90 lines
2.1 KiB
Go
90 lines
2.1 KiB
Go
// Copyright The OpenTelemetry Authors
|
|
// SPDX-License-Identifier: Apache-2.0
|
|
|
|
package resource // import "go.opentelemetry.io/otel/sdk/resource"
|
|
|
|
import (
|
|
"bufio"
|
|
"context"
|
|
"errors"
|
|
"io"
|
|
"os"
|
|
"regexp"
|
|
|
|
semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
|
|
)
|
|
|
|
type containerIDProvider func() (string, error)
|
|
|
|
var (
|
|
containerID containerIDProvider = getContainerIDFromCGroup
|
|
cgroupContainerIDRe = regexp.MustCompile(`^.*/(?:.*[-:])?([0-9a-f]+)(?:\.|\s*$)`)
|
|
)
|
|
|
|
type cgroupContainerIDDetector struct{}
|
|
|
|
const cgroupPath = "/proc/self/cgroup"
|
|
|
|
// Detect returns a *Resource that describes the id of the container.
|
|
// If no container id found, an empty resource will be returned.
|
|
func (cgroupContainerIDDetector) Detect(ctx context.Context) (*Resource, error) {
|
|
containerID, err := containerID()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if containerID == "" {
|
|
return Empty(), nil
|
|
}
|
|
return NewWithAttributes(semconv.SchemaURL, semconv.ContainerID(containerID)), nil
|
|
}
|
|
|
|
var (
|
|
defaultOSStat = os.Stat
|
|
osStat = defaultOSStat
|
|
|
|
defaultOSOpen = func(name string) (io.ReadCloser, error) {
|
|
return os.Open(name)
|
|
}
|
|
osOpen = defaultOSOpen
|
|
)
|
|
|
|
// getContainerIDFromCGroup returns the id of the container from the cgroup file.
|
|
// If no container id found, an empty string will be returned.
|
|
func getContainerIDFromCGroup() (string, error) {
|
|
if _, err := osStat(cgroupPath); errors.Is(err, os.ErrNotExist) {
|
|
// File does not exist, skip
|
|
return "", nil
|
|
}
|
|
|
|
file, err := osOpen(cgroupPath)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
defer file.Close()
|
|
|
|
return getContainerIDFromReader(file), nil
|
|
}
|
|
|
|
// getContainerIDFromReader returns the id of the container from reader.
|
|
func getContainerIDFromReader(reader io.Reader) string {
|
|
scanner := bufio.NewScanner(reader)
|
|
for scanner.Scan() {
|
|
line := scanner.Text()
|
|
|
|
if id := getContainerIDFromLine(line); id != "" {
|
|
return id
|
|
}
|
|
}
|
|
return ""
|
|
}
|
|
|
|
// getContainerIDFromLine returns the id of the container from one string line.
|
|
func getContainerIDFromLine(line string) string {
|
|
matches := cgroupContainerIDRe.FindStringSubmatch(line)
|
|
if len(matches) <= 1 {
|
|
return ""
|
|
}
|
|
return matches[1]
|
|
}
|