DB connection and transactor as separate class with config and IO

src/main/resources/postgres.conf

@@ -0,0 +1,3 @@
+username = "postgres"
+password = "mysecretpassword"
+url = "jdbc:postgresql://localhost:5432/weather-tool"

src/main/scala/app/Main.scala

@@ -2,25 +2,16 @@ package app
 
 import cats.effect._
 import cats.implicits.catsSyntaxTuple2Parallel
-import db.Main.transactor
+import db.{DBConnection, DataService, FileService, PostgresService}
-import db.{DataService, FileService, PostgresService}
-import doobie.Transactor
 import fetch.{FetchService, FileFetchScheduler}
 import server.Server
 
 object Main extends IOApp {
-
-  def transactor[F[_] : Async]: Transactor[F] = Transactor.fromDriverManager[F](
-    "org.postgresql.Driver",
-    "jdbc:postgresql://localhost:5432/weather-tool",
-    "postgres",
-    "mysecretpassword"
-  )
   def run(args: List[String]): IO[ExitCode] = {
-    val xa = transactor[IO]
-
     for {
-      postgresService <- PostgresService.of(xa)
+      transactor <- DBConnection.transactor[IO]
+      postgresService <- PostgresService.of(transactor)
+      _ <- postgresService.createWeatherTable // create table if it does not exists
       fileService <- FileService.of
       dataService <- DataService.of(fileService, postgresService)
 

src/main/scala/db/DBConnection.scala

@@ -0,0 +1,27 @@
+package db
+
+import cats.effect.{Async, IO}
+import doobie.Transactor
+import pureconfig._
+import pureconfig.generic.auto._
+import pureconfig.error.ConfigReaderFailures
+
+case class PostgresConfig(username: String, password: String, url: String)
+
+object DBConnection {
+  private def loadPostgresConfig: Either[ConfigReaderFailures, PostgresConfig] = {
+    ConfigSource.resources("postgres.conf").load[PostgresConfig]
+  }
+
+  def transactor[F[_] : Async]: IO[Transactor[F]] = {
+    loadPostgresConfig match {
+      case Right(config) => IO(Transactor.fromDriverManager[F](
+        "org.postgresql.Driver",
+        config.url,
+        config.username,
+        config.password
+      ))
+      case Left(errors) => IO.raiseError(new RuntimeException(s"Failed to load config: $errors"))
+    }
+  }
+}

src/main/scala/db/PostgresService.scala

@@ -75,7 +75,7 @@ class PostgresService(transactor: Transactor[IO], log: Logger[IO]) extends DataS
     }
   }
 
-  def createWeatherTable(): IO[Int] = {
+  def createWeatherTable: IO[Int] = {
     for {
       createTableSql <- getResourceContent("/db/create_weather_table.sql")
       result <- Update0(createTableSql, None).run.transact(transactor)