cloud-pubsub

Provides methods to consume messages from Google PubSub using Futures and Hyper.

Authentication

Authentication is provided by rust-goauth. The BaseClient expects to receive the path to the file containing your Google Cloud service account JSON key.

Token Renewal

The JWT token has a short life time and needs to be renewed periodically for long lived processes.

There is a provided helper which will renew the token every 15 mins:

``` let pubsub = match BaseClient::create(config.googleapplicationcredentials) { Err(e) => panic!("Failed to initialize pubsub: {}", e), Ok(p) => p, };

tokio::run(lazy(move || { pubsub.spawntokenrenew(); })) ```

Env Config

Envy is an excellent way to load your config.

```

[derive(Deserialize)]

struct Config { pubsubsubscription: String, googleapplication_credentials: String, }

fn main() { let parsedenv = envy::fromenv::(); if let Err(e) = parsedenv { eprintln!("ENV is not valid: {}", e); std::process::exit(1); } let config = parsedenv.unwrap();

let pubsub = match BaseClient::create(config.google_application_credentials) {
    Err(e) => panic!("Failed to initialize pubsub: {}", e),
    Ok(p) => p,
};

} ```

Log Config

In order to produce log output, executables have to use a logger implementation compatible with the log facade. There are many available implementations to chose from, for example:

env_logger is an excellent way to log in your executables.

[dependencies] log = "0.4" env_logger = "0.7"

``` fn main() { env_logger::init();

info!("starting up");

// ...

} ```

Subscribing

Connecting to existing subscription

let sub = my_client.subscribe("subscription-name")

Subscribing to a topic

When subscribing to a topic, a random subscription name will be generated. To prevent dangling subscriptions, you need to explicitly call subscription.destroy().