Couple of fixes and support for helm

Dockerfile

@@ -1,5 +1,5 @@
 FROM alpine:3
-RUN apk add --update --no-cache bash ca-certificates curl git jq openssh
+RUN apk add --update --no-cache bash ca-certificates curl git jq openssh tar lastversion
 RUN ["bin/sh", "-c", "mkdir -p /src"]
 COPY ["src", "/src/"]
 ENTRYPOINT ["/src/entrypoint.sh"]

README.md

@@ -47,6 +47,7 @@ Inputs configure Kustomize GitHub Actions to perform build action.
 * `kustomize_output_file` - (Optional) Path to to file to write the kustomize build output to.
 * `kustomize_build_options` - (Optional) Provide build options to kustomize build.
 * `enable_alpha_plugins` - (Optional) Enable Kustomize plugins. Defaults to `false`.
+* `helm_version` - (Optional) The helm version to install and use for `kustomize build --enable-helm`
 
 ## Outputs
 

action.yml

@@ -34,6 +34,10 @@ inputs:
     description: 'Enable Kustomize plugins'
     required: false
     default: '0'
+  helm_version:
+    description: 'Specify the version of helm to use (also passes --enable-helm)'
+    required: false
+    default: ''
   token:
     description: 'GitHub Token for Authentication to Github API (mainly for limit avoidance)'
     required: false

src/entrypoint.sh

@@ -37,10 +37,21 @@ function parse_inputs {
 
     enable_alpha_plugins=""
     if [ "${INPUT_ENABLE_ALPHA_PLUGINS}" == "1" ] || [ "${INPUT_ENABLE_ALPHA_PLUGINS}" == "true" ]; then
-       enable_alpha_plugins="--enable_alpha_plugins"
+      if lastversion "${kustomize_version}" --newer-than "4.0.0"; then
+        enable_alpha_plugins="--enable-alpha-plugins"
+      else
+        enable_alpha_plugins="--enable_alpha_plugins"
+      fi
+    fi
+
+    enable_helm=""
+    helm_version=""
+    if [ -n "${INPUT_HELM_VERSION}" ]; then
+      enable_helm="--enable-helm"
+      helm_version=${INPUT_HELM_VERSION}
     fi
 
-    with_token=""
+    with_token=()
     if [ "${INPUT_TOKEN}" != "" ]; then
        with_token=(-H "Authorization: token ${INPUT_TOKEN}")
     fi
@@ -86,18 +97,37 @@ function install_kustomize {
 
 }
 
+function install_helm {
+    url="https://get.helm.sh/helm-v${helm_version}-linux-amd64.tar.gz"
+
+
+    echo "Downloading helm v${helm_version}"
+    curl --retry 30 --retry-max-time 120 -s -S -L ${url} | tar -xzv -C /usr/bin --strip-components=1 --wildcards 'linux-*/helm'
+    if [ "${?}" -ne 0 ]; then
+        echo "Failed to download helm v${helm_version}."
+        exit 1
+    fi
+    echo "Successfully downloaded helm v${helm_version}."
+
+    echo "Allowing execute privilege to helm."
+    chmod +x /usr/bin/helm
+    if [ "${?}" -ne 0 ]; then
+        echo "Failed to update helm privilege."
+        exit 1
+    fi
+    echo "Successfully added execute privilege to helm."
+}
+
 function main {
 
     scriptDir=$(dirname ${0})
     source ${scriptDir}/kustomize_build.sh
     parse_inputs
 
-    if  [ "${kustomize_install}" == "1" ]; then
-      install_kustomize
-    fi
+    [ "${kustomize_install}" == "1" ] && install_kustomize
+    [ -n "${helm_version}" ] && install_helm
 
     kustomize_build
-
 }
 
 main "${*}"

src/kustomize_build.sh

@@ -4,7 +4,7 @@ function kustomize_build {
     # gather output
     echo "build: info: kustomize build in directory ${kustomize_build_dir}."
 
-    build_output=$(kustomize build ${enable_alpha_plugins} ${kustomize_build_options} ${kustomize_build_dir} 2>&1)
+    build_output=$(kustomize build ${enable_alpha_plugins} ${enable_helm} ${kustomize_build_options} ${kustomize_build_dir} 2>&1)
 
     build_exit_code=${?}