Add examples for PSM tests.

[wanlin31]

Added three examples to run PSM tests. To run these test, a new deployment is required.

[wanlin31]

@gnossen Hi Richard, I create this PR to show the examples of the test configurations for PSM tests. We will need a new release of the test-infra to run them. The scenarios were adopted from the original load test examples (minus the security parameters) to show the ability to run the full flow, the scenarios can be modified later.

[paulosjca]

So, this image is fixed and has version "test¨? I assume it is going to be part of some release? Perhaps these examples, unlike the regular ones, should be templates already. In this case, we may want to put them in config/samples/templates/psm.

Also, the path of the images we use should probably be something like gcr.io/grpc-testing/e2etest/runtime/xds-server (or perhaps runtime/psm/xds-server if we want to emphasize that these are psm components).

[wanlin31]

Right, since they requires the images like the pre-built examples I think they should be templates .
For the pefix, I agree with setting PSM_IMAGE_PREFIX=gcr.io/grpc-testing/e2etest/runtime/psm to emphasize psm test. I will update them to be template.

[wanlin31]

I was able to generate template for proxyless tests use command below:

 ./tools/run_tests/performance/loadtest_template.py \
    -i ../test-infra/config/samples/templates/psm/*_example_loadtest_proxyless.yaml \
    --inject_client_pool --inject_server_pool \
    --inject_big_query_table --inject_timeout_seconds \
    -o ./tools/run_tests/performance/templates/loadtest_template_psm_all_languages.yaml\
    --name psm_all_languages

The ready-to-run configurations can be generated as:

export PSM_IMAGE_PREFIX=gcr.io/grpc-testing/e2etest/runtime/psm
export PSM_IMAGE_TAG=test

./tools/run_tests/performance/loadtest_config.py -l go -l java \
    -t ./tools/run_tests/performance/templates/loadtest_template_psm_all_languages.yaml \
    -s client_pool=workers-8core -s driver_pool=drivers \
    -s server_pool=workers-8core \
    -s big_query_table=e2e_benchmarks.experimental_results \
    -s timeout_seconds=3600 --category=scalable \
    -s psm_image_prefix="${PSM_IMAGE_PREFIX}" \
    -s psm_image_tag="${PSM_IMAGE_TAG}" \
    -d --allow_client_language=c++ --allow_server_language=c++ \
    --runs_per_test=2 -o ./loadtest.yaml

Might need to change the names of the Templates.

[paulosjca]

You will need two templates, one for proxied and one for proxyless, since they use different clients.