Reliability: It’s not great

What an earnest post, and how damn refreshing it is to see such concern for users, accountability, honesty and openness (quite a contrast to another PaaS)!

I moved one app successfully from heroku to fly and attempted to move a few others. These are my experiences (both good and bad):

Great:

- The load time on the pages is insanely faster on fly than heroku. Sometimes I thought I was on the localhost version of the app, it was that snappy.

- Love that it uses a Dockerfile

- Love paying for what I use (compared to Heroku's rigid minimum of $16/month for hobby dyno w/ postgres for baby apps, or $34/month just to get a second web dyno for toddler apps). The same apps are <$5/month each on fly.

Not great:

- I find the fly.toml file hard to understand and use, and the cycle time slow to fix or tinker with it. It's partly (entirely?) a 'me' problem because I haven't spent a huge amount of time reading the documentation.

- I found scheduling a rake task in a rails app time consuming (~days) the first time, but very easy (15 minutes) the second and subsequent times, once I knew a way that worked (cron didn't work; had to use a tool I hadn't used before 'supercronic').

- Deploys sometimes time out with `Error failed to fetch an image or build from source: error rendering push status stream: EOF`. Most layers copied, but randomly, some layers wouldn't. All I could do is keep trying until it worked, which it did, 2 hours later. Not the end of the world, but an annoying complication when you're already trying to solve complex problems.

- I followed a youtube video on how to move a rails app from heroku to fly, and it worked on a modern app, but I couldn't quite get fly happy when moving the older app - something to do with postgres versions, and I didn't want to spend all day figuring it out. I'm not hugely experienced with docker, it could have been an easy fix for someone more experienced.

On reflection, 3 of the 4 negatives above are solvable by me reading the docs more thoroughly and getting more proficient with docker.

I look forward to continuing using and exploring fly, and can't be happier with the directness, transparency and care from fly staff. A platform with huge potential.

Did you try migrating with this guide? https://fly.io/docs/rails/getting-started/migrate-from-herok...

The issues you ran into with older versions of Rails was probably because the Dockerfile that `fly launch` generated was for new versions of Rails. We switched to https://github.com/rubys/dockerfile-rails to streamline Dockerfile generation and support older versions of Rails.

If you try it again and run into issues you can open an issue at https://github.com/rubys/dockerfile-rails/issues or post in https://community.fly.io and somebody will help get that sorted out.

The more versions of Rails we can deploy the better!