107 lines
2.7 KiB
Markdown
107 lines
2.7 KiB
Markdown
# ConfigMap example
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## Step Zero: Prerequisites
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This example assumes you have a Kubernetes cluster installed and running, and that you have
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installed the `kubectl` command line tool somewhere in your path. Please see [pick the right solution
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started](/docs/setup/pick-right-solution/) for installation instructions for your platform.
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## Step One: Create the ConfigMap
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A ConfigMap contains a set of named strings.
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Use the [`configmap.yaml`](configmap.yaml) file to create a ConfigMap:
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```shell
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$ kubectl create -f docs/user-guide/configmap/configmap.yaml
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```
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You can use `kubectl` to see information about the ConfigMap:
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```shell
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$ kubectl get configmap
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NAME DATA AGE
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test-configmap 2 6s
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$ kubectl describe configMap test-configmap
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Name: test-configmap
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Labels: <none>
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Annotations: <none>
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Data
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====
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data-1: 7 bytes
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data-2: 7 bytes
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```
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View the values of the keys with `kubectl get`:
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```shell
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$ kubectl get configmaps test-configmap -o yaml
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apiVersion: v1
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data:
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data-1: value-1
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data-2: value-2
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kind: ConfigMap
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metadata:
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creationTimestamp: 2016-02-18T20:28:50Z
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name: test-configmap
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namespace: default
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resourceVersion: "1090"
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selfLink: /api/v1/namespaces/default/configmaps/test-configmap
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uid: 384bd365-d67e-11e5-8cd0-68f728db1985
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```
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## Step Two: Create a pod that consumes a configMap in environment variables
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Use the [`env-pod.yaml`](env-pod.yaml) file to create a Pod that consumes the
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ConfigMap in environment variables.
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```shell
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$ kubectl create -f docs/user-guide/configmap/env-pod.yaml
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```
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This pod runs the `env` command to display the environment of the container:
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```shell
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$ kubectl logs config-env-test-pod | grep KUBE_CONFIG
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KUBE_CONFIG_1=value-1
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KUBE_CONFIG_2=value-2
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```
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## Step Three: Create a pod that sets the command line using ConfigMap
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Use the [`command-pod.yaml`](command-pod.yaml) file to create a Pod with a container
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whose command is injected with the keys of a ConfigMap
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```shell
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$ kubectl create -f docs/user-guide/configmap/command-pod.yaml
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```
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This pod runs an `echo` command to display the keys:
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```shell
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$ kubectl logs config-cmd-test-pod
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value-1 value-2
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```
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## Step Four: Create a pod that consumes a configMap in a volume
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Pods can also consume ConfigMaps in volumes. Use the [`volume-pod.yaml`](volume-pod.yaml) file to create a Pod that consume the ConfigMap in a volume.
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```shell
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$ kubectl create -f docs/user-guide/configmap/volume-pod.yaml
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```
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This pod runs a `cat` command to print the value of one of the keys in the volume:
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```shell
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$ kubectl logs config-volume-test-pod
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value-1
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```
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Alternatively you can use [`mount-file-pod.yaml`](mount-file-pod.yaml) file to mount
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only a file from ConfigMap, preserving original content of /etc directory.
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