{"id":90611,"date":"2019-04-15T08:44:32","date_gmt":"2019-04-15T05:44:32","guid":{"rendered":"http:\/\/www.javacodegeeks.com\/?p=90611"},"modified":"2019-04-24T11:59:25","modified_gmt":"2019-04-24T08:59:25","slug":"build-microservice-architecture-spring-boot-kubernetes","status":"publish","type":"post","link":"https:\/\/www.javacodegeeks.com\/2019\/04\/build-microservice-architecture-spring-boot-kubernetes.html","title":{"rendered":"Build a Microservice Architecture with Spring Boot and Kubernetes"},"content":{"rendered":"

\u201cI love writing authentication and authorization code.\u201d ~ No Java Developer Ever.<\/b> Tired of building the same login screens over and over? Try the Okta API for hosted authentication, authorization, and multi-factor auth.<\/a><\/span><\/p>\n

In this tutorial, you\u2019re going to use Kubernetes to deploy a Spring Boot microservice architecture to Google Cloud, specifically the Google Kubernetes Engine (GKE). You\u2019re also going to use Istio to create a service mesh layer and to create a public gateway. The whole thing is going to be secured using Okta OAuth JWT authentication.<\/p>\n

That was a mess of jargon. We\u2019re not going to explain microservices in-depth here. In short, microservices are a design pattern that splits larger monolithic services into smaller, independent \u201cmicro\u201d services. These services are loosely coupled over a network. The benefits of this architecture are that each service becomes testable, maintainable, and independently deployable. At internet scale, and in enormous companies like Amazon and Netflix, this architecture is great because it allows companies to assign small teams responsibility for manageable, discrete units of function; as opposed to having enormous monolithic blocks of code overseen by thousands of people. The downside is the high initial cost of complexity and infrastructure, which may not make sense for smaller projects that aren\u2019t going to scale.<\/p>\n

Kubernetes<\/strong> is a platform for deploying containerized services. You can think of it as a container orchestrator for Docker containers (this is a simplification, but it\u2019ll work). It will allow us to write YAML scripts that automate the deployment of our microservice architecture to our chosen platform, GKE. It\u2019s a huge project with lots to dig into. Take a look at their docs<\/a> for more info.<\/p>\n

Istio<\/strong> adds another layer of features on top of Kubernetes, adding some great monitoring, security, access control, and load balancing features. Check out their website<\/a> for more info.<\/p>\n

The last piece of the microservice architecture is Google Cloud and GKE<\/strong>. This is the platform you\u2019ll be using to deploy the microservice. Another option not covered in this tutorial is Minikube. Minikube runs locally on your computer and might work great for some people; I found Google Kubernetes Engine easier to use and more performant.<\/p>\n

We\u2019re going to assume you\u2019re familiar with Spring Boot and Java. If not, take a look at the end of the tutorial for some links to get you started.<\/p>\n

Requirements for Spring Boot and Kubernetes<\/h2>\n

HTTPie<\/strong>: Install HTTPie from their website<\/a> so that we can run HTTP requests easily from the terminal.<\/p>\n

Docker<\/strong>: Please download and install Docker Desktop from their website<\/a> if you don\u2019t have it already installed.<\/p>\n

kubectl<\/strong>: This is Kubernetes\u2019 command line interface. Instructions for installing it are on their website<\/a>.<\/p>\n

Google Cloud<\/strong>: You\u2019ll need a Google Cloud account with billing enabled. A free trial is available and should include more than enough credit and time to get you through this tutorial. Go to the Google Cloud website<\/a> and sign up.<\/p>\n

developer.okta.com<\/strong>: We offer free developer accounts on our developer site<\/a>. Please sign up for one now. You\u2019ll use it toward the end of the tutorial.<\/p>\n

gcloud<\/strong>: This is the Google Cloud CLI. Install it using the instructions from their website.<\/a>. Once that is done, you\u2019ll need to install the gcloud kubectl<\/code> components by running the following command:<\/p>\n

gcloud components install kubectl<\/pre>\n
Did I mention microservices have a high initial complexity cost?<\/p>\n
Create a Google Kubernetes Engine Project with Istio<\/h2>\n
You should now have a Google Cloud account with billing enabled. Again, you shouldn\u2019t need to actually spend any money, but without billing, you won\u2019t be able to access the free trial.<\/p>\n
Create a new project. Name it spring-boot-gke<\/code> (or whatever you want, but you\u2019ll need the project ID for the various commands). Wait for the project to be created.<\/p>\n
The project name will likely end up with an ID number tacked onto the end, like spring-boot-gke-232934<\/code>. You\u2019ll need this project name a few times, so go ahead and store it in a shell variable and take note of it.<\/p>\n
PROJECT_NAME=<your project name and ID>\n<\/pre>\n
Once the project is ready, open the project dashboard, open the navigation menu, and click on Kubernetes Engine<\/strong>. Click the Enable Billing<\/strong> button (if you haven\u2019t already enabled billing) and select a billing account.<\/p>\n
Click Create Cluster<\/strong>.<\/p>\n
\n
\"Microservice<\/figure>\n<\/div>\n
From the left-side panel, select Your First Cluster<\/strong>.<\/p>\n
Name the cluster \u201cspring-boot-cluster\u201d.<\/p>\n
Select the zone \u201cus-west1-a\u201d.<\/p>\n
Click on the Advanced Options<\/strong> link at the bottom of the cluster config panel to show the advanced options. Scroll down to the bottom and check the box for Enable Istio (beta)<\/strong>. This will automatically install Istio on the cluster.<\/p>\n
\n
\"Microservice<\/figure>\n<\/div>\n
At the bottom, click Create<\/strong> to create the cluster. Grab a coffee or take a break; it will take a few minutes to create the cluster.<\/p>\n
Meanwhile, if you haven\u2019t already, go ahead and initialize the gcloud<\/code> CLI by running:<\/p>\n
gcloud init<\/pre>\n
During the initialization process, you can set your new project as the default project and the project\u2019s region as your default region.<\/p>\n
Once the cluster is deployed, you need to connect your local gcloud<\/code> and kubectl<\/code> CLI to it with the following command:<\/p>\n
gcloud container clusters get-credentials {yourClusterName} --zone us-west1-a --project {yourProjectId}<\/pre>\n
If you used a different project name, you\u2019ll need to change the command to reflect that.<\/p>\n
NOTE:<\/strong> If you click on the Connect<\/strong> button to the right of the Google Cloud Platform dashboard, you\u2019ll see the correct command to enter:<\/p>\n
\n
\"Microservice<\/figure>\n<\/div>\n
You should see something like the following as a result:<\/p>\n
Fetching cluster endpoint and auth data.\nkubeconfig entry generated for spring-boot-cluster.<\/pre>\n
You will also need to give yourself admin privileges on the cluster:<\/p>\n
kubectl create clusterrolebinding cluster-admin-binding --clusterrole=cluster-admin --user=$(gcloud config get-value core\/account)\n<\/pre>\n
Now you need to check and make sure the Istio services were installed and are running. There are a couple of ways to check this. First, in your Google Cloud Platform Kubernetes Engine dashboard, click on the Services<\/strong> button. You should see a list of Istio services in your spring-boot-cluster<\/code>. They should all have green \u201cOk\u201d under the status column.<\/p>\n
While you\u2019re there, note the service named istio-ingressgateway<\/code> of type LoadBalancer<\/code>. This is the public load balancer for your cluster, and the entry shows the public IP and open ports.<\/p>\n
\n
\"Microservice<\/figure>\n<\/div>\n
Another way to check is by using the kubectl<\/code> CLI.<\/p>\n
To check the services use the following command: kubectl get services --all-namespaces<\/code>. The --all-namespaces<\/code> is required to show the Istio services, which are in the istio-system<\/code> namespace.<\/p>\n
$ kubectl get services --all-namespaces\nNAMESPACE      NAME                     TYPE           CLUSTER-IP      EXTERNAL-IP      PORT(S)                                                                                                                   AGE\ndefault        kubernetes               ClusterIP      10.31.240.1     <none>           443\/TCP                                                                                                                   5m\nistio-system   istio-citadel            ClusterIP      10.31.252.214   <none>           8060\/TCP,9093\/TCP                                                                                                         3m\nistio-system   istio-egressgateway      ClusterIP      10.31.247.186   <none>           80\/TCP,443\/TCP                                                                                                            3m\nistio-system   istio-galley             ClusterIP      10.31.249.131   <none>           443\/TCP,9093\/TCP                                                                                                          3m\nistio-system   istio-ingressgateway     LoadBalancer   10.31.244.186   35.185.213.229   80:31380\/TCP,443:31390\/TCP,31400:31400\/TCP,15011:30675\/TCP,8060:31581\/TCP,853:32460\/TCP,15030:30998\/TCP,15031:31606\/TCP   3m\nistio-system   istio-pilot              ClusterIP      10.31.251.44    <none>           15010\/TCP,15011\/TCP,8080\/TCP,9093\/TCP                                                                                     3m\nistio-system   istio-policy             ClusterIP      10.31.246.176   <none>           9091\/TCP,15004\/TCP,9093\/TCP                                                                                               3m\nistio-system   istio-sidecar-injector   ClusterIP      10.31.240.214   <none>           443\/TCP                                                                                                                   3m\nistio-system   istio-telemetry          ClusterIP      10.31.247.23    <none>           9091\/TCP,15004\/TCP,9093\/TCP,42422\/TCP                                                                                     3m\nistio-system   promsd                   ClusterIP      10.31.246.88    <none>           9090\/TCP                                                                                                                  3m\nkube-system    default-http-backend     NodePort       10.31.250.134   <none>           80:31955\/TCP                                                                                                              4m\nkube-system    heapster                 ClusterIP      10.31.250.242   <none>           80\/TCP                                                                                                                    4m\nkube-system    kube-dns                 ClusterIP      10.31.240.10    <none>           53\/UDP,53\/TCP                                                                                                             4m\nkube-system    metrics-server           ClusterIP      10.31.245.127   <none>           443\/TCP\n<\/pre>\n
To check the Kubernetes pods, use: kubectl get pods --all-namespaces<\/code><\/p>\n
$ kubectl get pods --all-namespaces\nNAMESPACE      NAME                                                      READY     STATUS      RESTARTS   AGE\nistio-system   istio-citadel-7c4864c9d5-7xq9x                            1\/1       Running     0          10m\nistio-system   istio-cleanup-secrets-ghqbl                               0\/1       Completed   0          10m\nistio-system   istio-egressgateway-c7f44ff8-tz7br                        1\/1       Running     0          10m\nistio-system   istio-galley-698f5c74d6-hmntq                             1\/1       Running     0          10m\nistio-system   istio-ingressgateway-774d77cb7c-qvhkb                     1\/1       Running     0          10m\nistio-system   istio-pilot-6bd6f7cdb-gb2gd                               2\/2       Running     0          10m\nistio-system   istio-policy-678bd4cf9-r8p6z                              2\/2       Running     0          10m\nistio-system   istio-sidecar-injector-6555557c7b-99c6k                   1\/1       Running     0          10m\nistio-system   istio-telemetry-5f4cfc5b6-vj8cf                           2\/2       Running     0          10m\nistio-system   promsd-ff878d44b-hlkpg                                    2\/2       Running     1          10m\nkube-system    heapster-v1.6.0-beta.1-8c76f98c7-2b4dm                    2\/2       Running     0          9m\nkube-system    kube-dns-7549f99fcc-z5trl                                 4\/4       Running     0          10m\nkube-system    kube-dns-autoscaler-67c97c87fb-m52vb                      1\/1       Running     0          10m\nkube-system    kube-proxy-gke-spring-boot-cluster-pool-1-b6988227-p09h   1\/1       Running     0          10m\nkube-system    l7-default-backend-7ff48cffd7-ppvnn                       1\/1       Running     0          10m\nkube-system    metrics-server-v0.2.1-fd596d746-njws2                     2\/2       Running     0          10m\n<\/pre>\n
The pods need to all have a status of Completed<\/code> or Running<\/code>. I ran into a problem a couple of times where the auto-configuration didn\u2019t work and some of the pods never reached the Running<\/code> status and were stuck in ContainerCreating<\/code>. I had to delete the cluster and reinstall it to get it to work.
 
<\/div> <\/div><\/p>\n
If this happens you can use the describe pods<\/code> command to see what\u2019s going on: kubectl describe pods -n istio-system<\/code>. This will give you a TON of information on all of the pods in the istio-system<\/code> namespace, which is specified using the -n<\/code> options.<\/p>\n
If you\u2019ve gotten this far without problems, you now have a Kubernetes cluster deployed on GKE with Istio installed! Pretty sweet.<\/p>\n
Both Google and Istio have some pretty helpful docs if you have a problem. Check out the Google GKE docs<\/a> and the Istio GKE docs<\/a> for further support.<\/p>\n
Create a Spring Boot Project for Your Microservices<\/h2>\n
Now go to the Spring Initializer<\/a> and create your starter project.<\/p>\n