I want to list my k8s jobs with a label selector by client-go like this command:
$ kubectl get jobs -l 'hello-world in (London, China, NewYork)'
I looked through the source code of client-go, then I wrote some code like this:
func listJobs(cli *kubernetes.Clientset) (*batchv1.JobList, error) {
label := metav1.LabelSelector{
MatchExpressions: []metav1.LabelSelectorRequirement{
{
Key: "hello-world",
Operator: metav1.LabelSelectorOpIn,
Values: []string{
"London",
"China",
"NewYork",
},
},
},
}
fmt.Println(label.String())
return cli.BatchV1().Jobs("default").List(context.TODO(), metav1.ListOptions{
LabelSelector: label.String(),
})
}
and then I got the error:
&LabelSelector{MatchLabels:map[string]string{},MatchExpressions:[]LabelSelectorRequirement{LabelSelectorRequirement{Key:hello-world,Operator:In,Values:[London China NewYork],},},}
2021/01/28 17:58:07 unable to parse requirement: invalid label key "&LabelSelector{MatchLabels:map[string]string{}": name part must consist of alphanumeric characters, '-', '_' or '.', and must start and end with an alphanumeric character (e.g. 'MyName', or 'my.name', or '123-abc', regex used for validation is '([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9]')
Where did I go wrong? How do I list my jobs with a label selector which is a complex expression?
Using the Kubernetes client-go library, you can simply write label selectors the same way you would with kubectl.
Writing hello-world in (London, China, NewYork) should work just fine.
func listJobs(cli *kubernetes.Clientset) (*batchv1.JobList, error) {
return cli.BatchV1().Jobs("default").List(context.TODO(), metav1.ListOptions{
LabelSelector: "hello-world in (London, China, NewYork)",
})
}
If what you want is to dynamically generate hello-world in (London, China, NewYork) from a programmatic object however, that is another question, which is already answered on StackOverflow here.