docs: add container-based cloud deployment to Heroku

1 files changed, 14 insertions, 1 deletions

diff --git a/flake.nix b/flake.nix
index b8616f8..5f63359 100644
--- a/flake.nix
+++ b/flake.nix
@@ -31,6 +31,9 @@
     develPackagesAndScripts = [
       postgresql_13        # PostgreSQL server with the standard admin tools.
       python.pkgs.ipython  # Interactive Python REPL for experimenting.
+      heroku               # CLI for the Heroku hosting platform.
+      skopeo               # Docker container upload utility.
+      pwgen                # Simple random token generator.
 
       # More pleasant alternative to psql, with colours and auto-completion.
       # Custom configuration to suppress irrelevant warnings and messages.
@@ -92,7 +95,7 @@
 
   in {
 
-    packages = {
+    packages = rec {
       # Minimal production server.
       # This includes only application files tracked by git.
       # Using `gunicorn` on top of `uvicorn` is recommended for bigger loads.
@@ -100,6 +103,16 @@
         cd ${./.}
         ${pythonWithDependencies}/bin/uvicorn --app-dir app app:main "$@"
       '';
+
+      # Minimal docker image.
+      # The Heroku hosting service assigns the `$PORT` dynamically.
+      docker = dockerTools.streamLayeredImage {
+        maxLayers = 2;
+        name = "app-docker";
+        config.EntryPoint = writeShellScript "run.sh" ''
+          ${server} --host 0.0.0.0 --port $PORT
+        '';
+      };
     };
 
     devShell = mkShell rec {