consulrs

An asynchronous Rust client library for the Hashicorp Consul API

The following features are currently supported:

• Catalog
• Checks
• KV Store
• Services
• Sessions

Additionally, all optional API features such as consistency modes, blocking, etc. are also supported.

Installation

Add consulrs as a dependency to your cargo.toml:

[dependencies]
consulrs = "0.1.0"

Usage

Basic

The client is used to configure the connection to Consul and is required to be passed to all API calls for execution. Behind the scenes it uses an asynchronous client from Reqwest for communicating to Consul.

use consulrs::client::{ConsulClient, ConsulClientSettingsBuilder};

// Create a client
let client = ConsulClient::new(
    ConsulClientSettingsBuilder::default()
        .address("https://127.0.0.1:8200")
        .build()
        .unwrap()
).unwrap();

The client supports all features required to interact with a production Consul service including the option to specify ACL tokens as well as client and CA certificates.

Using KV store

use std::convert::TryInto;
use consulrs::kv;

// Set `mykey` to "myvalue"
kv::set(&client, "mykey", b"myvalue", None).await;

// Read `mykey`
let mut res = kv::read(&client, "mykey", None).await.unwrap();

// All responses are base64 encoded by default. The below attempts to coerce
// the response back into a UTF-8 encoded string.
let mykey: String = res.response.pop().unwrap().value.unwrap().try_into().unwrap();

assert_eq!(mykey, "myvalue".to_string());

Registering a service

use consulrs::api::check::common::AgentServiceCheckBuilder;
use consulrs::api::service::requests::RegisterServiceRequest
use consulrs::service;

// Create a service named "my_service" with a health check that queries the
// service via HTTP every 10 seconds.
service::register(
    &client,
    "my_service",
    Some(
        RegisterServiceRequest::builder()
            .address("http://myservice.lab.com")
            .port(1234)
            .check(
                AgentServiceCheckBuilder::default()
                    .name("health_check")
                    .interval("10s")
                    .http("http://myservice.lab.com/health")
                    .status("passing")
                    .build()
                    .unwrap(),
            ),
    ),
)
.await;

See the examples directory for additional examples.

Error Handling and Tracing

All errors generated by this crate are wrapped in the ClientError enum provided by the crate. API errors are captured and returned as their own variant including the response code and error message from the server. Connection related errors from rustify are wrapped and returned as a single variant.

All top level API operations are instrumented with tracing's #[instrument] attribute.

Testing

See the the tests directory for tests. Run tests with cargo test.

Note: All tests rely on bringing up a local Consul development server using Docker. In order to run tests Docker must be running locally (Docker Desktop works).

Contributing

Check out the issues for items needing attention or submit your own and then:

1. Fork the repo (https://github.com/jmgilman/consulrs/fork)
2. Create your feature branch (git checkout -b feature/fooBar)
3. Commit your changes (git commit -am 'Add some fooBar')
4. Push to the branch (git push origin feature/fooBar)
5. Create a new Pull Request