Add flag for ignoring the UI, don't start UI in jenkins tests. (#1021)

python/ray/scripts/scripts.py

@@ -63,11 +63,13 @@ def cli():
               help="the amount of a user-defined custom resource on this node")
 @click.option("--head", is_flag=True, default=False,
               help="provide this argument for the head node")
+@click.option("--no-ui", is_flag=True, default=False,
+              help="provide this argument if the UI should not be started")
 @click.option("--block", is_flag=True, default=False,
               help="provide this argument to block forever in this command")
 def start(node_ip_address, redis_address, redis_port, num_redis_shards,
           object_manager_port, num_workers, num_cpus, num_gpus,
-          num_custom_resource, head, block):
+          num_custom_resource, head, no_ui, block):
     # Note that we redirect stdout and stderr to /dev/null because otherwise
     # attempts to print may cause exceptions if a process is started inside of
     # an SSH connection and the SSH connection dies. TODO(rkn): This is a
@@ -103,7 +105,8 @@ def start(node_ip_address, redis_address, redis_port, num_redis_shards,
             num_cpus=num_cpus,
             num_gpus=num_gpus,
             num_custom_resource=num_custom_resource,
-            num_redis_shards=num_redis_shards)
+            num_redis_shards=num_redis_shards,
+            include_webui=(not no_ui))
         print(address_info)
         print("\nStarted Ray on this node. You can add additional nodes to "
               "the cluster by calling\n\n"
@@ -128,6 +131,9 @@ def start(node_ip_address, redis_address, redis_port, num_redis_shards,
         if num_redis_shards is not None:
             raise Exception("If --head is not passed in, --num-redis-shards "
                             "must not be provided.")
+        if no_ui:
+            raise Exception("If --head is not passed in, the --no-ui flag is "
+                            "not relevant.")
         redis_ip_address, redis_port = redis_address.split(":")
         # Wait for the Redis server to be started. And throw an exception if we
         # can't connect to it.

python/ray/services.py

@@ -1084,7 +1084,8 @@ def start_ray_head(address_info=None,
                    num_cpus=None,
                    num_gpus=None,
                    num_custom_resource=None,
-                   num_redis_shards=None):
+                   num_redis_shards=None,
+                   include_webui=True):
     """Start Ray in local mode.
 
     Args:
@@ -1119,6 +1120,7 @@ def start_ray_head(address_info=None,
         num_gpus (int): number of gpus to configure the local scheduler with.
         num_redis_shards: The number of Redis shards to start in addition to
             the primary Redis shard.
+        include_webui: True if the UI should be started and false otherwise.
 
     Returns:
         A dictionary of the address information for the processes that were
@@ -1137,7 +1139,7 @@ def start_ray_head(address_info=None,
         redirect_output=redirect_output,
         include_global_scheduler=True,
         include_log_monitor=True,
-        include_webui=True,
+        include_webui=include_webui,
         start_workers_from_local_scheduler=start_workers_from_local_scheduler,
         num_cpus=num_cpus,
         num_gpus=num_gpus,