MachineGun

HTTP client for Elixir. Based on Gun and Poolboy.

• Supports HTTP/1 and HTTP/2 with automatic detection;
• Maintains separate connection pool for each pool_group:host:port combination;
• Allows per-pool configuration;
• Drop-in replacement for HTTPoison.

Example

%MachineGun.Response{body: body, status_code: 200} =
  MachineGun.post!(
    "https://httpbin.org/anything",
    "{\"hello\":\"world!\"}",
    [{"content-type", "application/json"}, {"accept", "application/json"}],
    %{pool_timeout: 1000, request_timeout: 5000, pool_group: :default})

Options are included to show defaults and can be omitted. pool_timeout and request_timeout default to values specified in pool group configuration. If not specified in pool group configuration they default to the values in the example.

Configuration

config :machine_gun,
  # Default pool group
  default: %{
    pool_size: 4,         # Poolboy size
    pool_max_overflow: 4, # Poolboy max_overflow
    pool_timeout: 1000,
    request_timeout: 5000,
    conn_opts: %{}        # Gun connection options
  }

Configuration example shows defaults and can be omitted. See Poolboy options documentation for explanation of pool_size and pool_max_overflow. See Gun manual for explanation of conn_opts.

Notes

• When using MachineGun in a long-living process (for example genserver) make sure to handle messages in the form of {ref, _} tuples, which may be produced by pool timeouts.
• When using MachineGun with HTTP/2 and modern HTTP/1 servers we recommend using lowercase header names. For example content-type.
• MachineGun may timeout when request with empty body contains content-type header and does not contain content-length header. See this issue for details.