Fix for Expose DaemonSet transformer state linkerd#2149. Linkerd's cu…

…rrent view of each DaemonSet namer will be exposed to :9990/namer_state/io.l5d.k8s.daemonset/namespace/port/service , where namespace/port/service are the required config for the DaemonSet transformer. State is exposed for both namer and interpreter transformers. Multiple stacked transformers are supported, so, if a namer/interpreter has multiple transformers defined, state will be exposed for all of them.

Signed-off-by: dst4096 <[email protected]>

interpreter/k8s/src/main/scala/io/buoyant/transformer/k8s/DaemonSetTransformerInitializer.scala

@@ -44,11 +44,13 @@ case class DaemonSetTransformerConfig(
  override def mk(params: Params): NameTreeTransformer = {
  val client = mkClient(params).configured(param.Label("client"))
  def mkNs(ns: String) = Api(client.newService(dst)).withNamespace(ns)
- val namer = new MultiNsNamer(Path.empty, None, mkNs)
+
+ val namer = new MultiNsNamer(prefix, None, mkNs)
+
  val daemonSet = namer.bind(NameTree.Leaf(Path.Utf8(namespace, port, service)))
  if (hostNetwork.getOrElse(false))
- new MetadataGatewayTransformer(prefix, daemonSet, Metadata.nodeName)
+ new MetadataGatewayTransformer(prefix, daemonSet, Metadata.nodeName, namer.adminHandlers)
  else
- new SubnetGatewayTransformer(prefix, daemonSet, Netmask("255.255.255.0"))
+ new SubnetGatewayTransformer(prefix, daemonSet, Netmask("255.255.255.0"), namer.adminHandlers)
  }
 }

interpreter/subnet/src/main/scala/io/buoyant/transformer/SubnetGatewayTransformer.scala

@@ -2,7 +2,9 @@ package io.buoyant.transformer
 
 import com.twitter.finagle.Name.Bound
 import com.twitter.finagle._
+import com.twitter.finagle.naming.NameInterpreter
 import com.twitter.util.{Activity, Future, Var}
+import io.buoyant.admin.Admin
 import io.buoyant.namer.{DelegateTree, DelegatingNameTreeTransformer, RichActivity}
 
 /**
@@ -12,23 +14,29 @@ import io.buoyant.namer.{DelegateTree, DelegatingNameTreeTransformer, RichActivi
 class SubnetGatewayTransformer(
  prefix: Path,
  gatewayTree: Activity[NameTree[Bound]],
- netmask: Netmask
-) extends GatewayTransformer(prefix, gatewayTree, netmask.local)
+ netmask: Netmask,
+ handlers: Seq[Admin.Handler] = Seq.empty
+) extends GatewayTransformer(prefix, gatewayTree, netmask.local, handlers)
 
 class MetadataGatewayTransformer(
  prefix: Path,
  gatewayTree: Activity[NameTree[Bound]],
- metadataField: String
+ metadataField: String,
+ handlers: Seq[Admin.Handler] = Seq.empty
 ) extends GatewayTransformer(prefix, gatewayTree, {
  case (Address.Inet(_, a), Address.Inet(_, b)) => a.get(metadataField) == b.get(metadataField)
  case _ => true
-})
+},
+ handlers)
 
 class GatewayTransformer(
  prefix: Path,
  gatewayTree: Activity[NameTree[Bound]],
- gatewayPredicate: (Address, Address) => Boolean
-) extends DelegatingNameTreeTransformer {
+ gatewayPredicate: (Address, Address) => Boolean,
+ handlers: Seq[Admin.Handler] = Seq.empty
+) extends DelegatingNameTreeTransformer with Admin.WithHandlers {
+
+ override def adminHandlers: Seq[Admin.Handler] = handlers
 
  override protected def transformDelegate(tree: DelegateTree[Bound]): Future[DelegateTree[Bound]] =
  gatewayTree.toFuture.map { gateways =>

linkerd/admin/src/main/scala/io/buoyant/linkerd/admin/LinkerdAdmin.scala

@@ -10,7 +10,7 @@ import com.twitter.server.handler.ResourceHandler
 import io.buoyant.admin.Admin.{Handler, NavItem}
 import io.buoyant.admin.names.{BoundNamesHandler, DelegateApiHandler, DelegateHandler}
 import io.buoyant.admin.{Admin, ConfigHandler, StaticFilter, _}
-import io.buoyant.namer.EnumeratingNamer
+import io.buoyant.namer.{EnumeratingNamer, WithNameTreeTransformer}
 import io.buoyant.router.{Http, RoutingFactory}
 
 object LinkerdAdmin {
@@ -83,6 +83,22 @@ object LinkerdAdmin {
  }
  }
 
+ def extractTransformersNamerHandlers(namers: Seq[Namer]): Seq[Admin.Handler] = {
+ namers.flatMap(namer =>
+ namer match {
+ case withNameTreeTransformer: WithNameTreeTransformer =>
+ withNameTreeTransformer.transformers.toSeq.flatMap(transformer =>
+ transformer match {
+ case withHandlers: Admin.WithHandlers =>
+ withHandlers.adminHandlers
+ case _ =>
+ Seq()
+ })
+ case _ =>
+ Seq()
+ })
+ }
+
  def extractInterpreterHandlers(routers: Seq[Router]): Seq[Admin.Handler] = {
  routers.flatMap { router =>
  router.interpreter match {
@@ -96,6 +112,21 @@ object LinkerdAdmin {
  }
  }
 
+ def extractInterpreterTransformerHandlers(routers: Seq[Router]): Seq[Admin.Handler] = {
+ routers.flatMap(router =>
+ router.interpreter match {
+ case withNameTreeTransformer: WithNameTreeTransformer =>
+ withNameTreeTransformer.transformers.toSeq.flatMap(transformer =>
+ transformer match {
+ case withHandlers: Admin.WithHandlers => withHandlers.adminHandlers
+ case _ =>
+ Seq()
+ })
+ case _ =>
+ Seq()
+ })
+ }
+
  def apply(lc: Linker.LinkerConfig, linker: Linker): Seq[Handler] = {
  val navItems = Seq(
  NavItem("dtab", "delegator"),
@@ -119,7 +150,9 @@ object LinkerdAdmin {
  linker.namers.map(_._2) ++
  linker.routers ++
  linker.telemeters
- ) ++ extractInterpreterHandlers(linker.routers))
+ ) ++ extractTransformersNamerHandlers(linker.namers.map(_._2))
+ ++ extractInterpreterHandlers(linker.routers)
+ ++ extractInterpreterTransformerHandlers(linker.routers))
  .map {
  case Handler(url, service, css) =>
  val adminFilter = new AdminFilter(adminHandler, css)

linkerd/docs/transformer.md

@@ -67,7 +67,9 @@ This can be used to redirect traffic to a reverse-proxy that runs as a
 daemonset.
 
 This transformer assumes that there is a Kubernetes service for the daemonset
-which can be used to find all pods in the daemonset.
+which can be used to find all pods in the daemonset. The internal state of each daemonset namer can be viewed at the
+admin endpoint: `/namer_state/io.l5d.k8s.daemonset/$namespace/$port/$service.json`, where $namespace/$port/$service are the required key configs for the DaemonSetTransformer.
+
 
 Key | Default Value | Description
 --- | ------------- | -----------

namer/core/src/main/scala/io/buoyant/namer/NameTreeTransformer.scala

@@ -5,12 +5,18 @@ import com.twitter.finagle.naming.NameInterpreter
 import com.twitter.finagle._
 import com.twitter.util.{Activity, Future}
 import io.buoyant.admin.Admin
+import io.buoyant.admin.Admin.Handler
 
 /**
  * A NameTreeTransformer performs some kind of transformation on bound
  * NameTrees. These transformers are generally applied to the output of a
  * NameInterpreter to do post-processing.
  */
+
+trait WithNameTreeTransformer {
+ def transformers: Seq[NameTreeTransformer]
+}
+
 trait NameTreeTransformer {
 
  protected def transform(tree: NameTree[Name.Bound]): Activity[NameTree[Name.Bound]]
@@ -19,17 +25,24 @@ trait NameTreeTransformer {
  * Create a new NameInterpreter by applying this transformer to the output of
  * an existing one.
  */
- def wrap(underlying: NameInterpreter): NameInterpreter = new NameInterpreter with Admin.WithHandlers {
+ def wrap(underlying: NameInterpreter): NameInterpreter = new NameInterpreter with Admin.WithHandlers with WithNameTreeTransformer {
  override def bind(dtab: Dtab, path: Path): Activity[NameTree[Bound]] =
  underlying.bind(dtab, path).flatMap(transform)
 
  override def adminHandlers: Seq[Admin.Handler] = underlying match {
  case withHandlers: Admin.WithHandlers => withHandlers.adminHandlers
  case _ => Nil
  }
+
+ override def transformers: Seq[NameTreeTransformer] = underlying match {
+ case withNameTreeTransformer: WithNameTreeTransformer => withNameTreeTransformer.transformers ++ Seq(getSelf())
+ case _ => Seq(getSelf())
+ }
  }
 
- def wrap(underlying: Namer): Namer = new Namer with Admin.WithHandlers {
+ def getSelf(): NameTreeTransformer = this
+
+ def wrap(underlying: Namer): Namer = new Namer with Admin.WithHandlers with WithNameTreeTransformer {
  private[this] def isBound(tree: NameTree[Name]): Boolean = {
  tree match {
  case NameTree.Neg | NameTree.Empty | NameTree.Fail => true
@@ -49,6 +62,11 @@ trait NameTreeTransformer {
  }
  }
 
+ override def transformers: Seq[NameTreeTransformer] = underlying match {
+ case withNameTreeTransformer: WithNameTreeTransformer => withNameTreeTransformer.transformers ++ Seq(getSelf())
+ case _ => Seq(getSelf())
+ }
+
  override def adminHandlers: Seq[Admin.Handler] = underlying match {
  case withHandlers: Admin.WithHandlers => withHandlers.adminHandlers
  case _ => Nil
@@ -66,7 +84,7 @@ trait DelegatingNameTreeTransformer extends NameTreeTransformer {
  protected def transformDelegate(tree: DelegateTree[Name.Bound]): Future[DelegateTree[Name.Bound]]
 
  /** Like wrap, but preserving the ability of the NameInterpreter to delegate */
- def delegatingWrap(underlying: NameInterpreter with Delegator): NameInterpreter with Delegator = new NameInterpreter with Delegator with Admin.WithHandlers {
+ def delegatingWrap(underlying: NameInterpreter with Delegator): NameInterpreter with Delegator = new NameInterpreter with Delegator with Admin.WithHandlers with WithNameTreeTransformer {
  override def bind(dtab: Dtab, path: Path): Activity[NameTree[Bound]] =
  underlying.bind(dtab, path).flatMap(transform)
 
@@ -82,6 +100,11 @@ trait DelegatingNameTreeTransformer extends NameTreeTransformer {
  case withHandlers: Admin.WithHandlers => withHandlers.adminHandlers
  case _ => Nil
  }
+
+ override def transformers: Seq[NameTreeTransformer] = underlying match {
+ case withNameTreeTransformer: WithNameTreeTransformer => withNameTreeTransformer.transformers ++ Seq(getSelf())
+ case _ => Seq(getSelf())
+ }
  }
 }