nix: add migrations passthru and run-migrations scipt

Author: marijanp

flake.nix

@@ -94,6 +94,7 @@
               runtimeInputs = [
                 pkgs.tinyproxy
                 pkgs.simple-http-server
+                self'.packages.run-migrations
               ];
               text =
                 let
@@ -109,9 +110,12 @@
                   };
                 in
                 ''
+                  database_file=$(mktemp database.XXXX)
+                  run-migrations server/migrations "$database_file"
+
                   simple-http-server --index --port 8001 frontend &
                   PID_FRONTEND=$!
-                  cargo run -- --listen-address 0.0.0.0:8002 &
+                  cargo run -- --listen-address 0.0.0.0:8002 --database-url "sqlite://$database_file" &
                   PID_BACKEND=$!
                   tinyproxy -d -c ${proxyConfig} &
                   PID_PROXY=$!
@@ -125,9 +129,22 @@
                   trap cleanup SIGINT
 
                   wait $PID_FRONTEND $PID_BACKEND $PID_PROXY
+                  rm -rf "$database_file"
                 '';
             };
 
+            run-migrations = pkgs.writeShellApplication {
+              name = "run-migrations";
+              runtimeInputs = [ pkgs.sqlite ];
+              text = ''
+                >&2 echo "Applying migrations"
+                for migration_file in "$1"/*.sql; do
+                  >&2 echo "Applying migration: $migration_file"
+                  sqlite3 "$2" < "$migration_file"
+                done
+              '';
+            };
+
             server-deps = craneLib.buildDepsOnly commonAttrs;
 
             server-docs = craneLib.cargoDoc (
@@ -142,6 +159,10 @@
               // {
                 cargoArtifacts = self'.packages.server-deps;
                 meta.mainProgram = "server";
+                passthru = {
+                  migrations = ./server/migrations;
+                  inherit (self'.packages) run-migrations;
+                };
               }
             );
 

nixos/modules/server.nix

@@ -9,6 +9,8 @@ let
     optionals
     ;
   cfg = config.services.server;
+  stateDirectory = "/var/lib/server";
+  databasePath = "/var/lib/server/database.db";
 in
 {
   options.services.server = {
@@ -37,6 +39,15 @@ in
       '';
     };
 
+    database_url = mkOption {
+      type = types.str;
+      default = "sqlite://${databasePath}";
+      example = "sqlite://${databasePath}";
+      description = ''
+        SQlite database to connect to.
+      '';
+    };
+
     metrics = {
       enable = lib.mkEnableOption "Prometheus metrics server";
 
@@ -75,6 +86,8 @@ in
           [
             "--listen-address"
             "${cfg.address}:${toString cfg.port}"
+            "--database-url"
+            "sqlite://${databasePath}"
           ]
           ++ optionals cfg.metrics.enable [
             "--metrics-listen-address"
@@ -92,9 +105,11 @@ in
           RUST_LOG = cfg.logLevel;
         };
         serviceConfig = {
+          ExecStartPre = "${lib.getExe cfg.package.passthru.run-migrations} ${cfg.package.passthru.migrations} ${databasePath}";
           ExecStart = "${lib.getExe cfg.package} ${args}";
           Restart = "always";
           DynamicUser = true;
+          StateDirectory = baseNameOf stateDirectory;
         };
       };
   };