feat: Add helm3 binary

Add the helm beta version 3 binary into the docker container under the
name helm3. Can be selected with the helm input argument.

Dockerfile

@@ -1,4 +1,22 @@
-FROM alpine/helm:2.14.0
-RUN apk add --no-cache jq curl bash nodejs && helm init --client-only
+FROM alpine:3.10.2
+
+ENV BASE_URL="https://get.helm.sh"
+ENV HELM_2_FILE="helm-v2.14.3-linux-amd64.tar.gz"
+ENV HELM_3_FILE="helm-v3.0.0-beta.3-linux-amd64.tar.gz"
+
+RUN apk add --no-cache ca-certificates jq curl bash nodejs && \
+    # Install helm version 2:
+    curl -L ${BASE_URL}/${HELM_2_FILE} |tar xvz && \
+    mv linux-amd64/helm /usr/bin/helm && \
+    chmod +x /usr/bin/helm && \
+    rm -rf linux-amd64 && \
+    # Install helm version 3:
+    curl -L ${BASE_URL}/${HELM_3_FILE} |tar xvz && \
+    mv linux-amd64/helm /usr/bin/helm3 && \
+    chmod +x /usr/bin/helm3 && \
+    rm -rf linux-amd64 && \
+    # Init version 2 helm:
+    helm init --client-only
+
 COPY . /usr/src/
 ENTRYPOINT ["node", "/usr/src/index.js"]

index.js

@@ -146,6 +146,7 @@ async function run() {
     const version = getInput("version");
     const valueFiles = getValueFiles(getInput("value_files"));
     const removeCanary = getInput("remove_canary");
+    const helm = getInput("helm") || "helm";
 
     const dryRun = core.getInput("dry-run");
     const secrets = getSecrets(core.getInput("secrets"));
@@ -204,21 +205,21 @@ async function run() {
 
     // Remove the canary deployment before continuing.
     if (removeCanary) {
-      core.debug(`removing canart ${appName}-canary`);
-      await exec.exec("helm", ["delete", `${appName}-canary`, "--purge"], {
+      core.debug(`removing canary ${appName}-canary`);
+      await exec.exec(helm, ["delete", `${appName}-canary`, "--purge"], {
         ...opts,
         ignoreReturnCode: true
       });
     }
 
     // Actually execute the deployment here.
     if (task === "remove") {
-      await exec.exec("helm", ["delete", release, "--purge"], {
+      await exec.exec(helm, ["delete", release, "--purge"], {
         ...opts,
         ignoreReturnCode: true
       });
     } else {
-      await exec.exec("helm", args, opts);
+      await exec.exec(helm, args, opts);
     }
 
     await status("success");