add Docker deployment with Alpine image, release config and health check

- Alpine multi-stage Dockerfile (131 MB image)
- Release overlays (bin/server, bin/migrate), env.sh, Release module
- Health check endpoint at GET /health
- Fly.io config with SQLite volume mount
- Fix hardcoded paths in optimizer.ex and variant_cache.ex to use
  Application.app_dir/2 (breaks in releases where Plug.Static serves
  from a different directory than CWD)
- strip_beams: true in release config
- Optimised .dockerignore and .gitignore for mockup variants

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.dockerignore

@@ -0,0 +1,52 @@
+# Build artifacts
+_build/
+deps/
+.elixir_ls/
+
+# Git
+.git/
+.gitignore
+
+# Test and dev
+test/
+.formatter.exs
+.credo.exs
+.dialyzer_ignore.exs
+
+# Database files
+*.db
+*.db-wal
+*.db-shm
+
+# Docker
+Dockerfile*
+.dockerignore
+docker-compose*
+
+# IDE
+.vscode/
+.idea/
+
+# OS
+.DS_Store
+Thumbs.db
+
+# CI/docs
+CLAUDE.md
+PROGRESS.md
+ROADMAP.md
+docs/
+
+# Generated image variants (regenerated on startup from DB)
+priv/static/image_cache/
+
+# Mockup variants, digested copies, and converted formats.
+# Only the source .webp files (no size suffix) should enter the build context —
+# phx.digest creates its own hash-suffixed copies inside the builder.
+priv/static/mockups/*-400*
+priv/static/mockups/*-800*
+priv/static/mockups/*-1200*
+priv/static/mockups/*-thumb*
+priv/static/mockups/*.avif
+priv/static/mockups/*.jpg
+priv/static/mockups/*.gz

.gitignore

@@ -49,13 +49,15 @@ simpleshop_theme-*.tar
 /priv/static/images/*-*.svg.gz
 /priv/static/images/*.gz
 
-# Generated mockup variants (auto-generated on startup via Oban)
+# Generated mockup variants, digested copies, and converted formats.
-# Source .webp files are tracked, variants are regenerated
+# Only source .webp files (no size suffix) are tracked — everything else regenerates.
-/priv/static/mockups/*-400.*
+/priv/static/mockups/*-400*
-/priv/static/mockups/*-800.*
+/priv/static/mockups/*-800*
-/priv/static/mockups/*-1200.*
+/priv/static/mockups/*-1200*
-/priv/static/mockups/*-thumb.*
+/priv/static/mockups/*-thumb*
-# Digested versions of mockup variants and sources (from mix phx.digest)
+/priv/static/mockups/*.avif
+/priv/static/mockups/*.jpg
+/priv/static/mockups/*.gz
 /priv/static/mockups/*-????????????????????????????????.*
 
 # Generated image variants cache (regenerated from source images)

Dockerfile

@@ -0,0 +1,113 @@
+# Lean Alpine-based image for SimpleshopTheme.
+#
+# Builder and runner both use Alpine (musl). The vix NIF is compiled against
+# Alpine's system libvips instead of the glibc-linked precompiled binary.
+#
+# Build:  docker build -t simpleshop_theme .
+# Run:    docker run --rm -p 4000:4000 \
+#           -e SECRET_KEY_BASE=$(mix phx.gen.secret) \
+#           -e DATABASE_PATH=/data/simpleshop_theme.db \
+#           -e PHX_HOST=localhost \
+#           -v simpleshop_data:/data \
+#           simpleshop_theme
+#
+# Images:
+#   https://hub.docker.com/r/hexpm/elixir/tags?name=alpine
+#   https://hub.docker.com/_/alpine
+
+ARG ELIXIR_VERSION=1.19.5
+ARG OTP_VERSION=28.2
+ARG ALPINE_VERSION=3.23.3
+
+ARG BUILDER_IMAGE="hexpm/elixir:${ELIXIR_VERSION}-erlang-${OTP_VERSION}-alpine-${ALPINE_VERSION}"
+ARG RUNNER_IMAGE="alpine:${ALPINE_VERSION}"
+
+# --- Builder ---
+
+FROM ${BUILDER_IMAGE} AS builder
+
+# Build deps: C compiler for NIFs, git for hex deps, vips-dev for image processing
+RUN apk add --no-cache build-base git vips-dev
+
+WORKDIR /app
+
+RUN mix local.hex --force && mix local.rebar --force
+
+ENV MIX_ENV="prod"
+
+# Use Alpine's system libvips instead of the glibc-linked precompiled binary
+ENV VIX_COMPILATION_MODE="PLATFORM_PROVIDED_LIBVIPS"
+
+# Install mix dependencies
+COPY mix.exs mix.lock ./
+RUN mix deps.get --only $MIX_ENV
+RUN mkdir config
+
+# Compile dependencies (config needed first)
+COPY config/config.exs config/${MIX_ENV}.exs config/
+RUN mix deps.compile
+
+# Install tailwind and esbuild CLI tools
+RUN mix assets.setup
+
+# Copy priv in layers ordered by change frequency.
+# Mockups/fonts are stable; migrations and seeds change more often.
+COPY priv/static/mockups priv/static/mockups
+COPY priv/static/fonts priv/static/fonts
+COPY priv/static/images priv/static/images
+COPY priv/static/favicon.ico priv/static/robots.txt priv/static/
+COPY priv/repo priv/repo
+COPY priv/gettext priv/gettext
+
+# Application code and frontend assets (change most often)
+COPY lib lib
+COPY assets assets
+
+# Compile the application
+RUN mix compile
+
+# Build assets (both tailwind profiles + esbuild + phx.digest)
+RUN mix assets.deploy
+
+# Remove gzipped copies of mockup images — WebP is already compressed,
+# gzip saves ~0% and just wastes space in the release
+RUN find priv/static/mockups -name "*.gz" -delete 2>/dev/null || true
+
+# Runtime config doesn't need recompilation
+COPY config/runtime.exs config/
+
+# Release overlay scripts
+COPY rel rel
+
+# Build the release
+RUN mix release
+
+# --- Runner ---
+
+FROM ${RUNNER_IMAGE} AS runner
+
+# Runtime deps only — no compilers, no -dev packages
+RUN apk add --no-cache libstdc++ openssl ncurses-libs vips
+
+WORKDIR /app
+
+# Non-root user for security
+RUN adduser -D -h /app appuser
+RUN chown appuser:appuser /app
+
+# Prepare the data directory (for SQLite database)
+RUN mkdir -p /data && chown appuser:appuser /data
+
+ENV MIX_ENV="prod"
+
+# Copy the release from the builder
+COPY --from=builder --chown=appuser:appuser /app/_build/${MIX_ENV}/rel/simpleshop_theme ./
+
+USER appuser
+
+# Ensure /data is the default database location
+ENV DATABASE_PATH="/data/simpleshop_theme.db"
+
+EXPOSE 4000
+
+CMD ["/app/bin/server"]

PROGRESS.md

@@ -33,7 +33,7 @@
 
 ### Tier 2 — Production readiness (can deploy and run reliably)
 
-5. **Hosting & deployment** — Fly.io or similar deployment config. Release configuration, runtime env setup, health checks. Observability: structured logging, error tracking (Sentry or similar), basic metrics.
+5. **Hosting & deployment** — In progress. Alpine Docker image (131 MB), Fly.io config, release overlays, health check endpoint, hardcoded path fixes for releases. Still to do: observability (structured logging, error tracking, basic metrics).
 6. **Litestream / SQLite replication** — Litestream for continuous SQLite backup to S3-compatible storage. Point-in-time recovery. Simple sidecar process, no code changes needed, works with vanilla SQLite. For the hosted platform (Tier 5), evaluate [Turso](https://turso.tech/) (libSQL fork of SQLite) with embedded read replicas via [ecto_libsql](https://github.com/ocean/ecto_libsql) adapter — gives multi-node reads without a separate replication daemon, but adds a dependency on the libSQL fork.
 7. ~~**CI pipeline**~~ — ✅ Complete. `mix ci` alias: compile --warning-as-errors, deps.unlock --unused, format --check-formatted, credo, dialyzer, test. Credo configured with sensible defaults. Dialyzer with ignore file for false positives (Stripe types, Mix tasks, ExUnit internals). 612 tests, 0 failures.
 8. **PageSpeed in CI** — Lighthouse CI to catch regressions. Fail the build if score drops below threshold. Protects the current 100% score.
@@ -56,7 +56,7 @@
 
 17. **Hosted platform** — Marketing/brochure site for SimpleShop as a service. Subscribe/sign-up flow. Multi-tenancy with per-tenant databases. Stripe Connect for customer shops (each merchant connects their own Stripe account via OAuth).
 18. **Migration & export** — Let shop owners export their data (products, orders, customers, theme settings). Import from other platforms (Shopify, WooCommerce). Portable data as a selling point for the self-hosted story.
-19. **Internationalisation (i18n)** — Multi-language support via Gettext (already in Phoenix). Currency formatting (ex_cldr already in deps). RTL layout support. Per-shop locale configuration.
+19. **Internationalisation (i18n)** — Multi-language support via Gettext (already in Phoenix). Currency formatting. RTL layout support. Per-shop locale configuration. **Note:** `ex_money`/`ex_cldr` are currently used *only* for `Cart.format_price/1` (a single GBP formatting call) but add ~13 MB to the release (ex_cldr 9.5 MB, digital_token 3.7 MB, ex_cldr_numbers, ex_cldr_currencies). Consider replacing with a simple `format_price/2` function that handles GBP/EUR/USD directly — all three use 2 decimal places and are trivial to format. Re-add `ex_money` later if proper locale-aware number formatting is needed (e.g., German `12.345,67 €`).
 
 ---
 

config/runtime.exs

@@ -25,7 +25,7 @@ if config_env() == :prod do
     System.get_env("DATABASE_PATH") ||
       raise """
       environment variable DATABASE_PATH is missing.
-      For example: /etc/simpleshop_theme/simpleshop_theme.db
+      For example: /data/simpleshop_theme.db
       """
 
   config :simpleshop_theme, SimpleshopTheme.Repo,
@@ -97,22 +97,32 @@ if config_env() == :prod do
 
   # ## Configuring the mailer
   #
-  # In production you need to configure the mailer to use a different adapter.
+  # Uncomment ONE of the blocks below and set the matching env vars.
-  # Here is an example configuration for Mailgun:
+  # The API client is already configured in config/prod.exs (Swoosh.ApiClient.Req).
+  #
+  # Postmark (recommended):
+  #
+  #     config :simpleshop_theme, SimpleshopTheme.Mailer,
+  #       adapter: Swoosh.Adapters.Postmark,
+  #       api_key: System.get_env("POSTMARK_API_KEY")
+  #
+  # Mailgun:
   #
   #     config :simpleshop_theme, SimpleshopTheme.Mailer,
   #       adapter: Swoosh.Adapters.Mailgun,
   #       api_key: System.get_env("MAILGUN_API_KEY"),
   #       domain: System.get_env("MAILGUN_DOMAIN")
   #
-  # Most non-SMTP adapters require an API client. Swoosh supports Req, Hackney,
+  # SMTP (any provider):
-  # and Finch out-of-the-box. This configuration is typically done at
-  # compile-time in your config/prod.exs:
   #
-  #     config :swoosh, :api_client, Swoosh.ApiClient.Req
+  #     config :simpleshop_theme, SimpleshopTheme.Mailer,
-  #
+  #       adapter: Swoosh.Adapters.SMTP,
-  # See https://hexdocs.pm/swoosh/Swoosh.html#module-installation for details.
+  #       relay: System.get_env("SMTP_HOST"),
+  #       port: String.to_integer(System.get_env("SMTP_PORT") || "587"),
+  #       username: System.get_env("SMTP_USERNAME"),
+  #       password: System.get_env("SMTP_PASSWORD"),
+  #       tls: :if_available
 
-  # Stripe keys are stored encrypted in the database and loaded at runtime
+  # Stripe and Printify keys are stored encrypted in the database and loaded
-  # by SimpleshopTheme.Secrets. No env vars needed.
+  # at runtime by SimpleshopTheme.Secrets. No env vars needed for those.
 end

fly.toml

@@ -0,0 +1,50 @@
+# fly.toml — Fly.io deployment configuration
+#
+# Getting started:
+#   1. Install flyctl: curl -L https://fly.io/install.sh | sh
+#   2. Sign up / log in: fly auth login
+#   3. Create the app: fly launch --no-deploy
+#   4. Create a volume: fly volumes create simpleshop_data --size 1
+#   5. Set secrets:
+#        fly secrets set SECRET_KEY_BASE=$(mix phx.gen.secret)
+#        fly secrets set PHX_HOST=your-domain.com
+#   6. Deploy: fly deploy
+#   7. Open: fly open
+
+app = "simpleshop-theme"
+primary_region = "lhr"
+
+[build]
+  dockerfile = "Dockerfile"
+
+# SQLite needs a persistent volume — without this, your database is lost on every deploy.
+[mounts]
+  source = "simpleshop_data"
+  destination = "/data"
+
+[env]
+  PHX_SERVER = "true"
+  DATABASE_PATH = "/data/simpleshop_theme.db"
+
+[http_service]
+  internal_port = 4000
+  force_https = true
+  auto_stop_machines = "stop"
+  auto_start_machines = true
+  min_machines_running = 0
+
+  [http_service.concurrency]
+    type = "connections"
+    hard_limit = 1000
+    soft_limit = 1000
+
+[[http_service.checks]]
+  grace_period = "30s"
+  interval = "15s"
+  method = "GET"
+  timeout = "5s"
+  path = "/health"
+
+[[vm]]
+  size = "shared-cpu-1x"
+  memory = "1gb"

lib/simpleshop_theme/images/optimizer.ex

@@ -13,11 +13,10 @@ defmodule SimpleshopTheme.Images.Optimizer do
   # Only affects <5% of users (legacy browsers without AVIF/WebP support)
   @pregenerated_formats [:avif, :webp]
   @thumb_size 200
-  @cache_dir "priv/static/image_cache"
   @max_stored_width 2000
   @storage_quality 90
 
-  def cache_dir, do: @cache_dir
+  def cache_dir, do: Application.app_dir(:simpleshop_theme, "priv/static/image_cache")
   def all_widths, do: @all_widths
 
   @doc """
@@ -72,7 +71,7 @@ defmodule SimpleshopTheme.Images.Optimizer do
         {:ok, :svg_skipped}
 
       %{data: data, source_width: width} = image ->
-        File.mkdir_p!(@cache_dir)
+        File.mkdir_p!(cache_dir())
 
         with {:ok, vips_image} <- Image.from_binary(data) do
           widths = applicable_widths(width)
@@ -93,7 +92,7 @@ defmodule SimpleshopTheme.Images.Optimizer do
   end
 
   defp generate_thumbnail(image, id) do
-    path = Path.join(@cache_dir, "#{id}-thumb.jpg")
+    path = Path.join(cache_dir(), "#{id}-thumb.jpg")
 
     return_if_exists(path, fn ->
       with {:ok, thumb} <- Image.thumbnail(image, @thumb_size),
@@ -104,7 +103,7 @@ defmodule SimpleshopTheme.Images.Optimizer do
   end
 
   defp generate_variant(image, id, width, format) do
-    path = Path.join(@cache_dir, "#{id}-#{width}.#{format_ext(format)}")
+    path = Path.join(cache_dir(), "#{id}-#{width}.#{format_ext(format)}")
 
     return_if_exists(path, fn ->
       with {:ok, resized} <- Image.thumbnail(image, width),
@@ -140,12 +139,12 @@ defmodule SimpleshopTheme.Images.Optimizer do
   """
   def disk_variants_exist?(image_id, source_width) do
     widths = applicable_widths(source_width)
-    thumb = File.exists?(Path.join(@cache_dir, "#{image_id}-thumb.jpg"))
+    thumb = File.exists?(Path.join(cache_dir(), "#{image_id}-thumb.jpg"))
 
     variants =
       Enum.all?(widths, fn w ->
         Enum.all?(@pregenerated_formats, fn fmt ->
-          File.exists?(Path.join(@cache_dir, "#{image_id}-#{w}.#{format_ext(fmt)}"))
+          File.exists?(Path.join(cache_dir(), "#{image_id}-#{w}.#{format_ext(fmt)}"))
         end)
       end)
 
@@ -159,12 +158,12 @@ defmodule SimpleshopTheme.Images.Optimizer do
   """
   def generate_variant_on_demand(image_data, image_id, width, format)
       when is_binary(image_data) and format in [:avif, :webp, :jpg] do
-    path = Path.join(@cache_dir, "#{image_id}-#{width}.#{format_ext(format)}")
+    path = Path.join(cache_dir(), "#{image_id}-#{width}.#{format_ext(format)}")
 
     if File.exists?(path) do
       {:ok, path}
     else
-      File.mkdir_p!(@cache_dir)
+      File.mkdir_p!(cache_dir())
 
       with {:ok, vips_image} <- Image.from_binary(image_data),
            {:ok, resized} <- Image.thumbnail(vips_image, width),

lib/simpleshop_theme/images/variant_cache.ex

@@ -19,7 +19,7 @@ defmodule SimpleshopTheme.Images.VariantCache do
   alias SimpleshopTheme.Sync.ImageDownloadWorker
   import Ecto.Query
 
-  @mockup_dir "priv/static/mockups"
+  defp mockup_dir, do: Application.app_dir(:simpleshop_theme, "priv/static/mockups")
 
   def start_link(opts) do
     GenServer.start_link(__MODULE__, opts, name: __MODULE__)
@@ -87,9 +87,9 @@ defmodule SimpleshopTheme.Images.VariantCache do
   end
 
   defp ensure_mockup_variants do
-    if File.dir?(@mockup_dir) do
+    if File.dir?(mockup_dir()) do
       sources =
-        Path.wildcard(Path.join(@mockup_dir, "*.webp"))
+        Path.wildcard(Path.join(mockup_dir(), "*.webp"))
         |> Enum.reject(&is_variant?/1)
 
       missing = Enum.reject(sources, &mockup_variants_exist?/1)

lib/simpleshop_theme/release.ex

@@ -0,0 +1,32 @@
+defmodule SimpleshopTheme.Release do
+  @moduledoc """
+  Release tasks that can be run via `bin/migrate` or `bin/simpleshop_theme eval`.
+
+  Migrations run automatically on startup (see Application), so this is mainly
+  useful as a standalone tool for debugging or manual recovery.
+  """
+
+  @app :simpleshop_theme
+
+  def migrate do
+    load_app()
+
+    for repo <- repos() do
+      {:ok, _, _} = Ecto.Migrator.with_repo(repo, &Ecto.Migrator.run(&1, :up, all: true))
+    end
+  end
+
+  def rollback(repo, version) do
+    load_app()
+    {:ok, _, _} = Ecto.Migrator.with_repo(repo, &Ecto.Migrator.run(&1, :down, to: version))
+  end
+
+  defp repos do
+    Application.fetch_env!(@app, :ecto_repos)
+  end
+
+  defp load_app do
+    Application.ensure_all_started(:ssl)
+    Application.load(@app)
+  end
+end

lib/simpleshop_theme_web/controllers/health_controller.ex

@@ -0,0 +1,7 @@
+defmodule SimpleshopThemeWeb.HealthController do
+  use SimpleshopThemeWeb, :controller
+
+  def show(conn, _params) do
+    json(conn, %{status: "ok"})
+  end
+end

lib/simpleshop_theme_web/router.ex

@@ -52,6 +52,13 @@ defmodule SimpleshopThemeWeb.Router do
     post "/checkout", CheckoutController, :create
   end
 
+  # Health check (no auth, no theme loading — for load balancers and uptime monitors)
+  scope "/", SimpleshopThemeWeb do
+    pipe_through [:api]
+
+    get "/health", HealthController, :show
+  end
+
   # Cart API (session persistence for LiveView)
   scope "/api", SimpleshopThemeWeb do
     pipe_through [:browser]

mix.exs

@@ -10,6 +10,7 @@ defmodule SimpleshopTheme.MixProject do
       start_permanent: Mix.env() == :prod,
       aliases: aliases(),
       deps: deps(),
+      releases: [simpleshop_theme: [strip_beams: true]],
       compilers: [:phoenix_live_view] ++ Mix.compilers(),
       listeners: [Phoenix.CodeReloader],
       dialyzer: [ignore_warnings: ".dialyzer_ignore.exs"]

rel/env.sh.eex

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+# Single-node by default (no distributed Erlang)
+export RELEASE_DISTRIBUTION=none
+
+# Writable temp dir for the BEAM
+export RELEASE_TMP="${RELEASE_TMP:-/tmp}"

rel/overlays/bin/migrate

@@ -0,0 +1,4 @@
+#!/bin/sh
+set -eu
+
+exec bin/simpleshop_theme eval "SimpleshopTheme.Release.migrate()"

rel/overlays/bin/server

@@ -0,0 +1,4 @@
+#!/bin/sh
+set -eu
+
+PHX_SERVER=true exec bin/simpleshop_theme start