server

Kubetail Backend Server

Go-based HTTP server that handles web requests from the Kubetail frontend

Overview

The Kubetail backend server is a Go-based HTTP server that's designed to proxy requests from the Kubetail frontend to the user's Kubernetes API and to the Kubetail backend agents as well as provide some other custom functionality such as authentication. It uses the Gin Web framework to serve HTTP requests. Under the hood, it uses the Kubernetes Go-client to communicate with the Kubernetes API and gRPC to communicate with Kubetail backend agents. Externally, it responds to Kubernetes-related queries via a GraphQL endpoint powered by gqlgen and serves other requests via a simple REST API.

In development, the backend and frontend servers are kept separate but in production the frontend website is packaged as a static site and deployed to the server's website directory from where it is served at the apex endpoint.

Configure

CLI Flags

The Kubetail backend server executable supports the following command line configuration options:

Flag	Datatype	Description	Default
-c, --config	string	Path to Kubetail config file	""
-a, --addr	string	Host address to bind to	":4000"
--gin-mode	string	Gin mode (release, debug)	"release"
-p, --param	[]string	Config params ("key:val" format)	[]

Config file

The Kubetail backend server can be configured using a configuration file written in YAML, JSON, TOML, HCL or envfile format. The application will automatically replace ENV variables written in the format ${NAME} with their corresponding values. The config file supports the following options (also see hack/config.yaml):

Name	Datatype	Description	Default
auth-mode	string	Auth mode (token, cluster, local)	"token"
allowed-namespaces	[]string	If populated, restricts namespace access	[]
server.addr	string	Host address to bind to	":4000"
server.agent-dispatch-url	string	Url for sending dispatch requests to agent	"kubernetes://kubetail-agent:50051"
server.base-path	string	URL path prefix	"/"
server.gin-mode	string	Gin mode (release, debug)	"release"
server.csrf.enabled	bool	Enable CSRF protection	true
server.csrf.field-name	string	CSRF token name in forms	"csrf_token"
server.csrf.secret	string	CSRF hash key	""
server.csrf.cookie.name	string	CSRF cookie name	"csrf"
server.csrf.cookie.path	string	CSRF cookie path	"/"
server.csrf.cookie.domain	string	CSRF cookie domain	""
server.csrf.cookie.max-age	int	CSRF cookie max age (in seconds)	43200
server.csrf.cookie.secure	bool	CSRF cookie secure property	false
server.csrf.cookie.http-only	bool	CSRF cookie HttpOnly property	true
server.csrf.cookie.same-site	string	CSRF cookie SameSite property (strict, lax, none)	"strict"
server.logging.enabled	bool	Enable logging	true
server.logging.level	string	Log level	"info"
server.logging.format	string	Log format (json, pretty)	"json"
server.logging.access-log.enabled	bool	Enable access log	true
server.logging.access-log.hide-health-checks	bool	Hide requests to /healthz from access log	false
server.session.secret	string	Session hash key	""
server.session.cookie.name	string	Session cookie name	"session"
server.session.cookie.path	string	Session cookie path	"/"
server.session.cookie.domain	string	Session cookie domain	""
server.session.cookie.max-age	int	Session cookie max age (in seconds)	43200
server.session.cookie.secure	bool	Session cookie secure property	false
server.session.cookie.http-only	bool	Session cookie HttpOnly property	true
server.session.cookie.same-site	string	Session cookie SameSite property (strict, lax, none)	"strict"
server.tls.enabled	bool	Enable TLS endpoint termination	false
server.tls.cert-file	string	Path to cert file	""
server.tls.key-file	string	Path to key file	""

GraphQL

The GraphQL schema can be found here: GraphQL schema. To run the gqlgen GraphQL code generator use the go generate command:

go generate ./...

Test

This project uses the stretchr/testify library for testing. To run the test suite execute this command:

go test ./...