Mutable Meta client for node
Service Discovery and Config manager
This package is a wrapper to the background service Mutable Meta. Mutable Meta is responsible for service discovery and service configuration.
API
const Meta = require('@mutable/meta')All methods are asynchronous, and take a node-style error-first callback as last argument. If no callback is supplied, a promise is returned instead.
Service Discovery
Meta.services() -> Array
Returns all the currently known service names.
Example:
Meta.services()
.then((_services) => {
// returns an object {}
})Meta.service(service: String) -> Service
Returns a particular service.
Example:
Meta.service("email")
.then((service) => {
request.post(`http://${service}/api/v1/demo/email`,
{json:req.body},
(error, response, body) => {
if(error){
console.error('can not reach email service')
return res.send(500,{error:error,result:'can not reach email service'})
}
res.send({result:"email sent"})
})
})or
Meta.service("email", (config) => {
// returns a object
// {"hostname":"127.0.0.1", "port":3001, toString(): "127.0.0.1:3001" }
// in a string it prints concat host and port
request.post(`http://${service}/api/v1/demo/email`,
{json:req.body},
(error, response, body) => {
if(error){
console.error('can not reach email service')
return res.send(500,{error:error,result:'can not reach email service'})
}
res.send({result:"email sent"})
})
})Config
Meta.config() -> JSON
Fetches the JSON configuration for the current service.
Example:
Meta.config()
.then((_config) => {
// returns an object {}
})For non-mutable deployments set USE_SECRETS=true environment variable to set secrets in the config.
Use CONFIG environment variable to store configs when using secrets.
Use SECRET_ prefix to set secrets as object in the config.
Example:
USE_SECRETS=true CONFIG={"key":"value"} SECRET_SENDGRID_KEY='your_key' SECRET_REDIS='{"db":00}' node app.js
Resulting in this config object:
{
"key": "value",
sendgrid_key: "your_key",
redis: {
"db": 00
}
}
SECRET_ prefix gets removed when setting the key in the config object.
DNS
For non-mutable deployments set DNS environment variable to true and use DNS_POSTFIX variable to modify the service url
Example:
DNS=true DNS_POSTFIX='.default.csv.cluster.local' node app.js
Result target: http://your-web-service.default.scv.cluster.local/