feat(terraform): allow setting version to null to use terraform on PATH

core/package.json

@@ -132,6 +132,7 @@
     "unzipper": "^0.10.11",
     "username": "^5.1.0",
     "uuid": "^8.1.0",
+    "which": "^2.0.2",
     "winston": "^3.2.1",
     "wrap-ansi": "^7.0.0",
     "ws": "^7.3.0",
@@ -196,6 +197,7 @@
     "@types/unzip": "^0.1.1",
     "@types/unzipper": "^0.10.3",
     "@types/uuid": "^8.0.0",
+    "@types/which": "^1.3.2",
     "@types/wrap-ansi": "^3.0.0",
     "amplitude-js": "^6.2.0",
     "chai": "^4.2.0",
@@ -247,4 +249,4 @@
     ]
   },
   "gitHead": "b0647221a4d2ff06952bae58000b104215aed922"
-}
+}

core/src/plugins/terraform/cli.ts

@@ -6,23 +6,45 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-import { ConfigurationError } from "../../exceptions"
+import { ConfigurationError, RuntimeError } from "../../exceptions"
 import { PluginToolSpec } from "../../types/plugin/tools"
 import { TerraformProvider } from "./terraform"
 import { PluginContext } from "../../plugin-context"
+import which from "which"
+import { CliWrapper } from "../../util/ext-tools"
+import { LogEntry } from "../../logger/log-entry"
 
 export function terraform(ctx: PluginContext, provider: TerraformProvider) {
   const version = provider.config.version
-  const cli = ctx.tools["terraform.terraform-" + version.replace(/\./g, "-")]
 
-  if (!cli) {
-    throw new ConfigurationError(`Unsupported Terraform version: ${version}`, {
-      version,
-      supportedVersions,
-    })
+  if (version === null) {
+    return new GlobalTerraform()
+  } else {
+    const cli = ctx.tools["terraform.terraform-" + version.replace(/\./g, "-")]
+
+    if (!cli) {
+      throw new ConfigurationError(`Unsupported Terraform version: ${version}`, {
+        version,
+        supportedVersions,
+      })
+    }
+
+    return cli
+  }
+}
+
+export class GlobalTerraform extends CliWrapper {
+  constructor() {
+    super("terraform", "terraform")
   }
 
-  return cli
+  async getPath(_: LogEntry) {
+    try {
+      return await which("terraform")
+    } catch (err) {
+      throw new RuntimeError(`Terraform version is set to null, and terraform CLI could not be found on PATH`, {})
+    }
+  }
 }
 
 export const terraformCliSpecs: { [version: string]: PluginToolSpec } = {

core/src/plugins/terraform/commands.ts

@@ -53,7 +53,7 @@ function makeRootCommand(commandName: string) {
 
       const root = join(ctx.projectRoot, provider.config.initRoot)
 
-      await tfValidate({ log, ctx, provider, root, variables: provider.config.variables })
+      await tfValidate({ log, ctx, provider, root })
 
       args = [commandName, ...(await prepareVariables(root, provider.config.variables)), ...args]
       await terraform(ctx, provider).spawnAndWait({
@@ -87,7 +87,7 @@ function makeModuleCommand(commandName: string) {
       const root = join(module.path, module.spec.root)
 
       const provider = ctx.provider as TerraformProvider
-      await tfValidate({ log, ctx, provider, root, variables: provider.config.variables })
+      await tfValidate({ log, ctx, provider, root })
 
       args = [commandName, ...(await prepareVariables(root, module.spec.variables)), ...args.slice(1)]
       await terraform(ctx, provider).spawnAndWait({

core/src/plugins/terraform/common.ts

@@ -27,7 +27,7 @@ export interface TerraformBaseSpec {
   autoApply: boolean
   dependencies: string[]
   variables: PrimitiveMap
-  version: string
+  version: string | null
 }
 
 export async function tfValidate({

core/src/plugins/terraform/module.ts

@@ -62,8 +62,9 @@ export const schema = joi.object().keys({
         If you specified \`variables\` in the \`terraform\` provider config, those will be included but the variables
         specified here take precedence.
       `),
-  version: joi.string().allow(...supportedVersions).description(dedent`
+  version: joi.string().allow(...supportedVersions, null).description(dedent`
       The version of Terraform to use. Defaults to the version set in the provider config.
+      Set to \`null\` to use whichever version of \`terraform\` that is on your PATH.
     `),
 })
 

core/src/plugins/terraform/terraform.ts

@@ -54,9 +54,9 @@ const configSchema = providerConfigBaseSchema()
     // May be overridden by individual \`terraform\` modules.
     version: joi
       .string()
-      .allow(...supportedVersions)
+      .allow(...supportedVersions, null)
       .default(defaultTerraformVersion).description(dedent`
-        The version of Terraform to use.
+        The version of Terraform to use. Set to \`null\` to use whichever version of \`terraform\` that is on your PATH.
       `),
   })
   .unknown(false)

core/src/util/ext-tools.ts

@@ -47,79 +47,17 @@ export interface SpawnParams extends ExecParams {
   rawMode?: boolean // Only used if tty = true. See also: https://nodejs.org/api/tty.html#tty_readstream_setrawmode_mode
 }
 
-interface PluginToolOpts {
-  platform?: string
-  architecture?: string
-}
-
-export interface PluginTools {
-  [key: string]: PluginTool
-}
-
-/**
- * This helper class allows you to declare a tool dependency by providing a URL to a single-file binary,
- * or an archive containing an executable, for each of our supported platforms. When executing the tool,
- * the appropriate URL for the current platform will be downloaded and cached in the user's home directory
- * (under .garden/tools/<name>/<url-hash>).
- *
- * Note: The binary or archive currently needs to be self-contained and work without further installation steps.
- */
-export class PluginTool {
+export class CliWrapper {
   name: string
-  type: string
-  spec: PluginToolSpec
-  buildSpec: ToolBuildSpec
-
-  private lock: any
-  private toolPath: string
-  private versionDirname: string
-  protected versionPath: string
-  protected targetSubpath: string
-  private chmodDone: boolean
-
-  constructor(spec: PluginToolSpec, opts: PluginToolOpts = {}) {
-    const _platform = opts.platform || getPlatform()
-    const architecture = opts.architecture || getArchitecture()
-
-    this.buildSpec = spec.builds.find((build) => build.platform === _platform && build.architecture === architecture)!
+  protected toolPath: string
 
-    if (!this.buildSpec) {
-      throw new ConfigurationError(
-        `Command ${spec.name} doesn't have a spec for this platform/architecture (${platform}-${architecture})`,
-        {
-          spec,
-          platform,
-          architecture,
-        }
-      )
-    }
-
-    this.lock = new AsyncLock()
-
-    this.name = spec.name
-    this.type = spec.type
-    this.spec = spec
-    this.toolPath = join(toolsPath, this.name)
-    this.versionDirname = hashString(this.buildSpec.url, 16)
-    this.versionPath = join(this.toolPath, this.versionDirname)
-
-    this.targetSubpath = this.buildSpec.extract ? this.buildSpec.extract.targetPath : basename(this.buildSpec.url)
-    this.chmodDone = false
+  constructor(name: string, path: string) {
+    this.name = name
+    this.toolPath = path
   }
 
-  async getPath(log: LogEntry) {
-    await this.download(log)
-    const path = join(this.versionPath, ...this.targetSubpath.split(posix.sep))
-
-    if (this.spec.type === "binary") {
-      // Make sure the target path is executable
-      if (!this.chmodDone) {
-        await chmod(path, 0o755)
-        this.chmodDone = true
-      }
-    }
-
-    return path
+  async getPath(_: LogEntry) {
+    return this.toolPath
   }
 
   async exec({ args, cwd, env, log, timeoutSec, input, ignoreError, stdout, stderr }: ExecParams) {
@@ -199,6 +137,82 @@ export class PluginTool {
       tty,
     })
   }
+}
+
+interface PluginToolOpts {
+  platform?: string
+  architecture?: string
+}
+
+export interface PluginTools {
+  [key: string]: PluginTool
+}
+
+/**
+ * This helper class allows you to declare a tool dependency by providing a URL to a single-file binary,
+ * or an archive containing an executable, for each of our supported platforms. When executing the tool,
+ * the appropriate URL for the current platform will be downloaded and cached in the user's home directory
+ * (under .garden/tools/<name>/<url-hash>).
+ *
+ * Note: The binary or archive currently needs to be self-contained and work without further installation steps.
+ */
+export class PluginTool extends CliWrapper {
+  type: string
+  spec: PluginToolSpec
+  buildSpec: ToolBuildSpec
+
+  private lock: any
+  private versionDirname: string
+  protected versionPath: string
+  protected targetSubpath: string
+  private chmodDone: boolean
+
+  constructor(spec: PluginToolSpec, opts: PluginToolOpts = {}) {
+    super(spec.name, "")
+
+    const _platform = opts.platform || getPlatform()
+    const architecture = opts.architecture || getArchitecture()
+
+    this.buildSpec = spec.builds.find((build) => build.platform === _platform && build.architecture === architecture)!
+
+    if (!this.buildSpec) {
+      throw new ConfigurationError(
+        `Command ${spec.name} doesn't have a spec for this platform/architecture (${platform}-${architecture})`,
+        {
+          spec,
+          platform,
+          architecture,
+        }
+      )
+    }
+
+    this.lock = new AsyncLock()
+
+    this.name = spec.name
+    this.type = spec.type
+    this.spec = spec
+    this.toolPath = join(toolsPath, this.name)
+    this.versionDirname = hashString(this.buildSpec.url, 16)
+    this.versionPath = join(this.toolPath, this.versionDirname)
+
+    this.targetSubpath = this.buildSpec.extract ? this.buildSpec.extract.targetPath : basename(this.buildSpec.url)
+    this.chmodDone = false
+  }
+
+  async getPath(log: LogEntry) {
+    await this.download(log)
+    const path = join(this.versionPath, ...this.targetSubpath.split(posix.sep))
+
+    if (this.spec.type === "binary") {
+      // Make sure the target path is executable
+      if (!this.chmodDone) {
+        await chmod(path, 0o755)
+        this.chmodDone = true
+      }
+    }
+
+    return path
+  }
 
   protected async download(log: LogEntry) {
     return this.lock.acquire("download", async () => {

core/test/data/test-projects/terraform-provider/garden.yml

@@ -8,6 +8,7 @@ providers:
     allowDestroy: ${environment.name != 'prod'}
     autoApply: ${environment.name != 'prod'}
     initRoot: tf
+    version: "0.13.3"
     variables:
       my-variable: foo
       env: ${environment.name}

docs/reference/module-types/terraform.md

@@ -137,6 +137,7 @@ root: .
 variables:
 
 # The version of Terraform to use. Defaults to the version set in the provider config.
+# Set to `null` to use whichever version of `terraform` that is on your PATH.
 version:
 ```
 
@@ -389,6 +390,7 @@ specified here take precedence.
 ### `version`
 
 The version of Terraform to use. Defaults to the version set in the provider config.
+Set to `null` to use whichever version of `terraform` that is on your PATH.
 
 | Type     | Required |
 | -------- | -------- |

yarn.lock

@@ -2931,6 +2931,11 @@
   resolved "https://registry.yarnpkg.com/@types/uuid/-/uuid-8.3.0.tgz#215c231dff736d5ba92410e6d602050cce7e273f"
   integrity sha512-eQ9qFW/fhfGJF8WKHGEHZEyVWfZxrT+6CLIJGBcZPfxUh/+BnEj+UCGYMlr9qZuX/2AltsvwrGqp0LhEW8D0zQ==
 
+"@types/which@^1.3.2":
+  version "1.3.2"
+  resolved "https://registry.yarnpkg.com/@types/which/-/which-1.3.2.tgz#9c246fc0c93ded311c8512df2891fb41f6227fdf"
+  integrity sha512-8oDqyLC7eD4HM307boe2QWKyuzdzWBj56xI/imSl2cpL+U3tCMaTAkMJ4ee5JBZ/FsOJlvRGeIShiZDAl1qERA==
+
 "@types/wrap-ansi@^3.0.0":
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/@types/wrap-ansi/-/wrap-ansi-3.0.0.tgz#18b97a972f94f60a679fd5c796d96421b9abb9fd"
@@ -18797,7 +18802,7 @@ which@1, [email protected], which@^1.2.14, which@^1.2.9, which@^1.3.0, which@^1.3.1:
   dependencies:
     isexe "^2.0.0"
 
-[email protected], which@^2.0.1:
+[email protected], which@^2.0.1, which@^2.0.2:
   version "2.0.2"
   resolved "https://registry.yarnpkg.com/which/-/which-2.0.2.tgz#7c6a8dd0a636a0327e10b59c9286eee93f3f51b1"
   integrity sha512-BLI3Tl1TW3Pvl70l3yq3Y64i+awpwXqsGBYWkkqMtnbXgrMD+yj7rhW0kuEDxzJaYXGjEW5ogapKNMEKNMjibA==