Allow running tests with podman (#197)

Author: senekor

bin/run-tests-in-docker.sh

@@ -3,7 +3,7 @@
 set -e
 
 # Synopsis:
-# Test the test runner Docker image by running it against a predefined set of 
+# Test the test runner Docker image by running it against a predefined set of
 # solutions with an expected output.
 # The test runner Docker image is built automatically.
 
@@ -14,16 +14,34 @@ set -e
 # Example:
 # ./bin/run-tests-in-docker.sh
 
+mnt_opt=""
+run_opt=""
+if ! command -v docker > /dev/null ; then
+    if ! command -v podman > /dev/null ; then
+        echo "Docker or Podman must be installed to run the tests in a container."
+        exit 1
+    fi
+    # Docker is unavailable, use Podman
+    docker() {
+        podman "$@"
+    }
+    # for SELinux systems, permit container access to mounted directories
+    mnt_opt=",Z"
+    # use same user ID for container, avoids file ownership problems
+    run_opt="--userns=keep-id"
+fi
+
 # Build the Docker image
 docker build --rm -t exercism/rust-test-runner .
 
 # Run the Docker image using the settings mimicking the production environment
 docker run \
     --rm \
     --network none \
-    --mount type=bind,src="${PWD}/tests",dst=/opt/test-runner/tests \
+    --mount type=bind,src="${PWD}/tests,dst=/opt/test-runner/tests$mnt_opt" \
     --mount type=tmpfs,dst=/tmp \
-    --volume "${PWD}/bin/run-tests.sh:/opt/test-runner/bin/run-tests.sh" \
+    --mount type=bind,src="${PWD}/bin/run-tests.sh,dst=/opt/test-runner/bin/run-tests.sh$mnt_opt" \
+    $run_opt \
     --workdir /opt/test-runner \
     --entrypoint /opt/test-runner/bin/run-tests.sh \
     exercism/rust-test-runner

bin/run-tests.sh

@@ -35,7 +35,7 @@ for test_dir in tests/*; do
     bin/run.sh "${slug}" "${test_dir_path}" "${test_dir_path}"
 
     # Normalize the results file
-    jq 'if (.tests != null) then .tests |= sort_by(.name) else . end' "${results_file_path}" > tmp && mv tmp "${results_file_path}"
+    jq 'if (.tests != null) then .tests |= sort_by(.name) else . end' "${results_file_path}" > /tmp/res && mv /tmp/res "${results_file_path}"
     sed -i -e 's/warning: build failed, waiting for other jobs to finish.*//' "${results_file_path}"
 
     echo "${test_dir_name}: comparing results.json to expected_results.json"