specgen, cgroup2: check whether memory swap is enabled
add a similar check to what we do on cgroup v1.
package generate
import (
+ "os"
+ "path/filepath"
+
"github.com/containers/common/pkg/sysinfo"
"github.com/containers/podman/v2/pkg/cgroups"
"github.com/containers/podman/v2/pkg/specgen"
+ "github.com/containers/podman/v2/utils"
"github.com/pkg/errors"
)
@@ -158,7 +162,34 @@ func verifyContainerResourcesCgroupV1(s *specgen.SpecGenerator) ([]string, error
// Verify resource limits are sanely set when running on cgroup v2.
func verifyContainerResourcesCgroupV2(s *specgen.SpecGenerator) ([]string, error) {
- return []string{}, nil
+ warnings := []string{}
+
+ if s.ResourceLimits == nil {
+ return warnings, nil
+ }
+
+ if s.ResourceLimits.Memory != nil && s.ResourceLimits.Memory.Swap != nil {
+ own, err := utils.GetOwnCgroup()
+ if err != nil {
+ return warnings, err
+ }
+ memoryMax := filepath.Join("/sys/fs/cgroup", own, "memory.max")
+ memorySwapMax := filepath.Join("/sys/fs/cgroup", own, "memory.swap.max")
+ _, errMemoryMax := os.Stat(memoryMax)
+ _, errMemorySwapMax := os.Stat(memorySwapMax)
+ // Differently than cgroup v1, the memory.*max files are not present in the
+ // root directory, so we cannot query directly that, so as best effort use
+ // the current cgroup.
+ // Check whether memory.max exists in the current cgroup and memory.swap.max
+ // does not. In this case we can be sure memory swap is not enabled.
+ // If both files don't exist, the memory controller might not be enabled
+ // for the current cgroup.
+ if errMemoryMax == nil && errMemorySwapMax != nil {
+ warnings = append(warnings, "Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.")
+ s.ResourceLimits.Memory.Swap = nil
+ }
+ }
+ return warnings, nil
}
// Verify resource limits are sanely set, removing any limits that are not
