102 lines
2.8 KiB
JavaScript
102 lines
2.8 KiB
JavaScript
const http = require('http');
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const debug = require('debug')('truss:gateway');
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const {createDispatcher, sendActionToService} = require('@truss/truss');
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let listener = require('./listener');
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// ---
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if (!process.env.SERVICES) {
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console.error('$SERVICES must be defined!');
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process.exit(1);
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}
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const services = process.env.SERVICES.split(',');
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// get all schemas
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const schemas$ = services.map((service) => {
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return sendActionToService({type: 'truss/schema'}, service);
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});
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// build service map
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const reduceServiceMap$ = Promise.all(schemas$).then((schemas) => {
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return schemas.reduce((l, r, i) => {
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for (const type of (r.executors || [])) {
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if (l.executors[type]) {
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throw new Error(`
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Only one executor may be specified per action type! "${services[i]}" tried to
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register an executor but "${l.executors[type]}" already registered one for
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${type}.
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`);
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}
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l.executors[type] = services[i];
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}
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for (const type of (r.listeners || [])) {
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(l.listeners[type] = l.listeners[type] || []).push(services[i]);
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}
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for (const hook of (r.hooks || [])) {
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(l.hooks[hook] = l.hooks[hook] || []).push(services[i]);
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}
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return l;
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}, {
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executors: {},
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hooks: {},
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listeners: {},
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});
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});
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// hey, listen
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const httpServer = http.createServer();
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reduceServiceMap$.then((serviceMap) => {
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debug(`service map: ${JSON.stringify(serviceMap)}`);
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const port = process.env.GATEWAY_PORT || 8000;
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httpServer.listen(port);
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httpServer.on('listening', () => {
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debug(`HTTP listening on port ${port}...`);
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})
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httpServer.on('request', (req, res) => {
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listener(serviceMap, req, res);
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});
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// hooks
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createDispatcher({
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'truss/hook-services': ({payload: {hook, args}}) => {
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if (!(hook in serviceMap.hooks)) { return []; }
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return serviceMap.hooks[hook];
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},
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'truss/invoke': ({payload: {hook, args}}) => {
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if (!(hook in serviceMap.hooks)) { return {}; }
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return invokeHook(serviceMap.hooks[hook], hook, args);
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},
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'truss/invoke-flat': ({payload: {hook, args}}) => {
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if (!(hook in serviceMap.hooks)) { return []; }
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return invokeHookFlat(serviceMap.hooks[hook], hook, args);
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},
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}).connect();
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}).catch(console.error);
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function invokeHookFlat(services, hook, args) {
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debug(`invoking hook flat(${hook}(${JSON.stringify(args)}))...`);
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const action = {type: 'truss/hook', payload: {hook, args}};
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return Promise.all(services.map((service) => {
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return sendActionToService(action, service);
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}));
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}
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function invokeHook(services, hook, args) {
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debug(`invoking hook ${hook}(${JSON.stringify(args)})...`);
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return invokeHookFlat(services, hook, args).then((result) => {
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return result.reduce((l, r, i) => (l[services[i]] = r, l), {});
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});
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}
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if (module.hot) {
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module.hot.accept('./listener', () => {
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listener = require('./listener');
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});
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}
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