Name	Description	Default
NAGG_HTTP_PORT	Defines which port to start built in server on	8080
NAGG_LOG_LEVEL	Determines which log level should be used	info
NAGG_HTTP_BASE_PATH	Determines which base path that NAGG will listen for requests on	/
NAGG_CONFIG_JSON	Gateway configuration in JSON format (has precedence)	-
NAGG_CONFIG_FILE_PATH	Gateway configuration in JSON format	-

See examples/gateway.json for an example.

Expansion

When configuration is loaded from NAGG_CONFIG_JSON, standard Golang environment expansion will be applied to expand any variable statements in the string.

Given that there is an environment variable named FOO with the value bar then the following string in NAGG_CONFIG_JSON:

'{"foo":"$FOO"}'

Would result in the following string to be parsed as a config.

'{"foo":"bar"}'

Structure

Gateway

Global space for configuration in JSON structure and have two attributes that can be configured.

Middlewares, global middlewares to apply on each request and response. Routes, routes to handle requests for in the gateway.

Middleware

Middlewares has three attributes.

Name, which determines which middleware is loaded. Phase, either pre or post which determines if it's applied before upstream request is done or after. Pre are mainly for request handling while post are mainly for response handling. Args, List of args that are passed to the middleware factory function.

Default middlewares

Name	Description	Args
setHeader	Sets header on request or response	key,value
removeHeader	Removes header from request or response	key
moveHeader	Moves a headers value to another and removes original header	sourceKey,destinationKey
setPath	Sets an absolute path for upstream request	path
setPathPrefix	Adds a prefix to the incoming requests path	prefix
setRequestParameter	Adds a query parameter to the upstream request	key,value
removeRequestParameter	Removes a query parameter from the upstream request	key
dedupeResponseHeaders	Ensures that specified header only has one value, value with index 0 will be used	keys...
redirect	Redirects request	statusCode,destination

Route

Routes has four attributes.

Name, plainly an identifier for the route.

Predicates, object (described more in detail further down) that determines which requests will use this route.

Address, which upstream URL to use for requests. Can use the env:<environment variable key> to load ad-hoc from environment when route is triggered.

Middlewares, list of middlewares to apply to route.