Slap.Streams.HTTP.Router (slap_streams v0.3.0)

The Durable Streams protocol (§5) as a Plug, over Slap.Streams. The stream's name is the full request path, under :prefix (default /v1/stream). When mounted with Plug.forward/4, the mount path precedes :prefix and is part of the stream name.

It does not authenticate: every request is allowed. Put authentication in front of it, in the Plug pipeline that mounts it or in a proxy. An authorization check by path must also cover the Stream-Forked-From header of a PUT: creating a fork copies its source, so it reads that path. With authentication, set :private_cache.

Options:

• :prefix - only paths under it are streams (default "/v1/stream").
• :long_poll_timeout - ms a long-poll waits for data (default 30,000).
• :sse_timeout - ms before an SSE response ends, so clients reconnect and CDNs can collapse them (default 60,000).
• :max_body - the largest request body, in bytes (default 64 MiB). A larger Content-Length gets 413 before the body is read.
• :max_buffered - bytes of request bodies this VM holds at once (default 512 MiB). All Streams routers in the VM share the counter; configure the same limit on each. A request over it gets 503 with Retry-After before its body is read.
• :trust_forwarded - build the Location of a created stream from X-Forwarded-Proto and X-Forwarded-Host (set it only behind a proxy that sets them). Default false.
• :max_read - about how many bytes one read returns (default 1 MiB).
• :max_path - the longest stream path, in bytes (default 512; 414 above it).
• :private_cache - send Cache-Control: private rather than public on cacheable historical reads (§8), so that a shared cache (a CDN) does not serve one user's reads to another. Default false.
• :cors - "*" (default), a specific origin such as "https://app.example", or false to omit CORS response headers.
• :cluster - Streams cluster serving these requests (default Slap.Streams.Cluster).

Each response sends a [:slap, :streams, :http, :request] telemetry event.