Azure Identity Rust

# Azure Identity SDK for Rust

Authentication library for Azure SDK clients using Microsoft Entra ID (formerly Azure AD).

Installation

cargo add azure_identity

Environment Variables

# Service Principal (for production/CI)
AZURE_TENANT_ID=<your-tenant-id>
AZURE_CLIENT_ID=<your-client-id>
AZURE_CLIENT_SECRET=<your-client-secret>

# User-assigned Managed Identity (optional)
AZURE_CLIENT_ID=<managed-identity-client-id>

DeveloperToolsCredential

The recommended credential for local development. Tries developer tools in order (Azure CLI, Azure Developer CLI):

use azure_identity::DeveloperToolsCredential;
use azure_security_keyvault_secrets::SecretClient;

let credential = DeveloperToolsCredential::new(None)?;
let client = SecretClient::new(
    "https://my-vault.vault.azure.net/",
    credential.clone(),
    None,
)?;

Credential Chain Order

| Order | Credential | Environment |

|-------|-----------|-------------|

| 1 | AzureCliCredential | `az login` |

| 2 | AzureDeveloperCliCredential | `azd auth login` |

Credential Types

| Credential | Usage |

|------------|-------|

| `DeveloperToolsCredential` | Local development - tries CLI tools |

| `ManagedIdentityCredential` | Azure VMs, App Service, Functions, AKS |

| `WorkloadIdentityCredential` | Kubernetes workload identity |

| `ClientSecretCredential` | Service principal with secret |

| `ClientCertificateCredential` | Service principal with certificate |

| `AzureCliCredential` | Direct Azure CLI auth |

| `AzureDeveloperCliCredential` | Direct azd CLI auth |

| `AzurePipelinesCredential` | Azure Pipelines service connection |

| `ClientAssertionCredential` | Custom assertions (federated identity) |

ManagedIdentityCredential

For Azure-hosted resources:

use azure_identity::ManagedIdentityCredential;

// System-assigned managed identity
let credential = ManagedIdentityCredential::new(None)?;

// User-assigned managed identity
let options = ManagedIdentityCredentialOptions {
    client_id: Some("<user-assigned-mi-client-id>".into()),
    ..Default::default()
};
let credential = ManagedIdentityCredential::new(Some(options))?;

ClientSecretCredential

For service principal with secret:

use azure_identity::ClientSecretCredential;

let credential = ClientSecretCredential::new(
    "<tenant-id>".into(),
    "<client-id>".into(),
    "<client-secret>".into(),
    None,
)?;

Best Practices

1. **Use `DeveloperToolsCredential` for local dev** — automatically picks up Azure CLI

2. **Use `ManagedIdentityCredential` in production** — no secrets to manage

3. **Clone credentials** — credentials are `Arc`-wrapped and cheap to clone

4. **Reuse credential instances** — same credential can be used with multiple clients

5. **Use `tokio` feature** — `cargo add azure_identity --features tokio`

Reference Links

| Resource | Link |

|----------|------|

| API Reference | https://docs.rs/azure_identity |

| Source Code | https://github.com/Azure/azure-sdk-for-rust/tree/main/sdk/identity/azure_identity |

| crates.io | https://crates.io/crates/azure_identity |

When to Use

This skill is applicable to execute the workflow or actions described in the overview.