implemented image list functions... workd with crictl images

grpc_server/test/test_grpc_server.py

@@ -6,6 +6,44 @@
 from concurrent import futures
 import subprocess 
 
+# ImageService defines the public APIs for managing images.
+class ImageServiceServicer(cri_pb2_grpc.ImageServiceServicer):
+   # Lists existing images
+   def ListImages(self, request, context):
+      print("in List Images") # DEBUG
+
+      # creates empty respone
+      response = cri_pb2.ListImagesResponse()
+
+      # calls ch-image list and stores stdout
+      cmd = "/usr/local/src/charliecloud/bin/ch-image"
+      ca = [cmd, "list"]
+      output = subprocess.check_output(ca, stderr=subprocess.STDOUT)
+
+      # images as strings 
+      # note: decode changes bytes to string, split converts string to array, and finally remove the empty string
+      images = output.decode("utf-8").split("\n")[:-1]
+
+      # for every image in charliecloud cache: 
+      #   create an image object with the name as the ID and append to the repeated field 
+      for img in images:
+         response.images.append(cri_pb2.Image(id=img)) # note: incomplete... image missing fields
+
+      print(response.images) # DEBUG
+      return response
+
+   # ImageFSInfo returns information of the filesystem that is used to store images.
+   def ImageFsInfo(self, request, context):
+      print("In Image Fs Info") # DEBUG
+
+      # dummy placeholders
+      filesystem_info = cri_pb2.FilesystemUsage()
+      response = cri_pb2.ImageFsInfoResponse(image_filesystems=[filesystem_info])
+
+      return response 
+
+
+
 # organise version information to return as protobuf
 VERSION_INFO = { "KubeVersion": "v1",           # version of the kubelet runtime api
                  "RuntimeName": "Charliecloud", # name of the container runtime (const)
@@ -29,13 +67,21 @@ def Version(self, request, context):
 
       return response
 
+   # dummy start container function
+   def StartContainer(self, request, context):
+      print("start container:", request.container_id) # DEBUG
+      return cri_pb2.StartContainerResponse() 
+
+
 def serve():
     server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
     cri_pb2_grpc.add_RuntimeServiceServicer_to_server(RuntimeServiceServicer(), server)
+    cri_pb2_grpc.add_ImageServiceServicer_to_server(ImageServiceServicer(), server)
     server.add_insecure_port(f'unix:///tmp/test.sock')
     server.start()
     print("Server listening on port 50052...") # DEBUG
     server.wait_for_termination() 
 
 if __name__ == '__main__':
+    # start gRPC server
     serve()