Add a way to change the Docker build context

README.md

@@ -89,6 +89,17 @@ with:
   workdir: mySubDirectory
 ```
 
+### context
+Use `context` when you would like to change the Docker build context.
+
+```yaml
+with:
+  name: myDocker/repository
+  username: ${{ secrets.DOCKER_USERNAME }}
+  password: ${{ secrets.DOCKER_PASSWORD }}
+  context: myContextDirectory
+```
+
 ### buildargs
 Use `buildargs` when you want to pass a list of environment variables as [build-args](https://docs.docker.com/engine/reference/commandline/build/#set-build-time-variables---build-arg). Identifiers are separated by comma.   
 All `buildargs` will be masked, so that they don't appear in the logs.  

entrypoint.sh

@@ -23,6 +23,7 @@ function main() {
   echo ${INPUT_PASSWORD} | docker login -u ${INPUT_USERNAME} --password-stdin ${INPUT_REGISTRY}
 
   BUILDPARAMS=""
+  CONTEXT="."
 
   if uses "${INPUT_DOCKERFILE}"; then
     useCustomDockerfile
@@ -30,6 +31,9 @@ function main() {
   if uses "${INPUT_BUILDARGS}"; then
     addBuildArgs
   fi
+  if uses "${INPUT_CONTEXT}"; then
+    CONTEXT="${INPUT_CONTEXT}"
+  fi
   if usesBoolean "${INPUT_CACHE}"; then
     useBuildCache
   fi
@@ -123,14 +127,14 @@ function pushWithSnapshot() {
   local SHORT_SHA=$(echo "${GITHUB_SHA}" | cut -c1-6)
   local SNAPSHOT_TAG="${TIMESTAMP}${SHORT_SHA}"
   local SHA_DOCKER_NAME="${INPUT_NAME}:${SNAPSHOT_TAG}"
-  docker build $BUILDPARAMS -t ${DOCKERNAME} -t ${SHA_DOCKER_NAME} .
+  docker build $BUILDPARAMS -t ${DOCKERNAME} -t ${SHA_DOCKER_NAME} ${CONTEXT}
   docker push ${DOCKERNAME}
   docker push ${SHA_DOCKER_NAME}
   echo ::set-output name=snapshot-tag::"${SNAPSHOT_TAG}"
 }
 
 function pushWithoutSnapshot() {
-  docker build $BUILDPARAMS -t ${DOCKERNAME} .
+  docker build $BUILDPARAMS -t ${DOCKERNAME} ${CONTEXT}
   docker push ${DOCKERNAME}
 }
 

test.bats

@@ -412,6 +412,39 @@ teardown() {
   [ "$status" -eq 2 ]
 }
 
+@test "it can set a custom context" {
+  export GITHUB_REF='refs/heads/master'
+  export INPUT_CONTEXT='/myContextFolder'
+
+  run /entrypoint.sh
+
+  expectMockCalled "/usr/local/bin/docker login -u USERNAME --password-stdin
+/usr/local/bin/docker build -t my/repository:latest /myContextFolder
+/usr/local/bin/docker push my/repository:latest
+/usr/local/bin/docker logout"
+}
+
+@test "it can set a custom context when building snapshot" {
+  export GITHUB_REF='refs/heads/master'
+  export INPUT_CONTEXT='/myContextFolder'
+  export GITHUB_SHA='12169ed809255604e557a82617264e9c373faca7'
+  export INPUT_SNAPSHOT='true'
+
+  declare -A -p MOCK_RETURNS=(
+  ['/usr/local/bin/docker']=""
+  ['/usr/bin/date']="197001010101"
+  ) > mockReturns
+
+  run /entrypoint.sh
+
+  expectMockCalled "/usr/local/bin/docker login -u USERNAME --password-stdin
+/usr/bin/date +%Y%m%d%H%M%S
+/usr/local/bin/docker build -t my/repository:latest -t my/repository:19700101010112169e /myContextFolder
+/usr/local/bin/docker push my/repository:latest
+/usr/local/bin/docker push my/repository:19700101010112169e
+/usr/local/bin/docker logout"
+}
+
 function expectStdOut() {
   echo "Expected: |$1|
   Got: |$output|"