kt-connect/docs/quickstart.md

Quick Start Guide

In this chapter, we will deployment a sample app(tomcat:7) in Kubernetes cluster. With Kt to access the app from user labtop or exchange the request to user labtop.

Create a Demo APP in Cluster

$ kubectl run tomcat --image=tomcat:7 --expose --port=8080
kubectl run --generator=deployment/apps.v1 is DEPRECATED and will be removed in a future version. Use kubectl run --generator=run-pod/v1 or kubectl create instead.
service/tomcat created
deployment.apps/tomcat created

# Deployment info
$ kubectl get deployments -o wide --selector run=tomcat
NAME     DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES     SELECTOR
tomcat   1         1         1            1           12m   tomcat       tomcat:7   run=tomcat

# Pods info
$ kubectl get pods -o wide --selector run=tomcat
NAME                     READY   STATUS        RESTARTS   AGE   IP             NODE                                NOMINATED NODE
tomcat-cc7648444-r9tw4   1/1     Running       0          2m    172.16.0.147   cn-beijing.i-2ze11lz4lijf1pmecnwp   <none>

# Service info
$ kubectl get svc tomcat
NAME     TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)    AGE
tomcat   ClusterIP   172.19.143.139   <none>        8080/TCP   4m

Connect: Access APP From Local

Connect to kubernetes cluster, KT will deployment a proxy pod in cluster：

$ sudo ktctl connect
2019/06/19 11:11:07 Deploying proxy deployment kt-connect-daemon in namespace default
2019/06/19 11:11:07 Pod status is Pending
2019/06/19 11:11:09 Pod status is Running
2019/06/19 11:11:09 Success deploy proxy deployment kt-connect-daemon in namespace default
2019/06/19 11:11:18 KT proxy start successful

Access PodIP from local:

$ curl http://172.16.0.147:8080             

Access ClusterIP

$ curl http://172.19.143.139:8080             

Access Server internal DNS address

$ curl http://tomcat:8080

Exchange: Access local from cluster

Create Tomcat 8 in local and expose 8080 port

$ docker run -itd -p 8080:8080 tomcat:8

$ ktctl exchange tomcat --expose 8080
2019/06/19 11:19:10  * tomcat (0 replicas)
2019/06/19 11:19:10 Scale deployment tomcat to zero
2019/06/19 11:19:10 Deploying proxy deployment tomcat-kt-oxpjf in namespace default
2019/06/19 11:19:10 Pod status is Pending
2019/06/19 11:19:12 Pod status is Running
2019/06/19 11:19:12 Success deploy proxy deployment tomcat-kt-oxpjf in namespace default
SSH Remote port-forward for POD starting
2019/06/19 11:19:14 ssh remote port-forward start at pid: 3567

Access local tomcat by internal service DNS address:

Note: if kubectl connect not running, you can only access from cluster

$ curl http://tomcat:8080 | grep '<h1>'
<h1>Apache Tomcat/8.5.37</h1> #

Mesh: Build large test environemnt with ServiceMesh

The most different from mesh and exchange is exchange will scale the origin workload replicas to zero. And messh will keep it and create a pod instance with random version, after this user can modifi the Istio route rule let the specific request redirect to local, and the environment is working as normal:

$ ktctl mesh tomcat --expose 8080
2019/06/19 22:10:23 'KT Connect' not runing, you can only access local app from cluster
2019/06/19 22:10:24 Deploying proxy deployment tomcat-kt-ybocr in namespace default
2019/06/19 22:10:24 Pod status is Pending
2019/06/19 22:10:26 Pod status is Pending
2019/06/19 22:10:28 Pod status is Running
2019/06/19 22:10:28 Success deploy proxy deployment tomcat-kt-ybocr in namespace default
2019/06/19 22:10:28 -----------------------------------------------------------
2019/06/19 22:10:28 |    Mesh Version 'ybocr' You can update Istio rule       |
2019/06/19 22:10:28 -----------------------------------------------------------
2019/06/19 22:10:30 exchange port forward to local start at pid: 53173
SSH Remote port-forward POD 172.16.0.217 22 to 127.0.0.1:2217 starting
2019/06/19 22:10:30 ssh remote port-forward exited
2019/06/19 22:10:32 ssh remote port-forward start at pid: 53174