Container check does not work

[johnmaguire]

We're seeing failures to "run" the service under Docker due to syslog not being available. It seems there are container checks present but they are not firing:

service/service_linux.go

Lines 80 to 89 in a1c091b

	f, err := os.Open(cgroupPath)
	if err != nil {
	return false, err
	}
	defer f.Close()
	scan := bufio.NewScanner(f)
	lines := 0
	for scan.Scan() && !(lines > maxlines) {
	if strings.Contains(scan.Text(), "docker") || strings.Contains(scan.Text(), "lxc") {

Inside the container, the cgroup file does not show "lxc" or "docker." (Tested Alpine 3.17 and Debian 11.6 under Arch Linux 6.1.3 and MacOS Ventura 13.2.

❯ docker run alpine cat /proc/1/cgroup
0::/
❯ docker run debian cat /proc/1/cgroup
0::/

❯ uname -a
Linux Acheron 6.1.3-arch1-1 #1 SMP PREEMPT_DYNAMIC Wed, 04 Jan 2023 16:28:15 +0000 x86_64 GNU/Linux
❯ docker info
Client:
 Context:    default
 Debug Mode: false
 Plugins:
  compose: Docker Compose (Docker Inc.)
    Version:  2.16.0
    Path:     /usr/lib/docker/cli-plugins/docker-compose

Server:
 Containers: 14
  Running: 13
  Paused: 0
  Stopped: 1
 Images: 36
 Server Version: 20.10.22
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Native Overlay Diff: false
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 io.containerd.runtime.v1.linux nvidia runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 9ba4b250366a5ddde94bb7c9d1def331423aa323.m
 runc version:
 init version: de40ad0
 Security Options:
  seccomp
   Profile: default
  cgroupns
 Kernel Version: 6.1.3-arch1-1
 Operating System: Arch Linux
 OSType: linux
 Architecture: x86_64
 CPUs: 4
 Total Memory: 31.32GiB
 Name: Acheron
 ID: J6LO:L2GH:7KPO:5P2B:XWUN:HHW4:IOJZ:TBJH:GP6M:HXK4:FUBM:5EV3
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Username: jmaguire
 Registry: https://index.docker.io/v1/
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

❯ uname -a
Darwin Johns-MacBook-Pro.local 22.3.0 Darwin Kernel Version 22.3.0: Thu Jan  5 20:48:54 PST 2023; root:xnu-8792.81.2~2/RELEASE_ARM64_T6000 arm64
❯ docker info
Client:
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc., v0.7.1)
  compose: Docker Compose (Docker Inc., v2.2.3)
  scan: Docker Scan (Docker Inc., v0.16.0)

Server:
 Containers: 48
  Running: 3
  Paused: 0
  Stopped: 45
 Images: 50
 Server Version: 20.10.12
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 io.containerd.runtime.v1.linux runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 7b11cfaabd73bb80907dd23182b9347b4245eb5d
 runc version: v1.0.2-0-g52b36a2
 init version: de40ad0
 Security Options:
  seccomp
   Profile: default
  cgroupns
 Kernel Version: 5.10.76-linuxkit
 Operating System: Docker Desktop
 OSType: linux
 Architecture: aarch64
 CPUs: 5
 Total Memory: 3.841GiB
 Name: docker-desktop
 ID: U5SA:S6XL:A6EC:AB5K:YE5E:HDC5:LWFY:3ZTU:BIPX:2BHE:USKA:KHIE
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false