App Configuration client library for JavaScript
Azure App Configuration is a managed service that helps developers centralize their application and feature settings simply and securely.
Use the client library for App Configuration to:
- Create flexible key representations and mappings
- Tag keys with labels
- Replay settings from any point in time
Source code | Package (NPM) | API reference documentation | Product documentation | Samples
Getting started
Currently supported environments
- Node.js version 8.x.x or higher
Prerequisites: You must have an Azure Subscription and an App Configuration resource to use this package.
@azure/app-configuration
package
1. Install the npm install @azure/app-configuration
2. Create an App Configuration resource
You can use the Azure Portal or the Azure CLI to create an Azure App Configuration resource.
Example (Azure CLI):
az appconfig create --name <app-configuration-resource-name> --resource-group <resource-group-name> --location eastus
AppConfigurationClient
3. Create and authenticate an AppConfigurationClient can authenticate using a service principal or using a connection string.
Authenticating with a service principal
Authentication via service principal is done by:
- Creating a credential using the
@azure/identity
package. - Setting appropriate RBAC rules on your AppConfiguration resource. More information on App Configuration roles can be found here.
Using DefaultAzureCredential
const azureIdentity= require("@azure/identity");
const appConfig = require("@azure/app-configuration");
const credential = new azureIdentity.DefaultAzureCredential();
const client = new appConfig.AppConfigurationClient(
endpoint, // ex: <https://<your appconfig resource>.azconfig.io>
credential
);
More information about @azure/identity
can be found here
Authenticating with a connection string
To get the Primary connection string for an App Configuration resource you can use this Azure CLI command:
az appconfig credential list -g <resource-group-name> -n <app-configuration-resource-name> --query "([?name=='Primary'].connectionString)[0]"
And in code you can now create your App Configuration client with the connection string you got from the Azure CLI:
const client = new AppConfigurationClient("<connection string>");
Key concepts
The AppConfigurationClient
has some terminology changes from App Configuration in the portal.
- Key/Value pairs are represented as
ConfigurationSetting
objects - Locking and unlocking a setting is represented in the
isReadOnly
field, which you can toggle usingsetReadOnly
.
The client follows a simple design methodology - ConfigurationSetting
can be passed into any method that takes a ConfigurationSettingParam
or ConfigurationSettingId
.
This means this pattern works:
const setting = await client.getConfigurationSetting({
key: "hello"
});
setting.value = "new value!";
await client.setConfigurationSetting(setting);
// fields unrelated to just identifying the setting are simply
// ignored (for instance, the `value` field)
await client.setReadOnly(setting, true);
// delete just needs to identify the setting so other fields are
// just ignored
await client.deleteConfigurationSetting(setting);
or, for example, re-getting a setting:
let setting = await client.getConfigurationSetting({
key: "hello"
});
// re-get the setting
setting = await.getConfigurationSetting(setting);
Examples
Create and get a setting
const appConfig = require("@azure/app-configuration");
const client = new appConfig.AppConfigurationClient(
"<App Configuration connection string goes here>"
);
async function run() {
const newSetting = await client.setConfigurationSetting({
key: "testkey",
value: "testvalue",
// Labels allow you to create variants of a key tailored
// for specific use-cases like supporting multiple environments.
// https://docs.microsoft.com/en-us/azure/azure-app-configuration/concept-key-value#label-keys
label: "optional-label"
});
let retrievedSetting = await client.getConfigurationSetting("testkey", {
label: "optional-label"
});
console.log("Retrieved value:", retrievedSetting.value);
}
run().catch((err) => console.log("ERROR:", err));
Next steps
The following samples show you the various ways you can interact with App Configuration:
-
helloworld.ts
- Get, set, and delete configuration values. -
helloworldWithLabels.ts
- Use labels to add additional dimensions to your settings for scenarios like beta vs production. -
optimisticConcurrencyViaEtag.ts
- Set values using etags to prevent accidental overwrites. -
setReadOnlySample.ts
- Marking settings as read-only to prevent modification. -
getSettingOnlyIfChanged.ts
- Get a setting only if it changed from the last time you got it. -
listRevisions.ts
- List the revisions of a key, allowing you to see previous values and when they were set.
More in-depth examples can be found in the samples folder on GitHub.
Contributing
If you'd like to contribute to this library, please read the contributing guide to learn more about how to build and test the code.
This module's tests are a mixture of live and unit tests, which require you to have an Azure App Configuration instance. To execute the tests you'll need to run:
rush update
rush build -t @azure/app-configuration
- Create a .env file with these contents in the
sdk\appconfiguration\app-configuration
folder:AZ_CONFIG_CONNECTION=connection string for your App Configuration instance
cd sdk\appconfiguration\app-configuration
-
npm run test
.
View our tests folder for more details.