Assign data in onPreResponse lifecycle extension with takeover

[suhanw]

Support plan

• which support plan is this issue covered by? (e.g. Community, Core, Plus, or Enterprise): Community
• is this issue currently blocking your project? (yes/no): no
• is this issue affecting a production system? (yes/no): yes

Context

• node version: 12.14.0
• module version: [email protected], [email protected]
• environment (e.g. node, browser, native): node
• used with (e.g. hapi application, another framework, standalone, ...): hapi application
• any other relevant information: n/a

How can we help?

Hi! I'm fairly new to yar and hapi, but let me do my best to explain what I'm trying to accomplish:

• My Hapi server is making calls to another API service, and I use keepAlive agent on these calls, but the challenge we are facing now is every once in a while the service closes the connection and responds with ECONNRESET error.
• So our 'band-aid' solution for now is to detect these ECONNRESET errors, redirect to homepage, and show a simple alert.
• What I was hoping to do is to (a) detect the ECONNRESET response on the onPreResponse lifecycle, (b) set an alert message in session, and (c) change the response to a redirect to homepage. Here's the snippet:

server.ext('onPreResponse', function (request, h){
    let response = request.response;

    if (response.message && typeof response.message.includes === 'function' && response.message.includes('ECONNRESET')) {
        request.yar.set('alerts', `Uh-oh. Something went wrong on our end. Please try again.`);
        return h.response().takeover().redirect('/');
    }

    // other code
}

• Then, I was going to retrieve the alert message from session in one of my homepage route pre-handlers, and save the alert into an app state object that gets sent to the front-end to display the alert.

server.route({
    method: 'GET',
    path: '/',
    config: {
        pre: [
            // other pre-handlers
            { method: getBase, assign: 'basePayload' },
            // other pre-handlers
        ],
        handler: Methods.render
    }
});


const getBase = async (request, h) => {
    let alerts = request.yar.get('alerts');

    // other code
}

But for some reason, the alerts in session did not persist from onPreResponse to the homepage pre-handler, i.e., request.yar.get('alerts') === null in the pre-handler. Is there something about onPreResponse lifecycle that doesn't allow me to save data into session? Any help is greatly appreciated.

Below are my yar options. I tried to distill the code snippets to just the relevant parts, but let me know if I can provide any further info that might help.

{
    plugin: require('yar'),
    options: {
        name: nconf.get('redis:cookieName'),
        maxCookieSize: 0,
        cache: {
            expiresIn: nconf.get('redis:ttl')
        },
        cookieOptions: {
            ttl: nconf.get('redis:ttl'),
            password: nconf.get('redis:secret'),
            isSecure:
                process.env.NODE_ENV === 'production' ||
                process.env.NODE_ENV === 'staging' ||
                process.env.NODE_ENV === 'ephemeral',
            isHttpOnly:
                process.env.NODE_ENV === 'production' ||
                process.env.NODE_ENV === 'staging' ||
                process.env.NODE_ENV === 'ephemeral'
        },
        storeBlank: false
    }
},

Many thanks!

[hueniverse]

What is happening first, yar registration or your custom onPreResponse ext setup?

[suhanw]

They are both plugins included in the same array, but yar appears first in the array:

const plugins = [
    // other plugins
    {
        plugin: require('yar'),
        options: {
            name: nconf.get('redis:cookieName'),
            maxCookieSize: 0,
            cache: {
                expiresIn: nconf.get('redis:ttl')
            },
            cookieOptions: {
                ttl: nconf.get('redis:ttl'),
                password: nconf.get('redis:secret'),
                isSecure:
                    process.env.NODE_ENV === 'production' ||
                    process.env.NODE_ENV === 'staging' ||
                    process.env.NODE_ENV === 'ephemeral',
                isHttpOnly:
                    process.env.NODE_ENV === 'production' ||
                    process.env.NODE_ENV === 'staging' ||
                    process.env.NODE_ENV === 'ephemeral'
            },
            storeBlank: false
        }
    },
    // other plugins
    { plugin: require('./routes/main') },
    // other plugins
];

await server.register(plugins)

require('./routes/main') is the plugin where the onPreResponse ext setup lives.

[hueniverse]

You need to call the new await request.yar.commit(h) before returning the redirect.

[suhanw]

Is this a new feature that's not available in [email protected]?

[hueniverse]

Only in 10.1.0.