chore!: Require setup-terraform to be run before action (#255)

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### Related issue

Fixes #243 

### Description

This PR makes it so that this action doesn't install Terraform
automatically. The expectation is that terraform with the specific
version is already installed on the runner. This can be done with the
[setup-terraform
action](https://github.com/marketplace/actions/hashicorp-setup-terraform).
The examples are updated to explain the usage.

### Checklist

- [ ] I have updated the PR title to match [CDKTF's style
guide](https://github.com/hashicorp/terraform-cdk-action/blob/main/.github/CONTRIBUTING.md#pull-requests-1)
- [ ] I have performed a self-review of my code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works if applicable
- [ ] New and existing unit tests pass locally with my changes

<!-- If this is still a work in progress, feel free to open a draft PR
until you're able to check off all the items on the list above -->

---------

Signed-off-by: team-tf-cdk <[email protected]>
Co-authored-by: team-tf-cdk <[email protected]>
Co-authored-by: Ansgar Mertens <[email protected]>

README.md

@@ -48,6 +48,10 @@ jobs:
         with:
           node-version: 20
 
+      - use: actions/setup-terraform@v3
+        with:
+          terraform_version: 1.10.4
+
       - name: Install dependencies
         run: yarn install
 
@@ -96,6 +100,10 @@ jobs:
         with:
           node-version: 20
 
+      - use: actions/setup-terraform@v3
+        with:
+          terraform_version: 1.10.4
+
       - name: Install dependencies
         run: yarn install
 
@@ -140,6 +148,10 @@ jobs:
         with:
           node-version: 20
 
+      - use: actions/setup-terraform@v3
+        with:
+          terraform_version: 1.10.4
+
       - name: Install dependencies
         run: yarn install
 

scripts/update-terraform.sh

@@ -20,4 +20,5 @@ CI=0 npx projen
 npx projen build
 
 echo "Updating README"
+sed -i 's/terraform_version: .*/terraform_version: '"$TERRAFORM_VERSION"'/' "$PROJECT_ROOT/README.md"
 sed -i 's/terraformVersion: .*/terraformVersion: '"$TERRAFORM_VERSION"'/' "$PROJECT_ROOT/README.md"

src/action.ts

@@ -10,7 +10,7 @@ import * as github from "@actions/github";
 import { CommentController } from "./comment";
 import * as input from "./inputs";
 import { Inputs } from "./models";
-import { setupTerraform } from "./setup-terraform";
+import { ensureTerraform } from "./setup-terraform";
 
 function hasTerraformChanges(output: string): Boolean {
   return !output.includes(
@@ -76,8 +76,8 @@ async function execute(
     runUrl?: string
   ) => Promise<void>
 ): Promise<void> {
-  core.debug(`Installing terraform`);
-  await setupTerraform(inputs.terraformVersion);
+  core.debug(`Checking if terraform is installed`);
+  await ensureTerraform(inputs.terraformVersion);
 
   const mainCommand = `${cdktfCommand} ${inputs.cdktfArgs}`;
   const fullCdktfCommand = inputs.customNpxArgs

src/setup-terraform.ts

@@ -8,61 +8,12 @@
 
 // Node.js core
 import { execSync } from "child_process";
-import * as os from "os";
 
 // External
 import * as core from "@actions/core";
-import * as io from "@actions/io";
-import * as tc from "@actions/tool-cache";
-import * as releases from "@hashicorp/js-releases";
-
-// arch in [arm, x32, x64...] (https://nodejs.org/api/os.html#os_os_arch)
-// return value in [amd64, 386, arm]
-function mapArch(arch: string) {
-  const mappings: Record<string, string> = {
-    x32: "386",
-    x64: "amd64",
-  };
-  return mappings[arch] || arch;
-}
-
-// os in [darwin, linux, win32...] (https://nodejs.org/api/os.html#os_os_platform)
-// return value in [darwin, linux, windows]
-function mapOS(operatingSystem: string) {
-  const mappings: Record<string, string> = {
-    win32: "windows",
-  };
-  return mappings[operatingSystem] || operatingSystem;
-}
-
-async function downloadCLI(url: string) {
-  core.debug(`Downloading Terraform CLI from ${url}`);
-  const pathToCLIZip = await tc.downloadTool(url);
-
-  let pathToCLI = "";
-
-  core.debug("Extracting Terraform CLI zip file");
-  if (os.platform().startsWith("win")) {
-    core.debug(`Terraform CLI Download Path is ${pathToCLIZip}`);
-    const fixedPathToCLIZip = `${pathToCLIZip}.zip`;
-    await io.mv(pathToCLIZip, fixedPathToCLIZip);
-    core.debug(`Moved download to ${fixedPathToCLIZip}`);
-    pathToCLI = await tc.extractZip(fixedPathToCLIZip);
-  } else {
-    pathToCLI = await tc.extractZip(pathToCLIZip);
-  }
-
-  core.debug(`Terraform CLI path is ${pathToCLI}.`);
-
-  if (!pathToCLIZip || !pathToCLI) {
-    throw new Error(`Unable to download Terraform from ${url}`);
-  }
-
-  return pathToCLI;
-}
 
 /**
- * Check if wanted version of Terraform is already available to prevent extra downloads
+ * Check if wanted version of Terraform is already available
  *
  * @param version expected version of Terraform
  */
@@ -75,6 +26,7 @@ async function checkVersionAvailability(version: string): Promise<boolean> {
         stdio: "pipe",
       })
     ).terraform_version;
+
     if (terraformVersion !== version) {
       core.debug(
         `Installed Terraform version is ${terraformVersion} while expecting ${version}`
@@ -91,38 +43,10 @@ async function checkVersionAvailability(version: string): Promise<boolean> {
   }
 }
 
-export async function setupTerraform(version: string) {
-  if (await checkVersionAvailability(version)) {
-    return;
-  }
-  // Gather OS details
-  const osPlatform = os.platform();
-  const osArch = os.arch();
-
-  core.debug(`Finding releases for Terraform version ${version}`);
-  const release = await releases.getRelease(
-    "terraform",
-    version,
-    "GitHub Action: Terraform CDK"
-  );
-  const platform = mapOS(osPlatform);
-  const arch = mapArch(osArch);
-  core.debug(
-    `Getting build for Terraform version ${release.version}: ${platform} ${arch}`
-  );
-  const build = release.getBuild(platform, arch);
-  if (!build) {
+export async function ensureTerraform(version: string) {
+  if (!(await checkVersionAvailability(version))) {
     throw new Error(
-      `Terraform version ${version} not available for ${platform} and ${arch}`
+      `Terraform not installed, please use the setup-terraform action with the specified version to install terraform. You can find it at github.com/hashicorp/setup-terraform`
     );
   }
-
-  // Download requested version
-  const pathToCLI = await downloadCLI(build.url);
-  // cache directory
-  const cachedCLIPath = await tc.cacheDir(pathToCLI, "terraform", version);
-  // Add to path
-  core.addPath(cachedCLIPath);
-
-  return cachedCLIPath;
 }