oci-api

A Rust client library for Oracle Cloud Infrastructure (OCI) APIs.

Currently supports:

• Email Delivery Service - Send emails via OCI Email Delivery

Features

• 🔐 OCI HTTP request signing (compliant with OCI specifications)
• 📧 Email Delivery API support
• 🔄 Async/await support (Tokio)
• 🛡️ Type-safe API with comprehensive error handling
• ⚙️ Flexible configuration (environment variables, config files, or programmatic)

Installation

Add this to your Cargo.toml:

[dependencies]
oci-api = "0.1"
tokio = { version = "1", features = ["full"] }

Import commonly used types:

use oci_api::{OciConfig, OciClient};
use oci_api::email::{EmailClient, Email, EmailAddress, Recipients};

Configuration

There are two ways to configure OCI credentials which are used for generating(signing) Authorization headers and requests:

Option 1: Environment Variables (Recommended)

Using OCI_CONFIG (supports both file path and INI content directly)

OCI_CONFIG can provide the following information:

• user → user_id
• tenancy → tenancy_id
• region
• fingerprint
• key_file → path to private key file

# use dotenvy or similar to load environment variables from `.env` in development

# point to a config file path
OCI_CONFIG=/path/to/.oci/config

# or provide content(INI) directly
OCI_CONFIG="[DEFAULT]
user=ocid1.user.oc1..aaaaaa...
tenancy=ocid1.tenancy.oc1..aaaaaa...
region=ap-chuncheon-1
fingerprint=aa:bb:cc:dd:ee:ff:11:22:33:44:55:66:77:88:99:00
key_file=~/.oci/private-key.pem"

Using OCI_PRIVATE_KEY (supports both file path and PEM content directly):

# it overrides the private key specified in OCI_CONFIG if both are set

# Provide private key file path
OCI_PRIVATE_KEY=/path/to/private-key.pem
# or provide PEM content directly:
OCI_PRIVATE_KEY="-----BEGIN PRIVATE KEY-----
MIIEvwIBADANBgk...
-----END PRIVATE KEY-----"

Individual environment variables override OCI_CONFIG example:

# if you use individual vars, you don't need to set OCI_CONFIG
# but you can still use it as a base
OCI_CONFIG=/path/to/.oci/config

# Override specific values (higher priority than OCI_CONFIG)
OCI_USER_ID=ocid1.user.oc1..different...      # Overrides 'user' from config
OCI_TENANCY_ID=ocid1.tenancy.oc1..different...  # Overrides 'tenancy' from config
OCI_REGION=ap-seoul-1                          # Overrides 'region' from config
OCI_FINGERPRINT=11:22:33:44:55:66:77:88:99:00:aa:bb:cc:dd:ee:ff  # Overrides 'fingerprint'
OCI_PRIVATE_KEY=/different/path/to/key.pem    # Overrides 'key_file' from config
OCI_COMPARTMENT_ID=ocid1.compartment.oc1..aaaaaa...  # Optional, defaults to tenancy_id, but needed for APIs if you use specific compartment

Load configuration:

use oci_api::OciConfig;

let config = OciConfig::from_env()?;

Priority Summary:

* OCI_USER_ID, OCI_TENANCY_ID, OCI_REGION, OCI_FINGERPRINT, and OCI_PRIVATE_KEY are required if OCI_CONFIG is not set. * OCI_PRIVATE_KEY is recommended even if OCI_CONFIG is used, if you do not want to change the config file content between environments.

Option 2: Programmatic Configuration

use oci_api::OciConfig;

// build from scratch using individual fields
let config = OciConfig::builder()
    .user_id("ocid1.user.oc1..aaaaaa...")
    .tenancy_id("ocid1.tenancy.oc1..aaaaaa...")
    .region("ap-chuncheon-1")
    .fingerprint("aa:bb:cc:dd:ee:ff:11:22:33:44:55:66:77:88:99:00")
    .private_key("/path/to/private-key.pem")?
    .compartment_id("ocid1.compartment.oc1..aaaaaa...")
    .build()?;

// or load from config file and override specific fields
let config = OciConfig::builder()
    .config("/path/to/.oci/config")?  // Load from file
    .private_key("/production/path/to/key.pem")?  // Override key_file from config
    .compartment_id("ocid1.compartment.oc1..aaaaaa...")  // Set compartment
    .build()?;

Email Delivery API

use oci_api::{OciConfig, OciClient};
use oci_api::email::{EmailClient, Email, EmailAddress, Recipients};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Load configuration and create clients
    let config = OciConfig::from_env()?;
    let oci_client = OciClient::new(&config)?;
    let email_client = EmailClient::new(oci_client).await?;
    
    // Prepare email
    let email = Email::builder()
        .sender(EmailAddress::new("approved-sender@example.com"))  // Must be an approved sender
        .recipients(Recipients::to(vec![EmailAddress::new("recipient@example.com")]))
        .subject("Hello from OCI!")
        .body_html("<h1>This is a test email</h1><p>Sent via <strong>OCI Email Delivery API</strong>.</p>")
        .body_text("This is a test email sent via OCI Email Delivery API.")
        .build()?;
    
    // Send email
    let response = email_client.send(email).await?;
    println!("Email sent! Message ID: {}", response.message_id);
    
    Ok(())
}

Body Text & HTML

you can send body as text or HTML or both, but at least one is required. if both are provided(recommended), email clients will choose HTML if available, otherwise plain text.

use oci_api::{OciConfig, OciClient};
use oci_api::email::{EmailClient, Email, EmailAddress, Recipients};

let email = Email::builder()
    .sender(EmailAddress::new("approved-sender@example.com"))
    .recipients(Recipients::to(vec![EmailAddress::new("user@example.com")]))
    .subject("Simple Email")
    .body_html("<h1>Hello</h1><p>This is <strong>HTML</strong> content.</p>")
    .body_text("Plain text content")
    .build()?;

let response = email_client.send(email).await?;

Email Address

EmailAddress is used for specifying sender, recipients, reply-to, etc. it can be created with just an email(new) or with a display name(with_name).

let just_email = EmailAddress::new("user@example.com");
let with_name = EmailAddress::with_name("user@example.com", "User Name");

Recipients

Recipients needs at least one to or cc or bcc recipient. You can use builder pattern or multiple Recipients constructors(to(=new), cc, bcc) to create recipients, and you can also add more recipients using add_to, add_cc, add_bcc methods. each to, cc, bcc recipients will be unique by EmailAddress.email when constructed or added.

// Option 1: Using builder pattern (flexible for multiple fields)
let email = Email::builder()
    .sender(EmailAddress::new("approved-sender@example.com"))
    .subject("Group Email")
    .body_text("This email has CC and BCC recipients")
    .recipients(
        Recipients::builder() // it must be built with at least one of `to`, `cc`, `bcc`
            .to(vec![
                EmailAddress::new("to1@example.com"),
                EmailAddress::with_name("to1@example.com", "to1"), // duplicate, will be ignored
                EmailAddress::with_name("to2@example.com", "User Two"),
            ])
            .cc(vec![EmailAddress::new("cc@example.com")])
            .bcc(vec![EmailAddress::new("bcc@example.com")])
            .build()
    )
    .build()?;

// Option 2: Using specific constructor and add with `add_*` methods (chainable)
let email = Email::builder()
    .sender(EmailAddress::new("approved-sender@example.com"))
    .subject("Group Email")
    .body_text("This email has CC and BCC recipients")
    .recipients(
        Recipients::to(vec![EmailAddress::new("to@example.com")]) // create with `to` recipients
            .add_to(vec![
                EmailAddress::with_name("to@example.com", "To User"), // duplicate, will be ignored
                EmailAddress::new("to2@example.com"), // will be added to `to` recipients
            ])
            .add_cc(vec![EmailAddress::new("cc@example.com")])
            .add_bcc(vec![EmailAddress::new("bcc@example.com")])
    )
    .build()?;

let response = email_client.send(email).await?;

You can also use headers(headerFields), reply_to(replyTo), and message_id(messageId) fields in Email struct. you can reference here

For OCI Email Delivery documentation, see:

• OCI Email Delivery Overview
• OCI Email Delivery API Reference
• OCI Email Delivery Submission API Reference

Error Handling

The library provides comprehensive error types:

use oci_api::{OciError, Result};

match email_client.send(email).await {
    Ok(response) => println!("Sent: {}", response.message_id),
    Err(OciError::ApiError(status, body)) => {
        eprintln!("API error {}: {}", status, body);
    }
    Err(OciError::AuthError(msg)) => {
        eprintln!("Authentication error: {}", msg);
    }
    Err(e) => eprintln!("Other error: {}", e),
}

Error types:

• ConfigError - Configuration loading/validation errors
• EnvError - Environment variable errors
• KeyError - Private key loading errors
• AuthError - Authentication/signing errors
• ApiError - OCI API errors (with HTTP status and response body)
• NetworkError - Network/HTTP client errors
• IniError - Config file parsing errors
• Other - Other errors

License

MIT

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Support

For issues and feature requests, please use GitHub Issues. You can request any OCI APIs, and I will try to implement them as soon as possible.