nryanov / consul4s

A native Scala client for interacting with Consul built on top of sttp-client.

consul4s

A native Scala client for interacting with Consul built on top of sttp-client.

Features

Currently consul4s supports these endpoints:

• agent
• catalog
• coordinate
• event
• health
• kv
• prepared queries (only existing query execution)
• session
• status
• transaction

Modules

Consul4s uses multi-project structure and contains of the following modules_:

• consul4s-core - core classes/functions
• consul4s-circe - circe integration
• consul4s-json4s - json4s integration
• consul4s-spray-json - spray-json integration

Installation

consul4s is published for Scala 2.13 and 2.12 to Maven Central, so just add the following to your build.sbt:

libraryDependencies ++= Seq(
  "com.nryanov.consul4s" %% "consul4s-core" % "[version]",
  // And one of the following:
  "com.nryanov.consul4s" %% "consul4s-circe" % "[version]",
  "com.nryanov.consul4s" %% "consul4s-json4s" % "[version]",
  "com.nryanov.consul4s" %% "consul4s-spray-json" % "[version]",
)

Also you can add any sttp-client backend you want.

Getting Started

Without any additional dependencies you can use the default HttpURLConnectionBackend as backend for requests. But sttp also supports other backend implementations:

STTP: Backend implementations include ones based on akka-http, async-http-client, http4s, OkHttp, and HTTP clients which ship with Java. They integrate with Akka, Monix, fs2, cats-effect, scalaz and ZIO.

import consul4s.v1._
import consul4s.circe._
import sttp.client.HttpURLConnectionBackend

object Main {
 def main(args: Array[String]): Unit = {
    val backend = HttpURLConnectionBackend()
    val client = ConsulClient(backend) // will use default host and port: http://localhost:8500

    for {
      datacenters <- client.getDatacenters().body
    } yield datacenters
  }
}

consul4s's Issues

Update examples section

• CatsBackendExample still using cats-effect 2.x, but sttp client was updated and now uses cats-effect 3.x

Upgrade sttp to 3.x

It would be nice if sttp could be updated to 3.x :)
To be fair sttp 3 changed its package name and organization, to allow sttp 2 to be included in projects side by side, so there shouldn't be cases of dependency hell.
Nonetheless I think that depending on the most recent major release could be beneficial in the long term, given that sttp 2 is also unlikely to receive many more updates and backports.

I'm soon going to migrate another project to sttp3, I can help migrating consul4s too after that if there is a desire!

Can we make Node optional in NewSession ?

Hi,

When creating a new session through the Session API, the Node name is mandatory in NewSession.

def createSession(newSession: NewSession, dc: Option[String] = None, token: Option[String] = None): F[Result[SessionId]]  


final case class NewSession(
  Node: String, //Mandatory
  LockDelay: String,
  Name: Option[String] = None,
  ID: Option[String] = None,
  Checks: Option[List[String]] = Some(List("serfHealth")),
  Behavior: SessionBehavior = SessionBehavior.Release,
  TTL: Option[String] = None
)

The Consul API does not require this as mandatory and it can be excluded, such that the requests is submitted to the cluster as opposed to a specific node.

Would be possible to make Node optional in NewSession?

final case class NewSession(
  Node: Option[String], //Optional
  LockDelay: String,
  Name: Option[String] = None,
  ID: Option[String] = None,
  Checks: Option[List[String]] = Some(List("serfHealth")),
  Behavior: SessionBehavior = SessionBehavior.Release,
  TTL: Option[String] = None
)

I'm happy to submit a PR to update this, if this change is acceptable.

Integrate scala-steward and mergify to keep dependencies up-to-date

By opening a PR to scala-steward public instance and (eventually) adding mergify, it's way easier to keep dependencies of a public project up to date.
It should be just a matter of opening a PR to https://github.com/scala-steward-org/repos/blob/master/repos-github.md (adding a line with the repo name) and then signing up to mergify with the github account (free for OSS).
Example configurations for Mergify:

• https://github.com/http4s/http4s/blob/main/.mergify.yml
• https://github.com/softwaremill/sttp/blob/master/.mergify.yml
• https://github.com/profunktor/redis4cats/blob/master/.mergify.yml

Update sttp3 -> sttp4

Request for new release

Hi, is it possible to get a new release published?
My team uses consul4s and the latest timepit.refined bump will unblock us from updating out sbt version.

Add scalafmt?

From what I can see the project contains a .scalafmt.conf file. Scalafmt sbt plugin is not present though, not sure if it's just an oversight or if the file was included by accident.

Update to cats-effect 3.x

Scala 3.x support