Scan deployments for agent injection

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

pkg/controller/jaeger/jaeger_controller.go

@@ -239,6 +239,30 @@ func (r *ReconcileJaeger) apply(jaeger v1.Jaeger, str strategy.S) error {
 		}
 	}
 
+	if err := r.scanDeployments(jaeger); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (r *ReconcileJaeger) scanDeployments(jaeger v1.Jaeger) error {
+	pods := &v1.JaegerList{}
+	deps := &appsv1.DeploymentList{}
+
+	opts := &client.ListOptions{}
+	if err := r.client.List(context.Background(), opts, pods); err != nil {
+		return err
+	}
+	if err := r.client.List(context.Background(), opts, deps); err != nil {
+		return err
+	}
+	injectedDeps := inject.RequireInjections(&jaeger, pods, deps)
+	for _, d := range injectedDeps {
+		if err := r.client.Update(context.Background(), d); err != nil {
+			return err
+		}
+	}
 	return nil
 }
 

pkg/inject/sidecar.go

@@ -199,4 +199,34 @@ func CleanSidecars(deployments []appsv1.Deployment) {
 			}
 		}
 	}
+
+// RequireInjections deployments
+func RequireInjections(jaeger *v1.Jaeger, pods *v1.JaegerList, deps *appsv1.DeploymentList) []*appsv1.Deployment {
+	requireUpdates := make([]*appsv1.Deployment, 0)
+	for i := 0; i < len(deps.Items); i++ {
+		dep := &deps.Items[i]
+		if Needed(dep) {
+			if belongsToJaegerInstance(dep, jaeger, len(pods.Items) == 1) {
+				// a suitable jaeger instance was found! let's inject a sidecar pointing to it then
+				log.WithFields(log.Fields{
+					"deployment":       dep.Name,
+					"namespace":        dep.Namespace,
+					"jaeger":           jaeger.Name,
+					"jaeger-namespace": jaeger.Namespace,
+				}).Info("Injecting Jaeger Agent sidecar")
+				dep.Annotations[Annotation] = jaeger.Name
+				newDep := Sidecar(jaeger, dep)
+				requireUpdates = append(requireUpdates, newDep)
+			} else {
+				log.WithField("deployment", dep.Name).Info("No suitable Jaeger instances found to inject a sidecar")
+			}
+		}
+	}
+	return requireUpdates
+}
+
+func belongsToJaegerInstance(dep *appsv1.Deployment, instance *v1.Jaeger, uniqueInstance bool) bool {
+	annotation := dep.Annotations[Annotation]
+	return strings.EqualFold(annotation, "true") &&
+		uniqueInstance || annotation == instance.Name
 }