I have a spring web application that I start locally with these java proxy properties:

-Dhttp.proxyHost=localhost
-Dhttp.proxyPort=1080
-Dhttp.nonProxyHosts=

I am starting a local WireMock server with http port 1080. The spring application is definitely routing requests through the designated proxy, but my WireMock server is not forwarding these requests to their destination. My goal is to have WireMock return stubs if there is a mapping match, otherwise forward the request to its destination and log the forwarded request. Is WireMock able to act as a proxy server in this way? I am using

wiremock-jre8-standalone

2.35.0. The WireMock Proxy docs mentions a WireMockServer option

passThroughProxy(Boolean)

(which it says defaults to “true”), which sounds exactly like what I want. But I don’t see this option available on this version of WireMock.

Hi @Steve Teplica, provided you start WireMock with browser proxying (which is just forward proxying) enabled, then it will behave in the way you’re asking for. To do this you either do

.enableBrowserProxying(true)

in the Java startup options, or

--enable-browser-proxying

from the CLI.

It looks like HTTP requests are working fine with this setup. Right now I’m floundering with getting HTTPS requests working. Changes to Spring Application: • I added these JVM proxy settings for HTTPS

-Dhttps.proxyHost=localhost
-Dhttps.proxyPort=1083
-Dhttps.nonProxyHosts=

Changes to WireMock Server: • I configured WireMock’s HTTPS port to 1083 • I added a

ConsoleNotifyingWiremockNetworkTrafficListener

to log info on incoming/outgoing network traffic. • These are the current relevent WireMock configurations:

WireMockServer wireMockServer = new WireMockServer(WireMockConfiguration.options()
        .port(1080)
        .httpsPort(1083)
        .enableBrowserProxying(true)
        .trustAllProxyTargets(true)
        .preserveHostHeader(true)
        ...
)

Observed behavior: • It looks like the initial HTTP CONNECT request (to open a tunnel to client’s request destination) is closing prematurely or failing:

2023-03-29 16:25:53.924 Opened Socket[addr=/127.0.0.1,port=53213,localport=1083]
2023-03-29 16:25:53.930 Incoming bytes: CONNECT <http://subdomain.domain.com:443|subdomain.domain.com:443> HTTP/1.1
Host: <http://subdomain.domain.com:443|subdomain.domain.com:443>
Proxy-Connection: Keep-Alive
User-Agent: okhttp/3.8.1


2023-03-29 16:25:53.938 Outgoing bytes: P
2023-03-29 16:25:53.943 Closed Socket[unconnected]

@Tom Do you have any advice for debugging this further? Or does this appear as an obvious symptom, to you, of something being misconfigured? Any help is greatly appreciated 😄

You’ll need to ensure that the Spring app trusts WireMock’s CA certificate otherwise it’ll (correctly) detect that it’s doing an MITM attack and refuse to send traffic.

Thanks Tom! The cause of these SSL problems for me was how I configured the java proxy ports. I stumbled across JvmProxyConfigurer in WireMock and saw that it sets

http.proxyPort

and

https.proxyPort

to the same port. So I did the same thing for my spring app, and then everything was working!