- The 'pageserver' fixture now sets up the repository and starts up
the Page Server automatically. In other words, the 'pageserver'
fixture provides a Page Server that's up and running and ready to
use in tests.
- The 'pageserver' fixture now also creates a branch called 'empty',
right after initializing the repository. By convention, all the
tests start by createing a new branch off 'empty' for the test. This
allows running all the tests against the same Page Server
concurrently. (I haven't tested that though. pytest doensn't
provide an option to run tests in parallel but there are extensions
for that.)
- Remove the 'zen_simple' fixture. Now that 'pageserver' provides
server that's up and running, it's pretty simple to use the
'pageserver' and 'postgres' fixtures directly.
- Don't assume host name or ports in the tests. They now use the
fields in the fixtures for that. That allows assigning the ports
dynamically, making it possible to run multiple page servers in
parallel, or running the tests in parallel with another page
server. This commit still hard codes the Page Server's port in the
fixture, though, so more work is needed to actually make it
possible.
- I made some changes to the 'postgres' fixture in commit 532918e13d,
which broke the other tests. Fix them.
- Divide the tests into two "batches" of roughly equal runtime, which
can be run in parallel
- Merge the 'test_file' and 'test_filter' options in CircleCI config
into one 'test_selection' option, for simplicity.
This patch started as an effort to support CLI working against remote
pageserver, but turned into a pretty big refactoring.
* CLI now does not look into repository files directly. New commands
'branch_create' and 'identify_system' were introduced into page_service to
support that.
* Branch management that was scattered between local_env and
zenith/main.rs is moved into pageserver/branches.rs. That code could better fit
in Repository/Timeline impl, but I'll leave that for a different patch.
* All tests-related code from local_env went into integration_tests/src/lib.rs as an
extension to PostgresNode trait.
* Paths-generating functions were concentrated around corresponding config
types (LocalEnv and PageserverConf).
It's quite hard to get python2 to exit gracefully when the code was
intended for python3, because the interpreter will SyntaxError before
running a single line of code. Thankfully, the pytest developers put a
version check in their .ini config, so that should gracefully handle
both wrong-pytest-version and wrong-python-version.
Also document the woes of trying to run the pytest version shipped by
e.g. Debian or Ubuntu.
Use pytest to manage background services, paths, and environment
variables.
Benefits:
- Tests are a little easier to write.
- Cleanup is more reliable. You can CTRL-C a test and it will still shut
down gracefully. If you manually start a conflicting process, the test
fixtures will detect this and abort at startup.
- Don't need to worry about remembering '--test-threads=1'
- Output of sub-processes can be captured to files.
- Test fixtures configure everything to operate under a single test
output directory, making it easier to capture logs in CI.
- Detects all the necessary paths if run from the git root, but can also
run from arbitrary paths by setting environment variables.
There is also a deliberately broken test (test_broken.py) that can be
used to test whether the test fixtures properly clean up after
themselves. It won't run by default; the comment at the top explains how
to enable it.
