prom-remote-api

Prometheus remote storage API for Rust.

Usage

There are two interfaces in Prometheus remote storage API: write/read.

Both interfaces use a snappy-compressed protocol buffer encoding over HTTP.

This crate provides: - Rust-binding to prometheus remote storage protocol buffer definitions - Various web framework utils to serve the remote wire protocols, which are controlled by corresponding feature-gates. Available features: - warp - actix - more web framework will be added

Any third-party storage can integrate with Prometheus by implementing RemoteStorage trait.

```rust pub trait RemoteStorage: Sync { type Err: Send; type Context: Send + Sync;

/// Write samples to remote storage.
async fn write(&self, ctx: Self::Context, req: WriteRequest) -> Result<(), Self::Err>;

/// Process one query within [ReadRequest](crate::types::ReadRequest).
///
/// Note: Prometheus remote protocol sends multiple queries by default,
/// use [read](crate::types::RemoteStorage::read) to serve ReadRequest.
async fn process_query(
    &self,
    ctx: &Self::Context,
    q: Query,
) -> Result<QueryResult, Self::Err>;

/// Read samples from remote storage.
///
/// [ReadRequest](crate::types::ReadRequest) may contain more than one sub [queries](crate::types::Query).
async fn read(
    &self,
    ctx: Self::Context,
    req: ReadRequest,
) -> Result<ReadResponse, Self::Err> {
    let results = futures::future::join_all(
        req.queries
            .into_iter()
            .map(|q| async { self.process_query(&ctx, q).await }),
    )
    .await
    .into_iter()
    .collect::<Result<Vec<_>, Self::Err>>()?;

    Ok(ReadResponse { results })
}

} ```

See warp-demo.rs, actix-demo.rs to learn how to build a remote storage.