Server Configuration Guide

Overview

A configuration file consists of:

• A single [server] section with process‐wide parameters.
• An ordered list of [[listener]] blocks. Order matters: the first listener config is bound to the first stream handler template parameter, the second to the second stream handler, and so on.

[server]
threads = 4
backlog = 128

[[listener]]            # listener[0]
port = 25565
ssl  = false

[[listener]]            # listener[1]
port      = 8443
ssl       = true
key_file  = "key.pem"
cert_file = "cert.pem"

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Mapping config → server type

Your server type determines how many listeners you must declare and in what order they are interpreted.

1) Plain HTTP only

using Server = usub::server::ServerImpl<
    protocols::http::HTTPEndpointHandler,
    usub::server::PlainHTTPStreamHandler
>;

• Stream handler parameters: PlainHTTPStreamHandler → 1 listener required

• Expected listener layout:

• listener[0] → plain TCP (must be ssl = false)

Minimal config

[server]
threads = 4
backlog = 128

[[listener]]            # binds to PlainHTTPStreamHandler
port = 8080
ssl  = false

2) Mixed (Plain + TLS)

using MixedServerRadix = usub::server::Server<
    protocols::http::HTTPEndpointHandler,
    usub::server::PlainHTTPStreamHandler,
    usub::server::TLSHTTPStreamHandler
>;

• Stream handler parameters: PlainHTTPStreamHandler, TLSHTTPStreamHandler → 2 listeners required

• Expected listener layout:

• listener[0] → plain TCP (must be ssl = false)

• listener[1] → TLS (must be ssl = true, with key/cert)

Typical config

[server]
threads = 4
backlog = 256

[[listener]]            # binds to PlainHTTPStreamHandler
port = 80
ssl  = false

[[listener]]            # binds to TLSHTTPStreamHandler
port      = 443
ssl       = true
key_file  = "/etc/ssl/private/server.key"
cert_file = "/etc/ssl/certs/server.crt"

If you swap the two [[listener]] blocks, you change which handler handles each port, Keep the order consistent with your server type.

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Reference

[server]

• threads (int, ≥1) — size of the worker thread pool.
• backlog (int, ≥0) — listen backlog passed to the OS.

[[listener]]

• port (int, 1–65535) — TCP port to bind.
• ssl (bool) — false for plain TCP; true for TLS.
• key_file (string, required when ssl=true) — path to the private key.
• cert_file (string, required when ssl=true) — path to the certificate chain (server cert first).

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