Fix exec auth and add better tests.

Author: brendandburns

src/config_test.ts

@@ -685,7 +685,13 @@ describe('KubeConfig', () => {
         it('should exec with exec auth', () => {
             const config = new KubeConfig();
             const token = 'token';
-            const responseStr = `'{ "token": "${token}" }'`;
+            const responseStr = `'{
+                "apiVersion": "client.authentication.k8s.io/v1beta1",
+                "kind": "ExecCredential",
+                "status": {
+                  "token": "${token}"
+                }
+              }'`;
             config.loadFromClusterAndUser(
                 { skipTLSVerify: false } as Cluster,
                 {

src/exec_auth.ts

@@ -4,12 +4,25 @@ import { Authenticator } from './auth';
 import { User } from './config_types';
 
 export class ExecAuth implements Authenticator {
+    private tokenCache: any = {};
+
     public isAuthProvider(user: User) {
         return user.authProvider.name === 'exec' ||
             (user.authProvider.config && user.authProvider.config.exec);
     }
 
     public getToken(user: User): string | null {
+        // TODO: Handle client cert auth here, requires auth refactor.
+        // See https://kubernetes.io/docs/reference/access-authn-authz/authentication/#input-and-output-formats
+        // for details on this protocol.
+        const cachedToken = this.tokenCache[user.name];
+        if (cachedToken) {
+            const date = Date.parse(cachedToken.status.expirationTimestamp);
+            if (date < Date.now()) {
+                return cachedToken.status.token;
+            }
+            this.tokenCache[user.name] = null;
+        }
         const config = user.authProvider.config;
         if (!config.exec.command) {
             throw new Error('No command was specified for exec authProvider!');
@@ -27,7 +40,7 @@ export class ExecAuth implements Authenticator {
         const result = shell.exec(cmd, opts);
         if (result.code === 0) {
             const obj = JSON.parse(result.stdout);
-            return `Bearer ${obj.token}`;
+            return `Bearer ${obj.status.token}`;
         }
         throw new Error(result.stderr);
     }