Populate x-fb-product-log header in Mononoke Git

Summary: `x-fb-product-log` header is a special header that is used by all of traffic infra for E2E traceability of HTTP requests. We often face traffic/network related issues in our Git, Mononoke and LFS setup so having this header would help with debugging such issues.

Reviewed By: mzr, lmvasquezg

Differential Revision: D64069628

fbshipit-source-id: 22fc41ed0b9931e281802a128375b414d9768c4f

eden/mononoke/gotham_ext/src/middleware/scuba.rs

@@ -36,6 +36,8 @@ use crate::middleware::PostResponseInfo;
 use crate::response::HeadersMeta;
 use crate::state_ext::StateExt;
 
+const X_FB_PRODUCT_LOG_HEADER: &str = "x-fb-product-log";
+
 /// Common HTTP-related Scuba columns that the middlware will set automatically.
 /// Applications using the middleware are encouraged to follow a similar pattern
 /// when adding application-specific columns to the `ScubaMiddlewareState`.
@@ -83,6 +85,8 @@ pub enum HttpScubaKey {
     ConfigStoreVersion,
     /// The config store last update time at the time of the request.
     ConfigStoreLastUpdatedAt,
+    /// Request correlator ID that is recognized and standardized across all traffic infra for E2E tracebility.
+    XFBProductLog,
 }
 
 impl AsRef<str> for HttpScubaKey {
@@ -111,6 +115,7 @@ impl AsRef<str> for HttpScubaKey {
             RequestBytesReceived => "request_bytes_received",
             ConfigStoreVersion => "config_store_version",
             ConfigStoreLastUpdatedAt => "config_store_last_updated_at",
+            XFBProductLog => "x_fb_product_log",
         }
     }
 }
@@ -231,6 +236,14 @@ fn populate_scuba(scuba: &mut MononokeScubaSampleBuilder, state: &mut State) {
             header::USER_AGENT,
             |header| header.to_string(),
         );
+
+        add_header(
+            scuba,
+            headers,
+            HttpScubaKey::XFBProductLog,
+            X_FB_PRODUCT_LOG_HEADER,
+            |header| header.to_string(),
+        );
     }
 
     if let Some(metadata_state) = MetadataState::try_borrow_from(state) {

eden/mononoke/tests/integration/mononoke_git_server/test-mononoke-git-server-push-with-fb-product-log.t

@@ -0,0 +1,61 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License found in the LICENSE file in the root
+# directory of this source tree.
+
+  $ . "${TEST_FIXTURES}/library.sh"
+  $ REPOTYPE="blob_files"
+  $ setup_common_config $REPOTYPE
+  $ GIT_REPO_ORIGIN="${TESTTMP}/origin/repo-git"
+  $ GIT_REPO="${TESTTMP}/repo-git"
+  $ SCUBA="$TESTTMP/scuba.json"
+
+# Setup git repository
+  $ mkdir -p "$GIT_REPO_ORIGIN"
+  $ cd "$GIT_REPO_ORIGIN"
+  $ git init -q
+  $ echo "this is file1" > file1
+  $ git add file1
+  $ git commit -qam "Add file1"
+  $ git tag -a -m "new tag" first_tag
+  $ echo "this is file2" > file2
+  $ git add file2
+  $ git commit -qam "Add file2"
+  $ master_commit=$(git rev-parse HEAD)
+
+  $ cd "$TESTTMP"
+  $ git clone --mirror "$GIT_REPO_ORIGIN" repo-git
+  Cloning into bare repository 'repo-git'...
+  done.
+
+# Import it into Mononoke
+  $ cd "$TESTTMP"
+  $ quiet gitimport "$GIT_REPO" --derive-hg --generate-bookmarks full-repo
+
+# Set Mononoke as the Source of Truth
+  $ set_mononoke_as_source_of_truth_for_git
+
+# Start up the Mononoke Git Service
+  $ mononoke_git_service
+# Clone the Git repo from Mononoke
+  $ git_client clone $MONONOKE_GIT_SERVICE_BASE_URL/$REPONAME.git
+  Cloning into 'repo'...
+  $ cd repo
+
+# Add some new commits to the master branch
+  $ echo "Just another file" > another_file
+  $ git add .
+  $ git commit -qam "Another commit on master"
+
+# Push all the changes made so far
+  $ git_client push origin master
+  To https://localhost:$LOCAL_PORT/repos/git/ro/repo.git
+     e8615d6..4981a25  master -> master
+
+# Wait for the warm bookmark cache to catch up with the latest changes
+  $ wait_for_git_bookmark_move HEAD $master_commit
+
+# Verify the push validation errors got recorded in scuba
+  $ jq -S .normal "$SCUBA" | grep product | wc -l
+  25