Guide for creating a Slab board

package com.criteo.slab.example import java.text.DecimalFormat import com.criteo.slab.core._ import com.criteo.slab.lib.Values.{Latency, Version} import scala.concurrent.Future import scala.util.Random object SimpleBoard {  

A box for the web service, which contains latency checks

lazy val webService = Box( "Webservice alpha", 

The list of checks concerned in this box

makeVersionCheck("web.service.version", "Version", 1.2, Status.Success, Some("V1.2")) :: Nil, 

A function that aggregates the views of the children checks

takeMostCritical[Version], 

You can write a description for the box (supports Markdown)

Some( """ |# Doc for web server (markdown) |<br/> |## URL |- http://example.io |- http://10.0.0.1 """.stripMargin) ) lazy val gateway = Box( "Gateway Beta", List( makeRandomLatencyCheck("gateway.beta.eu", "EU Gateway latency"), makeRandomLatencyCheck("gateway.beta.us", "US Gateway latency") ), takeMaxLatency ) lazy val pipelineZeta = Box( "Pipeline Zeta", List( makeRandomLatencyCheck("pipeline.zeta.a", "Job A latency"), makeRandomLatencyCheck("pipeline.zeta.b", "Job B latency"), makeRandomLatencyCheck("pipeline.zeta.c", "Job C latency") ), takeMaxLatency ) lazy val pipelineOmega = Box( "Pipeline Omega", List( makeRandomLatencyCheck("pipeline.omega.a", "Job A latency", Some("Top Job")), makeRandomLatencyCheck("pipeline.omega.b", "Job B latency"), makeRandomLatencyCheck("pipeline.omega.c", "Job C latency"), makeRandomLatencyCheck("pipeline.omega.d", "Job D latency"), makeRandomLatencyCheck("pipeline.omega.e", "Job E latency") ), takeMaxLatency, 

Limit the number of labels shown on the box

labelLimit = Some(3) ) lazy val databaseKappa = Box( "Database Kappa", List( makeRandomLatencyCheck("database.kappa.dc1", "DC1 Latency"), makeRandomLatencyCheck("database.kappa.dc2", "DC2 Latency") ), takeMaxLatency ) lazy val ui = Box( "User interface", makeVersionCheck("ui.version", "Version 1000", 1000, Status.Success) :: Nil, takeMostCritical[Version], labelLimit = Some(0) )  

Define the layout of the board

lazy val layout = Layout( 

Define 3 columns, each takes 33.3% of the width of the board

Column( 33.3, 

We put the web server box in this row

Row("Tier 1", 100, Seq(webService)) ), Column( 33.3, 

Define two rows, each row takes 50% of the height of the column

Row("Tier 2 - 1", 50, Seq(gateway)), Row("Tier 2 - 2", 50, Seq(pipelineZeta, pipelineOmega)) ), Column( 33.3, Row("Tier 3", 100, Seq(databaseKappa, ui)) ) )  

Create a board

lazy val board = Board( "Simple board", webService :: gateway :: pipelineZeta :: pipelineOmega :: databaseKappa :: ui :: HNil, (views, _) => views.maxBy(_._2)._2, layout, 

Declare the links between boxes, which be shown in the UI

Seq(webService -> gateway, gateway -> pipelineZeta, pipelineZeta -> databaseKappa) )  

A function that aggregates the views of the children checks

def takeMostCritical[T](views: Map[Check[T], CheckResult[T]], ctx: Context): View = views.maxBy(_._2.view)._2.view.copy(message = "")  

Aggregate the latency values and display the max latency

def takeMaxLatency(views: Map[Check[Latency], CheckResult[Latency]], ctx: Context): View = { val maxLatency = views.map(_._2.value.map(_.underlying)).flatten.foldLeft(0L)(Math.max) View( views.maxBy(_._2.view)._2.view.status, s"max latency $maxLatency ms" ) } val versionFormatter = new DecimalFormat("##.###")  

A mock check generator for version values

def makeVersionCheck(id: String, title: String, value: Double, status: Status, label: Option[String] = None) = Check[Version]( id, title, () => Future.successful(Version(value)), display = (v: Version, _: Context) => View(status, s"version ${versionFormatter format v.underlying}", label) )  

A mock check generator for latency values

def makeRandomLatencyCheck(id: String, title: String, label: Option[String] = None) = Check[Latency]( id, title, () => Future.successful(Latency(Random.nextInt(1000))), display = (l: Latency, _: Context) => { val status = if (l.underlying >= 990) { Status.Error } else if (l.underlying >= 980) { Status.Warning } else { Status.Success } 

A view represents the result of a check, such as status, message and label, the message can be in Markdown

View(status, s"latency **${l.underlying}** ms", label) } ) }