kube-job
is a command line tool to run one off job on Kubernetes. The feature is
- Override args argument and docker image in a kubernetes job template, and run the job.
- Wait for completion of the job execution
- Get logs from kubernetes pods and output in stream
This is a command line tool, but you can use job as a package. So when you write own job execition script for Kubernetes, you can embed job package in your golang source code and customize task recipe. Please check the godoc.
$ wget https://github.com/h3poteto/kube-job/releases/download/v0.7.0/kube-job_v0.7.0_linux_amd64.zip
$ unzip kube-job_v0.7.0_linux_amd64.zip
$ ./kube-job help
Run one off job on kubernetes
Usage:
kube-job [command]
Available Commands:
help Help about any command
run Run a job on Kubernetes
version Print the version number
Flags:
--config KUBECONFIG Kubernetes config file path (If you don't set it, use environment variables KUBECONFIG)
-h, --help help for kube-job
-v, --verbose Enable verbose mode
Use "kube-job [command] --help" for more information about a command.
At first, you have to prepare kuberenetes config file. If you are using kubectl, you can use the same file.
apiVersion: v1
clusters:
- cluster:
server: https://example.com
certificate-authority-data: certificate
name: kubernetes
contexts:
- context:
cluster: kubernetes
user: hoge
name: hoge
current-context: hoge
kind: Config
preferences: {}
users:
# ...
Next, please write job template file. It can be the same as used for kubectl, as below:
apiVersion: batch/v1
kind: Job
metadata:
name: example-job
namespace: default
labels:
app: example-job
spec:
template:
metadata:
labels:
app: example
spec:
containers:
- name: alpine
image: alpine:latest
imagePullPolicy: Always
args: ["env"]
env:
- name: HOGE
value: fuga
restartPolicy: Never
backoffLimit: 2
metadata.name
and spec.template.spec.containers[0].args
, spec.template.spec.containers[0].image
are overrided when you use kube-job
.
Kubernetes creates a job based on the job template yaml file, so if you use kube-job
more than once at the same time, it is failed.
Because Kubernetes can not register duplicate job name.
But, I think the usecase of kube-job
, then I think that sometimes users want to use kube-job
more than once at the same time for another commands.
So it is necessary to make it possible to perform multiple activation.
As a solution, kube-job
adds random string to the name of the job.
Please provide Kuberenetes config file, job template yaml file, and command. The container parameter receives which container do you want to execute the command.
$ ./kube-job run --config=$HOME/.kube/config --template-file=./job.yaml --args="echo fuga" --container="alpine"
fuga
You can specify an URL as a template file, like this:
$ ./kube-job run --template-file=https://raw.githubusercontent.com/h3poteto/kube-job/master/example/job.yaml --args="echo fuga" --container="alpine"
If your template file is located in private repository, please export personal access token of GitHub. And please use an API URL endpoint.
$ export GITHUB_TOKEN=hogehogefugafuga
$ ./kube-job run --template-file=https://api.github.com/repos/h3poteto/kube-job/contents/example/job.yaml --args="echo fuga" --container="alpine"
The user to be executed needs the following role.
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
name: job-user-role
rules:
- apiGroups: [""]
verbs: ["get", "list", "delete", "deletecollection"]
resources: ["pods", "pods/log"]
- apiGroups: ["batch"]
verbs: ["create", "get", "delete"]
resources: ["jobs", "jobs/status"]
The package is available as open source under the terms of the MIT License.