Access MockWebServer from outside of the JVM

Question

I am writing Espresso UI tests with okhttp3.mockwebserver.MockWebServer. I am facing an issue, that my MockWebServer is not accessible from the application running in AVD.

This works:

• Access the MockWebServer from the same process as the MockWebServer was started (I just executed a dummy request directly after I started the MockWebServer from the Kotlin code)
• Internet access from Chrome running on the Android VM in the AVD
• Access from AVD to my working machine to any other web application I host locally. I can reach it by http://10.0.2.2:8080
• Use MockWebServer in UnitTests

This doesn't work:

• Access the MockWebServer from my Browser (using http://localhost:8080)
• Access the MockWebServer from my Android app running in AVD (using http://10.0.2.2:8080) => timeout in 10seconds
• Use MockWebServer in UI (Integration) Tests

I ensured:

• cleartextTrafficPermitted="true"
• MockWebServer is started on port 8080

My best guess is, that the MockWebServer runs in a JVM machine and is not accessible from a different process, because it is not starting a real web server, but it just intercepts the HTTP traffic within one JVM process, could it be? Do you see any other possible root cause or is my wish to make it work a no-go?

Answer 1

The problem is solved, my mistake was the assumption, that the UI Tests are executed on my working machine in a separate JVM.

Instead, the tests are executed directly on the AVD, so there is no need to replace localhost with 10.0.2.2