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Deploying Elixir to Render.com
I've deployed a few different Elixir services to the hosting platform https://render.com and found their provided documentation to be lacking for real-world Phoenix apps. Especially if you're using Live View. Here's an augmentation to their guide with the extra steps you might be missing.
Follow the official guide: https://render.com/docs/deploy-phoenix but don't deploy your service yet. You'll need to make some changes:
Add some new evars:
ELIXIR_VERSION = 1.10.3 or whatever version you like. But the default version is older and breaks the build for new Elixir appsDATABASE_URL = The connection string for the database you'll be usingAfter, do these things. MAKE SURE YOU REPLACE WITH YOUR APP NAME :
./build_and_migrate.sh):
#!/usr/bin/env bash
# exit on error
set -o errexit
./build.sh
# Run migrations
_build/prod/rel/<app_name>/bin/<app_name> eval "Render.Release.migrate"lib/<app_name>_web/render_release.ex):
defmodule Render.Release do
@moduledoc """
Responsible for custom release commands
"""
@app :<app_name>
def migrate do
# Allows the migration script to connect to a database using SSL.
Application.ensure_all_started(:ssl)
for repo <- repos() do
{:ok, _, _} = Ecto.Migrator.with_repo(repo, &Ecto.Migrator.run(&1, :up, all: true))
end
end
def rollback(repo, version) do
# Allows the migration script to connect to a database using SSL.
Application.ensure_all_started(:ssl)
{:ok, _, _} = Ecto.Migrator.with_repo(repo, &Ecto.Migrator.run(&1, :down, to: version))
end
defp repos do
Application.load(@app)
Application.fetch_env!(@app, :ecto_repos)
end
end./build_and_migrate.sh instead of ./build.sh
Unless you're using a private database on Render, you'll want to connect to your PG instance using SSL. To do that, you've got to
releases.exs that says ssl: true for your app's repo:
...
config :<app_name>, <AppName>.Repo,
ssl: true, <-- this line, it's commented by default.
url: database_url,And then
:ssl application to extra_applications in mix.exs:
def application do
[
mod: {<AppName>.Application, []},
extra_applications: [:logger, :runtime_tools, :ssl] <-- added :ssl to the end of this list.
]
endIf you run into an issue with Phoenix Live View breaking and reloading the page every few seconds, you might have enabled
force_ssl in your endpoint, and it could be trying to redirect your web socket traffic to an https scheme. Which is strange. I ran into this once, and haven't found a great workaround for it.If your database does pooling using
pg_bouncer then open up releases.exs and add prepare: :unnamed to your repo config.config :<app_name>, <AppName>.Repo,
ssl: true,
url: database_url,
pool_size: String.to_integer(System.get_env("POOL_SIZE") || "10"),
prepare: :unnamed <-- this line!