APM agent not using full server_url

[RandalMoss]

Describe the bug:
I'm having a similar issue that was described in the apm-agent-java issues: elastic/apm-agent-java#339

I am using a url that looks like: https://test.url/with/path
The logs from the APM agent show the following:
Failed to submit message: 'Connection to APM Server timed out (url: https://test.url/intake/v2/events, timeout: 5 seconds)'

The path that I have at the end gets removed.

To Reproduce

1. Configure SERVER_URL=https://test.url/
2. Trigger an APM event

Expected behavior:

I expected that the SERVER_URL variable would take the full URL and not just the domain part.

Environment (please complete the following information)

• OS: Using Docker for Mac version 2.0.0.0-mac81 with base image python:3.7
• Python version: python 3.7
• Framework and version [e.g. Django 2.1]: Flask 1.0.2
• APM Server version: docker.elastic.co/apm/apm-server:6.5.4
• Agent version: 4.0.3

[beniwohli]

@RandalMoss thanks for opening the issue. This is caused by a (in my opinion) somewhat surprising behavior of urljoin(url, path) if the path argument starts with a /. It basically strips the whole path from url.

I have a fix ready in #376, and will merge/release it in the coming days

[beniwohli]

merged to master in 073a539

[beniwohli]

This has been released in the 4.1.0 version of the agent