[core] Enable cgroup unit tests in CI (#51864)

Signed-off-by: dentiny <[email protected]>

Author: dentiny

.buildkite/core.rayci.yml

@@ -292,34 +292,41 @@ steps:
       - "3.13"
 
   # cpp tests
+  - label: ":ray: core: cgroup tests"
+    tags: core_cpp
+    instance_type: medium
+    commands:
+      - bazel run //ci/ray_ci:test_in_docker -- //:all //src/... core --only-tags=cgroup --build-type cgroup
+        --privileged --cache-test-results
+
   - label: ":ray: core: cpp tests"
     tags: core_cpp
     instance_type: medium
     commands:
-      - bazel run //ci/ray_ci:test_in_docker -- //:all //src/... core --build-type clang
+      - bazel run //ci/ray_ci:test_in_docker -- //:all //src/... core --except-tags=cgroup --build-type clang
         --cache-test-results --parallelism-per-worker 2
 
   - label: ":ray: core: cpp asan tests"
     tags: core_cpp
     instance_type: medium
     commands:
-      - bazel run //ci/ray_ci:test_in_docker -- //:all //src/... core --build-type asan-clang
-        --cache-test-results --parallelism-per-worker 2
+      - bazel run //ci/ray_ci:test_in_docker -- //:all //src/... core --except-tags=cgroup
+        --build-type asan-clang --cache-test-results --parallelism-per-worker 2
 
   - label: ":ray: core: cpp ubsan tests"
     tags: core_cpp
     instance_type: large
     commands:
-      - bazel run //ci/ray_ci:test_in_docker -- //:all //src/... core --build-type ubsan
-        --except-tags no_ubsan
+      - bazel run //ci/ray_ci:test_in_docker -- //:all //src/... core
+        --build-type ubsan --except-tags no_ubsan,cgroup
         --cache-test-results --parallelism-per-worker 2
 
   - label: ":ray: core: cpp tsan tests"
     tags: core_cpp
     instance_type: medium
     commands:
-      - bazel run //ci/ray_ci:test_in_docker -- //:all //src/... core --build-type tsan-clang
-        --except-tags no_tsan
+      - bazel run //ci/ray_ci:test_in_docker -- //:all //src/... core
+        --build-type tsan-clang --except-tags no_tsan,cgroup
         --cache-test-results --parallelism-per-worker 2
 
   - label: ":ray: core: flaky cpp tests"

src/ray/common/cgroup/test/BUILD

@@ -5,8 +5,7 @@ ray_cc_test(
     size = "small",
     srcs = ["cgroup_v2_utils_privileged_test.cc"],
     tags = [
-        # TODO(hjiang, ibrahim, lonnie): Setup CI for cgroup testing environment.
-        "manual",
+        "cgroup",
         "exclusive",
         "team:core",
     ],