Add ability to give containers names & check containers by name

scone/default/utensils/docker_utensils.py

@@ -1,11 +1,14 @@
+from enum import Enum
 from typing import Optional
 
 import attr
 
 try:
     import docker.errors
+    from docker.models.containers import Container
 except ImportError:
     docker = None
+    Container = None
 
 from scone.common.chanpro import Channel
 from scone.sous import Utensil
@@ -21,10 +24,46 @@ def _docker_client():
     return _docker_client_instance
 
 
+class ContainerState(Enum):
+    NOTFOUND = 0
+    RUNNING = 1
+    EXITED = 2
+    RESTARTING = 3
+
+
+@attr.s(auto_attribs=True)
+class DockerContainerState(Utensil):
+    # Name of the container to check the existence of.
+    name: str
+
+    async def execute(self, channel: Channel, worktop: Worktop):
+        client = _docker_client()
+        # this is essentially `docker ps -a`
+        # TODO(perf) run this in a threaded executor since docker can be slow.
+        for container in client.containers.list(all=True):
+            container: Container
+            if self.name == container.name:
+                if container.status == 'running':
+                    await channel.send(ContainerState.RUNNING)
+                elif container.status == 'exited':
+                    await channel.send(ContainerState.EXITED)
+                elif container.status == 'restarting':
+                    await channel.send(ContainerState.RESTARTING)
+                else:
+                    raise ValueError(f"Unknown container status: {container.status}")
+                break
+        else:
+            await channel.send(ContainerState.NOTFOUND)
+
+
 @attr.s(auto_attribs=True)
 class DockerContainerRun(Utensil):
+    # Name of the image to use to create the container.
     image: str
+    # Command to create the container with.
     command: str
+    # Custom name to give the container.
+    name: Optional[str] = None
 
     @attr.s(auto_attribs=True)
     class Result: