Cgroup v1 initialization causes "invalid format for CGroupSubsys" when cgroup path contains colon

[PoliM]

Describe the bug
The memory_ballast extensions fails to initialize when reading the cgroup configuration.
The cgroup configuration contains three fields separated by colons. Now it seems that when the cgroup driver is systemd, the third field (the cgroup path) can contain colons in its value too. Since the initialization code just splits the line by colons it detects a wrong number of fields which result in an error showing "invalid format for CGroupSubsys". More details below under "Additional context".

Steps to reproduce

• Kubernetes cluster 1.23 where the cgroup driver is configured to use systemd. See: https://kubernetes.io/docs/tasks/administer-cluster/kubeadm/configure-cgroup-driver/
• Deploy the otel collector with the memory_ballast extension and service active

What did you expect to see?
An empty log.

What did you see instead?
2022/10/21 14:21:12 collector server run finished with error: failed to start extensions: invalid format for CGroupSubsys: "13:rdma:/kubepods-burstable-pod4f4de620_8801_4afa_a9c5_e7bbae3a38bb.slice:cri-containerd:50aefe89fd66b08c88f54c9850c44f84e240455e777551429c31e799274efce2"

What version did you use?
Docker image: otel/opentelemetry-collector-contrib:0.60.0

What config did you use?
otel-collector-config.txt

Environment
Kubernetes: 1.23
OS: SUSE Linux Enterprise Server 15 SP4 Kernel: 5.14.21-150400.24.21-default

Additional context
The error is created in the operation NewCGroupSubsysFromLine where it splits the string by the separator and checks that there are three fields. See:

opentelemetry-collector/internal/cgroups/subsys.go

Line 72 in 9d3a8a4

func NewCGroupSubsysFromLine(line string) (*CGroupSubsys, error) {

Here is a sample of "old-style" cgroup configs:
sh-4.4$ cat /proc/self/cgroup
13:freezer:/kubepods/burstable/podd726b5c0-b28a-4a01-98a0-100a5bdc5c9a/c9976349bfb59dabbe1fd9ae8520c0517dd3e56702f4fa57b8929641fdf87eeb
12:cpuset:/kubepods/burstable/podd726b5c0-b28a-4a01-98a0-100a5bdc5c9a/c9976349bfb59dabbe1fd9ae8520c0517dd3e56702f4fa57b8929641fdf87eeb

And here some with the new format which contains colons in the path:
sh-4.4$ cat /proc/self/cgroup
13:pids:/system.slice/rke2-agent.service/kubepods-burstable-pod4d692290_f5ee_45b9_8093_50de46b24c12.slice:cri-containerd:811794ed3b7ecfb2f5f43eb3a3f3f66ab73944ed6258cc6377ffc8b513ce8a65
12:rdma:/kubepods-burstable-pod4d692290_f5ee_45b9_8093_50de46b24c12.slice:cri-containerd:811794ed3b7ecfb2f5f43eb3a3f3f66ab73944ed6258cc6377ffc8b513ce8a65

[rockdrilla]

Hi there! I've done minor fix for this issue. I've been hit the same issue too while writing own "/proc/{pid}/cgroup" parser.