Examining Key-Value Pairs in Azure App Configuration

Examining Key-Value Pairs in Azure App Configuration

In Azure App Configuration, key-value pairs are the core units of configuration storage. The key represents the name or identifier of a setting, and the value represents the actual configuration data. You can use these key-value pairs to store settings for your applications, manage feature flags, store environment-specific configurations, and even handle sensitive data securely.

Let’s examine the key aspects of key-value pairs in Azure App Configuration, including key design, labels, versioning, and querying.

1. Keys in Azure App Configuration

The key is the identifier for each configuration item. Azure App Configuration allows you to structure your keys with flexibility to support various naming conventions and environments.

Designing Key Namespaces

A namespace in Azure App Configuration refers to how you organize and structure your keys. Properly designing key namespaces is crucial for maintainability, scalability, and ease of use, especially when working in complex systems with many configurations.

1. Simple Naming Convention: Keys can be simple strings, such as appSettings:connectionString or logging:level.

2. Hierarchical Namespaces:

   • Keys can be designed using a colon : to represent a hierarchy.

   • For example:

     database:prod:connectionString database:test:connectionString featureFlags:betaFeature

   • Using hierarchical key names allows for better organization, particularly in environments where the same key may have different values for each environment or context.

3. Environment-based Namespaces:

   • To support multiple environments (development, staging, production), you can design the key namespaces with a suffix or prefix to distinguish between different environments.

   • For example:

     prod:appSettings:databaseUrl dev:appSettings:databaseUrl

Use of Scopes:

Keys can also be scoped to particular services or microservices, making it easier to segregate configurations for different components of an application.

For example:

service1:apiKey service2:apiKey

Best Practices for Key Design:

1. Consistency: Stick to a consistent naming convention to make it easier for teams to find and manage keys.

2. Avoid Overly Generic Keys: Avoid names like apiUrl that don’t specify which service, environment, or feature they relate to. Instead, use more descriptive keys like service1:prod:apiUrl or logging:prod:logLevel.

3. Separation of Concerns: Use namespaces or labels to separate configuration settings for different applications, services, or environments.

2. Labels for Keys in Azure App Configuration

Labels in Azure App Configuration provide a way to distinguish between configurations for different environments, versions, or any other logical separation within the same key store. A key can have different values associated with it under different labels, making it possible to manage configuration values for various stages (e.g., dev, staging, production) or versions.

Labeling Keys

1. Environment-based Labels:

   • You can use labels to specify which environment the key-value pair applies to.

   • Example: prod, dev, staging

   • For example:

     appSettings:databaseUrl|prod (Production environment) appSettings:databaseUrl|dev (Development environment)

2. Versioning with Labels:

   • Labels can also be used for versioning configurations, enabling you to manage different versions of configuration settings.

   • Example: v1, v2, beta

   • For example:

     featureFlags:showNewFeature|v1 (Version 1 configuration) featureFlags:showNewFeature|beta (Beta version configuration)

3. Application Feature Flags:

   • If you're managing feature flags, labels could represent different feature releases or phases in your pipeline (e.g., canary, production, staging).

   • Example:

     featureFlags:useNewLoginFlow|canary featureFlags:useNewLoginFlow|production

Best Practices for Labeling:

1. Use Descriptive Labels: Use labels that clearly indicate the environment or context of the configuration.

2. Limit Number of Labels: While labels are powerful, avoid overusing them as they can complicate configuration management. Keep the number of labels reasonable and consistent.

3. Semantic Versioning: If you’re versioning configurations (e.g., v1, v2), consider using semantic versioning to track the evolution of configurations.

3. Versioning Key Values

Each key in Azure App Configuration can have multiple versions of its value. Azure App Configuration supports versioning of key values, so you can track changes to configuration settings over time. This is particularly useful for rollback scenarios or when you need to review past configurations.

Versioning Behavior:

1. Automatic Versioning: Every time a new value is added to a key (either by direct modification or via an API call), Azure App Configuration automatically creates a new version.

2. Manual Versioning: You can also manually specify a version for each key if needed.

Versioning helps ensure that you can always access and restore previous versions of a configuration value if needed.

Benefits of Versioning:

1. Rollback: If a change to a configuration setting causes issues, you can easily roll back to a previous version.

2. Auditing: Versioning allows you to track changes to configuration values and understand the history of configuration changes.

How to Use Versioning in Azure App Configuration:

You can retrieve specific versions of a key using the Azure SDKs or the REST API by specifying the version number.

Example:

Retrieve a specific version of a key:

xxxxxxxxxx
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GET https://<your-app-config-store>.azconfig.io/kv/<key>?label=<label>&version=<version>

4. Querying Key Values in Azure App Configuration

Azure App Configuration allows you to query keys and retrieve configuration data in a flexible way. You can query key-value pairs based on the key, label, and other criteria.

Querying by Key:

You can query all values for a specific key across different labels or environments. If no label is specified, the default label is used.

Example:

Retrieve all key-value pairs for a given key:

xxxxxxxxxx
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GET https://<your-app-config-store>.azconfig.io/kv/<key>

Querying with Labels:

You can filter the configuration values based on labels to target specific environments or versions.

Example:

Retrieve configuration values for a specific label (e.g., prod):

xxxxxxxxxx
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GET https://<your-app-config-store>.azconfig.io/kv/<key>?label=prod

Querying Multiple Keys:

You can also query multiple keys in a single request, allowing you to retrieve a set of configurations that match specific filters.

Example:

Retrieve multiple key-value pairs using a filter:

xxxxxxxxxx
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GET https://<your-app-config-store>.azconfig.io/kv?key=<key1>,<key2>&label=<label>

Querying with Key Prefix:

Keys in Azure App Configuration are often designed with a common prefix to represent logical groupings (such as appSettings, database, api, etc.). You can filter key-value pairs based on the prefix of the key.

Example:

Retrieve all keys starting with appSettings:

xxxxxxxxxx
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GET https://<your-app-config-store>.azconfig.io/kv?key=appSettings

Best Practices for Querying:

1. Use Prefixes: Structure your keys in a way that makes it easy to query them using prefixes (e.g., logging:level, database:connectionString).

2. Filter by Labels: Use labels effectively to query keys for specific environments (e.g., dev, staging, prod) and versions (e.g., v1, beta).

3. Paginate Results: If you have a large number of keys, ensure that your queries handle pagination to avoid overwhelming the client with too many results.

5. Values in Azure App Configuration

The value associated with a key is the actual configuration data. Values can be simple text (e.g., a connection string), JSON, or even more complex data.

Types of Values:

1. String values: Simple key-value pairs like databaseUrl or apiKey.

2. JSON objects: For complex configurations, values can be stored as JSON, which can be parsed by your application. ' Example:

   xxxxxxxxxx
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   {
   2
   "database": {
   3
         "host": "prod-db.example.com",
   4
         "port": 5432
   5
      }
   6
   }
   

3. Boolean: Feature flags often use boolean values (true or false) to toggle features on or off.

Best Practices for Values:

1. Store Secrets Securely: Use Azure Key Vault integration to store sensitive values (e.g., API keys, connection strings).

2. Use Structured Values: When the configuration is complex, prefer structured formats like JSON for better flexibility.

3. Avoid Storing Sensitive Data Directly: Store sensitive data (e.g., passwords, tokens) in Azure Key Vault and reference them from Azure App Configuration.

Summary

Azure App Configuration offers a powerful way to manage application settings using key-value pairs, supporting complex, scalable, and secure configurations across different environments. By understanding how to design keys, use labels, version values, and query configurations, you can efficiently manage and maintain configurations in large-scale applications. Best practices in key design, querying, and value management ensure that your configurations are easily accessible, secure, and adaptable as your applications evolve.