NodePort exposes the service on each node's IP at a specific port. The Service provides load balancing for an application that has two running instances. For instructions, see the documentation for your cloud provider. I’d like to assign External IP addresses to my pods to allow SSH into the Pod. As there's no external IP for invoices_svc we'll need to get into a 1 min* to run a service in. Using External Service as Ingress Backend. Now, I'm running a GKE (3, actually) cluster with Kubernetes 1. By default, Services are only reachable from within the cluster. Traffic that ingresses into the cluster with the external IP (as destination IP), on the Service port, will be routed to one of the Service endpoints. Also, note that there is no external IP allocated for this Service. The user is responsible for ensuring that traffic arrives at a node with this IP. The set of pods forming the service is a dynamic set, so Kubernetes provides the Endpoints abstraction for the service, which gives the list of the pod's IP:PORT that match the service's label selector at the time of inquiry. 1 443/TCP 3d. This tutorial creates an external load balancer, which requires a cloud provider. Azure Kubernetes Service makes working with Kubernetes easier. Quite an idea, while I see I have no control over IP acquisition. This can be simpler than having to manage the port space of a limited number of shared IP addresses when manually assigning external IPs to services. External and local IP addresses both serve the same purpose, the difference is scope. externalTrafficPolicy - denotes if this Service desires to route external traffic to node-local or cluster-wide endpoints. Kubernetes ExternalName services and Kubernetes services with Endpoints let you create a local DNS alias to an external service. Service will be assigned an IP address (“cluster IP”), which is used by the service proxies. As per the Services page of the official Kubernetes documentation, the externalIPs option causes kube-proxy to route traffic sent to arbitrary IP addresses and on the Service ports to the endpoints of that Service. Assign External IP to a Kubernetes Service. A problem stands. Minikube runs a single-node Kubernetes cluster inside a VM (e. Azure Kubernetes Service. Using External Service as Ingress Backend. 0 without loss of any functionality. Use a Service to Access an Application in a Cluster. Kubernetes - Create Deployment YAML file Create a normal file with yaml extension and add some properties as below. To enable external access to the containers running within a pod, you will expose the pod as a service. You can run your applications as containers. Pods can go down and up again which can lead to different pod IP's while Services are immortal and a Service IP will never change. No need to wait for the external IP of the created service, since Minikube does not really deploy a load balancer and this feature will only work if you configure a Load Balancer provider. “If I have an application and I expose it to the external world through a load balancer, I have an IP externally and if my Kubernetes cluster is IPv4 or IPv6, that address will be IPv4 or IPv6 only. 219 8080:32640/TCP 5m In the sample output above, the node port for the web Service is 32640. Use alternative range of IP address for service VIPs. This page shows how to create a Kubernetes Service object that exposes an external IP address. For more details on service, please refer to. 03/04/2019; 4 minutes to read +7; In this article. Introduction This blog will show you how to deploy Apache Kafka cluster on Kubernetes. Kubernetes provides two options for service discovery, environments variables and DNS. What you've learned: Telepresence lets you replace an existing deployment with a proxy that reroutes traffic to a local process on your machine. If you have created loadbalancer services in your Kubernetes cluster, then the frontend public ip created by the service has been added to the Azure load balancer. Minikube runs a single-node Kubernetes cluster inside a VM (e. This page shows how to create a Kubernetes Service object that external clients can use to access an application running in a cluster. In the near future, we will add the following features of Kube-DNS:. Objectives; Before you begin. This will expose your deployment through a service and set up a Load Balancer on Google Cloud Platform. If your cluster is running in an environment that does not support an external load balancer (e. Lets walk through an example. By setting an external IP on the service, OpenShift Container Platform sets up IP table rules to allow traffic arriving at any cluster node that is targeting that IP address to be sent to one of the internal pods. For non-native applications, there is a virtual-IP-based bridge to Services which redirects to the backend Pods. This will print out a list of running services and their ports on the internet Kubernetes network similar to the following. ), the configuration file defines everything related to scraping jobs and their instances, as well as which rule files to load. Add another Service to create more DNS records. Already, I have created a basic deployment file with below objects to create a pod with single apache webserver container using httpd image. A simple kubectl get svc command shows that the service is of type Load Balancer. Change seviceName from myService to demo-app. externalTrafficPolicy - denotes if this Service desires to route external traffic to node-local or cluster-wide endpoints. 1 443/TCP 57m mysql 10. Deploying a Kubernetes service on Azure with a specific IP addresses. Configuring Envoy to allow access to any external service. We have learned about deploying an Azure Kubernetes Service (AKS) cluster using the Azure CLI (Command Line Interface). You must manually manage and maintain user-defined routes (UDRs). Check out your new service. If you have a cloud-hosted Kubernetes cluster, it should be able to automatically provision LoadBalancer type services with a public IP. This allows you to easily debug issues by running your code locally, while still giving your local process full access to your staging or testing cluster. The user is responsible for ensuring that traffic arrives at a node with this IP. For instructions, see the documentation for your cloud provider. and to assign external IP to frontend service run this command. Ens160 has Kubernetes API IP 172. See the deployment repository for details on how to deploy CoreDNS in Kubernetes. Project Calico is an open source container networking provider and network policy engine. But this is the IP generated by Kubernetes for inter-service communication within the cluster. 1 443/TCP 23h nginx LoadBalancer 10. Configuring Envoy to allow access to any external service. We are now ready to test access to the application. The response to a successful request is a hello message: Hello Kubernetes! Using a service configuration file. Reachability to Kubernetes Pods Using the IP Fabric Forwarding Feature, Service Isolation Through Virtual Networks, Contrail ip-fabric-snat Feature, Third-Party Ingress Controllers, Custom Network Support for Ingress Resources, Kubernetes Probes and Kubernetes Service Node-Port, Kubernetes 1. I’ve set up some Deep Learning containers which I’ve pushed to K8 and is managed really well. Build a simple Kubernetes cluster that runs "Hello World" for Node. I’d created a service with a type of LoadBalancer in order to get an external IP to connect to. Project Calico. This causes a couple of potential problems:. Send a cURL request to the IP of the NGINX service (replacing NGINX_SVC with the CLUSTER-IP from the previous step):. Already, I have created a basic deployment file with below objects to create a pod with single apache webserver container using httpd image. In particular, you can see the Cluster IP value that Kubernetes assigned to your Service. These external IP addresses are not managed by Kubernetes; they are the responsibility of the cluster administrator. And a lot of K8s examples use LoadBalancer to teach how you can expose a service to the external world with k8s. Service Discovery in Rancher 2. Azure Kubernetes Service management can be done from a development VM as well as using Azure Cloud Shell. As there's no external IP for invoices_svc we'll need to get into a 1 min* to run a service in. This document explains what happens to the source IP of packets sent to different types of Services, and how you can toggle this behavior according to your needs. The type of service depends on how the specific Kubernetes cluster is configured. A problem stands. The Ingress object in Kubernetes, although still in beta, is designed to signal the Kubernetes platform that a certain service needs to be accessible to the outside […]. If everything is looking good it's time to test it out end to end. Create a simple Prometheus object with one replica:. Each pod is given an IP address and a single DNS name, which Kubernetes uses to connect your services with each other and external traffic. Also, note that there is no external IP allocated for this Service. I used Kubernetes service on Google Cloud Platform and it was a great service. Edit This Page. However I need to supply SSH connectivity to the Pod via an external up address, so that each pod is seen as its own “VM instance” so to speak. Use the Service object to access the running application. Reserve a static external IP address for your application; Configure either Service or Ingress resources to use the static IP; Update DNS records of your domain name to point to your application; Before you begin Take the following steps to enable the Kubernetes Engine API: Visit the Kubernetes Engine page in the Google Cloud Platform Console. This external load balancer is associated with a specific IP address and routes external traffic to a Kubernetes service in your cluster. An external or public IP address is used across the entire Internet to locate computer systems and devices. Setting service. Kubernetes service types. When you view the service details, the IP address of the internal load balancer is shown in the EXTERNAL-IP column. As an alternative to using kubectl expose, you can use a service configuration file to create a Service. ExternalName, Exposes the Service using an arbitrary name (specified by externalName in the spec) by returning a CNAME record with the name. There are 2 options depending on whether the external service has an external IP or DNS record. A public IP address is assigned to the Load Balancer through which is the service is exposed. But the vm is available under myservices resource group. You can use the BIG-IP Controller for Kubernetes as an Ingress Controller in Kubernetes. yaml Since your external IP would have already been assigned to the nginx-ingress service, the DNS records pointing to the IP of the nginx-ingress service should be created within a minute. kubectl will push our updated definition back to the Kubernetes API, and voilà! Service web is now sending traffic to the corresponding deployment. I am running docker for windows Edge channel to experiment with kubernetes in docker. What gets assigned as the cluster DNS server inside pods, (the nameserver) is actually the Service IP of the kube-dns service. An ingress controller is a piece of software that provides reverse proxy, configurable traffic routing, and TLS termination for Kubernetes services. In this configuration, we create the Ambassador service and identify type: NodePort instead of LoadBalancer. In a Kubernetes environment, the Kubernetes Ingress Resource is used to specify services that should be exposed outside the cluster. Traffic that ingresses into the cluster with the external IP (as destination IP), on the service port, will be routed to one of the service endpoints. Lately I was playing around with the Ambassador Kubernetes-native microservices API gateway as an ingress controller on Azure Kubernetes Service. Ingress resources use an Ingress controller (the nginx one is common but not by any means the only choice) and an external load balancer or public IP to enable path-based routing of external requests to internal Services. Hi, I have successfully created Kubernetes cluster, installed nginx and also deployed front end and backend containerized applications. Before you begin. However, these IP addresses are not accessible from an external network. answered Oct 8, 2018 in Kubernetes by Nilesh • 6,880 points • 233 views. Using External Service as Ingress Backend. By default, the Loadbalancer Kubernetes service (in Azure) is set up as an external facing Loadbalancer with a Public IP that makes it publicly accessible, making it vulnerable to attacks or other exploits. root@rpi-4:~# kubectl get svc NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes 10. 1 443/TCP 23h nginx LoadBalancer 10. If we then went on to describe the service, we could see that the values carried through:. Kubernetes - Service - A service can be defined as a logical set of pods. LoadBalancer, Creates an external load balancer in the current cloud (if supported) and assigns a fixed, external IP to the Service. To expose the APIs over an internal IP we will use ingress objects, which require an Ingress Controller. Following is an alternative workaround to access Dashboard externally. Minikube for K8s is a popular method to get your hands dirty learning K8s. kubernetes-dashboard is a service file which provides dash-board functionality, to edit this we need to edit dashboard service and change service “type” from ClusterIP to NodePort:. To recap, the service brokerage extension in Kubernetes enables the consumption of services external to Kubernetes in a native way. This can be done by specifying the attribute type: “LoadBalancer” in the service manifest. $ kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 10. In managed Kubernetes Azure provides addresses from the public address space. Unfortunately, in our special use case the desired communication channel is with a client outside the kubernetes cluster (K8s), and this cannot be solved with headless-service since the created identity only exists inside K8s. When you view the service details, the IP address of the internal load balancer is shown in the EXTERNAL-IP column. Lets walk through an example. Create a Service object that exposes an external IP address. Before you begin. xxx 80:31552/TCP 39m. An external or public IP address is used across the entire Internet to locate computer systems and devices. In this episode of Kubernetes Best Practices, Sandeep Dinesh shows how to connect to services running outside your Kubernetes cluster to enable hybrid deployments in a Kubernetes native way. If you are looking for the solution to expose Kubernetes service externally (outside the cluster) then Kubernetes Ingress resource would be the best choice to achieve this goal. Add another Service to create more DNS records. Kubernetes announced two patches to address recently discovered security vulnerabilities for both Kubernetes and the Kubernetes dashboard. kubectl get services -n kube-system NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kube-dns ClusterIP 10. In this post I will use Flannel as an example. Routing to internal Kubernetes services using proxies and Ingress controllers CLUSTER-IP EXTERNAL-IP echoheaders service. 1 443/TCP 2d Note, no external port. --advertise-external-ip Add External IP of service to the RIB so that it gets advertised to the BGP peers. However I need to supply SSH connectivity to the Pod via an external up address, so that each pod is seen as its own “VM instance” so to speak. I’d created a service with a type of LoadBalancer in order to get an external IP to connect to. 1 443/TCP 51m [root@kube-master ~]# kubectl delete service kubernetes Service kubernetes will be automatically recreated. You must manually manage and maintain user-defined routes (UDRs). 4 in Minikube has issue with pod trying to access itself via Service IP. {% endcapture %} {% capture prerequisites %} Install kubectl. Ens160 has Kubernetes API IP 172. ExternalIPs is when your nodes have external IP addresses, and you want to use those to reach your service. A public IP address is assigned to the Load Balancer through which is the service is exposed. {% endcapture %} {% capture prerequisites %} Install kubectl. In particular, you can see the Cluster IP value that Kubernetes assigned to your Service. By default, the public IP address assigned to a load balancer resource created by an AKS cluster is only valid for the lifespan of that resource. (You can verify for yourself by retrieving the IP address of that service with kubectl get svc web and connecting to that IP address with curl. In this episode of Kubernetes Best Practices, Sandeep Dinesh shows how to connect to services running outside your Kubernetes cluster to enable hybrid deployments in a Kubernetes native way. xxx 80:31552/TCP 39m. where is the external IP address (LoadBalancer Ingress) of your Service, and is the value of Port in your Service description. This page shows how to create a Kubernetes Service object that exposes an external IP address. A problem stands. Recently I used Azure Kubernetes Service (AKS) for a different project and run into some issues. A Service exposed as a NodePort can be accessed via 443/TCP 32d nginx ClusterIP 10. Kubernetes 1. NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE web NodePort 10. NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE default service/kubernetes ClusterIP 10. It actually creates an Azure load balancer, but the service external ip isn't exposed. 1 443/TCP 3d. You can create a "ExternalName" Kubernetes service, which gives you a static Kubernetes service that redirects traffic to the external service. For more details on service, please refer to. To workaround this problem, I drained and brought down the other worker node, so that all pods run in the worker node who's IP address has been assigned to the load-balancer service. Kubernetes networking provides several rich constructs to manage traffic across workloads using Network Policies, and to manage inbound traffic using Services and Ingresses. What gets assigned as the cluster DNS server inside pods, (the nameserver) is actually the Service IP of the kube-dns service. There are 2 options depending on whether the external service has an external IP or DNS record. Now, I'm running a GKE (3, actually) cluster with Kubernetes 1. If routed correctly, external traffic can reach that service's endpoints via any TCP/UDP port the service exposes. $ kubectl -n kube-system get service kubernetes-dashboard NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes-dashboard 10. This page shows how to create a Kubernetes Service object that external clients can use to access an application running in a cluster. Virtualbox ) in your local development environment. Introduction This blog will show you how to deploy Apache Kafka cluster on Kubernetes. Use a service entry to register an accessible external service inside the mesh. If this IP is routed to a node, the service can be accessed by this IP in addition to its generated service IP. The YAML for the service looks like this:. Bare-metal considerations¶. Now we come to the interesting bit – the service. Inside the cluster, it will resolve to the same thing, and so using this name internally. That is, when looked up outside the cluster, foo. This is the IP address that internal clients can use to call the Service. In this tutorial, you will learn how to setup Kubernetes ingress using Nginx ingress controller and to route traffic to deployments using wildcard DNS. The egress router acts as a bridge between pods and an external system. A Kubernetes Service is an abstraction which groups a logical set of Pods that provide the same functionality. Create a Service object that exposes an external IP address. Add another Service to create more DNS records. Kubernetes will then create a service and assign that service a port to be exposed externally and direct traffic to Ambassador via the defined port. Well All the time passes still kubernetes service external ip pending? If Kubernetes is running in an environment that doesn't support LoadBalancer services, the load balancer will not be provisioned, but the service will still behave like a NodePort service, your cloud/K8 engine should support LoadBalancer Service. Stress your service to see Kubernetes autoscaling in action. Deploying Azure Kubernetes Service (AKS) is, like most other Kubernetes-as-a-service offerings such as those from DigitalOcean and Google, very straightforward. Browse to the external IP to test WordPress: I can see the power of the combination of Kubernetes and Helm together as it makes brand new users like me with Kubernetes able to quickly get popular applications running in Kubernetes without much effort. For more details of the announcements, see the Security Impact of Kubernetes API server external IP address proxying and Security release of dashboard v1. Bear in mind that it might take some time for the service-a external IP to be created (that’s why you’ll see a result for the external IP), since Azure backend has to create a new external Load Balancer service and configure the necessary firewall rules. Recently I had to look at horizontally scaling a traditional web-app on kubernetes. Expose the service on a cluster-internal IP, so if you choose this kind of service it will be only reachable within the Kubernetes cluster so Azure API Management won't be able to access. Use a cloud provider like Google Container Engine or Amazon Web Services to create a Kubernetes cluster. Use the Service object to access the running application. Using External Service as Ingress Backend. By setting an external IP on the service, OpenShift Container Platform sets up IP table rules to allow traffic arriving at any cluster node that is targeting that IP address to be sent to one of the internal pods. How does this apply to Kubernetes? Kubernetes provides multiple ways to expose service: NodePort, ClusterIP and external IP etc. This was an interesting component for me because it permits. Lets walk through an example. It actually creates an Azure load balancer, but the service external ip isn't exposed. The ClusterIP enables the applications running within the pods to access the service. If we kill the POD, the IP address will change. Then Azure Load Balancer will associate the nodes in the load balancer pool with the first frontend ip configured on the load balancer. It can be defined as an abstraction on the top of the pod which provides a single IP address and DNS name by. Load Testing With Jmeter On Kubernetes and OpenShift TYPE CLUSTER-IP EXTERNAL-IP PORT grafana service and expose it to the ip address of your minikube VM:. externalIPs are not managed by Kubernetes and are the responsibility of the cluster administrator. See the deployment repository for details on how to deploy CoreDNS in Kubernetes. 211 3306/TCP 17m nodechat 10. Note that it is specific to the cluster implementation if this is a "true" external IP, or just external to the cluster (which could still be from a private address space). For more information about finding and exposing an external IP for Kubernetes see the section below on How to Define Ingress and for more in depth information refer to the topic, Publishing Servicesin the Kubernetes documentation. To enable preservation of the client IP, the following fields can be configured in the service spec (supported in GCE/Google Kubernetes Engine environments): service. Now, I'm running a GKE (3, actually) cluster with Kubernetes 1. This service does a simple CNAME redirection at the kernel level, so there is very minimal impact on your performance. The external IP, in this case, is the IP address of the node. Moreover, if you're deploying Kubernetes on bare metal, you. A basic MicroK8s add-on to set up is the Grafana dashboard. Loss of client source IP for external traffic. x 443/TCP 42m mynginx 10. Accessing an application on Kubernetes in Docker and access the Aqua Security web service I've got running on my Kubernetes the service, but the External IP address will stay in Pending. NodePort, as the name implies, opens a specific port on all the. In our example, we deploy a PostgeSQL database server, RapidMiner Server, and some Job Agents on Kubernetes. The Kubernetes Service resource acts as the entry point to a set of pods that provide the same functional service. Deploying the guestbook app. The ClusterIP enables the applications running within the pods to access the service. A simplified view of the Cisco ACI policy model required for the north-south load balancer is shown in the following illustration. Bare-metal considerations¶. One of major annoying issues was that I could not get external IP…. As you can see, there’s no WildFly Kubernetes Service defined, that’s why we need many steps to get the IP address of the POD running WildFly. How does this apply to Kubernetes? Kubernetes provides multiple ways to expose service: NodePort, ClusterIP and external IP etc. K8S just became my favorite platform to play around with other platforms. Service discovery is the process of figuring out how to connect to a service. This tutorial creates an external load balancer, which requires a cloud provider. 48 80/TCP,443/TCP 13m. This external load balancer is associated with a specific IP address and routes external traffic to a Kubernetes service in your cluster. answered Oct 8, 2018 in Kubernetes by Nilesh • 6,880 points • 233 views. Now that the load balancer is ready let's hit it with curl and see what happens. xxx 80:31552/TCP 39m. Recently the Azure Kubernetes Service launched their preview of Windows node pools which allow us to create mixed OS Kubernetes clusters (I’ll refer to these as hybrid clusters). Kubernetes is a container orchestration tool which automates deploying, scaling and operating containers. Kubernetes - Create Deployment YAML file Create a normal file with yaml extension and add some properties as below. Edit This Page. Over the past years, Kubernetes has grown. In this tutorial, I'll walk through how you can expose a Service of type LoadBalancer in Kubernetes, and then get a public, routeable IP for any service on your local or dev cluster through the new inlets-operator. These IPs are not managed by Kubernetes. Use the Service object to access the running application. More on Helm here. The YAML for the service looks like this:. In this context, External is in relation to the external interface of the load balancer, not that it receives a public. It will show its External IP when ready. However, this service needs to whitelist my servers IP, refusing all other connections for security. It actually creates an Azure load balancer, but the service external ip isn't exposed. externalIPs are not managed by Kubernetes and are the responsibility of the cluster administrator. This because of how Minikube is built. K8S just became my favorite platform to play around with other platforms. Install kubectl. If this IP is routed to a node, the service can be accessed by this IP in addition to its generated service IP. kubectl get svc NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes 10. Ingress, specifically used to offer functionality for HTTP and HTTPS routing from outside the cluster to the nested Kubernetes services. It sets up DNS records at DNS providers external to Kubernetes such that Kubernetes services are discoverable via the external DNS providers, and allows the controlling of DNS records to be done dynamically, in a DNS provider agnostic way. To workaround this problem, I drained and brought down the other worker node, so that all pods run in the worker node who's IP address has been assigned to the load-balancer service. Build a simple Kubernetes cluster that runs "Hello World" for Node. OK, run the following to create the service: – kubectl create -f service. This means that if the service gets recreated it retains the same IP. Kubernetes announced two patches to address recently discovered security vulnerabilities for both Kubernetes and the Kubernetes dashboard. 1 443/TCP 23h nginx LoadBalancer 10. (You can verify for yourself by retrieving the IP address of that service with kubectl get svc web and connecting to that IP address with curl. The list details the name of the exposed service, its type, IP, port, external IP (if any) and how long it has been operational (age). Lets walk through an example. However, there is a command to expose a port to your host machine from Minikube: minikube service <service name>. More on Helm here. This will print out a list of running services and their ports on the internet Kubernetes network similar to the following. Maximum of 400 nodes per cluster. Create a Service object that exposes an external IP address. 1 443/TCP 39m As we can see from the output, we do not have any services running other than Kubernetes with CLUSTER-IP. Wait a few minutes for the external IP to show up. The Kubernetes Service resource acts as the entry point to a set of pods that provide the same functional service. Kubernetes will then create a service and assign that service a port to be exposed externally and direct traffic to Ambassador via the defined port. LoadBalancer exposes the service externally using a cloud provider's load balancer. Kubernetes Basic PHP Application with Nginx on Google Cloud. Add the IP on a. Project Calico. By default, the public IP address assigned to a load balancer resource created by an AKS cluster is only valid for the lifespan of that resource. Each pod is given an IP address and a single DNS name, which Kubernetes uses to connect your services with each other and external traffic. Unfortunately, in our special use case the desired communication channel is with a client outside the kubernetes cluster (K8s), and this cannot be solved with headless-service since the created identity only exists inside K8s. This is expected because Kubernetes, by default does not offer an implementation of network load-balancer for bare metal cluster. Minikube runs a single-node Kubernetes cluster inside a VM (e. Note that the ClusterIP does not have an external IP while the app Service external IP is pending. External clients call the Service by using the external IP address of a node along with the TCP port specified by nodePort. So we stick to Kubernetes 1. That is, when looked up outside the cluster, foo. The easiest way to expose Prometheus or Alertmanager is to use a Service of type NodePort. To expose the APIs over an internal IP we will use ingress objects, which require an Ingress Controller. Now that the load balancer is ready let's hit it with curl and see what happens. The Ingress controller will use information provided by the system to communicate with the API server. This is a user introduction to Service Accounts. By deploying the cluster into a Virtual Network (VNet), we can deploy internal applications without exposing them to the world wide web. A local or internal IP address is used inside a private network to locate the computers and devices connected to it. Each component has its own Kubernetes service for routing traffic to replicated pods. Kubernetes ingress resources are used to configure the ingress rules and routes for individual Kubernetes services. While there is a service discovery option based on environment variables available, the DNS-based service discovery is preferable. Although pods and services have their own IP addresses on Kubernetes, these IP addresses are only reachable within the Kubernetes cluster and not accessible to the outside clients. Service Discovery with Java and Database application in DC/OS explains why service discovery is an important aspect for a multi-container application. Useful commands. Use a cloud provider like Google Kubernetes Engine or Amazon Web Services to create a Kubernetes cluster. Alternatively, the address can be used as a virtual IP (VIP). This is the recommended approach.