The following program will run a Docker image of Postgres, given a password. It will wait 5 seconds, and then connect using Doobie JDBC:<\/p>\n
\nimplicit val timer = IO.timer(ExecutionContext.global)\n\n val info = (msg: String) => println(\"OUT \" + msg)\n val err = (msg: String) => println(\"ERR \" + msg)\n\n def putStrlLn(value: String) = IO(println(value))\n val readLn = IO(scala.io.StdIn.readLine)\n\n def cmd(cmd: String, runId: String): IO[Int] = {\n\n IO.cancelable(\n (cb: (Either[Throwable, Int] => Unit)) => {\n val isCancelled = new AtomicBoolean(false)\n\n var process: Option[Process] = None\n\n val asyncResult = Future {\n import sys.process._\n info(s\"${runId} Running `${cmd}`:\")\n\n val log = ProcessLogger(\n (msg) => info(s\"${runId} ${msg}\"),\n (msg) => err(s\"${runId} ${msg}\")\n )\n\n val proc = Process(cmd)\n process = Some(proc.run(log))\n\n process.get.exitValue()\n }\n\n asyncResult.onComplete {\n case Success(value) => cb(Right(value))\n case Failure(e) => cb(Left(e))\n }\n\n IO {\n isCancelled.set(true)\n\n process match {\n case Some(process) => process.destroy()\n case None => {\n info(\"No process to cancel\")\n }\n }\n\n info(\"# # # set isCancelled = true\")\n }\n }\n )\n }\n\n def docker(id: String, params: String, runId: String) = cmd(s\"docker run --rm -i ${params} ${id}\", runId)\n\n def main(args: Array[String]): Unit = {\n val contextShift = IO.contextShift(global)\n\n import doobie._\n import doobie.implicits._\n\n val xa = Transactor.fromDriverManager[IO](\n \"org.postgresql.Driver\", \"jdbc:postgresql:\/\/localhost:6432\/postgres\", \"postgres\", \"pwd\"\n )\n\n val program = for (\n runId <- FUUID.randomFUUID[IO];\n IO.race(\n docker(\"postgres\", \"-p 6432:5432 -e POSTGRES_PASSWORD=pwd\", runId.show),\n IO.sleep(5 seconds) *> sql\"select 42\".query[Int].unique.transact(xa).flatMap(\n x => IO({\n println(x)\n })\n )\n )(contextShift) *>\n IO({\n println(\"success\")\n })) yield program\n<\/pre>\n","protected":false},"excerpt":{"rendered":"Example of using Doobie, Cats Effects, Postgres in Docker<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[4],"tags":[102,176,244,437,438,480],"aioseo_notices":[],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.garysieling.com\/blog\/wp-json\/wp\/v2\/posts\/5792"}],"collection":[{"href":"https:\/\/www.garysieling.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.garysieling.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.garysieling.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.garysieling.com\/blog\/wp-json\/wp\/v2\/comments?post=5792"}],"version-history":[{"count":0,"href":"https:\/\/www.garysieling.com\/blog\/wp-json\/wp\/v2\/posts\/5792\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.garysieling.com\/blog\/wp-json\/wp\/v2\/media?parent=5792"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.garysieling.com\/blog\/wp-json\/wp\/v2\/categories?post=5792"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.garysieling.com\/blog\/wp-json\/wp\/v2\/tags?post=5792"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}