feat: add support for repeated build-args

action.yml

@@ -1,40 +1,58 @@
----
 # SPDX-FileCopyrightText: 2024 Håvard Moen <post@haavard.name>
 #
 # SPDX-License-Identifier: GPL-3.0-only
+
 name: kaniko-action
 author: Håvard Moen
 description: |
   Build and optionally push images using [Kaniko](https://github.com/GoogleContainerTools/kaniko)
+
 inputs:
   cache:
-    description: 'Set this flag as true to opt into caching with kaniko.'
+    description: 'Set this flag as true to opt into caching with Kaniko.'
     required: false
     default: false
   cache_repo:
     description: 'Repository to use for cache, required if cache is true'
+    required: false
   cache_ttl:
-    description: Cache timeout in hours. Defaults to Kaniko default
+    description: 'Cache timeout in hours. Defaults to Kaniko default'
     required: false
   context:
     description: 'Path to the build context. Default to the workspace'
     required: false
   credentials:
-    description: Whitespace separated list of authentication credentials in the format registry_server=user:password
+    description: |
+      Whitespace-separated list of authentication credentials in the format 
+      registry_server=user:password
     required: false
   destinations:
-    description: Destinations to push images to, whitespace separated . Required if push is true
+    description: |
+      Destinations to push images to, whitespace-separated. 
+      Required if push is true.
     required: false
   docker_file:
-    description: 'Path to the Dockerfile. Default to Dockerfile. It must be in the context. If set, this action passes the relative path to Kaniko, same as the behavior of docker build	--dockerfile'
+    description: |
+      Path to the Dockerfile. 
+      Defaults to Dockerfile. It must be in the context. 
+      If set, this action passes the relative path to Kaniko, 
+      similar to the behavior of `docker build --dockerfile`
     required: false
   push:
     description: "Push an image to the registry. Default to true"
     required: false
     default: true
   version:
-    description: "Version of the software, to be added as org.opencontainers.image.version label"
+    description: |
+      Version of the software, to be added as 
+      `org.opencontainers.image.version` label
     required: false
+  build_args:
+    description: |
+      Build arguments to pass to Kaniko. 
+      Each line represents a separate build argument in the format KEY=VALUE.
+    required: false
+
 runs:
   using: docker
   image: Dockerfile

entrypoint.sh

@@ -5,68 +5,63 @@
 
 set -e
 
+# Initialize the Kaniko executor command
 set -- /kaniko/executor
 
-if [ -n "${INPUT_CREDENTIALS}" ]
+# Handle Docker credentials
-then
+if [ -n "${INPUT_CREDENTIALS}" ]; then
   echo '{"auths": {' > /kaniko/.docker/config.json
-  for CREDENTIAL in ${INPUT_CREDENTIALS}
+  for CREDENTIAL in ${INPUT_CREDENTIALS}; do
-  do
+    echo "${CREDENTIAL}" | (
-    echo "${CREDENTIAL}" | ( IFS='=' read -r server creds
+      IFS='=' read -r server creds
       auth="$(echo -n "${creds}" | base64 -w0)"
       echo "\"${server}\": {\"auth\": \"${auth}\"}," >> /kaniko/.docker/config.json
     )
   done
-  # remove last comma
+  # Remove the trailing comma
   sed -i '$s/,$//' /kaniko/.docker/config.json
   echo '}}' >> /kaniko/.docker/config.json
 fi
 
-
+# Handle Dockerfile path
-if [ -n "${INPUT_DOCKER_FILE}" ]
+if [ -n "${INPUT_DOCKER_FILE}" ]; then
-then
   set -- "$@" --dockerfile "${INPUT_DOCKER_FILE}"
 fi
 
-if [ -n "${INPUT_CONTEXT}" ]
+# Handle build context
-then
+if [ -n "${INPUT_CONTEXT}" ]; then
   CONTEXT="${INPUT_CONTEXT}"
 else
   CONTEXT=.
 fi
 set -- "$@" --context "dir://${CONTEXT}"
 
-if [ "${INPUT_PUSH}" = "false" ]
+# Handle push flag
-then
+if [ "${INPUT_PUSH}" = "false" ]; then
   set -- "$@" --no-push
 fi
 
-if [ "${INPUT_CACHE}" = "true" ] && [ -n "${INPUT_CACHE_REPO}" ]
+# Handle caching
-then
+if [ "${INPUT_CACHE}" = "true" ] && [ -n "${INPUT_CACHE_REPO}" ]; then
-  COMMAND="${COMMAND} --cache=true --cache-repo ${INPUT_CACHE_REPO}"
   set -- "$@" --cache=true --cache-repo "${INPUT_CACHE_REPO}"
-  if [ -n "${INPUT_CACHE_TTL}" ]
+  if [ -n "${INPUT_CACHE_TTL}" ]; then
-  then
     set -- "$@" --cache-ttl="${INPUT_CACHE_TTL}"
   fi
 fi
 
-if [ -n "${INPUT_DESTINATIONS}" ]
+# Handle destinations
-then
+if [ -n "${INPUT_DESTINATIONS}" ]; then
-  for DESTINATION in ${INPUT_DESTINATIONS}
+  for DESTINATION in ${INPUT_DESTINATIONS}; do
-  do
     set -- "$@" --destination "${DESTINATION}"
   done
 fi
 
-if [ -d "${CONTEXT}/LICENSES" ]
+# Handle licenses
-then
+if [ -d "${CONTEXT}/LICENSES" ]; then
   licenses=""
-  for l in LICENSES/*;
+  for l in LICENSES/*; do
-  do
     license=$(basename "$l" .txt)
-    if [ -z "${licenses}" ]
+    if [ -z "${licenses}" ]; then
-    then
       licenses="${license}"
     else
       licenses="${licenses} AND ${license}"
@@ -75,9 +70,22 @@ then
   set -- "$@" --label "org.opencontainers.image.licenses=${licenses}"
 fi
 
-if [ -n "${INPUT_VERSION}" ]
+# Handle version label
-then
+if [ -n "${INPUT_VERSION}" ]; then
   set -- "$@" --label "org.opencontainers.image.version=${INPUT_VERSION}"
 fi
 
+# Handle build arguments
+if [ -n "${INPUT_BUILD_ARGS}" ]; then
+  while IFS= read -r line; do
+    # Skip empty lines and comments
+    [ -z "$line" ] && continue
+    echo "$line" | grep -qE '^\s*#' && continue
+    set -- "$@" --build-arg "$line"
+  done <<EOF
+${INPUT_BUILD_ARGS}
+EOF
+fi
+
+# Execute the Kaniko command
 exec "$@"