Feature/mssql-big-data-cluster (#4107)

* Adding kubernetes installer.

* Adding variety of kubectl support and integrating into the kubeconfig target cluster page.

* Addressing PR comments, refactored utility file locations and added missing license headers.

extensions/big-data-cluster/src/main.ts

@@ -6,10 +6,22 @@
 
 import vscode = require('vscode');
 import { MainController } from './mainController';
+
+import { fs } from './utility/fs';
+
+import { host } from './kubectl/host';
+import { sqlserverbigdataclusterchannel } from './kubectl/kubeChannel';
+import { shell, Shell } from './utility/shell';
+import { CheckPresentMessageMode, create as kubectlCreate } from './kubectl/kubectl';
+import { installKubectl } from './installer/installer';
+import { Errorable, failed } from './interfaces';
+
+const kubectl = kubectlCreate(host, fs, shell, installDependencies);
 export let controller: MainController;
 
 export function activate(context: vscode.ExtensionContext) {
-	controller = new MainController(context);
+    kubectl.checkPresent(CheckPresentMessageMode.Activation);
+	controller = new MainController(context, kubectl);
 	controller.activate();
 }
 
@@ -19,3 +31,28 @@ export function deactivate(): void {
 		controller.deactivate();
 	}
 }
+
+export async function installDependencies() {
+    const gotKubectl = await kubectl.checkPresent(CheckPresentMessageMode.Silent);
+
+
+    const installPromises = [
+        installDependency("kubectl", gotKubectl, installKubectl),
+    ];
+
+    await Promise.all(installPromises);
+
+    sqlserverbigdataclusterchannel.showOutput("Done");
+}
+
+async function installDependency(name: string, alreadyGot: boolean, installFunc: (shell: Shell) => Promise<Errorable<null>>): Promise<void> {
+    if (alreadyGot) {
+        sqlserverbigdataclusterchannel.showOutput(`Already got ${name}...`);
+    } else {
+        sqlserverbigdataclusterchannel.showOutput(`Installing ${name}...`);
+        const result = await installFunc(shell);
+        if (failed(result)) {
+            sqlserverbigdataclusterchannel.showOutput(`Unable to install ${name}: ${result.error[0]}`);
+        }
+    }
+}