From 825d350ab40e20d83f44acb8038f30a401565b25 Mon Sep 17 00:00:00 2001
From: fruchti <fruchti@gvfr.de>
Date: Fri, 5 Dec 2025 11:23:03 +0100
Subject: [PATCH] Add migrations directory for temporary helpers

---
 hosts/Rupert.nix                              |  2 --
 .../open_pgsql.nix                            |  0
 migrations/pgsql_upgrade.nix                  | 33 +++++++++++++++++++
 3 files changed, 33 insertions(+), 2 deletions(-)
 rename hosts/open-pgsql.nix => migrations/open_pgsql.nix (100%)
 create mode 100644 migrations/pgsql_upgrade.nix

diff --git a/hosts/Rupert.nix b/hosts/Rupert.nix
index 58130a0..8e9b780 100644
--- a/hosts/Rupert.nix
+++ b/hosts/Rupert.nix
@@ -13,8 +13,6 @@ in
         ./transcode.nix
         ./development.nix
         ./bspwm.nix
-
-        # ./open-pgsql.nix
     ];
 
     nixpkgs.overlays = let
diff --git a/hosts/open-pgsql.nix b/migrations/open_pgsql.nix
similarity index 100%
rename from hosts/open-pgsql.nix
rename to migrations/open_pgsql.nix
diff --git a/migrations/pgsql_upgrade.nix b/migrations/pgsql_upgrade.nix
new file mode 100644
index 0000000..6aeb991
--- /dev/null
+++ b/migrations/pgsql_upgrade.nix
@@ -0,0 +1,33 @@
+{ config, lib, pkgs, ... }:
+{
+    environment.systemPackages = [(
+        let
+            # XXX specify the postgresql package you'd like to upgrade to.
+            # Do not forget to list the extensions you need.
+            newPostgres = pkgs.postgresql_16.withPackages (pp: [
+                # pp.plv8
+            ]);
+            cfg = config.services.postgresql;
+        in
+        pkgs.writeScriptBin "upgrade-pg-cluster" ''
+            set -eux
+            # XXX it's perhaps advisable to stop all services that depend on postgresql
+            systemctl stop postgresql
+
+            export NEWDATA="/var/lib/postgresql/${newPostgres.psqlSchema}"
+            export NEWBIN="${newPostgres}/bin"
+
+            export OLDDATA="${cfg.dataDir}"
+            export OLDBIN="${cfg.finalPackage}/bin"
+
+            install -d -m 0700 -o postgres -g postgres "$NEWDATA"
+            cd "$NEWDATA"
+            sudo -u postgres "$NEWBIN/initdb" -D "$NEWDATA" ${lib.escapeShellArgs cfg.initdbArgs}
+
+            sudo -u postgres "$NEWBIN/pg_upgrade" \
+                --old-datadir "$OLDDATA" --new-datadir "$NEWDATA" \
+                --old-bindir "$OLDBIN" --new-bindir "$NEWBIN" \
+                "$@"
+        ''
+    )];
+}