Method ReadFile

lib/manager/container.go:403–419

ReadFile reads a file from inside the container, trying each of the container's processes' root filesystem in turn. Used by application-metrics collectors to read collector config files declared via container labels.

(filepath string, inHostNamespace bool)

// container's processes' root filesystem in turn. Used by application-metrics
// collectors to read collector config files declared via container labels.
func (cd *containerData) ReadFile(filepath string, inHostNamespace bool) ([]byte, error) {
	pids, err := cd.handler.ListProcesses(container.ListSelf)
	if err != nil {
		return nil, err
	}
	rootfs := "/"
	if !inHostNamespace {
		rootfs = "/rootfs"
	}
	for _, pid := range pids {
		fp := path.Join(rootfs, "/proc", strconv.Itoa(pid), "/root", filepath)
		if data, rerr := os.ReadFile(fp); rerr == nil {
			return data, nil
		}
	}
	return nil, fmt.Errorf("file %q does not exist", filepath)
}

// Calculate new smoothed load average using the new sample of runnable threads.
// The decay used ensures that the load will stabilize on a new constant value within