nix: shorten postgrest-with-postgresql-xx scripts

Renames these scripts to `postgrest-with-pg-xx`. The renaming
helps reduce the length of temporary filenames. This is needed
to ensure that socket file names remain under the maximum
allowed length of 107 chars.

Closes #4461.

Signed-off-by: Taimoor Zaeem <taimoorzaeem@gmail.com>

nix/README.md

@@ -91,11 +91,11 @@ postgrest-gen-ctags               postgrest-watch
 postgrest-gen-jwt                 postgrest-with-all
 postgrest-gen-secret              postgrest-with-git
 postgrest-git-hooks               postgrest-with-pgrst
-postgrest-hsie-graph-modules      postgrest-with-postgresql-13
-postgrest-hsie-graph-symbols      postgrest-with-postgresql-14
-postgrest-hsie-minimal-imports    postgrest-with-postgresql-15
-postgrest-lint                    postgrest-with-postgresql-16
-postgrest-loadtest                postgrest-with-postgresql-17
+postgrest-hsie-graph-modules      postgrest-with-pg-13
+postgrest-hsie-graph-symbols      postgrest-with-pg-14
+postgrest-hsie-minimal-imports    postgrest-with-pg-15
+postgrest-lint                    postgrest-with-pg-16
+postgrest-loadtest                postgrest-with-pg-17
 postgrest-loadtest-against        postgrest-with-slow-pg
 postgrest-loadtest-report         postgrest-with-slow-postgrest
 postgrest-nixpkgs-upgrade
@@ -174,7 +174,7 @@ $ nix-shell --run "postgrest-with-all postgrest-test-spec"
 
 # Run the tests against a specific version of PostgreSQL (use tab-completion in
 # nix-shell to see all available versions):
-$ nix-shell --run "postgrest-with-postgresql-13 postgrest-test-spec"
+$ nix-shell --run "postgrest-with-pg-13 postgrest-test-spec"
 
 ```
 
@@ -284,7 +284,7 @@ Tools like `postgrest-build`, `postgrest-run`, `postgrest-repl` etc. are simple
 also run in CI, with the exception of the IO and Memory checks that need to be run
 separately.
 
-`postgrest-with-postgresql-*` take a command as an argument and will run it
+`postgrest-with-pg-*` take a command as an argument and will run it
 with a temporary database. `postgrest-with-all` will run the command against
 all supported PostgreSQL versions. Tests run without `postgrest-with-*` are
 run against the latest PostgreSQL version by default.

nix/tools/withTools.nix

@@ -46,7 +46,7 @@ let
         }
 
         # Avoid starting multiple layers of withTmpDb, but make sure to have the last invocation
-        # load fixtures. Otherwise postgrest-with-postgresql-xx postgrest-test-io would not be possible.
+        # load fixtures. Otherwise postgrest-with-pg-xx postgrest-test-io would not be possible.
         if ! test -v PGHOST; then
 
           mkdir -p "$tmpdir"/{db,socket}
@@ -74,7 +74,13 @@ let
             >> "$setuplog"
 
           log "Starting the database cluster..."
+
           # Instead of listening on a local port, we will listen on a unix domain socket.
+          # NOTE: unix domain socket filename name must remain under max limit.
+          # On Linux, it's 108 chars (including '\0' terminator)
+          # On MacOS, it's 104 chars
+          # See: https://serverfault.com/questions/641347/check-if-a-path-exceeds-maximum-for-unix-domain-socket
+
           pg_ctl -l "$tmpdir/db.log" -w start -o "-F -c listen_addresses=\"\" -c hba_file=$HBA_FILE -k $PGHOST -c log_statement=\"all\" " \
             >> "$setuplog"
 
@@ -433,7 +439,7 @@ buildToolbox
       withSlowPg
       withSlowPgrst;
   } // builtins.listToAttrs (
-    # Create a `postgrest-with-postgresql-` for each PostgreSQL version
+    # Create a `postgrest-with-pg-` for each PostgreSQL version
     builtins.map (pg: { inherit (pg) name; value = withTmpDb pg; }) postgresqlVersions
   );
   # make latest withPg available for other nix files