Fix #2308: kubeconfig with external authentication command doesn't work

[rohanKanojia]

Description

Fix #2308

Iterate over PATH values in order to find correct absolute path for command being executed.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• Feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change
• Chore (non-breaking change which doesn't affect codebase;
  test, version modification, documentation, etc.)

Checklist

• Code contributed by me aligns with current project license: Apache 2.0
• I Added CHANGELOG entry regarding this change
• I have implemented unit tests to cover my changes
• I have added/updated the javadocs and other documentation accordingly
• No new bugs, code smells, etc. in SonarCloud report
• I tested my code in Kubernetes
• I tested my code in OpenShift

[rohanKanojia]

retest this please

[rohanKanojia]

Steps to test

• Create a script which returns your auth token:

#! /bin/bash

date >> /home/rohaan/run-log
echo "{\"kind\": \"ExecCredential\", \"apiVersion\": \"client.authentication.k8s.io/v1alpha1\",\"status\":{\"token\":\"your-token\"}, \"spec\": {}}"

• Place this script in some directory not in your $PATH, I placed it in /home/rohaan/temp-scripts/testScript
• Add script to your $PATH

export PATH=$HOME/temp-scripts:$PATH

• Edit users section of your .kube/config file to add exec section for this script to execute:

- name: rohanKanojia/api-rh-idev-openshift-com:443
  user:
    exec:
      apiVersion: client.authentication.k8s.io/v1alpha1
      command: testScript

• Check whether kubectl is working after modifying .kube/config, also each run of script populates run-log

~ : $ kubectl get pods
NAME               READY   STATUS      RESTARTS   AGE
demo-1-t5l9n       1/1     Running     0          4h
demo-s2i-2-build   0/1     Completed   0          4h
~ : $ cat run-log 
Fri 07 Aug 2020 04:52:46 PM IST

• Do the same thing from kubernetes-client:

try (KubernetesClient client = new DefaultKubernetesClient()) {
    PodList podList = client.pods().inNamespace("rokumar").list();
    podList.getItems().forEach(p -> System.out.println(p.getMetadata().getName()));
}

[manusa]

Following (testScript.bat) script can be used from a Windows OS:

@echo off
for /f "delims=" %%i in ('date /t') do (set curr_date=%%i)
echo %curr_date%_%TIME% >>00_kube_auth_log.txt
echo {"kind": "ExecCredential", "apiVersion": "client.authentication.k8s.io/v1alpha1","status":{"token":"your_SECRET_token"}, "spec": {}}

[manusa]

Tested on Windows, provided test scenario works well.

[sonarcloud]

SonarCloud Quality Gate failed.

0 Bugs
0 Vulnerabilities (and 0 Security Hotspots to review)
0 Code Smells

72.0% Coverage
0.0% Duplication

[manusa]

[merge]