Before deploy

Before deployment, we've found an issue in production with the new content security policy headers. Basically, you need to add wss://...and your domain to the :content_security_policy default_src array, like below.
config :my_app, :content_security_policy, %{
default_src: [
Read more:

Removing CSP

If you don't care about content security policies, you can remove this config and then in router.exs change:
# Change this:
plug(:put_secure_browser_headers, %{
"content-security-policy" =>
struct(ContentSecurityPolicy.Policy, PetalPro.config(:content_security_policy))
# To this:
plug :put_secure_browser_headers

Deployment with Fly.io

We have found Fly.io to be the best combination of cheap and easy. Petal Pro has been set up for users to quickly deploy on Fly.io's servers.
If you haven't already, download the Fly.io CLI. Then you will need to register or sign in.
Once signed in, you can create a new project with:
fly launch
Give your app a name (this can't be changed in future). Hit Y to setting up a DB as we'll need that. Pick a server size.
When it asks "Do you want to deploy now", hit N - we need to make a couple of changes before we deploy.
We need a service to send our emails out. We've found that the simplest and cheapest solution is Amazon SES, and so Petal defaults to using this. We don't really use Amazon for much else, but its email service is cheap and the emails don't get sent to spam as easily as other services we've tried.
Setting up Amazon SES is beyond the scope of this guide - you can google how to do it. The end result should be you are able to provide the following secrets that we'll provide to our production server:
fly secrets set AWS_ACCESS_KEY="xxx" AWS_SECRET="xxx" AWS_REGION="xxx"
Finally, we can run fly deploy.
After deploying you can run fly open to see it in your browser.