trooba-http-transport
v2.1.0
Published
HTTP transport for trooba pipeline
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trooba-http-transport
HTTP transport for trooba pipeline.
The transport provides server and client API with trooba context propagation support. For more information one might want to read this.
Get Involved
- Contributing: Pull requests are welcome!
- Read
CONTRIBUTING.md
and check out our bite-sized and help-wanted issues - Submit github issues for any feature enhancements, bugs or documentation problems
- Read
- Support: Join our gitter chat to ask questions to get support from the maintainers and other Trooba developers
- Questions/comments can also be posted as github issues
Install
npm install trooba-http-transport --save
Usage
The context serialization logic depends on type of the pipeline:
- Web application
- Service application
- Service invocation
Web application pipeline
This type of pipeline needs to deserialize context from cookies into pipe.context and in the response flow from pipe.context into cookies.
const Cookies = require('cookies');
const app = Trooba.use(httpTransport, {
port: 0,
context: {
serialize: (context, serverContext) => {
const target = Object.keys(context).forEach(name => {
if (name.charAt(0) !== '$') {
const options = context[name] === undefined ?
// delete cookie if the property is deleted
{maxAge: -1} :
{}
serverContext.cookies.set(name, context[name], options);
}
}, {});
},
deserialize: (serverContext, context) => {
serverContext.cookies = new Cookies(
serverContext.request,
serverContext.response,
{ keys: keys });
context.userName = serverContext.cookies.get('username');
context.locale = serverContext.cookies.get('locale');
context.jsEnabled = serverContext.cookies.get('jsEnabled');
}
}
});
Service application pipeline
This type of pipeline needs to deserialize context from request header/headers into pipe.context and in the response flow from pipe.context into response header/headers.
const app = Trooba.use(httpTransport, {
port: 0,
context: {
serialize: (context, serverContext) => {
const deleted = [];
const target = Object.keys(context).reduce((memo, name) => {
if (name.charAt(0) !== '$') {
if (context[name] === undefined) {
// remember what was deleted
deleted.push(name);
return memo;
}
memo[name] = context[name];
}
return memo;
}, {});
// propagate deleted fields
target['@deleted'] = deleted.length ? deleted : undefined;
serverContext.response.setHeader('x-trooba-context', JSON.stringify(target));
},
deserialize: (serverContext, context) => {
const pipeContext = serverContext.request.headers['x-trooba-context'];
if (pipeContext) {
Object.assign(context, JSON.parse(pipeContext));
}
}
}
});
Service invocation pipeline
This type of pipeline needs to serialize context into a special request header/headers and in the response flow deserialize from response header/headers into pipe.context.
For example, one can use the following context provider:
require('trooba')
.use(httpTransport, {
protocol: 'http:',
hostname: 'www.google.com',
connectTimeout: 100,
socketTimeout: 1000,
context: { // context is optional
serialize: (context, serverContext) => {
const target = Object.keys(context).reduce((memo, name) => {
if (name.charAt(0) !== '$') {
memo[name] = context[name];
}
return memo;
}, {});
serverContext.response.setHeader('x-trooba-context', JSON.stringify(target));
},
deserialize: (serverContext, context) => {
const troobaContext = serverContext.request.headers['x-trooba-context'];
if (troobaContext) {
Object.assign(context, JSON.parse(troobaContext));
}
}
}
})
.build('client:default')
.get({
q: 'nike'
})
.set('some', 'header')
.end(function (err, response) {
console.log(err, response && response.body)
});