test: add openmpi container test

[bhagyapathak]

Add Openmpi container test

1. test_openmpi_mpirun_version
   Validates that OpenMPI runtime is installed and usable.
   Runs mpirun --version with required OpenMPI runtime env configuration.
   Fails fast if basic OpenMPI runtime wiring is broken.
2. test_openmpi_runs_multiple_ranks
   Validates that mpirun actually launches two MPI ranks in the container.
   Executes a two-rank command and checks exact rank output: rank=0 and rank=1.
   Provides stable rank-launch verification without depending on version-string formatting.
3. test_openmpi_send_receive_between_two_ranks
   Validates real MPI communication semantics, not just process launch.
   Compiles the checked-in C program copied into the image, then runs it with two ranks.
   Asserts tagged message exchange output, proving rank-to-rank send and receive behavior works end to end.

[bhagyapathak]

Test Logs openmpi_container_runtime_test_logs.txt

[Copilot]

Pull request overview

This PR adds a new container-base runtime test case that validates OpenMPI on the image-under-test. It follows the existing @pytest.mark.dockerfile() pattern: a small Dockerfile layers OpenMPI on top of the base image, and the test suite exercises mpirun version reporting, multi-rank process launch, and a compiled two-rank send/receive program. The MPI send/receive assertions correctly track the per-tag non-overtaking ordering guaranteed by MPI, and the Dockerfile build context correctly includes the copied C source.

Changes:

• Adds test_openmpi.py with three tests (mpirun --version, 2-rank launch, and a tagged send/receive round-trip).
• Adds send_receive.c, a minimal MPI program exchanging tagged messages between two ranks.
• Adds a Dockerfile that installs openmpi, openmpi-devel, and gcc and stages the C source under /opt/mpi-tests.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
base/images/tests/cases/runtime/container-base/test_openmpi/test_openmpi.py	New pytest cases for OpenMPI runtime; minor style deviations (E265/E302) and duplicated path literals vs. existing constants.
base/images/tests/cases/runtime/container-base/test_openmpi/send_receive.c	MPI two-rank tagged send/receive program; logic aligns with the test assertions.
base/images/tests/cases/runtime/container-base/test_openmpi/Dockerfile	Layers OpenMPI + gcc on BASE_IMAGE and copies the C source into the build context.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.

[christopherco]

issue: A deadlock can occur if rank 0's first MPI_Send() with tag1 blocks waiting for a matching receive. Rank 0 then never sends tag2, while rank 1 is already blocked waiting to receive a tag2 message

Please either receive messages in send order or use nonblocking sends, like 4 MPI_Isend()s followed by MPI_Waitall().