Fly.io: The reclaimer of Heroku's magic

I don’t feel that way at all.

Every time I’ve tried Fly (trust me I’ve wanted to love it), there’s always a rough edge or the service breaks for me.

First time I tried it, the web panel wasn’t even loading. Second time, months later, everything was 500ing and I couldn’t find a way to SFTP into a disk (!!!). Total dealbreaker.

This was easily done in Render.com with an even more magical experience. Deploy from a GitHub repo and I was live in minutes. Upload the files from local and done.

I want to love Fly so much. I align with their mission. I love their first class Elixir support. But so far I’m not impressed.

It looks to me like Render is seriously taking the PaaS crown at the moment, with innovation after innovation, affordable pricing and excellent user experience.

Why do you need to SFTP into a disk?

I was moving a Ghost blog from Render. Ghost is notorious for having a difficult time with hosting assets in S3, so it uses disks.

I needed to move the Ghost assets directory for all the posts.

This was a ten minute thing in Render. SOL in Fly.

We've been kicking around ideas for managing files on volumes. This is a common problem – it's actually more difficult than you'd expect because "securitah". Once your volume is mounted in one of your VMs, we can't run tools outside the VM to let you manage the file system. On something like k8s with vanilla Docker, we could. But no one should run multitenant Docker.

It's not really an excuse, just a reason it's taking longer to solve than we'd like.

The errors on the web UI sucked. These have improved drastically in the last three months (because we have smart, dedicated people working on fullstack for us now).

Thank you for the response. I want to love your service.

Will keep an eye on the changelogs to see when I can test deploy my apps.

Can you not ssh into a fly instance and then pull?

No. Flyctl SSH does not allow this functionality.

We definitely don't do SFTP! My general M.O. for moving files to running VMs is Magic Wormhole. But that's not optimal either. You've got a legit irritation and I'm glad you put it on our radar.

> We've been kicking around ideas for managing files on volumes. This is a common problem – it's actually more difficult than you'd expect because "securitah". Once your volume is mounted in one of your VMs, we can't run tools outside the VM to let you manage the file system. On something like k8s with vanilla Docker, we could. But no one should run multitenant Docker.

Was there a reason for not using something similar to kata containers where you run a microvm but still use containers inside them? It seems like it would make such things easier while getting the isolation of a VM.

So let me get this straight. Fly has a ‘flyctl ssh’ feature where you can gain console/ssh/whatever into the OS of the fly instance/firecracker/container/thing. So you are saying that once in, you cannot use curl even to pull/download something? (I believe curl supports sftp protocol as well)

You can. You gotta get Wireguard running on your local machine [0] and be able to see the ".internal" network, but once you do, you can ssh into any edge VM and if access its filesystem. I've SCP'd SQLite db files and dumps. It's also a pretty anti-pattern way of debugging an app if you're an outlaw :)

[0] https://fly.io/docs/reference/private-networking/

They do that already AFAICT by using Firecracker.

Unless they’ve changed things, there is no containerization within the VM a la kata. They run their own custom init inside the VM and use it to start the entry point. https://github.com/superfly/init-snapshot is the source.