Support PORT env var in dev using runtime.exs

The config/dev.exs file is for build time configuration. This commit
updates the support for the PORT environment variable in new projects
generated with `phx.new` to be done in runtime.exs instead.

Author: rhcarvalho

installer/templates/phx_single/config/dev.exs

@@ -10,10 +10,10 @@ config :<%= @app_name %>, <%= @endpoint_module %>,<%= if @inside_docker_env? do
   # Bind to 0.0.0.0 to expose the server to the docker host machine.
   # This makes make the service accessible from any network interface.
   # Change to `ip: {127, 0, 0, 1}` to allow access only from the server machine.
-  http: [ip: {0, 0, 0, 0}, port: String.to_integer(System.get_env("PORT") || "4000")],<% else %>
+  http: [ip: {0, 0, 0, 0}],<% else %>
   # Binding to loopback ipv4 address prevents access from other machines.
   # Change to `ip: {0, 0, 0, 0}` to allow access from other machines.
-  http: [ip: {127, 0, 0, 1}, port: String.to_integer(System.get_env("PORT") || "4000")],<% end %>
+  http: [ip: {127, 0, 0, 1}],<% end %>
   check_origin: false,
   code_reloader: true,
   debug_errors: true,

installer/templates/phx_single/config/runtime.exs

@@ -20,6 +20,12 @@ if System.get_env("PHX_SERVER") do
   config :<%= @app_name %>, <%= @endpoint_module %>, server: true
 end
 
+port = String.to_integer(System.get_env("PORT", "4000"))
+
+if config_env() == :dev do
+  config :<%= @app_name %>, <%= @endpoint_module %>, http: [port: port]
+end
+
 if config_env() == :prod do
   # The secret key base is used to sign/encrypt cookies and other secrets.
   # A default value is used in config/dev.exs and config/test.exs but you
@@ -34,7 +40,6 @@ if config_env() == :prod do
       """
 
   host = System.get_env("PHX_HOST") || "example.com"
-  port = String.to_integer(System.get_env("PORT") || "4000")
 
   config :<%= @app_name %>, :dns_cluster_query, System.get_env("DNS_CLUSTER_QUERY")
 

installer/templates/phx_umbrella/apps/app_name_web/config/dev.exs

@@ -10,10 +10,10 @@ config :<%= @web_app_name %>, <%= @endpoint_module %>,<%= if @inside_docker_env?
   # Bind to 0.0.0.0 to expose the server to the docker host machine.
   # This makes make the service accessible from any network interface.
   # Change to `ip: {127, 0, 0, 1}` to allow access only from the server machine.
-  http: [ip: {0, 0, 0, 0}, port: String.to_integer(System.get_env("PORT") || "4000")],<% else %>
+  http: [ip: {0, 0, 0, 0}],<% else %>
   # Binding to loopback ipv4 address prevents access from other machines.
   # Change to `ip: {0, 0, 0, 0}` to allow access from other machines.
-  http: [ip: {127, 0, 0, 1}, port: String.to_integer(System.get_env("PORT") || "4000")],<% end %>
+  http: [ip: {127, 0, 0, 1}],<% end %>
   check_origin: false,
   code_reloader: true,
   debug_errors: true,

installer/templates/phx_umbrella/apps/app_name_web/config/runtime.exs

@@ -15,7 +15,7 @@ config :<%= @web_app_name %>, <%= @endpoint_module %>,
     # Enable IPv6 and bind on all interfaces.
     # Set it to  {0, 0, 0, 0, 0, 0, 0, 1} for local network only access.
     ip: {0, 0, 0, 0, 0, 0, 0, 0},
-    port: String.to_integer(System.get_env("PORT") || "4000")
+    port: port
   ],
   secret_key_base: secret_key_base
 

installer/templates/phx_umbrella/config/runtime.exs

@@ -6,6 +6,13 @@ import Config
 # and secrets from environment variables or elsewhere. Do not define
 # any compile-time configuration in here, as it won't be applied.
 # The block below contains prod specific runtime configuration.
+
+port = String.to_integer(System.get_env("PORT", "4000"))
+
+if config_env() == :dev do
+  config :<%= @app_name %>, <%= @endpoint_module %>, http: [port: port]
+end
+
 if config_env() == :prod do
   config :<%= @app_name %>, :dns_cluster_query, System.get_env("DNS_CLUSTER_QUERY")
 end

installer/test/phx_new_test.exs

@@ -31,6 +31,7 @@ defmodule Mix.Tasks.Phx.NewTest do
       Mix.Tasks.Phx.New.run([@app_name])
 
       assert_file("phx_blog/README.md")
+
       assert_file("phx_blog/AGENTS.md", fn file ->
         assert file =~ "### UI/UX & design guidelines"
       end)
@@ -63,7 +64,12 @@ defmodule Mix.Tasks.Phx.NewTest do
         assert file =~ "config :logger, level: :info"
       end)
 
-      assert_file("phx_blog/config/runtime.exs", ~r/ip: {0, 0, 0, 0, 0, 0, 0, 0}/)
+      assert_file("phx_blog/config/runtime.exs", fn file ->
+        assert file =~ ~r/^port = String.to_integer\(System.get_env\("PORT", "4000"\)\)$/
+        assert file =~ ~r/^config :phx_blog, PhxBlogWeb.Endpoint, http: \[port: port\]$/
+        assert file =~ ~r/^\s+ip: {0, 0, 0, 0, 0, 0, 0, 0},$/
+        assert file =~ ~r/^\s+port: port$/
+      end)
 
       assert_file("phx_blog/lib/phx_blog/application.ex", ~r/defmodule PhxBlog.Application do/)
       assert_file("phx_blog/lib/phx_blog.ex", ~r/defmodule PhxBlog do/)
@@ -145,7 +151,7 @@ defmodule Mix.Tasks.Phx.NewTest do
       assert_file("phx_blog/config/dev.exs", fn file ->
         assert file =~ "esbuild: {Esbuild,"
         assert file =~ "lib/phx_blog_web/(?:controllers|live|components|router)/?.*\\.(ex|heex)$"
-        assert file =~ "http: [ip: {127, 0, 0, 1}"
+        assert file =~ "http: [ip: {127, 0, 0, 1}]"
       end)
 
       # tailwind

lib/mix/tasks/phx.gen.cert.ex

@@ -122,7 +122,7 @@ defmodule Mix.Tasks.Phx.Gen.Cert do
     configuration in config/dev.exs:
 
       config #{inspect(app)}, #{inspect(Mix.Phoenix.web_module(base))}.Endpoint,
-        http: [port: String.to_integer(System.get_env("PORT") || "4000")],
+        ...,
         https: [
           port: 4001,
           cipher_suite: :strong,