How does one handle zero downtime deployments with single-file golang binaries? I remember I tried this setup some time ago and I couldn't successfully manage cleanly to accomplish no downtime when deploying a new version of my service. The reason was mainly port reuse. I couldn't have the old and the new version of my service running on the same port... so I started to hack together something and it became dirty pretty quickly. I'm talking about deployment of new version of service on the same machine/server as the old version was running.

Some of this is solved by using e.g. systemd, depending on your needs.

> I couldn't have the old and the new version of my service running on the same port...

You can, actually! You just can’t open the port twice by default. So one or both of the processes needs to inherit the port from a parent process, get passed the port over a socket (Unix sockets can transmit file descriptors), or use SO_REUSEADDR.

There are some libraries that abstract this, and some of this is provided by tools like systemd.

Some of this is probably going to have to be done in your application—like, once your new version starts, the old version should stop accepting new connections and finish the requests it has already started.

joncfoo

> Some of this is probably going to have to be done in your application...

FWICT tableflip does exactly this: https://github.com/cloudflare/tableflip