KUBECTL_EXTERNAL_DIFF variable --ignore-matching-lines="image:.* does not take effect

[bertreyking]

What happened:

cat harbor-portal.yaml harbor-portal-2.yaml | grep image 
      - image: docker.io/goharbor/harbor-portal:v2.11.21
        imagePullPolicy: IfNotPresent
      - image: docker.io/goharbor/harbor-portal:v2.11.1
        imagePullPolicy: IfNotPresent

diff -y --ignore-matching-lines="image:.*"  --suppress-common-lines harbor-portal.yaml harbor-portal-2.yaml   # echo $? = 0 

export KUBECTL_EXTERNAL_DIFF='diff -y --ignore-matching-lines="image:.*" --width=180 --suppress-common-lines'
kubectl diff -f harbor-portal.yaml 
diff -y '--width=180' --suppress-common-lines /tmp/LIVE-2161628695/apps.v1.Deployment.default.harbor-portal /tmp/MERGED-828643458/apps.v1.Deployment.default.harbor-portal
  generation: 4                                                                       |   generation: 5
      - image: docker.io/goharbor/harbor-portal:v2.11.1                      |       - image: docker.io/goharbor/harbor-portal:v2.11.21

Normally, only the generation should be shown as different—unless I exclude it.

What you expected to happen:

expect the --ignore-matching-lines parameter to correctly match and exclude specified lines.

How to reproduce it (as minimally and precisely as possible):

1. kubectl get deployment $deployment_name -o yaml > deplyment-1.yaml
2. kubectl get deployment $deployment_name -o yaml > deplyment-2.yaml
3. modify the image tag version
4. diff -y --ignore-matching-lines="image:.*" --suppress-common-lines deplyment-1.yaml deplyment-2.yaml # success
5. export KUBECTL_EXTERNAL_DIFF='diff -y --ignore-matching-lines="image:.*" --width=180 --suppress-common-lines'
6. kubectl diff -f deplyment-1.yaml # failed

Anything else we need to know?:
I am working in a CI/CD pipeline and need to compare YAML files in different Git commits to ensure they match the actual running resources, …except for the fields that should be ignored.

Environment:

• Kubernetes client and server versions (use kubectl version): 1.29.5
• Cloud provider or hardware configuration: none
• OS (e.g: cat /etc/os-release): centos7

[k8s-ci-robot]

This issue is currently awaiting triage.

SIG CLI takes a lead on issue triage for this repo, but any Kubernetes member can accept issues by applying the triage/accepted label.

The triage/accepted label can be added by org members by writing /triage accepted in a comment.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[bertreyking]

• diff.sh

#!/bin/bash
diff -y -B --width=180 --suppress-common-lines --ignore-matching-lines="image:.*" --ignore-matching-lines="generation:.*" $1 $2

• export KUBECTL_EXTERNAL_DIFF='./diff.sh'
• kubectl diff -f deplyment-1.yaml

it's ok

[mpuckett159]

/close
A work around has been provided and if you would like more information please see this issue
#1436

[k8s-ci-robot]

@mpuckett159: Closing this issue.

In response to this:

/close
A work around has been provided and if you would like more information please see this issue
#1436

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.