https://github.com/caicloud/leader-election-example

This example demonstrates how to write high availability controller with GO.
https://github.com/caicloud/leader-election-example

controller example golang kubernetes leader-election

Last synced: about 2 months ago
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This example demonstrates how to write high availability controller with GO.

• Host: GitHub
• URL: https://github.com/caicloud/leader-election-example
• Owner: caicloud
• Created: 2019-10-09T08:06:47.000Z (about 5 years ago)
• Default Branch: master
• Last Pushed: 2023-02-24T17:27:48.000Z (almost 2 years ago)
• Last Synced: 2024-06-21T16:55:32.454Z (7 months ago)
• Topics: controller, example, golang, kubernetes, leader-election
• Language: Go
• Size: 7.35 MB
• Stars: 10
• Watchers: 6
• Forks: 4
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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**Table of Contents**  *generated with [DocToc](https://github.com/thlorenz/doctoc)*

- [Leader Election Example](#leader-election-example)

  - [Running](#running)

  - [Health Check](#health-check)

# Leader Election Example

This example demonstrates how to use the leader election package.

## Running

Run the following three commands in separate terminals.

```bash

# first terminal

go run main.go -kubeconfig=/path/to/kubeconfig -logtostderr=true -lease-lock-name=example -lease-lock-namespace=default -id=0 -port=8080

# second terminal

go run main.go -kubeconfig=/path/to/kubeconfig -logtostderr=true -lease-lock-name=example -lease-lock-namespace=default -id=1 -port=8081

# third terminal

go run main.go -kubeconfig=/path/to/kubeconfig -logtostderr=true -lease-lock-name=example -lease-lock-namespace=default -id=2 -port=8082

```

> You can ignore the `-kubeconfig` flag if you are running these commands in the Kubernetes cluster.

Now kill the existing leader. You will see from the terminal outputs that one of the remaining two processes will be elected as the new leader.

## Health Check

```bash

$ curl -i localhost:8080/healthz

HTTP/1.1 200 OK

Content-Type: text/plain; charset=utf-8

X-Content-Type-Options: nosniff

Date: Thu, 19 Sep 2019 10:44:39 GMT

Content-Length: 2

ok%

$ curl -i localhost:8080/healthz/leaderElection

HTTP/1.1 200 OK

Date: Thu, 19 Sep 2019 10:44:31 GMT

Content-Length: 2

Content-Type: text/plain; charset=utf-8

ok%

```