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remove deprecated init container syntax (#15103) 

Init Containers were specified using custom annotations in k8s 1.5.  In
k8s 1.6, these annotations were replaced with the
`Pod.Spec.initContainers` collection and the old annotations were
deprecated in 1.6 and no longer supported in 1.8. There's no reason to
clutter the docs with the old annotation syntax.
This commit is contained in:
Jay Pipes 2019-06-25 06:54:36 -07:00 committed by Kubernetes Prow Robot
parent 6a6f1169a5
commit e3bc4bcb62
1 changed files with 1 additions and 45 deletions
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46
content/en/docs/concepts/workloads/pods/init-containers.md
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@ -97,39 +97,10 @@ and the [Production Pods guide](/docs/tasks/configure-pod-container/configure-po
### Init Containers in use
The following yaml file for Kubernetes 1.5 outlines a simple Pod which has two Init Containers.
The following yaml file outlines a simple Pod which has two Init Containers.
The first waits for `myservice` and the second waits for `mydb`. Once both
containers complete, the Pod will begin.
```yaml
apiVersion: v1
kind: Pod
metadata:
name: myapp-pod
labels:
app: myapp
annotations:
pod.beta.kubernetes.io/init-containers: '[
{
"name": "init-myservice",
"image": "busybox:1.28",
"command": ["sh", "-c", "until nslookup myservice; do echo waiting for myservice; sleep 2; done;"]
},
{
"name": "init-mydb",
"image": "busybox:1.28",
"command": ["sh", "-c", "until nslookup mydb; do echo waiting for mydb; sleep 2; done;"]
}
]'
spec:
containers:
- name: myapp-container
image: busybox:1.28
command: ['sh', '-c', 'echo The app is running! && sleep 3600']
```
There is a new syntax in Kubernetes 1.6, although the old annotation syntax still works for 1.6 and 1.7. The new syntax must be used for 1.8 or greater. We have moved the declaration of Init Containers to `spec`:
```yaml
apiVersion: v1
kind: Pod
@ -151,8 +122,6 @@ spec:
command: ['sh', '-c', 'until nslookup mydb; do echo waiting for mydb; sleep 2; done;']
```
1.5 syntax still works on 1.6, but we recommend using 1.6 syntax. In Kubernetes 1.6, Init Containers were made a field in the API. The beta annotation is still respected in 1.6 and 1.7, but is not supported in 1.8 or greater.
Yaml file below outlines the `mydb` and `myservice` services:
```yaml
@ -327,19 +296,6 @@ reasons:
forcing a restart, and the Init Container completion record has been lost due
to garbage collection.
## Support and compatibility
A cluster with Apiserver version 1.6.0 or greater supports Init Containers
using the `.spec.initContainers` field. Previous versions support Init Containers
using the alpha or beta annotations. The `.spec.initContainers` field is also mirrored
into alpha and beta annotations so that Kubelets version 1.3.0 or greater can execute
Init Containers, and so that a version 1.6 apiserver can safely be rolled back to version
1.5.x without losing Init Container functionality for existing created pods.
In Apiserver and Kubelet versions 1.8.0 or greater, support for the alpha and beta annotations
is removed, requiring a conversion from the deprecated annotations to the
`.spec.initContainers` field.
{{% /capture %}}