# google-cloud-storage

Google Cloud Platform Storage Client library.

[![crates.io](https://img.shields.io/crates/v/google-cloud-storage.svg)](https://crates.io/crates/google-cloud-storage)

* [About Cloud Storage](https://cloud.google.com/storage/)
* [JSON API Documentation](https://cloud.google.com/storage/docs/json_api/v1)

## Installation

```toml
[dependencies]
google-cloud-storage = "version"
```

## Quickstart

### Authentication
There are two ways to create a client that is authenticated against the google cloud.

#### Automatically

The function `with_auth()` will try and read the credentials from a file specified in the environment variable `GOOGLE_APPLICATION_CREDENTIALS`, `GOOGLE_APPLICATION_CREDENTIALS_JSON` or
from a metadata server.

This is also described in [google-cloud-auth](https://github.com/yoshidan/google-cloud-rust/blob/main/foundation/auth/README.md)

```rust
use google_cloud_storage::client::{ClientConfig, Client};

async fn run() {
    let config = ClientConfig::default().with_auth().await.unwrap();
    let client = Client::new(config);
}
```

#### Manually

When you can't use the `gcloud` authentication but you have a different way to get your credentials (e.g a different environment variable)
you can parse your own version of the 'credentials-file' and use it like that:

```rust
use google_cloud_auth::credentials::CredentialsFile;
// or google_cloud_storage::client::google_cloud_auth::credentials::CredentialsFile
use google_cloud_storage::client::{ClientConfig, Client};

async fn run(cred: CredentialsFile) {
    let config = ClientConfig::default().with_credentials(cred).await.unwrap();
    let client = Client::new(config);
}
```

### Anonymous Access

To provide [anonymous access without authentication](https://cloud.google.com/storage/docs/authentication), do the following.

```rust
use google_cloud_storage::client::{ClientConfig, Client};

async fn run() {
    let config = ClientConfig::default().anonymous();
    let client = Client::new(config);
}
```

### Passing a custom reqwest middleware client

```rust
use google_cloud_storage::client::Client;
use google_cloud_storage::client::ClientConfig;
use google_cloud_storage::http::Error;
use reqwest_middleware::ClientBuilder;
use reqwest_retry::policies::ExponentialBackoff;
use reqwest_retry::RetryTransientMiddleware;
use retry_policies::Jitter;

async fn run() -> Result<(), Error> {
    let retry_policy = ExponentialBackoff::builder()
        .base(2)
        .jitter(Jitter::Full)
        .build_with_max_retries(3);

    let mid_client = ClientBuilder::new(reqwest::Client::default())
        // reqwest-retry already comes with a default retry stategy that matches http standards
        // override it only if you need a custom one due to non standard behaviour
        .with(RetryTransientMiddleware::new_with_policy(retry_policy))
        .build();

    Client::new(
        ClientConfig {
            http: Some(mid_client),
            ..Default::default()
        }
        .with_auth()
        .await?,
    );

    Ok(())
}
```

### Usage

```rust
use google_cloud_storage::client::Client;
use google_cloud_storage::client::ClientConfig;
use google_cloud_storage::sign::SignedURLOptions;
use google_cloud_storage::sign::SignBy;
use google_cloud_storage::sign::SignedURLMethod;
use google_cloud_storage::http::Error;
use google_cloud_storage::http::objects::download::Range;
use google_cloud_storage::http::objects::get::GetObjectRequest;
use google_cloud_storage::http::objects::upload::{Media, UploadObjectRequest, UploadType};
use tokio::task::JoinHandle;
use std::fs::File;
use std::io::BufReader;
use std::io::Read;

async fn run(config: ClientConfig) -> Result<(), Error> {

    // Create client.
    let mut client = Client::new(config);

    // Upload the file
    let upload_type = UploadType::Simple(Media::new("file.png"));
    let uploaded = client.upload_object(&UploadObjectRequest {
        bucket: "bucket".to_string(),
        ..Default::default()
    }, "hello world".as_bytes(), &upload_type).await;

    // Download the file
    let data = client.download_object(&GetObjectRequest {
        bucket: "bucket".to_string(),
        object: "file.png".to_string(),
        ..Default::default()
   }, &Range::default()).await;

    // Create signed url with the default key and google-access-id of the client
    let url_for_download = client.signed_url("bucket", "foo.txt", None, None, SignedURLOptions::default());
    let url_for_upload = client.signed_url("bucket", "foo.txt", None, None, SignedURLOptions {
        method: SignedURLMethod::PUT,
        ..Default::default()
    });

    Ok(())
}
```