invalid json patch when running custom command

[part-time-githubber]

kubectl node-shell ip-10-240-27-191.eu-west-1.compute.internal -- echo 123
spawning "nsenter-dzp06n" on "ip-10-240-27-191.eu-west-1.compute.internal"
error: Invalid JSON Patch

kubectl version
Client Version: version.Info{Major:"1", Minor:"19", GitVersion:"v1.19.7", GitCommit:"1dd5338295409edcfff11505e7bb246f0d325d15", GitTreeState:"clean", BuildDate:"2021-01-13T13:23:52Z", GoVersion:"go1.15.5", Compiler:"gc", Platform:"darwin/amd64"}
Server Version: version.Info{Major:"1", Minor:"18+", GitVersion:"v1.18.9-eks-d1db3c", GitCommit:"d1db3c46e55f95d6a7d3e5578689371318f95ff9", GitTreeState:"clean", BuildDate:"2020-10-20T22:18:07Z", GoVersion:"go1.13.15", Compiler:"gc", Platform:"linux/amd64"}

thoughts?

[kvaps]

could you please provide more debug info?

bash -x kubectl-node_shell ip-10-240-27-191.eu-west-1.compute.internal -- echo 123

[pankajmt]

bash -x kubectl-node_shell ip-10-240-25-184.eu-west-1.compute.internal -- echo 123
+ set -e
+ kubectl=kubectl
+ generator=
+ node=
+ nodefaultctx=0
+ nodefaultns=0
+ cmd='[ "nsenter", "--target", "1", "--mount", "--uts", "--ipc", "--net", "--pid", "--", '
+ custom=false
+ '[' -p /dev/stdin ']'
+ '[' -p /dev/stdout ']'
+ tty=true
+ '[' 4 -gt 0 ']'
+ key=ip-10-240-25-184.eu-west-1.compute.internal
+ case $key in
+ '[' -z '' ']'
+ node=ip-10-240-25-184.eu-west-1.compute.internal
+ shift
+ '[' 3 -gt 0 ']'
+ key=--
+ case $key in
+ shift
+ break
+ '[' 0 = 1 ']'
++ kubectl config current-context
+ kubectl='kubectl --context=clusteradmin@alpha-euwe1-v1'
+ '[' 0 = 1 ']'
++ kubectl config view --minify --output 'jsonpath={.contexts..namespace}'
+ kubectl='kubectl --context=clusteradmin@alpha-euwe1-v1 --namespace=kube-system'
+ '[' 2 -gt 0 ']'
+ cmd='[ "nsenter", "--target", "1", "--mount", "--uts", "--ipc", "--net", "--pid", "--", "echo", '
+ custom=true
+ shift
+ '[' 1 -gt 0 ']'
+ cmd='[ "nsenter", "--target", "1", "--mount", "--uts", "--ipc", "--net", "--pid", "--", "echo", "123", '
+ custom=true
+ shift
+ '[' 0 -gt 0 ']'
+ '[' true = true ']'
++ echo '[ "nsenter", "--target", "1", "--mount", "--uts", "--ipc", "--net", "--pid", "--", "echo", "123", '
++ awk 1 'RS=, \n'
+ cmd='[ "nsenter"
 "--target"
 "1"
 "--mount"
 "--uts"
 "--ipc"
 "--net"
 "--pid"
 "--"
 "echo"
 "123"
  ]'
+ '[' -z ip-10-240-25-184.eu-west-1.compute.internal ']'
+ image=docker.io/library/alpine
++ env LC_ALL=C tr -dc a-z0-9
++ head -c 6
+ pod=nsenter-exwvp0
+ kubectl get node ip-10-240-25-184.eu-west-1.compute.internal
++ cat
+ overrides='{
  "spec": {
    "nodeName": "ip-10-240-25-184.eu-west-1.compute.internal",
    "hostPID": true,
    "hostNetwork": true,
    "containers": [
      {
        "securityContext": {
          "privileged": true
        },
        "image": "docker.io/library/alpine",
        "name": "nsenter",
        "stdin": true,
        "stdinOnce": true,
        "tty": true,
        "command": [ "nsenter"
 "--target"
 "1"
 "--mount"
 "--uts"
 "--ipc"
 "--net"
 "--pid"
 "--"
 "echo"
 "123"
  ]
      }
    ],
    "tolerations": [
      {
        "key": "CriticalAddonsOnly",
        "operator": "Exists"
      },
      {
        "effect": "NoExecute",
        "operator": "Exists"
      }
    ]
  }
}'
++ kubectl version --client -o yaml
++ awk '-F[ :"]+' '$2 == "minor" {print $3+0}'
+ m=19
+ '[' 19 -lt 18 ']'
+ trap 'EC=$?; kubectl --context=clusteradmin@alpha-euwe1-v1 --namespace=kube-system delete pod --wait=false nsenter-exwvp0 2>/dev/null || true; exit $EC' EXIT INT TERM
+ echo 'spawning "nsenter-exwvp0" on "ip-10-240-25-184.eu-west-1.compute.internal"'
spawning "nsenter-exwvp0" on "ip-10-240-25-184.eu-west-1.compute.internal"
+ kubectl --context=clusteradmin@alpha-euwe1-v1 --namespace=kube-system run --image docker.io/library/alpine --restart=Never '--overrides={
  "spec": {
    "nodeName": "ip-10-240-25-184.eu-west-1.compute.internal",
    "hostPID": true,
    "hostNetwork": true,
    "containers": [
      {
        "securityContext": {
          "privileged": true
        },
        "image": "docker.io/library/alpine",
        "name": "nsenter",
        "stdin": true,
        "stdinOnce": true,
        "tty": true,
        "command": [ "nsenter"
 "--target"
 "1"
 "--mount"
 "--uts"
 "--ipc"
 "--net"
 "--pid"
 "--"
 "echo"
 "123"
  ]
      }
    ],
    "tolerations": [
      {
        "key": "CriticalAddonsOnly",
        "operator": "Exists"
      },
      {
        "effect": "NoExecute",
        "operator": "Exists"
      }
    ]
  }
}' -ti nsenter-exwvp0
error: Invalid JSON Patch
+ EC=1
+ kubectl --context=clusteradmin@alpha-euwe1-v1 --namespace=kube-system delete pod --wait=false nsenter-exwvp0
+ true
+ exit 1

[gecube]

I believe that the part

        "command": [ "nsenter"
 "--target"
 "1"
 "--mount"
 "--uts"
 "--ipc"
 "--net"
 "--pid"
 "--"
 "echo"
 "123"
  ]

must look like:

        "command": [ "nsenter",
 "--target",
 "1",
 "--mount",
 "--uts",
 "--ipc",
 "--net",
 "--pid",
 "--",
 "echo",
 "123"
  ]

@kvaps any suggestions?
@pankajmt what is your OS and what particular bash version do you use?

[kvaps]

I guess problem not in bash, but in awk.
This @pankajmt please provide your awk --version info

According the provided debug info, awk is the one who spoils the output of $cmd.
I decided to avoid using RS variable at all.

This problem should be fixed in v1.2.4 by aae8212

[pankajmt]

Many thanks. Should I be able to get this now?

$ kubectl krew update
Updated the local copy of plugin index.
 $ kubectl krew upgrade node-shell
Updated the local copy of plugin index.
Upgrading plugin: node-shell
F0331 05:21:01.111818   48636 root.go:79] failed to upgrade plugin "node-shell": can't upgrade, the newest version is already installed
 ✘  $ kubectl krew list
PLUGIN      VERSION
get-all     v1.3.7
krew        v0.4.1
neat        v2.0.2
node-shell  v1.2.3

[kvaps]

Ah, I forgot to update default krew repo. It should be available after merge of this PR
kubernetes-sigs/krew-index#1159

[pankajmt]

awesome. works now. thanks.