rlproxy is a small TCP proxy with rate limiting capability. It uses a token bucket algorithm to apply a rate limit on the bandwidth allocated to downstream clients. The rate limit can be applied globally across all downstream clients or per client.

rlproxy can be configured using command line flags or a configuration file or both. Type rlproxy -h to find out the flags supported by rlproxy. Settings specified using command line flags take precedence over settings in the configuration file. The configuration file can be a JSON file with the following format:

{
    "name": "my-beloved-app",
    "addrs": [
        "127.0.0.1:12000"
    ],
    "upstream": "127.0.0.1:12001",
    "rate": "10M",
    "burst": "64KiB",
    "per_client": false,
    "no_splice": false,
    "buf_size": "1 Mi",
    "logging": {
        "level": "info",
        "console": {
            "enabled": true,
            "pretty": true,
            "use_stderr": false

        },
        "syslog": {
            "enabled": false,
            "facility": "local0"
        }
    }
}

or a YAML file:

name: my-beloved-app
addrs:
  - 127.0.0.1:12000
upstream: 127.0.0.1:12001
rate: 10M
burst: 64KiB
per_client: false
no_splice: false
buf_size: 1 Mi
logging:
  level: info
  console:
    enabled: true
    pretty: true
    use_stderr: false
  syslog:
    enabled: false
    facility: local0