context: only append flags if we know the driver supports them

Background: before this change, if i tried to use GHA with an experimental
driver, it would automatically append the flags

``
--allow-insecure-entitlement security.insecure --allow-insecure-entitlement network.host
```

even if the underlying driver did not support them.

Signed-off-by: Nick Santos <nick.santos@docker.com>

__tests__/context.test.ts

@@ -148,6 +148,21 @@ describe('getCreateArgs', () => {
         '--buildkitd-flags', '--allow-insecure-entitlement security.insecure --allow-insecure-entitlement network.host',
         '--platform', 'linux/amd64,linux/arm64,linux/arm/v7'
       ]
+    ],
+    [
+      7,
+      'v0.10.3',
+      new Map<string, string>([
+        ['install', 'false'],
+        ['use', 'false'],
+        ['driver', 'unknown'],
+        ['cleanup', 'true'],
+      ]),
+      [
+        'create',
+        '--name', 'builder-9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d',
+        '--driver', 'unknown',
+      ]
     ]
   ])(
     '[%d] given buildx %s and %p as inputs, returns %p',

src/context.ts

@@ -51,7 +51,7 @@ export async function getCreateArgs(inputs: Inputs, toolkit: Toolkit): Promise<A
     await Util.asyncForEach(inputs.driverOpts, async driverOpt => {
       args.push('--driver-opt', driverOpt);
     });
-    if (inputs.driver != 'remote' && inputs.buildkitdFlags) {
+    if (driverSupportsFlags(inputs.driver) && inputs.buildkitdFlags) {
       args.push('--buildkitd-flags', inputs.buildkitdFlags);
     }
   }
@@ -61,7 +61,7 @@ export async function getCreateArgs(inputs: Inputs, toolkit: Toolkit): Promise<A
   if (inputs.use) {
     args.push('--use');
   }
-  if (inputs.driver != 'remote') {
+  if (driverSupportsFlags(inputs.driver)) {
     if (inputs.config) {
       args.push('--config', toolkit.buildkit.config.resolveFromFile(inputs.config));
     } else if (inputs.configInline) {
@@ -85,7 +85,7 @@ export async function getAppendArgs(inputs: Inputs, node: Node, toolkit: Toolkit
     await Util.asyncForEach(node['driver-opts'], async driverOpt => {
       args.push('--driver-opt', driverOpt);
     });
-    if (inputs.driver != 'remote' && node['buildkitd-flags']) {
+    if (driverSupportsFlags(inputs.driver) && node['buildkitd-flags']) {
       args.push('--buildkitd-flags', node['buildkitd-flags']);
     }
   }
@@ -105,3 +105,7 @@ export async function getInspectArgs(inputs: Inputs, toolkit: Toolkit): Promise<
   }
   return args;
 }
+
+function driverSupportsFlags(driver: string): boolean {
+  return driver == '' || driver == 'docker-container' || driver == 'docker' || driver == 'kubernetes';
+}