feat(profiles/entropia-cluster-vm): actually backup postgres db

profiles/entropia-cluster-vm/backup.nix

@@ -1,8 +1,8 @@
-{ config, ... }: {
+{ config, lib, pkgs, ... }: {
   x.sops.secrets."hosts/${config.networking.hostName}/backup_zweitwohnsitz_password" = {};
 
   services.borgbackup.jobs.zweitwohnsitz = {
-    paths = [ "/var/lib" "/root" ];
+    paths = [ "/var/backup" "/var/lib" "/root" ];
     exclude = [ "'**/.cache'" ];
     doInit = true;
     repo =  "ssh://[email protected]/./${config.networking.hostName}.${config.networking.domain}";
@@ -14,7 +14,19 @@
       BORG_RSH = "ssh -i /etc/ssh/ssh_host_ed25519_key";
       BORG_RELOCATED_REPO_ACCESS_IS_OK = "yes";
     };
+    preHook = lib.mkIf config.services.postgresql.enable ''
+      ${lib.getExe pkgs.sudo} -u postgres ${pkgs.postgresql}/bin/pg_dumpall --globals-only > /var/backup/postgresql/globals
+      ${lib.getExe pkgs.sudo} -u postgres ${pkgs.postgresql}/bin/psql -t -A -c "SELECT datname FROM pg_database WHERE datname <> ALL ('{template0,template1,postgres}')" | ${pkgs.findutils}/bin/xargs -I DBNAME ${lib.getExe pkgs.sudo} -u postgres ${pkgs.postgresql}/bin/pg_dump -F directory -f /var/backup/postgresql/DBNAME DBNAME
+    '';
+    postCreate = lib.mkIf config.services.postgresql.enable ''
+      rm -r /var/backup/postgresql/*
+    '';
+    readWritePaths = lib.optionals config.services.postgresql.enable [ "/var/backup/postgresql" ];
     compression = "auto,zlib";
     startAt = "daily";
   };
+
+  systemd.tmpfiles.rules = lib.mkIf config.services.postgresql.enable [
+    "d /var/backup/postgresql 0700 postgres - - -"
+  ];
 }