sersan

README

Sersan

Sersan is an optimised Selenium/WebDriver and Appium hub for Kubernetes cluster written in Golang. It employs Kubernetes engine to manage the lifecycle and queue of browser or Android emulator containers, and ensures the test environment is always clean and fresh. Each time it receives a new session request, Sersan will ask Kubernetes to create a new pod based on the browser and version that matches the requested capabilities. Once the pod is running, the next request will be forwarded to the created pod. The pod will be deleted if Sersan receives a delete session request. The session ID is a JWT token containing, among other things, the original session ID from WebDriver, the pod's IP address, the Selenium/WebDriver port, and VNC port.

Features

• Support web (on Kubernetes cluster) and Android (on Google Cloud Platform) automation
• Easy setup and maintenance. Only execute a few commands to get everything up and ready to receive high concurrent browser testing. Updating the browser version is as easy as editing a YAML file.
• One pod for one test. This ensures the test environment is always clean and fresh.
• Less memory consumption.
• Unlimited auto-scale. Only a single cluster is required to handle tests from all projects.
• Unified load distribution.
• Stateless. You can scale up or deploy a new version of Sersan without worrying about the currently running test.
• Compatible with Selenium/WebDriver test. No need to modify any of your existing tests.
• Support VNC viewer to observe the running browser. Use Selenium Chrome/Firefox debug image to use VNC.

Prerequisites

1. Kubernetes cluster. You can use minikube or kind for local development.
2. Compute Engine on Google Cloud Platform (for Android emulator).

Installation

To install simply use helm install to apply resources.

$ helm install sersan ./sersan

By default, it requires service account named sersan. The service account must have permission to create and delete pod in the Kubernetes cluster.

Check the sersan namespace (or the namespace you have specific in namespace: ) and make sure the pods are running.

That's all. You can now run your tests just like you would run it on Selenium hub. Point your WebDriver remote address to Sersan service ip.

kubectl get services -lapp=sersan
# WebDriver remote address
http://<service ip>:4444/wd/hub

Development

Prerequisite

1. Go 1.13
2. Docker
3. Kubernetes Cluster

Build

Get Sersan source

go get -u https://github.com/salestock/sersan

build the application

cd $GOPATH/src/github.com/salestock/sersan
go build -o server
./server

Build docker image

docker build -t <your domain>/sersan:<tag> .

Finally, redeploy Sersan application.

Customisation

Sersan can be customised through environment variables. Supported environment variables are:

Variable	Description	Default Value
PORT	Sersan port.	4444
BROWSER_CONFIG_FILE	Custom browser config file.	config/browsers.yaml
STARTUP_TIMEOUT	Timeout from new session request until Selenium/WebDriver is running.	900000 (miliseconds)
NEW_SESSION_ATTEMPT_TIMEOUT	Timeout from pod running and new session created.	60000 (miliseconds)
RETRY_COUNT	Number of attempts to create a session.	30
SIGNING_KEY	Session ID signing key	secret_key
GRID_LABEL	Browser's pod label.	dev
NODE_SELECTOR_KEY	Node selector key.
NODE_SELECTOR_VALUE	Node selector value.
SERSAN_GRID_TIMEOUT	Maximum age of the pod, after which it will be deleted automatically.	300 (seconds)
CPU_LIMIT	CPU limit of browser containers.	600m
CPU_REQUEST	CPU request of browser containers.	400m
MEMORY_LIMIT	Memory limit of browser containers.	600Mi
MEMORY_REQUEST	Memory request of browser containers.	1000Mi

Browser Images

Sersan is compatible with the following Selenium standalone or selenoid browser images:

• Selenium Chrome
• Selenium Chrome Debug
• Selenium Firefox
• Selenium Firefox Debug
• Selenoid Chrome
• Selenoid Firefox

Contributing

Please read CONTRIBUTING.md for details on our code of conduct.

Authors

• Dimas Aryo - Initial work - dimasaryo

See also the list of contributors who participated in this project.

License

This project is licensed under the Apache License 2.0 License - see the LICENSE.md file for details

Acknowledgments

• Inspired by Selenoid