fix: hot reload in docker development by using polling & correct workdir

WATCHPACK_POLLING is enabled by default to use file change polling so
hot reload works more easily out-of-the-box

Tested and hot reload worked on Windows 11 + Docker Desktop + WSL2
using "docker compose up --build" and keeping the source code on the
host's NTFS file system, not inside the Linux file system in WSL2.

refs PT-1792

Dockerfile

@@ -45,6 +45,15 @@ FROM appbase AS development
 ARG NODE_ENV=development
 ENV NODE_ENV $NODE_ENV
 
+# Enable hot reload by default by polling for file changes.
+#
+# NOTE: Can be disabled by setting WATCHPACK_POLLING=false in file `.env`
+#       if hot reload works on your system without polling to save CPU time.
+ARG WATCHPACK_POLLING=true
+ENV WATCHPACK_POLLING=${WATCHPACK_POLLING}
+
+WORKDIR /app
+
 # copy in our source code last, as it changes the most
 COPY --chown=default:root . .
 

docker-compose.yml

@@ -4,6 +4,8 @@ services:
     build:
       context: .
       target: ${DOCKER_TARGET:-development}
+    environment:
+      - WATCHPACK_POLLING=${WATCHPACK_POLLING:-true}
     volumes:
       # Share local directory to enable development with hot reloading
       - .:/app

next.config.js

@@ -92,6 +92,13 @@ module.exports = {
       };
     }
 
+    // https://webpack.js.org/configuration/watch/#watchoptions
+    config.watchOptions = {
+      poll: 1000, // Check for changes every second
+      aggregateTimeout: 300, // Delay 0.3s before rebuilding to group changes
+      ignored: ['**/node_modules'],
+    };
+
     config.resolve.alias = {
       ...config.resolve.alias,
       '~hds-core': path.resolve(__dirname, './node_modules/hds-core'),