Flannel is a virtual network that gives a subnet to each host for use with container runtimes. Platforms like Google's Kubernetes assume that each container (pod) has a unique, routable IP inside the cluster. Issues go stale after 90d of inactivity. Mark the issue as fresh with /remove-lifecycle stale comment. Stale issues will be closed after an additional 30d of inactivity. Prevent issues from auto-closing with an /lifecycle frozen comment. If this issue is safe to close now please do so. When you deploy an IBM Cloud Private cluster on OpenStack, you may encounter issues such as the containers not being accessible, NodePort services not working, or a lack of communication between pods after restarting your master node.
- Pod To Clusterip Communication Not Working Issue 3099 Dockery
- Pod To Clusterip Communication Not Working Issue 3099 Dockers
Overview In this, we covered a theoretical introduction about Kubernetes. In this tutorial, we’ll discuss how to deploy a Spring Boot application on a local Kubernetes environment, also known as Minikube. As part of this article, we’ll:. Install Minikube on our local machine. Develop an example application consisting of two Spring Boot services.
Pod To Clusterip Communication Not Working Issue 3099 Dockery
Set up the application on a one-node cluster using Minikube. Deploy the application using config files 2.
Installing Minikube The installation of Minikube basically consists of three steps: installing a Hypervisor (like VirtualBox), the CLI kubectl, as well as Minikube itself. The provides detailed instructions for each of the steps, and for all popular operating systems. After completing the installation, we can start Minikube, set VirtualBox as Hypervisor, and configure kubectl to talk to the cluster called minikube: $ minikube start $ minikube config set vm-driver virtualbox $ kubectl config use-context minikube After that, we can verify that kubectl communicates correctly with our cluster: $ kubectl cluster-info The output should look like this: Kubernetes master is running at To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
At this stage, we’ll keep the IP in the response close ( 192.168.99.100 in our case). We’ll later refer to that as NodeIP, which is needed to call resources from outside of the cluster, e. From our browser. Finally, we can inspect the state of our cluster: $ minikube dashboard This command opens a site in our default browser, which provides an extensive overview about the state of our cluster.
Pod To Clusterip Communication Not Working Issue 3099 Dockers
Demo Application As our cluster is now running and ready for deployment, we need a demo application. For this purpose, we’ll create a simple “Hello world” application, consisting of two Spring Boot services, which we’ll call frontend and backend.
The backend provides one REST endpoint on port 8080, returning a String containing its hostname. The frontend is available on port 8081, it will simply call the backend endpoint and return its response. After that, we have to build a Docker image from each app. All files necessary for that are also available. For detailed instructions how to build Docker images, have a look at. We have to make sure here that we trigger the build process on the Docker host of the Minikube cluster, otherwise, Minikube won’t find the images later during deployment. Furthermore, the workspace on our host must be mounted into the Minikube VM: $ minikube ssh $ cd /c/workspace/tutorials/spring-cloud/spring-cloud-kubernetes/demo-backend $ docker build -file=Dockerfile -tag=demo-backend:latest -rm=true.
After that, we can logout from the Minikube VM, all further steps will be executed on our host using kubectl and minikube command-line tools. Simple Deployment Using Imperative Commands In a first step, we’ll create a Deployment for our demo-backend app, consisting of only one Pod. Based on that, we’ll discuss some commands so we can verify the Deployment, inspect logs, and clean it up at the end. Creating the Deployment We’ll use kubectl, passing all required commands as arguments: $ kubectl run demo-backend -image=demo-backend:latest -port=8080 -image-pull-policy Never As we can see, we create a Deployment called demo-backend, which is instantiated from an image also called demo-backend, with version latest.
With –port, we specify, that the Deployment opens port 8080 for its Pods (as our demo-backend app listens to port 8080). The flag –image-pull-policy Never ensures, that Minikube doesn’t try to pull the image from a registry, but takes it from the local Docker host instead.
Verifying the Deployment Now, we can check whether the deployment was successful: $ kubectl get deployments The output looks like this: NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE demo-backend 1 1 1 1 19s If we want to have a look at the application logs, we need the Pod ID first: $ kubectl get pods $ kubectl logs 5.3. Creating a Service for the Deployment To make the REST endpoint of our backend app available, we need to create a Service: $ kubectl expose deployment demo-backend -type=NodePort –type=NodePort makes the Service available from outside of the cluster. It will be available at:, i. The service maps any request incoming at to port 8080 of its assigned Pods.
We use the expose command, so NodePort will be set by the cluster automatically (this is a technical limitation), the default range is 7. To get a port of our choice, we can use a configuration file, as we’ll see in the next section.
We can verify that the service was created successfully: $ kubectl get services The output looks like this: NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE demo-backend NodePort 10.106.11.133 8080:30117/TCP 11m As we can see, we have one Service called demo-backend, of type NodePort, which is available at the cluster-internal IP 10.106.11.133. We have to take a closer look at column PORT(S): as port 8080 was defined in the Deployment, the Service forwards traffic to this port. However, if we want to call the demo-backend from our browser, we have to use port 30117, which is reachable from outside of the cluster. Calling the Service Now, we can call our backend service for the first time: $ minikube service demo-backend This command will start our default browser, opening.
In our example, that would be 5.5. Cleaning up Service and Deployment Afterward, we can remove Service and Deployment: $ kubectl delete service demo-backend $ kubectl delete deployment demo-backend 6. Complex Deployment Using Configuration Files For more complex setups, configuration files are a better choice, instead of passing all parameters via command line arguments. Configurations files are a great way of documenting our deployment, and they can be versioned controlled.
Service Definition for our Backend App Let’s redefine our service for the backend using a config file: kind: Service apiVersion: v1 metadata: name: demo-backend spec: selector: app: demo-backend ports: - protocol: TCP port: 8080 type: ClusterIP We create a Service named demo-backend, indicated by the metadata: name field. It targets TCP port 8080 on any Pod with the app=demo-backend label. Finally, type: ClusterIP indicates that it is only available from inside of the cluster (as we want to call the endpoint from our demo-frontend app this time, but not directly from a browser anymore, as in the previous example). Deployment Definition for Backend App Next, we can define the actual Deployment: apiVersion: apps/v1 kind: Deployment metadata: name: demo-backend spec: selector: matchLabels: app: demo-backend replicas: 3 template: metadata: labels: app: demo-backend spec: containers: - name: demo-backend image: demo-backend:latest imagePullPolicy: Never ports: - containerPort: 8080 We create a Deployment named demo-backend, indicated by the metadata: name field. The spec: selector field defines how the Deployment finds which Pods to manage. In this case, we merely select on one label defined in the Pod template ( app: demo-backend). We want to have three replicated Pods, which we indicate by the replicas field.
The template field defines the actual Pod:. The Pods are labeled as app: demo-backend. The template: spec field indicates that each Pod replication runs one container, demo-backend, with version latest. The Pods open port 8080 6.3. Trouble with the minikube start on high sierra. I’ve tried twice now, removing the.minikub dir in between.
It creates the virtual, and it is running in virtualbox, and showing VBoxHeadless taking up around 13% cpu in OS X. I can minikube ssh and run top but it is taking up.