Create a yaml template using kubectl

2 min read | by Jordi Prats

When you create a new deployment you usually focus on:

  • Number of replicas
  • How you are going to select the pods that are going to be managed by this deployment
  • Pod template

Beside this, all the other required lines on the yaml are boilerplate so it's quite easy to forget about them.

Using kubectl create in dry-run mode and setting the output as yaml we can get the yaml file it would use to create a new resource without actually applying any change:

$ kubectl create deployment demo --dry-run=client --image=nginx -r 3 -o yaml apiVersion: apps/v1 kind: Deployment metadata:  creationTimestamp: null  labels:  app: demo  name: demo spec:  replicas: 3  selector:  matchLabels:  app: demo  strategy: {}  template:  metadata:  creationTimestamp: null  labels:  app: demo  spec:  containers:  - image: nginx  name: nginx  resources: {} status: {}

We can create most resources this way, but not every single available resource:

$ kubectl create --help (...) Available Commands:  clusterrole Create a ClusterRole.  clusterrolebinding Create a ClusterRoleBinding for a particular ClusterRole  configmap Create a configmap from a local file, directory or literal value  cronjob Create a cronjob with the specified name.  deployment Create a deployment with the specified name.  ingress Create an ingress with the specified name.  job Create a job with the specified name.  namespace Create a namespace with the specified name  poddisruptionbudget Create a pod disruption budget with the specified name.  priorityclass Create a priorityclass with the specified name.  quota Create a quota with the specified name.  role Create a role with single rule.  rolebinding Create a RoleBinding for a particular Role or ClusterRole  secret Create a secret using specified subcommand  service Create a service using specified subcommand.  serviceaccount Create a service account with the specified name (...)

Posted on 14/01/2021

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