feat: Add helm action

Dockerfile

@@ -0,0 +1,4 @@
+FROM alpine/helm:2.14.0
+RUN apk add --no-cache jq curl bash nodejs && helm init --client-only
+COPY . /usr/src/
+ENTRYPOINT ["node", "/usr/src/index.js"]

action.yml

@@ -0,0 +1,15 @@
+name: 'Deliverybot Helm Action'
+description: 'Deploys a helm chart'
+author: 'deliverybot'
+inputs:
+  release:
+    description: 'Helm release name'
+  namespace:
+    description: 'Kubernetes namespace name'
+  chart:
+    description: 'Helm chart name'
+  values:
+    description: 'Helm chart values, expected to be a YAML or JSON string'
+runs:
+  using: 'docker'
+  image: 'Dockerfile'

index.js

@@ -0,0 +1,42 @@
+const core = require("@actions/core");
+const github = require("@actions/github");
+const exec = require("@actions/exec");
+const fs = require("fs");
+const util = require("util");
+
+const writeFile = util.promisify(fs.writeFile);
+
+const required = { required: true };
+
+async function run() {
+  try {
+    const release = core.getInput("release", required);
+    const namespace = core.getInput("namespace", required);
+    const chart = core.getInput("chart", required);
+    const values = core.getInput("values");
+    const context = github.context;
+    const deployment = context.payload.deployment;
+    const opts = {
+      env: {
+        KUBECONFIG: "./kubeconfig.yml",
+      }
+    }
+
+    await writeFile("./kubeconfig.yml", process.env.KUBECONFIG);
+    await writeFile("./values.yml", values);
+
+    if (deployment.task === "remove") {
+      exec.exec("helm", ["delete", release, "--purge"], opts);
+    } else {
+      exec.exec("helm", [
+        "upgrade", release, chart, "--install", "--wait", "--atomic",
+        "--namespace", namespace, "--values"
+      ], opts);
+    }
+  } catch (error) {
+    core.error(error);
+    core.setFailed(error.message);
+  }
+}
+
+run();