Merge pull request #1480 from apache/juerg/ci

CI improvements
diff --git a/.github/compose/ci.buildstream-remote-cache.yml b/.github/compose/ci.bst-artifact-server.yml
similarity index 71%
rename from .github/compose/ci.buildstream-remote-cache.yml
rename to .github/compose/ci.bst-artifact-server.yml
index 9f853fa..879e5ca 100644
--- a/.github/compose/ci.buildstream-remote-cache.yml
+++ b/.github/compose/ci.bst-artifact-server.yml
@@ -11,16 +11,17 @@
 #      push: true
 #
 # Basic usage:
-#  - docker-compose -f ci.buildstream-remote-cache.yml up
-#  - docker-compose -f ci.buildstream-remote-cache.yml down
+#  - docker-compose -f ci.bst-artifact-server.yml up
+#  - docker-compose -f ci.bst-artifact-server.yml down
 #
 version: "3.2"
 
 services:
   controller:
     image: buildstream/buildstream:dev
-    command: ["bst-artifact-server","--port",
-      "50052",
+    command: ["bst-artifact-server",
+      "--log-level", "warning",
+      "--port", "50052",
       "--enable-push",
       "/artifacts"
     ]
diff --git a/.github/compose/ci.buildbarn-remote-cache.yml b/.github/compose/ci.buildbarn.yml
similarity index 90%
rename from .github/compose/ci.buildbarn-remote-cache.yml
rename to .github/compose/ci.buildbarn.yml
index 349a289..c1e90e9 100644
--- a/.github/compose/ci.buildbarn-remote-cache.yml
+++ b/.github/compose/ci.buildbarn.yml
@@ -16,8 +16,8 @@
 #     push: true
 #
 # Basic usage:
-#  - docker-compose -f ci.buildbarn-remote-cache.yml up
-#  - docker-compose -f ci.buildbarn-remote-cache.yml down
+#  - docker-compose -f ci.buildbarn.yml up
+#  - docker-compose -f ci.buildbarn.yml down
 
 version: '3.4'
 
diff --git a/.github/compose/ci.remote-execution.yml b/.github/compose/ci.buildgrid.yml
similarity index 94%
rename from .github/compose/ci.remote-execution.yml
rename to .github/compose/ci.buildgrid.yml
index e58a2a3..211c320 100644
--- a/.github/compose/ci.remote-execution.yml
+++ b/.github/compose/ci.buildgrid.yml
@@ -19,8 +19,8 @@
 #        url: http://localhost:50051
 #
 # Basic usage:
-#  - docker-compose -f ci.remote-execution.yml up
-#  - docker-compose -f ci.remote-execution.yml down
+#  - docker-compose -f ci.buildgrid.yml up
+#  - docker-compose -f ci.buildgrid.yml down
 #
 version: "3.2"
 
diff --git a/.github/compose/ci.docker-compose.yml b/.github/compose/ci.docker-compose.yml
index 2ef1a24..ee8d8c8 100644
--- a/.github/compose/ci.docker-compose.yml
+++ b/.github/compose/ci.docker-compose.yml
@@ -58,7 +58,7 @@
     environment:
       BST_PLUGINS_EXPERIMENTAL_VERSION: master
 
-  remote-execution:
+  buildgrid:
     <<: *tests-template
     command: tox -vvvvv -- --color=yes --remote-execution
     environment:
@@ -72,7 +72,7 @@
     #
     network_mode: host
 
-  buildstream-remote-cache:
+  bst-artifact-server:
     <<: *tests-template
     command: tox -vvvvv -- --color=yes --remote-cache
     environment:
@@ -84,7 +84,7 @@
     #
     network_mode: host
 
-  buildbarn-remote-cache:
+  buildbarn:
     <<: *tests-template
     command: tox -vvvvv -- --color=yes --remote-cache
     environment:
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d9401b4..894caaa 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -87,9 +87,9 @@
         # and they also map to corresponding filenames of services which are expected
         # to be run in the background
         test-name:
-          - remote-execution
-          - buildstream-remote-cache
-          - buildbarn-remote-cache
+          - bst-artifact-server
+          - buildbarn
+          - buildgrid
 
     steps:
       - name: Check out repository
diff --git a/src/buildstream/_artifactelement.py b/src/buildstream/_artifactelement.py
index cf7f55d..4d482ca 100644
--- a/src/buildstream/_artifactelement.py
+++ b/src/buildstream/_artifactelement.py
@@ -24,7 +24,6 @@
 
 from . import Element
 from . import _cachekey
-from ._artifact import Artifact
 from ._artifactproject import ArtifactProject
 from ._exceptions import ArtifactElementError
 from ._loader import LoadElement
diff --git a/src/buildstream/_assetcache.py b/src/buildstream/_assetcache.py
index e096c5f..1435969 100644
--- a/src/buildstream/_assetcache.py
+++ b/src/buildstream/_assetcache.py
@@ -22,7 +22,6 @@
 import grpc
 
 from . import utils
-from .node import MappingNode
 from ._cas import CASRemote, CASCache
 from ._exceptions import AssetCacheError, RemoteError
 from ._remotespec import RemoteSpec, RemoteType
diff --git a/src/buildstream/_cas/casserver.py b/src/buildstream/_cas/casserver.py
index 04c5eb8..5ddd446 100644
--- a/src/buildstream/_cas/casserver.py
+++ b/src/buildstream/_cas/casserver.py
@@ -75,6 +75,9 @@
         super().__init__([m.lower() for m in LogLevel.Levels._member_names_])  # pylint: disable=no-member
 
     def convert(self, value, param, ctx) -> "LogLevel.Levels":
+        if isinstance(value, LogLevel.Levels):
+            value = value.value
+
         return LogLevel.Levels(super().convert(value, param, ctx))
 
     @classmethod