Ddapm-test-agent

Bug Fixes

- Fix the snapshot matching algorithm which had previously assumed that trace ids would be unique across both sets of traces.
- Fix sessions returning traces from all sessions.

New Features

- Move span attributes `type`, `meta` and `metrics` up in the JSON snapshot output to help with readability.

Bug Fixes

- Specify required Python version to >= 3.8. It was mistakenly set to >= 3.7 in setup.py.

New Features

- Span output in snapshots are now ordered to be more human readable with the important attributes (name, service, resource) moved to the top of the JSON object. This affects the output JSON but does not break existing snapshots.
- Add `-v/--version` command line option to display the version.

Bug Fixes

- Fix command line arguments not being parsed.
- Fix partial trace chunks (referring to spans in other chunks) causing 500s.

Prelude

The test agent has been rewritten in Python and the API being cleaned up substantially.

New Features

- <span class="title-ref">/test/traces/</span> has been added to retrieve traces collected by the agent.
- <span class="title-ref">/test/session/traces/</span> has been added to retrieve traces collected by the agent for a specific session.
- The test agent is now published to PyPI. It can be installed with <span class="title-ref">pip install ddapm-test-agent</span>.

Upgrade Notes

- <span class="title-ref">TEST_AGENT_PORT</span> has been renamed to <span class="title-ref">PORT</span>.
- <span class="title-ref">X-Datadog-Test-Token</span> has been renamed to <span class="title-ref">X-Datadog-Test-Session-Token</span>.
- <span class="title-ref">token</span> has been renamed to <span class="title-ref">test_session_token</span>. <span class="title-ref">X-Datadog-Test-Token</span> has been renamed to <span class="title-ref">X-Datadog-Test-Session-Token</span>.
- The default snapshot directory has been changed from <span class="title-ref">snaps</span> to <span class="title-ref">snapshots</span>.
- The <span class="title-ref">/test/start</span> endpoint has been renamed to <span class="title-ref">/test/session/start</span>.
- The <span class="title-ref">/test/snapshot</span> endpoint has been renamed to <span class="title-ref">/test/session/snapshot</span>.