我是分子和微服务的初学者。我通过nestjs 框架创建了一个api 网关，现在我想通过nestjs 的nats 消息调用分子中的微服务。所以我的问题是：如何在 molculer 中调用服务以及在 nestjs 中调用分子动作的消息模式是什么？
通过 molculer 创建模板后，我有以下文件，我想调用“greeter.hello”操作。我能怎么做？
greeter.service.js ：
"use strict";
/**
* @typedef {import('moleculer').Context} Context Moleculer's Context
*/
module.exports = {
name: "greeter",
/**
* Settings
*/
settings: {
},
/**
* Dependencies
*/
dependencies: [],
/**
* Actions
*/
actions: {
/**
* Say a 'Hello' action.
*
* @returns
*/
hello: {
rest: {
method: "GET",
path: "/hello"
},
async handler() {
return "Hello Moleculer";
}
},
/**
* Welcome, a username
*
* @param {String} name - User name
*/
welcome: {
rest: "/welcome",
params: {
name: "string"
},
/** @param {Context} ctx */
async handler(ctx) {
return `Welcome, ${ctx.params.name}`;
}
}
},
/**
* Events
*/
events: {
},
/**
* Methods
*/
methods: {
},
/**
* Service created lifecycle event handler
*/
created() {
},
/**
* Service started lifecycle event handler
*/
async started() {
},
/**
* Service stopped lifecycle event handler
*/
async stopped() {
}
};
分子.config.js：
"use strict";
/**
* Moleculer ServiceBroker configuration file
*
* More info about options:
* https://moleculer.services/docs/0.14/configuration.html
*
*
* Overwriting options in production:
* ================================
* You can overwrite any option with environment variables.
* For example to overwrite the "logLevel" value, use `LOGLEVEL=warn` env var.
* To overwrite a nested parameter, e.g. retryPolicy.retries, use `RETRYPOLICY_RETRIES=10` env var.
*
* To overwrite broker’s deeply nested default options, which are not presented in "moleculer.config.js",
* use the `MOL_` prefix and double underscore `__` for nested properties in .env file.
* For example, to set the cacher prefix to `MYCACHE`, you should declare an env var as `MOL_CACHER__OPTIONS__PREFIX=mycache`.
* It will set this:
* {
* cacher: {
* options: {
* prefix: "mycache"
* }
* }
* }
*/
module.exports = {
// Namespace of nodes to segment your nodes on the same network.
namespace: "mole",
// Unique node identifier. Must be unique in a namespace.
nodeID: "users",
// Custom metadata store. Store here what you want. Accessing: `this.broker.metadata`
metadata: {},
// Enable/disable logging or use custom logger. More info: https://moleculer.services/docs/0.14/logging.html
// Available logger types: "Console", "File", "Pino", "Winston", "Bunyan", "debug", "Log4js", "Datadog"
logger: {
type: "Console",
options: {
// Using colors on the output
colors: true,
// Print module names with different colors (like docker-compose for containers)
moduleColors: false,
// Line formatter. It can be "json", "short", "simple", "full", a `Function` or a template string like "{timestamp} {level} {nodeID}/{mod}: {msg}"
formatter: "full",
// Custom object printer. If not defined, it uses the `util.inspect` method.
objectPrinter: null,
// Auto-padding the module name in order to messages begin at the same column.
autoPadding: false
}
},
// Default log level for built-in console logger. It can be overwritten in logger options above.
// Available values: trace, debug, info, warn, error, fatal
logLevel: "info",
// Define transporter.
// More info: https://moleculer.services/docs/0.14/networking.html
// Note: During the development, you don't need to define it because all services will be loaded locally.
// In production you can set it via `TRANSPORTER=nats://localhost:4222` environment variable.
transporter: "nats://localhost:4222", //"NATS"
// Define a cacher.
// More info: https://moleculer.services/docs/0.14/caching.html
cacher: null,
// Define a serializer.
// Available values: "JSON", "Avro", "ProtoBuf", "MsgPack", "Notepack", "Thrift".
// More info: https://moleculer.services/docs/0.14/networking.html#Serialization
serializer: "JSON",
// Number of milliseconds to wait before reject a request with a RequestTimeout error. Disabled: 0
requestTimeout: 10 * 1000,
// Retry policy settings. More info: https://moleculer.services/docs/0.14/fault-tolerance.html#Retry
retryPolicy: {
// Enable feature
enabled: false,
// Count of retries
retries: 5,
// First delay in milliseconds.
delay: 100,
// Maximum delay in milliseconds.
maxDelay: 1000,
// Backoff factor for delay. 2 means exponential backoff.
factor: 2,
// A function to check failed requests.
check: err => err && !!err.retryable
},
// Limit of calling level. If it reaches the limit, broker will throw an MaxCallLevelError error. (Infinite loop protection)
maxCallLevel: 100,
// Number of seconds to send heartbeat packet to other nodes.
heartbeatInterval: 10,
// Number of seconds to wait before setting node to unavailable status.
heartbeatTimeout: 30,
// Cloning the params of context if enabled. High performance impact, use it with caution!
contextParamsCloning: false,
// Tracking requests and waiting for running requests before shuting down. More info: https://moleculer.services/docs/0.14/context.html#Context-tracking
tracking: {
// Enable feature
enabled: false,
// Number of milliseconds to wait before shuting down the process.
shutdownTimeout: 5000,
},
// Disable built-in request & emit balancer. (Transporter must support it, as well.). More info: https://moleculer.services/docs/0.14/networking.html#Disabled-balancer
disableBalancer: false,
// Settings of Service Registry. More info: https://moleculer.services/docs/0.14/registry.html
registry: {
// Define balancing strategy. More info: https://moleculer.services/docs/0.14/balancing.html
// Available values: "RoundRobin", "Random", "CpuUsage", "Latency", "Shard"
strategy: "RoundRobin",
// Enable local action call preferring. Always call the local action instance if available.
preferLocal: true
},
// Settings of Circuit Breaker. More info: https://moleculer.services/docs/0.14/fault-tolerance.html#Circuit-Breaker
circuitBreaker: {
// Enable feature
enabled: false,
// Threshold value. 0.5 means that 50% should be failed for tripping.
threshold: 0.5,
// Minimum request count. Below it, CB does not trip.
minRequestCount: 20,
// Number of seconds for time window.
windowTime: 60,
// Number of milliseconds to switch from open to half-open state
halfOpenTime: 10 * 1000,
// A function to check failed requests.
check: err => err && err.code >= 500
},
// Settings of bulkhead feature. More info: https://moleculer.services/docs/0.14/fault-tolerance.html#Bulkhead
bulkhead: {
// Enable feature.
enabled: false,
// Maximum concurrent executions.
concurrency: 10,
// Maximum size of queue
maxQueueSize: 100,
},
// Enable action & event parameter validation. More info: https://moleculer.services/docs/0.14/validating.html
validator: true,
errorHandler: null,
// Enable/disable built-in metrics function. More info: https://moleculer.services/docs/0.14/metrics.html
metrics: {
enabled: true,
// Available built-in reporters: "Console", "CSV", "Event", "Prometheus", "Datadog", "StatsD"
reporter: {
type: "Prometheus",
options: {
// HTTP port
port: 3030,
// HTTP URL path
path: "/metrics",
// Default labels which are appended to all metrics labels
defaultLabels: registry => ({
namespace: registry.broker.namespace,
nodeID: registry.broker.nodeID
})
}
}
},
// Enable built-in tracing function. More info: https://moleculer.services/docs/0.14/tracing.html
tracing: {
enabled: true,
// Available built-in exporters: "Console", "Datadog", "Event", "EventLegacy", "Jaeger", "Zipkin"
exporter: {
type: "Console", // Console exporter is only for development!
options: {
// Custom logger
logger: null,
// Using colors
colors: true,
// Width of row
width: 100,
// Gauge width in the row
gaugeWidth: 40
}
}
},
// Register custom middlewares
middlewares: [],
// Register custom REPL commands.
replCommands: null,
// Called after broker created.
created(broker) {
},
// Called after broker started.
async started(broker) {
},
// Called after broker stopped.
async stopped(broker) {
}
};
谢谢