این فرآیندی که من در هاست خود می بینم از کدام پاد (و فضای نام!) Kubernetes است؟

$ ps auxw | fgrep python
root       11282  0.0  0.0  94628 24372 ?        Ss   04:53   0:00 python app.py
root       11439  0.0  0.0  41968 13072 ?        Ss   04:53   0:00 python event-simulator.py
root       12527  0.0  0.0   6796  2292 pts/0    S+   04:57   0:00 grep -F --color=auto python

$ nsenter -t 11282 -u hostname
webapp-color

$ nsenter -t 11439 -u hostname
e-com-1123

$ for i in 11282 11439; do crictl inspect --output go-template --template '{{index .status.labels "io.kubernetes.pod.namespace" }}:{{index .status.labels "io.kubernetes.pod.name" }}'  $( head -n1 /proc/$i/cgroup | cut -f5 -d':' ) ; done
default:webapp-color
e-commerce:e-com-1123

$ nsenter -t 11439 -u hostname
e-com-1123

$ nsenter -h
Run a program with namespaces of other processes.
...
 -u, --uts[=<file>]     enter UTS namespace (hostname etc)
...

$ nsenter -h
Usage:
 nsenter [options] [<program> [<argument>...]]

Run a program with namespaces of other processes.
...
 -a, --all              enter all namespaces
 -t, --target <pid>     target process to get namespaces from
 -m, --mount[=<file>]   enter mount namespace
 -u, --uts[=<file>]     enter UTS namespace (hostname etc)
 -i, --ipc[=<file>]     enter System V IPC namespace
 -n, --net[=<file>]     enter network namespace
 -p, --pid[=<file>]     enter pid namespace
 -C, --cgroup[=<file>]  enter cgroup namespace
 -U, --user[=<file>]    enter user namespace
 -T, --time[=<file>]    enter time namespace

$ ps -wwo cgroup= 11439
12:hugetlb:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a,11:cpu,cpuacct:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a,10:memory:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a,9:perf_event:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a,8:net_cls,net_prio:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a,7:cpuset:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a,6:pids:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a,5:blkio:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a,4:devices:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a,3:rdma:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a,2:freezer:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a,1:name=systemd:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a

ps -wwo cgroup= 11439 | tr , '\n'
12:hugetlb:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
11:cpu
cpuacct:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
10:memory:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
9:perf_event:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
8:net_cls
net_prio:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
7:cpuset:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
6:pids:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
5:blkio:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
4:devices:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
3:rdma:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
2:freezer:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
1:name=systemd:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a

$ cat /proc/11439/cgroup 
12:hugetlb:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
11:cpu,cpuacct:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
10:memory:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
9:perf_event:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
8:net_cls,net_prio:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
7:cpuset:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
6:pids:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
5:blkio:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
4:devices:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
3:rdma:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
2:freezer:/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
1:name=systemd:/system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
0::/

$ cat /proc/11439/cgroup | cut -f3- -d':' | sort | uniq  -c 
      1 /
      6 /kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
      6 /system.slice/containerd.service/kubepods-besteffort-pod86811ae3_b633_4eb8_a508_e3eae190f6ce.slice:cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a

$ cat /proc/11439/cgroup | cut -f4- -d':' | sort | uniq  -c 
      1 
     12 cri-containerd:da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a

$ crictl ps --id da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
CONTAINER           IMAGE               CREATED             STATE               NAME                ATTEMPT             POD ID              POD
da1bdd84c8b25       ee4be8f9dfd10       7 minutes ago       Running             simple-webapp       0                   48ee11c897fa8       e-com-1123

$ crictl inspect da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a | jq '. | keys'
[
  "info",
  "status"
]

$ crictl inspect da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a | jq '.info | keys'
[
  "config",
  "pid",
  "removing",
  "runtimeOptions",
  "runtimeSpec",
  "runtimeType",
  "sandboxID",
  "snapshotKey",
  "snapshotter"
]

$ crictl inspect da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a | jq '.status | keys'
[
  "annotations",
  "createdAt",
  "exitCode",
  "finishedAt",
  "id",
  "image",
  "imageId",
  "imageRef",
  "labels",
  "logPath",
  "message",
  "metadata",
  "mounts",
  "reason",
  "resources",
  "startedAt",
  "state"
]

$ crictl inspect da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a | jq '.status.labels'
{
  "io.kubernetes.container.name": "simple-webapp",
  "io.kubernetes.pod.name": "e-com-1123",
  "io.kubernetes.pod.namespace": "e-commerce",
  "io.kubernetes.pod.uid": "86811ae3-b633-4eb8-a508-e3eae190f6ce"
}

$ crictl inspect --output go-template --template '{{.status.labels}}' da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
map[io.kubernetes.container.name:simple-webapp io.kubernetes.pod.name:e-com-1123 io.kubernetes.pod.namespace:e-commerce io.kubernetes.pod.uid:86811ae3-b633-4eb8-a508-e3eae190f6ce]

$ crictl inspect --output go-template --template '{{.status.labels.io.kubernetes.pod.name}}' da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
FATA[0000] getting the status of the container "da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a": failed to template data: template: tmplExecuteRawJSON:1:9: executing "tmplExecuteRawJSON" at <.status.labels.io.kubernetes.pod.name>: map has no entry for key "io" 

$ crictl inspect --output go-template --template '{{index .status.labels "io.kubernetes.pod.name" }}' da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
e-com-1123

$ crictl inspect --output go-template --template '{{index .status.labels "io.kubernetes.pod.namespace" }}:{{index .status.labels "io.kubernetes.pod.name" }}' da1bdd84c8b25938081afe48da7075e2a211d2b1a62e01c894b4e5f3ffab670a
e-commerce:e-com-1123

$ for i in $( pgrep python -d ' ' ); do crictl inspect --output go-template --template '{{index .status.labels "io.kubernetes.pod.namespace" }}:{{index .status.labels "io.kubernetes.pod.name" }}'  $( head -n1 /proc/$i/cgroup | cut -f5 -d':' ) ; done
default:webapp-color
e-commerce:e-com-1123

$ cat which-pod-am-i.sh 
#!/bin/bash

# This is NOT a production script!
# This was made just to make the techniques legible!

# Pieces of go templates.
# We need to retrieve two fields from .status.labels:
# .status.labels."io.kubernetes.pod.namespace" 
NAMESPACE_TMPL='{{index .status.labels "io.kubernetes.pod.namespace" }}'
# .status.labels."io.kubernetes.pod.name"
POD_TMPL='{{index .status.labels "io.kubernetes.pod.name" }}'

# I'm passing the process name from command line: 
for i in $( pgrep ${1?Parameter not passed} -d ' ' ); do 

  # Get the container ID from the cgroups:
  CONTAINER_ID=$( head -n1 /proc/$i/cgroup | cut -f5 -d':' )

  # Inspect with go templates:   
  crictl inspect --output go-template \
                 --template "$NAMESPACE_TMPL:$POD_TMPL" \
                 ${CONTAINER_ID:?Container not found}
done

$ ./which-pod-am-i.sh python
default:webapp-color
e-commerce:e-com-1123