Websocket request not routed through gateway global filter - spring

Question

Problem
I have setup a global filter for all requests that adds user information to the headers. This filter works for all my http requests but doesnt apply them to my websocket requests.
Questions
Do websocket requests got through GlobalFilters?
If websocket requests do not go through GlobalFilters is there a way to specify a filter for websockets?
Are there any approaches that will allow me to inject user info into the websocket requests via spring-cloud-gateway?
Setup
Gateway configuration
gateway:
routes:
- id: example
uri: http://localhost:80
predicates:
- Path=/example/**
filters:
- RewritePath=/example/(?<path>.*), /$\{path}
GloablFilter
#Component
class CustomGlobalFilter(private val jwtDecoder: ReactiveJwtDecoder) : GlobalFilter {
private val logger = KotlinLogging.logger {}
/**
* Given exchange, extract Authorization header value and modify to retrieve JWT token.
*/
fun extractJwtToken(exchange: ServerWebExchange): String {
return (exchange.request.headers["Authorization"]
?: throw JwtExtractionException("Request does not contain Authorization header"))[0]
.replace("Bearer ", "")
}
/**
* Modify request headers to add `username`.
*/
fun modifyHeaders(exchange: ServerWebExchange): Mono<ServerWebExchange> {
return try {
val jwt = extractJwtToken(exchange)
jwtDecoder
.decode(jwt)
.map {
val username = it.claims["username"] as String
val modRequest = exchange
.request
.mutate()
.header("username", username)
.build()
exchange.mutate()
.request(modRequest)
.build()
}
} catch (e: JwtExtractionException) {
exchange.toMono() // fall back on default exchange
}
}
/**
* Filter all outgoing requests to modify headers.
*/
override fun filter(exchange: ServerWebExchange, chain: GatewayFilterChain): Mono<Void> {
return modifyHeaders(exchange)
.flatMap { chain.filter(it) }
}
}

Answer 1

I was able to fix the routing issue by setting the custom filter order before the WebsocketRoutingFilter
#Component
class CustomGlobalFilter(
private val authFilterUtil: AuthFilterUtil,
) : GlobalFilter, Ordered {
override fun filter(exchange: ServerWebExchange, chain: GatewayFilterChain): Mono<Void> {
return authFilterUtil
.modifyHeaders(exchange)
.flatMap { chain.filter(it) }
}
override fun getOrder(): Int {
return Ordered.HIGHEST_PRECEDENCE
}
}