Support deployment of agent as a DaemonSet

Signed-off-by: Juraci Paixão Kröhling <[email protected]>

README.adoc

@@ -118,13 +118,16 @@ spec:
         max-traces: 100000
     ingress:
       enabled: false # <6>
+  agent:
+    strategy: DaemonSet # <7>
 ----
 <1> The default strategy is `all-in-one`. The only other possible value is `production`.
 <2> The image to use, in a regular Docker syntax
 <3> The options to be passed verbatim to the underlying binary.Refer to the Jaeger documentation and/or to the `--help` option from the related binary for all the available options
 <4> The option is a simple `key: value` map. In this case, we want the option `--log-level=debug` to be passed to the binary.
 <5> Some options are namespaced and we can alternatively break them into nested objects. We could have specified `memory.max-traces: 100000`.
 <6> By default, an ingress object is created for the query service. It can be disabled by setting its `enabled` option to `false`. This is also available for the `query` spec.
+<7> By default, the operator assumes that agents are deployed as sidecars within the target pods. Specifying the strategy as "DaemonSet" changes that and makes the operator deploy the agent as DaemonSet. Note that your tracer client will probably have to override the "JAEGER_AGENT_HOST" env var to use the node's IP.
 
 == Accessing the UI
 
@@ -164,6 +167,50 @@ oc get routes
 
 NOTE: make sure to use `https` with the hostname/port you get from the command above, otherwise you'll see a message like: "Application is not available".
 
+== Agent as DaemonSet
+
+By default, the Operator expects the agents to be deployed as sidecars to the target applications. This is convenient for several purposes, like in a multi-tenant scenario or to have better load balancing, but there are scenarios where it's desirable to install the agent as a `DaemonSet`. In that case, specify the Agent's strategy to `DaemonSet`, as follows:
+
+[source,yaml]
+----
+apiVersion: io.jaegertracing/v1alpha1
+kind: Jaeger
+metadata:
+  name: my-jaeger
+spec:
+  agent:
+    strategy: DaemonSet
+----
+
+IMPORTANT: if you attempt to install two Jaeger instances on the same cluster with `DaemonSet` as the strategy, only *one* will end up deploying a `DaemonSet`, as the agent is required to bind to well-known ports on the node. Because of that, the second daemon set will fail to bind to those ports.
+
+Your tracer client will then most likely need to be told where the agent is located. This is usually done by setting the env var `JAEGER_AGENT_HOST` and should be set to the value of the Kubernetes node's IP, like:
+
+[source,yaml]
+----
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: myapp
+spec:
+  selector:
+    matchLabels:
+      app: myapp
+  template:
+    metadata:
+      labels:
+        app: myapp
+    spec:
+      containers:
+      - name: myapp
+        image: acme/myapp:myversion
+        env:
+        - name: JAEGER_AGENT_HOST
+          valueFrom:
+            fieldRef:
+              fieldPath: status.hostIP
+----
+
 == Removing an instance
 
 To remove an instance, just use the `delete` command with the file used for the instance creation:

deploy/examples/agent-as-daemonset.yaml

@@ -0,0 +1,9 @@
+apiVersion: io.jaegertracing/v1alpha1
+kind: Jaeger
+metadata:
+  name: agent-as-daemonset
+spec:
+  agent:
+    strategy: DaemonSet
+    options:
+      log-level: debug

pkg/apis/io/v1alpha1/types.go

@@ -67,8 +67,9 @@ type JaegerCollectorSpec struct {
 
 // JaegerAgentSpec defines the options to be used when deploying the agent
 type JaegerAgentSpec struct {
-	Strategy string `json:"strategy"` // can be either 'DaemonSet' or 'Sidecar' (default)
-	Image    string `json:"image"`
+	Strategy string  `json:"strategy"` // can be either 'DaemonSet' or 'Sidecar' (default)
+	Image    string  `json:"image"`
+	Options  Options `json:"options"`
 }
 
 // JaegerStorageSpec defines the common storage options to be used for the query and collector

pkg/controller/all-in-one.go

@@ -27,6 +27,12 @@ func (c allInOneController) Create() []sdk.Object {
 
 	dep := deployment.NewAllInOne(c.jaeger)
 	os := []sdk.Object{dep.Get()}
+
+	ds := deployment.NewAgent(c.jaeger).Get()
+	if nil != ds {
+		os = append(os, ds)
+	}
+
 	for _, svc := range dep.Services() {
 		os = append(os, svc)
 	}

pkg/controller/all-in-one_test.go

@@ -21,7 +21,18 @@ func TestCreateAllInOneDeployment(t *testing.T) {
 	name := "TestCreateAllInOneDeployment"
 	c := newAllInOneController(context.TODO(), v1alpha1.NewJaeger(name))
 	objs := c.Create()
-	assertDeploymentsAndServicesForAllInOne(t, name, objs)
+	assertDeploymentsAndServicesForAllInOne(t, name, objs, false)
+}
+
+func TestCreateAllInOneDeploymentWithDaemonSetAgent(t *testing.T) {
+	name := "TestCreateAllInOneDeploymentWithDaemonSetAgent"
+
+	j := v1alpha1.NewJaeger(name)
+	j.Spec.Agent.Strategy = "DaemonSet"
+
+	c := newAllInOneController(context.TODO(), j)
+	objs := c.Create()
+	assertDeploymentsAndServicesForAllInOne(t, name, objs, true)
 }
 
 func TestUpdateAllInOneDeployment(t *testing.T) {
@@ -30,14 +41,22 @@ func TestUpdateAllInOneDeployment(t *testing.T) {
 	assert.Len(t, objs, 0)
 }
 
-func assertDeploymentsAndServicesForAllInOne(t *testing.T, name string, objs []sdk.Object) {
-	assert.Len(t, objs, 6)
+func assertDeploymentsAndServicesForAllInOne(t *testing.T, name string, objs []sdk.Object, hasDaemonSet bool) {
+	if hasDaemonSet {
+		assert.Len(t, objs, 7)
+	} else {
+		assert.Len(t, objs, 6)
+	}
 
 	// we should have one deployment, named after the Jaeger's name (ObjectMeta.Name)
 	deployments := map[string]bool{
 		name: false,
 	}
 
+	daemonsets := map[string]bool{
+		fmt.Sprintf("%s-agent-daemonset", name): !hasDaemonSet,
+	}
+
 	// and these services
 	services := map[string]bool{
 		fmt.Sprintf("%s-agent", name):     false,
@@ -51,5 +70,5 @@ func assertDeploymentsAndServicesForAllInOne(t *testing.T, name string, objs []s
 		fmt.Sprintf("%s-query", name): false,
 	}
 
-	assertHasAllObjects(t, name, objs, deployments, services, ingresses)
+	assertHasAllObjects(t, name, objs, deployments, daemonsets, services, ingresses)
 }

pkg/controller/controller_test.go

@@ -110,15 +110,17 @@ func getDeployments(objs []sdk.Object) []*appsv1.Deployment {
 	return deps
 }
 
-func assertHasAllObjects(t *testing.T, name string, objs []sdk.Object, deployments map[string]bool, services map[string]bool, ingresses map[string]bool) {
+func assertHasAllObjects(t *testing.T, name string, objs []sdk.Object, deployments map[string]bool, daemonsets map[string]bool, services map[string]bool, ingresses map[string]bool) {
 	for _, obj := range objs {
 		switch typ := obj.(type) {
 		case *appsv1.Deployment:
-			deployments[obj.(*appsv1.Deployment).ObjectMeta.Name] = true
+			deployments[obj.(*appsv1.Deployment).Name] = true
+		case *appsv1.DaemonSet:
+			daemonsets[obj.(*appsv1.DaemonSet).Name] = true
 		case *v1.Service:
-			services[obj.(*v1.Service).ObjectMeta.Name] = true
+			services[obj.(*v1.Service).Name] = true
 		case *v1beta1.Ingress:
-			ingresses[obj.(*v1beta1.Ingress).ObjectMeta.Name] = true
+			ingresses[obj.(*v1beta1.Ingress).Name] = true
 		default:
 			assert.Failf(t, "unknown type to be deployed", "%v", typ)
 		}
@@ -128,6 +130,10 @@ func assertHasAllObjects(t *testing.T, name string, objs []sdk.Object, deploymen
 		assert.True(t, v, "Expected %s to have been returned from the list of deployments", k)
 	}
 
+	for k, v := range daemonsets {
+		assert.True(t, v, "Expected %s to have been returned from the list of daemonsets", k)
+	}
+
 	for k, v := range services {
 		assert.True(t, v, "Expected %s to have been returned from the list of services", k)
 	}

pkg/controller/production.go

@@ -32,6 +32,11 @@ func (c *productionController) Create() []sdk.Object {
 		agent.InjectSidecar(*query.Get()),
 	}
 
+	ds := agent.Get()
+	if nil != ds {
+		components = append(components, ds)
+	}
+
 	for _, svc := range collector.Services() {
 		components = append(components, svc)
 	}

pkg/controller/production_test.go

@@ -23,7 +23,18 @@ func TestCreateProductionDeployment(t *testing.T) {
 	name := "TestCreateProductionDeployment"
 	c := newProductionController(context.TODO(), v1alpha1.NewJaeger(name))
 	objs := c.Create()
-	assertDeploymentsAndServicesForProduction(t, name, objs)
+	assertDeploymentsAndServicesForProduction(t, name, objs, false)
+}
+
+func TestCreateProductionDeploymentWithDaemonSetAgent(t *testing.T) {
+	name := "TestCreateProductionDeploymentWithDaemonSetAgent"
+
+	j := v1alpha1.NewJaeger(name)
+	j.Spec.Agent.Strategy = "DaemonSet"
+
+	c := newProductionController(context.TODO(), j)
+	objs := c.Create()
+	assertDeploymentsAndServicesForProduction(t, name, objs, true)
 }
 
 func TestUpdateProductionDeployment(t *testing.T) {
@@ -85,14 +96,22 @@ func TestOptionsArePassed(t *testing.T) {
 	}
 }
 
-func assertDeploymentsAndServicesForProduction(t *testing.T, name string, objs []sdk.Object) {
-	assert.Len(t, objs, 6)
+func assertDeploymentsAndServicesForProduction(t *testing.T, name string, objs []sdk.Object, hasDaemonSet bool) {
+	if hasDaemonSet {
+		assert.Len(t, objs, 7)
+	} else {
+		assert.Len(t, objs, 6)
+	}
 
 	deployments := map[string]bool{
 		fmt.Sprintf("%s-collector", name): false,
 		fmt.Sprintf("%s-query", name):     false,
 	}
 
+	daemonsets := map[string]bool{
+		fmt.Sprintf("%s-agent-daemonset", name): !hasDaemonSet,
+	}
+
 	services := map[string]bool{
 		fmt.Sprintf("%s-collector", name): false,
 		fmt.Sprintf("%s-query", name):     false,
@@ -103,5 +122,5 @@ func assertDeploymentsAndServicesForProduction(t *testing.T, name string, objs [
 		fmt.Sprintf("%s-query", name): false,
 	}
 
-	assertHasAllObjects(t, name, objs, deployments, services, ingresses)
+	assertHasAllObjects(t, name, objs, deployments, daemonsets, services, ingresses)
 }