+  export BUILDKITE_PLUGIN_DOCKER_COMPOSE_ARGS_0=MYARG=0
+  export BUILDKITE_PLUGIN_DOCKER_COMPOSE_ARGS_1=MYARG=1
+
+  stub docker-compose \
+    "-f docker-compose.yml -p buildkite1111 -f docker-compose.buildkite-1-override.yml build --pull --build-arg MYARG=0 --build-arg MYARG=1 myservice : echo built myservice"
+
+  run $PWD/hooks/command
+
+  assert_success
+  assert_output --partial "built myservice"
+  unstub docker-compose
+}
+
 @test "Build with a repository" {
   export BUILDKITE_JOB_ID=1111
   export BUILDKITE_PLUGIN_DOCKER_COMPOSE_BUILD=myservice