kubectl
in Reusable ScriptsFor a stable output in a script:
-o name
, -o json
, -o yaml
, -o go-template
, or -o jsonpath
--output-version
, because the output forms use a particular API version to output the resource with the exception of -o name
output form--generator
to pin to a specific behavior forever when you use generator-based commands such as kubectl run
or kubectl expose
kubectl run
For kubectl run
to satisfy infrastructure as code:
:v1234
, v1.2.3
, r03062016-1-4
, rather than :latest
(For more information, see Best Practices for Configuration).--record
to annotate the created objects with the command line for an image that is lightly parameterized.kubectl run
flags.kubectl run --generator=deployment/v1beta1
.You can generate the following resources in kubectl run
using --generator
flag:
run-pod/v1
.run/v1
.extensions/v1beta1
and for an endpoint - use deployment/v1beta1
(default).apps/v1beta1
and for an endpoint - use deployment/apps.v1beta1
(recommended).job/v1
.batch/v1beta1
and for an endpoint - use cronjob/v1beta1
(default).batch/v2alpha1
and for an endpoint - use cronjob/v2alpha1
(deprecated).If you do not specify a generator flag, other flags prompt you to use a specific generator. The following table lists the flags that force you to use specific generators, depending on the version of the cluster:
Generated Resource | Cluster v1.4 and later | Cluster v1.3 | Cluster v1.2 | Cluster v1.1 and earlier |
---|---|---|---|---|
Pod | --restart=Never |
--restart=Never |
--generator=run-pod/v1 |
--restart=OnFailure OR --restart=Never |
Replication Controller | --generator=run/v1 |
--generator=run/v1 |
--generator=run/v1 |
--restart=Always |
Deployment | --restart=Always |
--restart=Always |
--restart=Always |
N/A |
Job | --restart=OnFailure |
--restart=OnFailure |
--restart=OnFailure OR --restart=Never |
N/A |
Cron Job | --schedule=<cron> |
N/A | N/A | N/A |
Note: These flags use a default generator only when you have not specified
any flag. This means that when you combine --generator
with other flags the generator that you specified later does not change. For example, in a cluster v1.4, if you initially specify
--restart=Always
, a Deployment is created; if you later specify --restart=Always
and --generator=run/v1
, a Replication Controller is created.
This enables you to pin to a specific behavior with the generator,
even when the default generator is changed later.
The flags set the generator in the following order: first the schedule flag then restart policy and finally the generator.
To check the final resource that was created, use --dry-run
flag, which provides the object to be submitted to the cluster.
kubectl apply
kubectl apply
to create or update resources. However, to update a resource you should have created the resource by using kubectl apply
or kubectl create --save-config
. For more information about using kubectl apply to update resources, see Managing Resources.