add basic leader election on top of postgres

internal/app/app.go

@@ -21,5 +21,5 @@ func (a *App) Logger() *slog.Logger {
 }
 
 func (a *App) Scheduler() *scheduler.Scheduler {
-	return scheduler.NewScheduler(a.logger)
+	return scheduler.NewScheduler(a.logger, Postgres())
 }

internal/app/postgres.go

@@ -0,0 +1,23 @@
+package app
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"time"
+
+	"git.front.kjuulh.io/kjuulh/orbis/internal/utilities"
+	"github.com/jackc/pgx/v5"
+)
+
+var Postgres = utilities.Singleton(func() (*pgx.Conn, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
+	defer cancel()
+
+	conn, err := pgx.Connect(ctx, os.Getenv("ORBIS_POSTGRES_DB"))
+	if err != nil {
+		return nil, fmt.Errorf("failed to connect to orbis postgres database: %w", err)
+	}
+
+	return conn, nil
+})