Continuous Integration (CI)

A System has been devised for testing and continuous integration using GitHub Workflows. By leveraging these tools, the SENSEI project is able to ensure the quality of the software when it is integrated into the ECP software stack.

Setting up a new CI job

An example using the GitHub Workflows can be found at os-linux.

The three main steps of the CI workflow are:


This step sets the stage for the rest of the downstream steps. Here we configure the build and tests for the OS and features the CI will test. For this, SENSEI uses a collection of modular CMake scripts that build the CMakeCache.txt. The name of the configuration is generally the same as the name of the job. In the example os-linux the job linux-ecp using the configuration linux_ecp.

The configuration is controlled by two environment variables

  • CMAKE_CONFIGURATION: This variable is required to be set. An example is linux_ecp which is used for the linux-ecp job
  • CMAKE_GENERATOR: This sets the generator cmake will use to build, the default generator is “Ninja”.
  • CMAKE_BUILD_TYPE: This sets the build type, the default build type is “Debug”.
- name: Configure
run: ${{ env.LAUNCHER }} ctest -VV -S .github/ci/ctest_configure.cmake


The build step is where SENSEI is built using all of the features specified by the configuration.

There are some environment variables that may be set for the CI job to modify how the build step performs.

  • CTEST_MAX_PARALLELISM: This limits the number of consequtive compilations tasks, for GitHub Actions this currently defaults to “2”.
- name: Build
run: ${{ env.LAUNCHER }} ctest -VV -S .github/ci/ctest_build.cmake


The testing step is where the SENSEI tests are run. This includes the tests that use the miniapps and standalone drivers that test specific bridges. Depending on the features enabled during configuration, certain tests will be enable or disabled accordingly.

A note about GitHub Actions:

Due to that fact that GitHub Actions only provides two(2) cores for running CI it was decided to disable all tests that run with more than two(2) cores. Most of the tests marked PARALLEL run with 4 cores, so the current method of disabling tests that use more than two(2) cores is to disable all tests labeld PARALLEL if the environment variable CTEST_MAX_PARALLELISM < four(4).

- name: Test
run: ${{ env.LAUNCHER }} ctest -VV -S .github/ci/ctest_test.cmake

Upload Artifacts

This last step is to store the result of the CI. This step is optional because it may not be desirable or needed to keep artifacts of the CI job around.

- name: "Upload Artifacts"
uses: actions/upload-artifact@v2
# Call the compressed artifact the same name as the configuration with the job ID
# This will help avoid conflicts between CI artifacts
name: ${{ env.CMAKE_CONFIGURATION }}_${{ env.GITHUB_JOB }}

path: build # Save the entire build directory
retention-days: 1 # Limit the number of days the artifact persists to one day

Create New Workflow

For an example of creating a new CI configuration that uses HDF5 and ADIOS2 and tests on a Linux OS, let’s call it linux_hdf5_adios2. To get started we need a CMake configure file called configure_linux_hdf5_adios2.cmake. This file will be located in the directory <sensei-source>/.github/ci/.

The contents of this file will be pulling in the configurations for HDF5, ADIOS2, and Linux. Note the OS configuration always comes last as it will include additional configurations that may customize some settings based on the features that are configured. One example of this is VTK rendering.



Now that the configure file is setup, it is time to add a new job. Because this is a linux job, we will use the sensei-ci:latest docker image. This image contains all of the possible dependencies for SENSEI that may be tested in CI. As more features are made available to CI additional jobs will be introduced to build and test them.

  • ADIOS2
  • Catalyst
  • HDF5
  • Python 3
  • VTK

In the os-linux.yml a new job can be added under the jobs section of the yaml.

runs-on: ubuntu-latest
# By using the latest container the CI will automatically update dependencies
image: ryankrattiger/sensei-ci:latest
options: --user=root
# This launcher is required when using the sensei-ci container since it uses spack as a backend.
# Eventually this requirement will be removed
LAUNCHER: .github/ci/docker/spack/

CMAKE_CONFIGURATION: linux_hdf5_adios2
# GitHub Action to clone sensei and checkout the triggering branch
- uses: action/checkout@v2

# Run the Configure/Build/Test steps in order
- name: Configure
run: ${{ env.LAUNCHER }} ctest -VV -S .github/ci/ctest_configure.cmake

- name: Build
run: ${{ env.LAUNCHER }} ctest -VV -S .github/ci/ctest_build.cmake

- name: Test
run: ${{ env.LAUNCHER }} ctest -VV -S .github/ci/ctest_test.cmake

# (Optional) Upload the CI artifacts
- name: "Upload Artifacts"
uses: actions/upload-artifact@v2
name: ${{ env.CMAKE_CONFIGURATION }}_${{ env.GITHUB_JOB }}
path: build
retention-days: 1