Legion.RateLimiter.Rule (Legion v0.5.0)

One rate-limit rule: the group it applies to and the limits it enforces.

%Legion.RateLimiter.Rule{
  identity: %{"ip" => "203.0.113.42"},
  policy: %Legion.RateLimiter.Policy{window_ms: :timer.minutes(1), max_agents: 10}
}

Fields

:identity (required) - string-keyed map naming the group. Agents with matching identities consume the same rolling-window limits; how "matching" is decided belongs to the adapter (Legion.RateLimiter.Postgres uses JSON containment, so a broader identity also covers agents recorded with extra fields). %{} matches every agent.
:policy - the Legion.RateLimiter.Policy to enforce. May be left nil in Legion.start_link/2 options, where it is filled from config :legion, :rate_limit, default_policy: ...; adapters always receive a complete rule.

See Legion.RateLimiter for how rules are configured and combined.

Summary

Functions

validate!(rule)

Returns :ok when rule is complete and usable.

Types

t()

@type t() :: %Legion.RateLimiter.Rule{
  identity: Legion.RateLimiter.limit_identity(),
  policy: Legion.RateLimiter.Policy.t() | nil
}

Functions

validate!(rule)

Returns :ok when rule is complete and usable.

Raises ArgumentError naming the offending field: a non-map identity, identity keys that are not strings, or a missing or invalid policy (see Legion.RateLimiter.Policy.validate!/1). Legion calls this when an agent starts, so a bad rule fails at the agent that configured it.