Environment Variables

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Environment variables are config values that affect the way your app behaves. They are helpful
for situations when you need your app to behave differently depending on the environment. For example,
you might want your app to use one database when running in a certain environment, and a different database otherwise.

Dash Enterprise provides a way for you to set environment variables in the App Manager. By entering the environment variable name and value in Dash Enterprise, your app can use it without storing the value in code.
We recommend storing sensitive information like API keys as environment variables.
Because the key is not hardcoded in your app’s code, you don’t run the risk of mistakenly exposing or sharing it.

There are two types of environment variables: App environment variables and global environment variables. App environment variables are specific to an app (and its workspace, if applicable) while global environment variables are available to all apps and workspaces on Dash Enterprise. App environment variables can be managed by app owners, co-owners, and administrators, while global environment variables can only be managed by administrators.

All environment variables are used by your app at build time as well as at runtime.

Managing App Environment Variables

Some app environment variables are created automatically when you perform certain actions. In addition to these, you can add and manage your own app environment variables.

This page describes how to manage app environment variables using the Settings in the App Info, but you can also use the Dash Enterprise CLI.

System-Created App Environment Variables

The following app environment variables are created automatically by the system. They cannot be edited or deleted.

```
web: GUNICORN_CMD_ARGS=”–limit-request-field_size=8190” gunicorn app:server –workers 4

```
Learn more about this flag in the Gunicorn documentation.

Adding App Environment Variables

The environment variable for specifying a pip version, BP_PIP_VERSION, can also be set in a project.toml file. When it is set in both your app Settings and a project.toml file, the values in the Settings take precedence.

To add an environment variable to your app:

  1. In the Dash Enterprise App Manager, select the app.
  2. Go to Settings.
  3. Under Environment Variables, select Edit Variables.

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  1. Select New Variable.
  2. Enter a name and value for your environment variable (case sensitive). Names have a maximum character length of 250 and values have a maximum of 4096.

If your environment variable names contain more than one
word and you want to separate them, be sure to use underscores. Spaces are not supported.

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In this example, we’ve added credentials for a service using environment variables named SERVICE_USER and SERVICE_PASSWORD.

  1. Select Save. You are prompted to restart the app and its workspace (if one exists).

  2. Select Restart App and Workspace.

Once added, the values for your environment variables are hidden unless you
select Show Values.

You can now reference your environment variables in your app’s code with the os.environ module:

import os

service_username = os.environ['SERVICE_USER']

If you want to fall back to another value when the variable isn’t in your
environment, use:

import os

service_username = os.environ.get('SERVICE_USER', 'my-default-service-username')

Tip: Environment variables are case sensitive. Be sure to reference them exactly as they appear in the App Info.

Defining Environment Variables in Your Local Environment

If you’re working locally, the variables won’t be in your environment
unless you define them. You can define them on-the-fly when you run python app.py.
That is, instead of running python app.py, run:

$ SERVICE_USER=admin SERVICE_PASSWORD=my-password python app.py

replacing the example environment variables with the environment variables you want to define.

Alternatively, you can define them for your session with the export command.
For example:

$ export SERVICE_USER=admin
$ export SERVICE_PASSWORD=my-password
$ python app.py

Tip: Environment variables are case sensitive. Be sure to reference them exactly as they appear in the App Info.

Editing App Environment Variables

To edit an app environment variable:

  1. In the Dash Enterprise App Manager, select the app.
  2. Go to Settings.
  3. Under Environment Variables, select Edit Variables.
  4. Edit your environment variable names or values (case sensitive). Names have a maximum character length of 250 and values have a maximum of 4096.

If your environment variable names contain more than one
word and you want to separate them, be sure to use underscores. Spaces are not supported.

  1. Select Save. You are prompted to restart the app and its workspace (if one exists).
  2. Select Restart App and Workspace.

Deleting App Environment Variables

To delete an app environment variable:

  1. In the Dash Enterprise App Manager, select the app.
  2. Go to Settings.
  3. Under Environment Variables, select Edit Variables.
  4. Select Edit Variables.
  5. Select the Delete icon next to the environment variable you want to remove. You cannot delete environment variables that were created by the system.

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  1. Select Save. You are prompted to restart the app and its workspace (if one exists).
  2. Select Restart App and Workspace.

Viewing and Using Global Environment Variables

Under your app environment variables, you’ll see Global Environment Variables. These environment variables are managed by your administrator. You can use them in your app in the same way that you would use your own app environment variables.
However, you cannot see their values.

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If your app has an app environment variable that shares a name with a global environment variable, your app environment variable takes precedence.

When your administrator edits or deletes a global environment variable, a notification is displayed at the top of the App Info. The updated global environment variables are identified with a blue dot and bold font in the global environment variables list. Restart or redeploy your app, or rebuild your workspace for them to get the latest changes. When your administrator deletes a global environment variable, it is displayed in Recently Deleted until you restart or redeploy your app.

Managing Global Environment Variables (Admin)

Adding, editing, and deleting global environment variables are administrator actions and require the admin role.

Global environment variables are available to all apps and workspaces on Dash Enterprise.

App developers can use global environment variables in the same way that they use app environment variables.

Adding Global Environment Variables

If you need to define a private Python package index using PIP_EXTRA_INDEX_URL, do not add it as a global environment variable. Instead, use the provided setting in the KOTS Admin Console. See Configuring a Private Python Package Index for All Apps.

To add a global environment variable:

  1. In the App Manager, go to Platform and Users.
  2. Select Global environment variables.
  3. Select Add.
  4. In Name, enter a name for the environment variable (case sensitive). The following limitations apply:
    * Names beginning with DASH_ or DE_ are reserved by Plotly and cannot be used.

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  1. Select Add Variable.

Editing Global Environment Variables

When editing global environment variables, only the values and descriptions can be modified. If you need to modify a global environment variable’s name, delete it and create a new one.

To edit a global environment variable:

  1. In the App Manager, go to Platform and Users.
  2. Select Global environment variables.
  3. Select Edit next to the global environment variable that you want to edit.

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  1. Enter a new value or description.
  2. Select Save Changes.

Information about recently updated global environment variables is displayed to app developers so that they know to restart any apps or workspaces that are using them.

Deleting Global Environment Variables

To delete a global environment variable:

  1. In the App Manager, go to Platform and Users.
  2. Select Global environment variables.
  3. Select Delete next to the global environment variable that you want to delete.

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  1. Enter the variable name; then select Delete Forever to confirm.

Information about recently deleted global environment variables is displayed to app developers so that they understand why their app might behave differently or clean up unused code.

Deleted global environment variables stop being available to apps when the apps are restarted or redeployed. They stop being available to workspaces when the workspaces are rebuilt.