allow overriding the build command

README.md

@@ -29,8 +29,9 @@ Options are saved between runs into `package.json`. To invert a boolean options,
 
 ### Options:
 
-* `--build=defer` - may be needed when your build step requires access to secrets that are not available at image build time. Results in larger images and slower deployments.
-* `--cmd` - CMD to use in Dockerfile
+* `--build=CMD` - command to be used to build your application.
+* `--cmd=CMD` - CMD to use in Dockerfile
+* `--defer-build` - may be needed when your build step requires access to secrets that are not available at image build time. Results in larger images and slower deployments.
 * `--dev` - include `devDependencies` in the production image.
 * `--distroless` - use [distroless](https://github.com/GoogleContainerTools/distroless) base image to reduce image size
 * `--entrypoint` - ENTRYPOINT to use in Dockerfile

gdf.js

@@ -519,7 +519,8 @@ export class GDF {
 
   // Is there a build script?
   get build() {
-    return !!this.#pj.scripts?.build
+    if (this.options.build) return this.options.build
+    if (this.#pj.scripts?.build) return `${this.packager} run build`
   }
 
   // Descriptive form of detected runtime
@@ -657,9 +658,9 @@ export class GDF {
     this.#pj = JSON.parse(fs.readFileSync(path.join(appdir, 'package.json'), 'utf-8'))
 
     // backwards compatibility with previous definition of --build=defer
-    if (options.build == "defer") {
+    if (options.build === 'defer') {
       options.deferBuild = true
-      options.build = ""
+      options.build = ''
     }
 
     // install modules needed to run

templates/Dockerfile.ejs

@@ -85,7 +85,7 @@ COPY<% if (options.link) { %> --link<% } %> . .
 
 <% if (build && !options.deferBuild) { -%>
 # Build application
-RUN <%- mountSecrets %><%= packager %> run build
+RUN <%- mountSecrets %><%= build %>
 
 <% if (devDependencies && !options.dev && !nestjs && !adonisjs) { -%>
 # Remove development dependencies

test/base/build/.dockerignore

@@ -0,0 +1,6 @@
+/.git
+/node_modules
+.dockerignore
+.env
+Dockerfile
+fly.toml

test/base/build/Dockerfile

@@ -0,0 +1,45 @@
+# syntax = docker/dockerfile:1
+
+# Adjust NODE_VERSION as desired
+ARG NODE_VERSION=xxx
+FROM node:${NODE_VERSION}-slim as base
+
+LABEL fly_launch_runtime="Node.js"
+
+# Node.js app lives here
+WORKDIR /app
+
+# Set production environment
+ENV NODE_ENV="production"
+
+
+# Throw-away build stage to reduce size of final image
+FROM base as build
+
+# Install packages needed to build node modules
+RUN apt-get update -qq && \
+    apt-get install -y build-essential pkg-config python-is-python3
+
+# Install node modules
+COPY --link package-lock.json package.json ./
+RUN npm ci --include=dev
+
+# Copy application code
+COPY --link . .
+
+# Build application
+RUN npm run tsc
+
+# Remove development dependencies
+RUN npm prune --omit=dev
+
+
+# Final stage for app image
+FROM base
+
+# Copy built application
+COPY --from=build /app /app
+
+# Start the server by default, this can be overwritten at runtime
+EXPOSE 3000
+CMD [ "npm", "run", "start" ]