Ngrok support for local dev (#3481)

Tiltfile

@@ -36,6 +36,11 @@ else:
     local("echo 'Be careful that you aren't connected to a staging or prod cluster' && exit 1")
     exit()
 
+ngrok_url = os.getenv("NGROK_URL")
+if ngrok_url == "":
+    local("echo 'NGROK_URL env variable is required but not set' && exit 1")
+    exit()
+
 k8s_resource(
     workload='porter-server-web',
     port_forwards=["8080:8080"],
@@ -142,5 +147,7 @@ local_resource(
     resource_deps=["postgresql"],
     labels=["porter"]
 )
-# local_resource('public-url', serve_cmd='lt --subdomain "$(whoami)" --port 8080', resource_deps=["porter-dashboard"], labels=["porter"])
-# local_resource('public-url', serve_cmd='ngrok http 8081 --log=stdout', resource_deps=["porter-dashboard"], labels=["porter"])
+local_resource('public-url', 
+serve_cmd='''
+echo " \n\n****** NGROK URL ****** \n\n" && echo https://%s && echo "\n\n********\n\n" && ngrok http 8081 --log=stdout --domain=%s''' 
+% (ngrok_url, ngrok_url), resource_deps=["porter-dashboard"], labels=["porter"])