ci: Djanicek/infraeng 487/circle test runner (#8977)

* use circle test runner instead of splitter

* fix xargs syntax

.circleci/real_config.yml

@@ -567,39 +567,22 @@ commands:
                 port: <<parameters.master-port>>
 
       - run:
-          name: Split tests
+          name: Run e2e tests
           working_directory: ~/project/e2e_tests
+          no_output_timeout: 30m
           command: |
-            # Preselect the files that contain any matching tests to minimize how wrong CircleCI's
-            # splitting can get things. (The presence of files with no tests can cause the files
-            # with tests to be bunched up incorrectly, making the split suboptimal.)
-
-            # `--setup-plan` tells pytest to not run any tests but instead print out a description
-            # of the tests that would be run, along with some other stuff. Each file containing
-            # any selected tests is printed on a line by itself, except for (for some reason) a
-            # single trailing space.
             pytest --setup-plan -m '<<parameters.mark>>' | egrep '\.py s*$' | sed 's/\.py.*$/.py/' > /tmp/all-relevant-files
-
-            echo 'All files with tests matching mark "<<parameters.mark>>":'
-            sed 's/^/- /' </tmp/all-relevant-files
-
-            circleci tests split --split-by=timings < /tmp/all-relevant-files > /tmp/tests-to-run
-            echo "Running tests from these files:"
-            sed 's/^/- /' </tmp/tests-to-run
-
-            if [ ! -s /tmp/tests-to-run ]; then
+            if [ ! -s /tmp/all-relevant-files ]; then
               echo 'No test files found!'
               exit 1
             fi
-
-      - run:
-          name: Run e2e tests
-          working_directory: ~/project/e2e_tests
-          no_output_timeout: 30m
-          command: |
-            DD_CIVISIBILITY_AGENTLESS_ENABLED=true DD_SITE='datadoghq.com' DD_ENV=ci DD_SERVICE='pytest-<<parameters.mark>>' \
-            DET_MASTER_CERT_FILE=<<parameters.master-cert>> DET_MASTER_CERT_NAME=<<parameters.master-cert-name>> \
-            pytest -vv -s \
+            
+            cat /tmp/all-relevant-files | circleci tests run --command="DD_CIVISIBILITY_AGENTLESS_ENABLED=true \
+            DD_SITE='datadoghq.com' \
+            DD_ENV=ci DD_SERVICE='pytest-<<parameters.mark>>' \
+            DET_MASTER_CERT_FILE=<<parameters.master-cert>> \
+            DET_MASTER_CERT_NAME=<<parameters.master-cert-name>> \
+            xargs pytest -vv -s \
             -m '<<parameters.mark>>' \
             --durations=0 \
             --ddtrace \
@@ -608,8 +591,8 @@ commands:
             --master-port="<<parameters.master-port>>" \
             -o junit_family=xunit1 \
             --junit-xml="<<parameters.junit-path>>" \
-            <<parameters.extra-pytest-flags>> \
-            $(< /tmp/tests-to-run)
+            <<parameters.extra-pytest-flags>>" \
+            --verbose --split-by=timings
       - upload-test-job:
           only_on_branch: main
           test_results_path: <<parameters.junit-path>>