Skip to content

Add support for cgroup v1 #992

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
ogaca-dd wants to merge 1 commit into from
Closed

Add support for cgroup v1 #992

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
31 changes: 22 additions & 9 deletions process/process.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -30,9 +30,21 @@ import (
// GetMappings returns this error when no mappings can be extracted.
var ErrNoMappings = errors.New("no mappings")

const (
containerSource = "[0-9a-f]{64}"
taskSource = "[0-9a-f]{32}-\\d+"
)

//nolint:lll
var (
cgroupv2ContainerIDPattern = regexp.MustCompile(`0:.*?:.*?([0-9a-fA-F]{64})(?:\.scope)?(?:/[a-z]+)?$`)
// expLine matches a line in the /proc/<pid>/cgroup file. It has a submatch for the last element (path), which contains the container ID. Support both cgroup v1 and v2.
expLine = regexp.MustCompile(`^\d+:[^:]*:(.+)$`)

// Inspire from https://github.com/DataDog/dd-otel-host-profiler/blob/1e50a36d4c3a8a87f0cc828f37b48455ec436e55/containermetadata/container.go#L32-L47 with the following changes to handle unit tests in process_test.go:
// - support prefix after `scope` to handle "0::/system.slice/docker-b1eba9dfaeba29d8b80532a574a03ea3cac29384327f339c26da13649e2120df.scope/init"
// - remove uuidSource to doesn't match "0::/user.slice/user-1000.slice/user@1000.service/app.slice/app-org.gnome.Terminal.slice/vte-spawn-868f9513-eee8-457d-8e36-1b37ae8ae622.scope"

expContainerID = regexp.MustCompile(fmt.Sprintf(`(%s|%s)(?:.scope)?(?:/[a-z]+)?$`, containerSource, taskSource))
)

// systemProcess provides an implementation of the Process interface for a
Expand Down Expand Up @@ -127,7 +139,7 @@ func (sp *systemProcess) GetProcessMeta(cfg MetaConfig) ProcessMeta {
}
}

// parseContainerID parses cgroup v2 container IDs
// parseContainerID parses cgroup v1 and v2 container IDs
func parseContainerID(cgroupFile io.Reader) libpf.String {
scanner := bufio.NewScanner(cgroupFile)
buf := make([]byte, 512)
Expand All @@ -136,31 +148,32 @@ func parseContainerID(cgroupFile io.Reader) libpf.String {
// With a maximum of 4096 characters path in the kernel, 8192 should be fine here. We don't
// expect lines in /proc/<PID>/cgroup to be longer than that.
scanner.Buffer(buf, 8192)
var pathParts []string
for scanner.Scan() {
b := scanner.Bytes()
if bytes.Equal(b, []byte("0::/")) {
continue // Skip a common case
}
line := pfunsafe.ToString(b)
pathParts = cgroupv2ContainerIDPattern.FindStringSubmatch(line)
if pathParts == nil {
log.Debugf("Could not extract cgroupv2 path from line: %s", line)
continue
m := expLine.FindStringSubmatch(line)
if len(m) == 2 {
if parts := expContainerID.FindStringSubmatch(m[1]); len(parts) == 2 {
return libpf.Intern(parts[1])
}
}
return libpf.Intern(pathParts[1])
log.Debugf("Could not extract container ID from line: %s", line)
}

// No containerID could be extracted
return libpf.NullString
}

// extractContainerID returns the containerID for pid if cgroup v2 is used.
// extractContainerID returns the containerID for pid (supports both cgroup v1 and v2)
func extractContainerID(pid libpf.PID) (libpf.String, error) {
cgroupFile, err := os.Open(fmt.Sprintf("/proc/%d/cgroup", pid))
if err != nil {
return libpf.NullString, err
}
defer cgroupFile.Close()

return parseContainerID(cgroupFile), nil
}
Expand Down
10 changes: 10 additions & 0 deletions process/process_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -159,6 +159,16 @@ func TestExtractContainerID(t *testing.T) {
line: "0::/system.slice/docker-b1eba9dfaeba29d8b80532a574a03ea3cac29384327f339c26da13649e2120df.scope/init",
expectedContainerID: "b1eba9dfaeba29d8b80532a574a03ea3cac29384327f339c26da13649e2120df",
},
{
// cgroup v1
line: "11:memory:/kubepods/besteffort/poda9c80282-3f6b-4d5b-84d5-a137a6668011/ed89697807a981b82f6245ac3a13be232c1e13435d52bc3f53060d61babe1997",
expectedContainerID: "ed89697807a981b82f6245ac3a13be232c1e13435d52bc3f53060d61babe1997",
},
{
// cgroup v1
line: "11:cpucpuacct:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a",
expectedContainerID: "da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a",
},
}

for _, tc := range tests {
Expand Down