library_server_service_rest_axios

The outbound REST communication service for @thzero/library_server, built on axios.

Implements RestCommunicationService so an application can call another backend without assembling headers, correlation ids or base urls by hand. Host resolution goes through the framework's service discovery when it is configured, and falls back to a configured base url when it is not.

Requirements

NodeJs

NodeJs version 22+

Installation

npm install @thzero/library_server_service_rest_axios

This package declares "exports": "./index.js", so import it by the bare package name — a deep import will not resolve.

import communicationRestService from '@thzero/library_server_service_rest_axios';

Peer dependencies

• @thzero/library_common
• @thzero/library_common_service
• @thzero/library_server

What it provides

index.js — default export AxiosRestCommunicationService, extending RestCommunicationService.

| Method | Signature | |---|---| | get / delete | (correlationId, key, url, options) | | getById / deleteById | (correlationId, key, url, id, options) | | post | (correlationId, key, url, body, options) | | postById | (correlationId, key, url, id, body, options) |

key selects the backend from config. options is merged over the axios config, so anything axios accepts can be set per call.

Each call builds an axios instance that:

• sets baseURL from the resolved resource, with a trailing slash guaranteed;
• sends Content-Type: application/json;
• sends a correlationId header, generating one when the caller has none and writing it back onto options.correlationId so the caller can log the same value;
• sends an api key header when the resource or options supplies one, with options.apiKey winning;
• sends an Authorization bearer header when options.token is set, in the form the framework's own authentication middleware parses back;
• applies options.timeout, or the backend's configured timeout;
• treats any status from 200 to 503 as a resolved response rather than a throw, so failures arrive as responses.

_validate returns the payload on 200. On 401 it clears the user token through SERVICE_AUTH, when one is registered.

Configuration

Per-backend, read through _config.getBackend(correlationId, key):

{
    "app": {
        "backend": {
            "<key>": {
                "baseUrl": "https://service-host/",
                "apiKey": "<api key>",
                "timeout": 30000,
                "discoverable": {
                    "name": "<discovery service name>",
                    "enabled": true
                }
            }
        }
    }
}

• baseUrl — used directly when discovery is off or unavailable.
• apiKey — sent as the api key header. options.apiKey overrides it per call.
• timeout — milliseconds. options.timeout overrides it per call.
• discoverable — omit it to skip discovery entirely. With it present, discovery is used only when a SERVICE_DISCOVERY_RESOURCES service is registered and discoverable.enabled is not false.
• discoverable.name — the name looked up in discovery. Required once discovery is active. Discovered resources are cached per key.

A discovered resource's url is assembled as http(s)://<address>[:<port>], where the address is the resource's address, or a DNS name built from label, namespace and local.

Wiring it up

Register it as the REST communication service from your BootMain derived class or a boot plugin:

import communicationRestService from '@thzero/library_server_service_rest_axios';

this._injectService(LibraryServerConstants.InjectorKeys.SERVICE_COMMUNICATION_REST, new communicationRestService());

Then call it from a service:

const response = await this._serviceCommunicationRest.get(correlationId, 'inventory', 'items', {
    token: request.token
});

The service resolves SERVICE_AUTH and SERVICE_DISCOVERY_RESOURCES during init; both may legitimately be absent.

Development

npm run lint       # eslint .
npm run lint:fix   # eslint . --fix
npm test           # node --test "test/*.test.js"