Jenkins ERROR: Labels must follow required specs - jenkins

Question

I am trying to create a pipeline job for Angular code to deploy the application into k8 cluster. Below there is a code for pipeline container podTemplate, during the build I get the next error.
def label = "worker-${UUID.randomUUID().toString()}"
podTemplate(
cloud: 'kubernetes',
namespace: 'test',
imagePullSecrets: ['regcred'],
label: label,
containers: [
containerTemplate(name: 'nodejs', image: 'nodejscn/node:latest', ttyEnabled: true, command: 'cat'),
containerTemplate(name: 'docker', image: 'nodejscn/node:latest', ttyEnabled: true, command: 'cat'),
containerTemplate(name: 'kubectl', image: 'k8spoc1/kubctl:latest', ttyEnabled: true, command: 'cat')
],
volumes: [
hostPathVolume(hostPath: '/var/run/docker.sock', mountPath: '/var/run/docker.sock'),
hostPathVolume(hostPath: '/root/.m2/repository', mountPath: '/root/.m2/repository')
]
) {
node(label) {
def scmInfo = checkout scm
def image_tag
def image_name
sh 'pwd'
def gitCommit = scmInfo.GIT_COMMIT
def gitBranch = scmInfo.GIT_BRANCH
def commitId
commitId= scmInfo.GIT_COMMIT[0..7]
image_tag = "${scmInfo.GIT_BRANCH}-${scmInfo.GIT_COMMIT[0..7]}"
stage('NPM Install') {
container ('nodejs') {
withEnv(["NPM_CONFIG_LOGLEVEL=warn"]) {
sh 'npm install'
}
}
}
}
}
Error from Jenkins:
[Pipeline] Start of Pipeline
[Pipeline] podTemplate
[Pipeline] // podTemplate
[Pipeline] End of Pipeline
ERROR: Labels must follow required specs - https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#syntax-and-character-set: Ubuntu-82f3782f-b5aa-4029-9c51-57610153747c
Finished: FAILURE
Do I need to mention a spec value of my Jenkins file?

Answer 1

The error message you get:
ERROR: Labels must follow required specs - https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#syntax-and-character-set: Ubuntu-82f3782f-b5aa-4029-9c51-57610153747c
points out quite precisely what can be wrong with your Pod template. As you can see in link to kubernetes documentation given in the ERROR message, you need to follow certain rules when defining a Pod. labels element is a dictionary/map field that requires you to provide at least one key-value pair so you cannot just write label: label in your specification.
You can try to define your PodTemplate in yaml format (which is mostly used in kubernetes) like in this example:
podTemplate(yaml: """
apiVersion: v1
kind: Pod
metadata:
labels:
some-label: some-label-value
spec:
containers:
- name: busybox
image: busybox
command:
- cat
tty: true
"""
) {
node(POD_LABEL) {
container('busybox') {
sh "hostname"
}
}
}
As you can read here:
label The label of the pod. Can be set to a unique value to avoid
conflicts across builds, or omitted and POD_LABEL will be defined
inside the step.
label field can be omitted at all so first you can try without it and you shouldn't get any error message.

Answer 2

ERROR: Labels must follow required specs - https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#syntax-and-character-set: Ubuntu-82f3782f-b5aa-4029-9c51-57610153747c
Your label Ubuntu-82f3782f-b5aa-4029-9c51-57610153747c has a space before Ubuntu which is not valid
But that error message doesn't seem to match the pod definition you posted as there is no mention of Ubuntu anywhere. Maybe inherited