Running apps

Private networking

Apps reach each other by name, on any server in the cluster, over an encrypted network.

Apps talk to each other by name#

Inside your apps, <app>.internal reaches another app, and <process>.<app>.internal one of its process types, on any server in the cluster.

Name	Reaches
`cache.internal`	The `cache` app's `web` instances (or its only process type)
`worker.shop.internal`	The `shop` app's `worker` instances
`cache`	From any app, the `cache` app
`worker`	From `shop`, shop's own worker processes

Connect on the port the app listens on:

Terminal

jokku config:set myapp REDIS_URL=redis://cache.internal:6379

Names resolve to the addresses of the instances that should be running, preferring healthy ones, so a name follows a deploy as the new instances pass their checks. Answers live for five seconds, since instances come and go with deploys and moves.

Under the hood#

Each server runs a small DNS server for its microVMs, jokku-dns, separate from the main daemon, so updating Jokku never interrupts lookups. Every other name goes to the server's own resolvers.
Servers are joined by a WireGuard mesh on UDP port 51820. Traffic between instances on different servers is encrypted and routed straight to the server that hosts them.
The cluster network is 10.210.0.0/16. Server N owns 10.210.N.0/24, and its microVMs get addresses from it.
Instances reach the internet through their server.