initial, copy postgres stuff for migrations, main.go test

cmd/hammyd/main.go

@@ -0,0 +1,37 @@
+// cmd/hammyd/main.go
+package main
+
+import (
+    "context"
+    "log"
+    "os"
+
+    "github.com/jackc/pgx/v5/pgxpool"
+)
+
+func main() {
+    ctx := context.Background()
+
+    dsn := os.Getenv("HAMMY_DSN")
+    if dsn == "" {
+        log.Fatal("HAMMY_DSN is not set!")
+    }
+
+    pool, err := pgxpool.New(ctx, dsn)
+    if err != nil {
+        log.Fatalf("connect: %v", err)
+    }
+    defer pool.Close()
+
+    if err := pool.Ping(ctx); err != nil {
+        log.Fatalf("ping: %v", err)
+    }
+
+    var n int
+    err = pool.QueryRow(ctx, "SELECT count(*) FROM core.users").Scan(&n)
+    if err != nil {
+        log.Fatalf("query: %v", err)
+    }
+
+    log.Printf("connected, %d users", n)
+}