Configuration

Rift uses Mountebank-compatible JSON configuration with optional _rift extensions for advanced features.

Mountebank Format

Use the standard Mountebank JSON format for creating imposters:

{
  "imposters": [
    {
      "port": 4545,
      "protocol": "http",
      "stubs": [
        {
          "predicates": [{ "equals": { "path": "/api/users" } }],
          "responses": [{ "is": { "statusCode": 200, "body": "[]" } }]
        }
      ]
    }
  ]
}

Load at startup:

docker run -v $(pwd)/imposters.json:/imposters.json \
  zainalpour/rift-proxy:latest --configfile /imposters.json

Or create dynamically via API:

curl -X POST http://localhost:2525/imposters \
  -H "Content-Type: application/json" \
  -d @imposter.json

Full Mountebank Format Reference

Rift Extensions (`_rift` namespace)

Extend Mountebank configurations with advanced chaos engineering features:

{
  "port": 4545,
  "protocol": "http",
  "_rift": {
    "flowState": {
      "backend": "inmemory",
      "ttlSeconds": 300
    }
  },
  "stubs": [{
    "predicates": [{ "equals": { "path": "/api/users" } }],
    "responses": [{
      "is": { "statusCode": 200, "body": "[]" },
      "_rift": {
        "fault": {
          "latency": {
            "probability": 0.3,
            "minMs": 100,
            "maxMs": 500
          }
        }
      }
    }]
  }]
}

Available _rift features:

Flow State: Stateful testing with in-memory or Redis backends
Fault Injection: Probabilistic latency, error, and TCP faults
Scripting: Multi-engine scripting (Rhai, Lua, JavaScript)

Full Rift Extensions Reference

Environment Variables

Configure Rift behavior via environment variables:

Variable	Description	Default
`MB_PORT`	Admin API port	`2525`
`MB_HOST`	Bind hostname	`0.0.0.0`
`MB_CONFIGFILE`	Imposter config file
`MB_DATADIR`	Persistent storage directory
`MB_ALLOW_INJECTION`	Enable JavaScript injection	`false`
`MB_LOCAL_ONLY`	Localhost only	`false`
`MB_LOGLEVEL`	Log level	`info`
`RIFT_METRICS_PORT`	Prometheus metrics port	`9090`
`RUST_LOG`	Detailed log configuration	`info`

docker run -e MB_PORT=2525 -e MB_ALLOW_INJECTION=true \
  -e RUST_LOG=debug zainalpour/rift-proxy:latest

Command Line Options

rift-http-proxy [OPTIONS]

Options:
      --port <PORT>          Admin API port [default: 2525]
      --host <HOST>          Bind hostname [default: 0.0.0.0]
      --configfile <FILE>    Load imposters from JSON file
      --datadir <DIR>        Persistent storage directory
      --allow-injection      Enable JavaScript injection
      --local-only           Localhost only
      --loglevel <LEVEL>     Log level [default: info]
      --metrics-port <PORT>  Prometheus metrics port [default: 9090]
  -h, --help                 Print help
  -V, --version              Print version

Full CLI Reference

Use Cases

Standard API Mocking

Use Mountebank JSON format for:

Migrating from Mountebank
Creating API mocks for integration tests
Working with existing Mountebank tooling
Service virtualization

Advanced Chaos Engineering

Add _rift extensions for:

Probabilistic fault injection
Stateful testing scenarios
Complex conditional logic with scripting
Distributed state with Redis backend