Workaround

Dockerfile

@@ -1,7 +1,9 @@
-ARG BASE_IMAGE
-
-FROM $BASE_IMAGE
+FROM alpine:latest
 
+COPY docker-action /docker-action
 COPY entrypoint.sh /entrypoint.sh
 
+RUN apk add --update --no-cache docker
+RUN ["chmod", "+x", "/entrypoint.sh"]
+
 ENTRYPOINT ["/entrypoint.sh"]

README.md

@@ -29,6 +29,15 @@ the container. Defaults to `".github/workflows/build.sh"`
 **Required** The iRODS client builder image to use as a base image. Defaults to
 `"ghcr.io/wtsi-npg/ub-18.04-irods-clients-dev-4.2.11:latest"`
 
+## `docker-network`
+
+**Required** The Docker network on which to run the jobs. Defaults to "host".
+Use this if your calling workflow has configured some services that are running
+in Docker containers. The correct value is available in the job context. E.g.
+if you have a service called "mysql-server" then the Docker network name will
+be available as `${{ job.services.myswl-server.network }}` in the workflow
+that uses this Action.
+
 ## Outputs
 
 ## None
@@ -43,4 +52,6 @@ the container. Defaults to `".github/workflows/build.sh"`
       ghcr.io/wtsi-npg/ub-22.04-irods-clients-dev-4.3.2:latest
     build-script:
       .github/workflows/build.sh
+    docker-network:
+      service-network
 ```

action.yml

@@ -11,28 +11,28 @@ inputs:
     description: "Build script to run in the container"
     required: true
     default: ".github/workflows/build.sh"
+  docker-network:
+    description: "Docker network to use for the container"
+    required: false
+    default: "host"
 
 # The simple approach to implementing this Action described here:
 # https://docs.github.com/en/actions/creating-actions/creating-a-docker-container-action
-# does not work because value given in input.build-image is not available to the
+# does not work because a value given in input.build-image is not available to the
 # run.image field.
 #
-# One workaround is to use a composite run action, although that's not very well
-# documented and I maye be doing it wrong.
+# One workaround is described here:
+# https://github.com/JavierZolotarchuk/parameterizable-docker-action-example
+#
+# Credit to JavierZolotarchuk for the workaround described in the link above. I've used
+# it here. In order for the Action to be able to use Docker services set up by the calling
+# workflow, it must know the name of the Docker network to use. This is passed in as a
+# another parameter.
 
 runs:
-  using: "composite"
-  steps:
-    - name: "Build a new image for this run"
-      env:
-        BASE_IMAGE: ${{ inputs.build-image }}
-      run: |
-        docker pull $BASE_IMAGE
-        pwd
-        ls -l
-        docker build --build-arg BASE_IMAGE=$BASE_IMAGE -t test-img-${{github.run_id}} .
-      shell: bash
-    - name: "Run the client build in the new image"
-      run: |
-        docker run --rm -t -v $(pwd):/github/workspace --workdir /github/workspace test-img-${{github.run_id}} ${{ inputs.build-script }}
-      shell: bash
+  using: 'docker'
+  image: 'Dockerfile'
+  args:
+    - ${{ inputs.build-image }}
+    - ${{ inputs.build-script }}
+    - ${{ inputs.docker-network }}

docker-action/Dockerfile

@@ -0,0 +1,9 @@
+ARG BASE_IMAGE
+
+FROM $BASE_IMAGE
+
+COPY entrypoint.sh /entrypoint.sh
+
+RUN ["chmod", "+x", "/entrypoint.sh"]
+
+ENTRYPOINT ["/entrypoint.sh"]

docker-action/entrypoint.sh

@@ -0,0 +1,8 @@
+#!/bin/bash -l
+
+set -x
+
+echo $PWD
+ls -l
+
+exec "$1"

entrypoint.sh

@@ -1,8 +1,25 @@
-#!/bin/bash -l
+#!/bin/sh -l
 
-set -x
+set -ex
 
-echo $PWD
-ls -l
+BASE_IMAGE=$1
+BUILD_SCRIPT=$2
+NETWORK=$3
 
-exec "$1"
+cd /docker-action
+
+echo "Creating Docker image from: $BASE_IMAGE"
+docker build -t docker-action --build-arg BASE_IMAGE="$BASE_IMAGE" .
+
+# Credit to https://github.com/zmingxie/packer-ami-builder for the following
+# logic to determine the workspace directory
+REPO_NAME=$(basename $RUNNER_WORKSPACE)
+WORKSPACE="$RUNNER_WORKSPACE/$REPO_NAME"
+
+echo "Using Docker network: $NETWORK"
+
+echo "Running build script: $BUILD_SCRIPT"
+docker run -t -v $WORKSPACE:$GITHUB_WORKSPACE \
+--workdir $GITHUB_WORKSPACE \
+--network $NETWORK \
+ docker-action "$BUILD_SCRIPT"