config.ts

import fs from 'fs'
import jsonschema from 'jsonschema'

export type SystemConfig = {
    signature: SignatureConfig
    clients: SenderConfig[]
    nodes: NodeConfig[]
    params: ParamConfig
}

export type SignatureConfig = {
    enabled: boolean
}

export type ParamConfig = {
    // f is the max number of faulty nodes tolerated
    f: number
    // k is a big number that is used to calculate the high-water mark
    // NOTE: k is slightly different from the k in the osdi99 paper
    // if checkpoint is genereated at every 100 requests, then k can be 100
    // highWaterMark will be 2 * k + lowWaterMark
    k: number
}

export type SenderConfig = {
    name: string
    pubkey: string
    prikey: string
}

export type NodeConfig = {
    host: string
    port: number
} & SenderConfig

export const schema = {
    '$schema': 'http://json-schema.org/draft-07/schema#',
    'type': 'object',
    'properties': {
        'signature': {
            'type': 'object',
            'properties': {
                'enabled': {
                    'type': 'boolean',
                    'default': 'true'
                }
            },
        },
        'nodes': {
            'type': 'array',
            'items': {
                'type': 'object',
                'properties': {
                    'name': {
                        'type': 'string'
                    },
                    'host': {
                        'type': 'string'
                    },
                    'port': {
                        'type': 'number'
                    },
                    'pubkey': {
                        'type': 'string'
                    },
                    'prikey': {
                        'type': 'string'
                    }
                },
                'required': ['name', 'host', 'port', 'pubkey', 'prikey']
            }
        },
        'clients': {
            'type': 'array',
            'items': {
                'type': 'object',
                'properties': {
                    'name': {
                        'type': 'string'
                    },
                    'pubkey': {
                        'type': 'string'
                    },
                    'prikey': {
                        'type': 'string'
                    }
                },
                'required': ['name', 'pubkey', 'prikey']
            }
        },
        'params': {
            'type': 'object',
            'properties': {
                'f': {
                    'type': 'number'
                },
                'k': {
                    'type': 'number'
                }
            },
            'required': ['f', 'k']
        }
    },
    'required': ['nodes', 'params']
}

export function readConfig(path?: string): SystemConfig {
    path = path ?? 'configs/cluster.json'
    console.log(`reading config from ${path}`)

    const obj = JSON.parse(fs.readFileSync(path).toString())
    const validator = new jsonschema.Validator()
    const result = validator.validate(obj, schema)
    if (!result.valid) {
        throw new Error(`invalid config: ${result.errors}`)
    }
    const config = obj as SystemConfig
    config.signature = config.signature ?? { enabled: true }
    return config
}