Add connections inside a plugin

[duro]

I have a plugin that gets registered via a manifest (Glue). I am wondering if it can define it's own connection via the server object it is passed? Or can connections only be created by the main Server instance, and accessed via a label in the plugin?

[hueniverse]

It's a bit delicate. It can use server.root.connection() but that connection is not going to show up within the plugin own server.connections. Handle with care.

[duro]

@hueniverse: so then the recommended approach is to setup connections at the highest level of the Server. These does seem to fly in the face of Hapi's modular approach where everything is a plugin. Because now I have a parent that is defining things that the plug-ins have to assume will be present. Makes moving a plugin from one server to another require that the new server implement the plug-ins connection.

No big deal for my app, but seems like a chink in the foundation that Hapi establishes.

[hueniverse]

The contract is that server.connections doesn't change once you enter the register() plugin method. This creates the limitation that when a plugin calls server.root.connection(), that connection is not directly available to it. You could make it available to a sub-plugin of that by calling server.root.select() to get the connection you just added and then server.register() on the returned selection.

The current API protects you from unexpected changes in the environment such as a new connection showing up during the registration process. By forcing you to use server.root, it is making it clear that you are basically stepping outside of the current plugin realm.

Also keep in mind that adding a connection halfway through the registration process could mess things up for the entire server. For example, if the plugin adding the connection is being registered after some authentication plugins, those registrations will not apply to the newly created connection.

There is a lot to consider when setting up your server and this is why this API while possible, isn't a great idea.

[hueniverse]

Now with the introduction of connectionless plugins, you have a new pattern that is safer to use. You create a plugin with attributes.connections set to false and inside called server.connection(). The connection() method will return a new server object you can use from that point on instead of the server object passed to the register() method.