Merge pull request #5905 from lincolnauster/flake-update-custom-commit

Custom commit messages when commiting the lockfile

doc/manual/src/release-notes/rl-next.md

@@ -9,3 +9,7 @@
   as `lib.zipAttrsWith` from nixpkgs, but much more efficient.
 * New command `nix store copy-log` to copy build logs from one store
   to another.
+* The `commit-lockfile-summary` option can be set to a non-empty string
+  to override the commit summary used when commiting an updated lockfile.
+  This may be used in conjunction with the nixConfig attribute in
+  `flake.nix` to better conform to repository conventions.

src/libexpr/flake/flake.cc

@@ -633,12 +633,24 @@ LockedFlake lockFlake(
 
                         newLockFile.write(path);
 
+                        std::optional<std::string> commitMessage = std::nullopt;
+                        if (lockFlags.commitLockFile) {
+                            std::string cm;
+
+                            cm = settings.commitLockFileSummary.get();
+
+                            if (cm == "") {
+                                cm = fmt("%s: %s", relPath, lockFileExists ? "Update" : "Add");
+                            }
+
+                            cm += "\n\nFlake lock file updates:\n\n";
+                            cm += filterANSIEscapes(diff, true);
+                            commitMessage = cm;
+                        }
+
                         topRef.input.markChangedFile(
                             (topRef.subdir == "" ? "" : topRef.subdir + "/") + "flake.lock",
-                            lockFlags.commitLockFile
-                            ? std::optional<std::string>(fmt("%s: %s\n\nFlake lock file changes:\n\n%s",
-                                    relPath, lockFileExists ? "Update" : "Add", filterANSIEscapes(diff, true)))
-                            : std::nullopt);
+                            commitMessage);
 
                         /* Rewriting the lockfile changed the top-level
                            repo, so we should re-read it. FIXME: we could

src/libstore/globals.hh

@@ -966,6 +966,13 @@ public:
 
     Setting<bool> acceptFlakeConfig{this, false, "accept-flake-config",
         "Whether to accept nix configuration from a flake without prompting."};
+
+    Setting<std::string> commitLockFileSummary{
+        this, "", "commit-lockfile-summary",
+        R"(
+          The commit summary to use when commiting changed flake lock files. If
+          empty, the summary is generated based on the action performed.
+        )"};
 };