Quick Start Guide

In this chapter, we will deployment a sample app(tomcat:9) 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:9 --expose --port=8080
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           47s       tomcat       tomcat:9   run=tomcat

# Pods info
$ kubectl get pods -o wide --selector run=tomcat
NAME                      READY     STATUS    RESTARTS   AGE       IP             NODE
tomcat-5b75798b56-228r4   1/1       Running   0          1m        172.23.2.231   cn-beijing.192.168.0.8

# Service info
$ kubectl get svc tomcat
NAME      TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)    AGE
tomcat    ClusterIP   172.21.14.57   <none>        8080/TCP   1m

Connect: Access APP From Local

KT Connect support VPN mode and Socks5 mode to access cluster from local:

VPN Mode

VPN Mode is base on sshuttle, only support Mac and Linux User

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

$ sudo ktctl connect --method=vpn
11:48PM INF Connect Start At 27758
11:48PM INF Client address 192.168.3.120
11:48PM INF Deploying shadow deployment kt-connect-daemon-uhojp in namespace default

11:48PM INF Shadow Pod status is Pending
11:48PM INF Shadow Pod status is Running
11:48PM INF Shadow is ready.
11:48PM INF Success deploy proxy deployment kt-connect-daemon-uhojp in namespace default

Forwarding from 127.0.0.1:2222 -> 22
Forwarding from [::1]:2222 -> 22
Handling connection for 2222
Warning: Permanently added '[127.0.0.1]:2222' (ECDSA) to the list of known hosts.
client: Connected.

$ curl http://172.23.2.231:8080 #Access PodIP from local
<!doctype html><html lang="en"><head><title>HTTP Status 404 – Not Found</title><style type="text/css">body {font-family:Tahoma,Arial,sans-serif;} h1, h2, h3, b {color:white;background-color:#525D76;} h1 {font-size:22px;} h2 {font-size:16px;} h3 {font-size:14px;} p {font-size:12px;} a {color:black;} .line {height:1px;background-color:#525D76;border:none;}</style></head><body><h1>HTTP Status 404 – Not Found</h1><hr class="line" /><p><b>Type</b> Status Report</p><p><b>Message</b> Not found</p><p><b>Description</b> The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.</p><hr class="line" /><h3>Apache Tomcat/9.0.31</h3></body></html>
$ curl http://172.21.14.57:8080 #Access ClusterIP
<!doctype html><html lang="en"><head><title>HTTP Status 404 – Not Found</title><style type="text/css">body {font-family:Tahoma,Arial,sans-serif;} h1, h2, h3, b {color:white;background-color:#525D76;} h1 {font-size:22px;} h2 {font-size:16px;} h3 {font-size:14px;} p {font-size:12px;} a {color:black;} .line {height:1px;background-color:#525D76;border:none;}</style></head><body><h1>HTTP Status 404 – Not Found</h1><hr class="line" /><p><b>Type</b> Status Report</p><p><b>Message</b> Not found</p><p><b>Description</b> The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.</p><hr class="line" /><h3>Apache Tomcat/9.0.31</h3></body></html>
$ curl http://tomcat:8080 #Access Server internal DNS address

SOCKS5 Mode

Socks5 Mode is base SSH can support windows/linux/mac

use --method=socks tell kt connect use socks5 mode, and --dump2hosts option will sync all service in namespace to hosts file.

$ sudo ktctl connect --method=socks5 --dump2hosts
6:37PM INF Connect Start At 74032
6:37PM INF Dump hosts successful.
6:37PM INF Client address 30.5.124.242
6:37PM INF Deploying shadow deployment kt-connect-daemon-mkevz in namespace default
6:37PM INF Shadow is ready.
6:37PM INF Success deploy proxy deployment kt-connect-daemon-mkevz in namespace default

Forwarding from 127.0.0.1:2222 -> 22
Forwarding from [::1]:2222 -> 22
6:38PM INF ==============================================================
6:38PM INF Start SOCKS5 Proxy: export http_proxy=socks5://127.0.0.1:2223
6:38PM INF ==============================================================
Handling connection for 2222
Warning: Permanently added '[127.0.0.1]:2222' (ECDSA) to the list of known hosts.
6:38PM INF KT proxy start successful

Set HTTP_PROXY Environment in shell and then access cluster resource from local：

$ export http_proxy=socks5://127.0.0.1:2223
$ curl http://172.16.0.147:8080 #本地直接访问PodIP
$ curl http://172.19.143.139:8080 # 本地直接访问ClusterIP
$ curl http://tomcat:8080 #使用Service的域名访问

when ktctl hosts file will auto clean

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

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