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Chapter 28. Managing Environment Variables
28.1. Overview
You can set, unset or list environment variables in pods or pod templates using the oc env command.
28.2. CLI Interface
OpenShift Enterprise provides the oc env command to set or unset environment variables for objects that have a pod template, such as replication controllers or deployment configurations. It can also list environment variables in pods or any object that has a pod template.
The oc env command uses the following general syntax:
$ oc env <object-selection> <environment-variables> [options]
There are several ways to express <object-selection>.
| Syntax | Description | Example |
|---|---|---|
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| Selects <object-name> of type <object-type>. |
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| Selects <object-name> of type <object-type>. |
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| Selects objects of type <object-type> that match <object-label-selector>. |
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| Selects all objects of type <object-type>. |
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| Look in <ref> — a filename, directory name, or URL — for the definition of the object to edit. |
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Supported common options for set, unset or list environment variables:
| Option | Description |
|---|---|
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Select containers by |
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Display the changed objects in |
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Output the changed objects with |
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Proceed only if |
28.3. Set Environment Variables
To set environment variables in the pod templates:
$ oc env <object-selection> KEY_1=VAL_1 ... KEY_N=VAL_N [<set-env-options>] [<common-options>]
Set environment options:
| Option | Description |
|---|---|
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| Set given key value pairs of environment variables. |
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| Confirm updating existing environment variables. |
In the following example, both commands modify environment variable STORAGE in the deployment config registry. The first adds, with value /data. The second updates, with value /opt.
$ oc env dc/registry STORAGE=/data $ oc env dc/registry --overwrite STORAGE=/opt
The following example finds environment variables in the current shell whose names begin with RAILS_ and adds them to the replication controller r1 on the server:
$ env | grep RAILS_ | oc env rc/r1 -e -
The following example does not modify the replication controller defined in file rc.json. Instead, it writes a YAML object with updated environment STORAGE=/local to new file rc.yaml.
$ oc env -f rc.json STORAGE=/opt -o yaml > rc.yaml
28.3.1. Automatically Added Environment Variables
| Variable Name |
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Example Usage
The service KUBERNETES which exposes TCP port 53 and has been allocated cluster IP address 10.0.0.11 produces the following environment variables:
KUBERNETES_SERVICE_PORT=53 MYSQL_DATABASE=root KUBERNETES_PORT_53_TCP=tcp://10.0.0.11:53 KUBERNETES_SERVICE_HOST=10.0.0.11
Use the oc rsh command to SSH into your container and run oc env to list all available variables.
28.4. Unset Environment Variables
To unset environment variables in the pod templates:
$ oc env <object-selection> KEY_1- ... KEY_N- [<common-options>]
The trailing hyphen (-, U+2D) is required.
This example removes environment variables ENV1 and ENV2 from deployment config d1:
$ oc env dc/d1 ENV1- ENV2-
This removes environment variable ENV from all replication controllers:
$ oc env rc --all ENV-
This removes environment variable ENV from container c1 for replication controller r1:
$ oc env rc r1 --containers='c1' ENV-
28.5. List Environment Variables
To list environment variables in pods or pod templates:
$ oc env <object-selection> --list [<common-options>]
This example lists all environment variables for pod p1:
$ oc env pod/p1 --list
