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Version: ZIO 2.x

ZIO K8s

ZIO K8S is an idiomatic ZIO client for the Kubernetes API.

Introduction

This library provides a client for the full Kubernetes API as well as providing code generator support for custom resources and higher-level concepts such as operators, taking full advantage of the ZIO library.

Using ZIO K8S we can talk to the Kubernetes API that helps us to:

  • Write an operator for our custom resource types
  • Schedule some jobs in our cluster
  • Query the cluster for monitoring purposes
  • Write some cluster management tools

Installation

In order to use this library, we need to add the following line in our build.sbt file:

libraryDependencies += "com.coralogix" %% "zio-k8s-client" % "1.3.3"

And then we need to choose the proper sttp backend:

"com.softwaremill.sttp.client3" %% "httpclient-backend-zio" % "3.1.1",
"com.softwaremill.sttp.client3" %% "slf4j-backend" % "3.1.1"

Or the asynchronous version:

"com.softwaremill.sttp.client3" %% "async-http-client-backend-zio" % "3.1.1"
"com.softwaremill.sttp.client3" %% "slf4j-backend" % "3.1.1"

Example

This is an example of printing the tail logs of a container:

import com.coralogix.zio.k8s.client.K8sFailure
import com.coralogix.zio.k8s.client.config.httpclient._
import com.coralogix.zio.k8s.client.model.K8sNamespace
import com.coralogix.zio.k8s.client.v1.pods
import com.coralogix.zio.k8s.client.v1.pods.Pods
import zio._
import zio.console.Console

import scala.languageFeature.implicitConversions

object ZIOK8sLogsExample extends zio.App {
override def run(args: List[String]): URIO[zio.ZEnv, ExitCode] = (args match {
case List(podName) => tailLogs(podName, None)
case List(podName, containerName) => tailLogs(podName, Some(containerName))
case _ => console.putStrLnErr("Usage: <podname> [containername]")
})
.provideCustom(k8sDefault >>> Pods.live)
.exitCode

def tailLogs(podName: String,
containerName: Option[String]
): ZIO[Pods with Console, K8sFailure, Unit] =
pods
.getLog(
name = podName,
namespace = K8sNamespace.default,
container = containerName,
follow = Some(true)
)
.tap { line: String =>
console.putStrLn(line).ignore
}
.runDrain
}

Resources

  • ZIO World - ZIO Kubernetes (ZIO K8S 1.0) by Daniel Vigovszky (March 2020) — ZIO K8S 1.0, a new library by Daniel Vigovszky and Coralogix for working with Kubernetes, which includes support for the whole API, including event processors and compositional aspects for metrics and logging.