Scan deployments for agent injection

Signed-off-by: Ruben Vargas <ruben.vp8510@gmail.com>

pkg/autodetect/main.go

@@ -7,13 +7,15 @@ import (
 
 	log "github.com/sirupsen/logrus"
 	"github.com/spf13/viper"
+	appsv1 "k8s.io/api/apps/v1"
 	authenticationapi "k8s.io/api/authentication/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/discovery"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/manager"
 
-	v1 "github.com/jaegertracing/jaeger-operator/pkg/apis/jaegertracing/v1"
+	"github.com/jaegertracing/jaeger-operator/pkg/apis/jaegertracing/v1"
+	"github.com/jaegertracing/jaeger-operator/pkg/inject"
 )
 
 // Background represents a procedure that runs in the background, periodically auto-detecting features
@@ -66,6 +68,57 @@ func (b *Background) Stop() {
 	b.ticker.Stop()
 }
 
+func (b *Background) RequireInjections(deps *appsv1.DeploymentList) []*appsv1.Deployment {
+	instances := &v1.JaegerList{}
+	opts := &client.ListOptions{}
+	if err := b.cl.List(context.Background(), opts, instances); err != nil {
+		return nil
+	}
+	requireUpdates := make([]*appsv1.Deployment, 0)
+	for i := 0; i < len(deps.Items); i++ {
+		dep := &deps.Items[i]
+		if inject.Needed(dep) { // If sidecar is not present and should be
+			jaeger := inject.Select(dep, instances)
+			if jaeger != nil { // Instance exists.
+				jaeger.Logger().WithFields(log.Fields{
+					"deploymentName":      dep.Name,
+					"deploymentNamespace": dep.Namespace,
+				}).Info("Injecting Jaeger Agent sidecar")
+				dep.Annotations[inject.Annotation] = jaeger.Name
+				newDep := inject.Sidecar(jaeger, dep)
+				requireUpdates = append(requireUpdates, newDep)
+			}
+		} else {
+			// Try to update the sidecar if is required
+			jaeger := inject.Select(dep, instances)
+			updated := inject.UpdateSideCar(jaeger, dep)
+			if updated {
+				if err := b.cl.Update(context.Background(), dep); err != nil {
+					return nil
+				}
+			}
+		}
+	}
+	return requireUpdates
+}
+
+func (b *Background) detectDeploymentUpdates() error {
+	opts := &client.ListOptions{}
+	deps := &appsv1.DeploymentList{}
+
+	if err := b.cl.List(context.Background(), opts, deps); err != nil {
+		return err
+	}
+	injectedDeps := b.RequireInjections(deps)
+	for _, d := range injectedDeps {
+		if err := b.cl.Update(context.Background(), d); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 func (b *Background) autoDetectCapabilities() {
 	apiList, err := b.availableAPIs()
 	if err != nil {
@@ -79,6 +132,7 @@ func (b *Background) autoDetectCapabilities() {
 	}
 
 	b.detectClusterRoles()
+	b.detectDeploymentUpdates()
 }
 
 func (b *Background) availableAPIs() (*metav1.APIGroupList, error) {

pkg/inject/sidecar.go

@@ -53,6 +53,16 @@ func Sidecar(jaeger *v1.Jaeger, dep *appsv1.Deployment) *appsv1.Deployment {
 	return dep
 }
 
+func UpdateSideCar(jaeger *v1.Jaeger, dep *appsv1.Deployment) bool {
+	for i := range dep.Spec.Template.Spec.Containers {
+		if dep.Spec.Template.Spec.Containers[i].Name == "jaeger-agent" {
+			dep.Spec.Template.Spec.Containers[i] = container(jaeger)
+			return true
+		}
+	}
+	return false
+}
+
 // Needed determines whether a pod needs to get a sidecar injected or not
 func Needed(dep *appsv1.Deployment) bool {
 	if dep.Annotations[Annotation] == "" {
@@ -196,7 +206,6 @@ func hasEnv(name string, vars []corev1.EnvVar) bool {
 func CleanSidecars(deployments []appsv1.Deployment) {
 	for i := 0; i < len(deployments); i++ {
 		dep := &deployments[i]
-		delete(dep.Annotations, Annotation)
 		delete(dep.Labels, Annotation)
 		for c := 0; c < len(dep.Spec.Template.Spec.Containers); c++ {
 			if dep.Spec.Template.Spec.Containers[c].Name == "jaeger-agent" {