@@ -53,13 +53,13 @@ Use the file `examples/kubernetes-namespaces/namespace-dev.json` which describes
```js
{
"kind":"Namespace",
"apiVersion":"v1beta1",
"id":"development",
"spec":{},
"status":{},
"labels":{
"name":"development"
},
"apiVersion":"v1beta3",
"metadata":{
"name":"development",
"labels":{
"name":"development"
}
}
}
```
...
...
@@ -79,12 +79,13 @@ To be sure things are right, let's list all of the namespaces in our cluster.
```shell
$ cluster/kubectl.sh get namespaces
NAME LABELS
default <none>
development name=development
production name=production
NAME LABELS STATUS
default <none> Active
development name=development Active
production name=production Active
```
### Step Three: Create pods in each namespace
A Kubernetes namespace provides the scope for pods, services, and replication controllers in the cluster.
...
...
@@ -93,11 +94,40 @@ Users interacting with one namespace do not see the content in another namespace
To demonstrate this, let's spin up a simple replication controller and pod in the development namespace.
The first step is to define a context for the kubectl client to work in each namespace.
We first check what is the current context:
```shell
apiVersion: v1
clusters:
- cluster:
certificate-authority-data: REDACTED
server: https://130.211.122.180
name: lithe-cocoa-92103_kubernetes
contexts:
- context:
cluster: lithe-cocoa-92103_kubernetes
user: lithe-cocoa-92103_kubernetes
name: lithe-cocoa-92103_kubernetes
current-context: lithe-cocoa-92103_kubernetes
kind: Config
preferences: {}
users:
- name: lithe-cocoa-92103_kubernetes
user:
client-certificate-data: REDACTED
client-key-data: REDACTED
token: 65rZW78y8HbwXXtSXuUw9DbP4FLjHi4b
- name: lithe-cocoa-92103_kubernetes-basic-auth
user:
password: h5M0FtUUIflBSdI7
username: admin
```
The next step is to define a context for the kubectl client to work in each namespace. The value of "cluster" and "user" fields are copied from the current context.
```shell
$ cluster/kubectl.sh config set-context dev --namespace=development
Kubernetes Namespaces help different projects, teams, or customers to share a Kubernetes cluster.
It does this by providing the following:
1. A scope for [Names](../../../docs/identifiers.md).
2. A mechanism to attach authorization and policy to a subsection of the cluster.
Use of multiple namespaces is optional.
This example demonstrates how to use Kubernetes namespaces to subdivide your cluster.
### Step Zero: Prerequisites
This example assumes the following:
1. You have an existing Kubernetes cluster.
2. You have a basic understanding of Kubernetes pods, services, and replication controllers.
### Step One: Understand the default namespace
By default, a Kubernetes cluster will instantiate a default namespace when provisioning the cluster to hold the default set of pods,
services, and replication controllers used by the cluster.
Assuming you have a fresh cluster, you can introspect the available namespace's by doing the following:
```shell
$ cluster/kubectl.sh get namespaces
NAME LABELS
default <none>
```
### Step Two: Create new namespaces
For this exercise, we will create two additional Kubernetes namespaces to hold our content.
Let's imagine a scenario where an organization is using a shared Kubernetes cluster for development and production use cases.
The development team would like to maintain a space in the cluster where they can get a view on the list of pods, services, and replication-controllers
they use to build and run their application. In this space, Kubernetes resources come and go, and the restrictions on who can or cannot modify resources
are relaxed to enable agile development.
The operations team would like to maintain a space in the cluster where they can enforce strict procedures on who can or cannot manipulate the set of
pods, services, and replication controllers that run the production site.
One pattern this organization could follow is to partition the Kubernetes cluster into two namespaces: development and production.
Let's create two new namespaces to hold our work.
Use the file `examples/kubernetes-namespaces/v1beta3/namespace-dev.json` which describes a development namespace:
We have just created a replication controller whose replica size is 2 that is running the pod called snowflake with a basic container that just serves the hostname.
