How to configure Krakend so it return http redirect response as-is instead of following the http redirect? - api

Question

I am currently using Krakend (https://krakend.io) API Gateway to proxy request to my backend service. One of my backend service API response is a redirect response with http 303. The redirect response looks like this below :
HTTP/1.1 303 See Other
content-length: 48
content-type: text/plain; charset=utf-8
date: Thu, 16 Jul 2020 10:25:41 GMT
location: https://www.detik.com/
vary: Accept
x-powered-by: Express
x-envoy-upstream-service-time: 17
server: istio-envoy
The problem is that, instead of returning the http 303 response to client (with location response header) as-is, Krakend is actually following the http redirect and return the response of the redirect Url, which is the html response of https://www.detik.com/.
My current krakend configuration looks like this below :
{
"version": 2,
"extra_config": {
"github_com/devopsfaith/krakend-cors": {
"allow_origins": [],
"expose_headers": [
"Content-Length",
"Content-Type",
"Location"
],
"allow_headers": [
"Content-Type",
"Origin",
"X-Requested-With",
"Accept",
"Authorization",
"secret",
"Host"
],
"max_age": "12h",
"allow_methods": [
"GET",
"POST",
"PUT"
]
},
"github_com/devopsfaith/krakend-gologging": {
"level": "ERROR",
"prefix": "[GATEWAY]",
"syslog": false,
"stdout": true,
"format": "default"
},
"github_com/devopsfaith/krakend-logstash": {
"enabled": false
}
},
"timeout": "10000ms",
"cache_ttl": "300s",
"output_encoding": "json",
"name": "api-gateway",
"port": 8080,
"endpoints": [
{
"endpoint": "/ramatestredirect",
"method": "GET",
"extra_config": {},
"output_encoding": "no-op",
"concurrent_calls": 1,
"backend": [
{
"url_pattern": "/",
"encoding": "no-op",
"sd": "static",
"extra_config": {},
"method": "GET",
"host": [
"http://ramatestredirect.default.svc.cluster.local"
],
"disable_host_sanitize": false
}
]
}
]
}
So how can I make krakend to return original http 303 response unaltered from my backend service to the client ?
Thank You

Answer 1

I assume that you're calling this endpoint /ramatestredirect
To get backend http status code (as you said it return 303 http status code), you can use this way:
{
"endpoint": "/ramatestredirect",
"method": "GET",
"extra_config": {},
"output_encoding": "no-op",
"concurrent_calls": 1,
"backend": [
{
"url_pattern": "/",
"encoding": "no-op",
"sd": "static",
"extra_config": {
"github.com/devopsfaith/krakend/http": {
"return_error_details": "authentication"
}
},
"method": "GET",
"host": [
"http://ramatestredirect.default.svc.cluster.local"
],
"disable_host_sanitize": false
}
]
}
So, basically with this plugin you can get the original backend http status code
"github.com/devopsfaith/krakend/http": {
"return_error_details": "authentication"
}

Answer 2

If you use Lura Framework (formerly known as Kraken framework), then you may have to disable redirects for your http client.
client := &http.Client{
CheckRedirect: func(req *http.Request, via []*http.Request) error {
return http.ErrUseLastResponse
},
}