just serve: add remote execution endpoint and --fetch-absent option

The serve service will communicate with this endpoint when needed,
as well as ensure artifacts it provides are synced with the remote
execution CAS, if requested by the client.

If just-mr is given the --fetch-absent option, it Always produce
present roots irrespective of the 'absent' pragma. For Git repositories
marked with the 'absent' pragma, first try to fetch any commit
trees provided by the serve endpoint from the execution endpoint
CAS, before reverting to a network fetch.

Co-authored-by: Klaus Aehlig <klaus.aehlig@huawei.com>
Co-authored-by: Alberto Sartori <alberto.sartori@huawei.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/test/utils/serve_service/test_runner.py b/test/utils/serve_service/test_runner.py
index 08681646..b043b363 100755
--- a/test/utils/serve_service/test_runner.py
+++ b/test/utils/serve_service/test_runner.py
@@ -62,6 +62,7 @@ if os.path.exists(TEST_SERVE_REPO_2):
 SERVE_REPOSITORIES = ";".join([TEST_SERVE_REPO_1, TEST_SERVE_REPO_2])
 
 REMOTE_SERVE_INFO = os.path.join(REMOTE_DIR, "info_serve.json")
+SERVE_LBR = os.path.join(REMOTE_DIR, "serve-build-root")
 
 if os.path.exists(REMOTE_SERVE_INFO):
     print(f"Warning: removing unexpected info file {REMOTE_SERVE_INFO}")
@@ -79,7 +80,8 @@ with open(SERVE_CONFIG_FILE, "w") as f:
             },
             "remote service": {
                 "info file": REMOTE_SERVE_INFO
-            }
+            },
+            "local build root": SERVE_LBR
         }))
 
 serve_cmd = ["./bin/just", "serve", SERVE_CONFIG_FILE]