Deployment Error on Fly.io: Cannot Find Module '/app/serve'

Question

INFO Preparing to run: `docker-entrypoint.sh serve -s dist -l 80` as root
INFO [fly api proxy] listening at /.fly/api
Error: Cannot find module '/app/serve'

is it serve NPM package? not sure...

I’m encountering a deployment error when building images for my React-Express app using a GitHub Action CI-CD pipeline. The images build successfully and been pushed to Docker Hub, but when attempting to deploy to fly.io, a build error occurs related to the client (the second image), which hasn’t started to deploy yet.

I suspect the issue lies with the TOML file - the [processes] imageName . Additionally, in case it's a build issue, then i can say:

• the npm serve package has been installed globally,
• run as the root user.
• All files and locations have been validated through the build log.
• serve installation has been validated through the build log.

the error:

Node.js v20.9.0
 INFO Main child exited normally with code: 1
 INFO Starting clean up.
 WARN could not unmount /rootfs: EINVAL: Invalid argument
[    1.783213] reboot: Restarting system
2024-10-30T13:41:51.854035368 [01JBETFRV3V83QRDVVN8ZE241T:main] Running Firecracker v1.7.0
 INFO Starting init (commit: 693c179a)...
 INFO Preparing to run: `docker-entrypoint.sh serve -s dist -l 80` as root
 INFO [fly api proxy] listening at /.fly/api
   Machine started in 1.012s
2024/10/30 13:41:52 INFO SSH listening listen_address=[fdaa:a:ac95:a7b:86:f79e:5bd1:2]:22 dns_server=[fdaa::3]:53
node:internal/modules/cjs/loader:1051
  throw err;
  ^
Error: Cannot find module '/app/serve'
    at Module._resolveFilename (node:internal/modules/cjs/loader:1048:15)
    at Module._load (node:internal/modules/cjs/loader:901:27)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:83:12)
    at node:internal/main/run_main_module:23:47 {
  code: 'MODULE_NOT_FOUND',
  requireStack: []

this is the ./fly.toml

app = "x-realestate"
primary_region = "fra"


[[vm]]
  memory = "256mb"
  cpu_kind = "shared"
  cpus = 1

[env]
  NODE_ENV = "production"


[processes]
  server = "node --trace-warnings dist/index.js"  # server start command
  client = "serve -s dist -l 80"  # run static server

[[services]]
  processes = ["server"]
  internal_port = 8000
  protocol = "tcp"
  image = "registry.fly.io/x-realestate:server-latest"

  [services.concurrency]
    hard_limit = 25
    soft_limit = 20
  [[services.ports]]
    handlers = ["http"]
    port = 80

[[services]]
  processes = ["client"]
  internal_port = 80  # Keep NGINX on port 80 for ngnix
  protocol = "tcp"
  image = "registry.fly.io/x-realestate:client-latest"
  
  [services.concurrency]
    hard_limit = 25
    soft_limit = 20
  [[services.ports]]
    handlers = ["http"]
    port = 80

this is the ./client./Dockerfile

# Production Dockerfile for the client
FROM node:20.9.0 AS build_stage 

# Set the container runtime environment variables (used at build time)
ARG VITE_FIREBASE_API_KEY
ARG VITE_AUTH_DOMAIN
ARG VITE_PROJECT_ID
ARG VITE_STORAGE_BUCKET
ARG VITE_MESSAGING_SENDER_ID
ARG VITE_APP_ID
ARG VITE_NODE_ENV=production
ARG VITE_APP_API_ENDPOINT

ENV VITE_FIREBASE_API_KEY=${VITE_FIREBASE_API_KEY}
ENV VITE_AUTH_DOMAIN=${VITE_AUTH_DOMAIN}
ENV VITE_PROJECT_ID=${VITE_PROJECT_ID}
ENV VITE_STORAGE_BUCKET=${VITE_STORAGE_BUCKET}
ENV VITE_MESSAGING_SENDER_ID=${VITE_MESSAGING_SENDER_ID}
ENV VITE_APP_ID=${VITE_APP_ID}
ENV VITE_NODE_ENV=${VITE_NODE_ENV}
ENV VITE_APP_API_ENDPOINT=${VITE_APP_API_ENDPOINT}

WORKDIR /app

USER root


RUN npm cache clean --force && npm install -g serve --verbose




# Copy package.json and install production dependencies only
COPY ./package*.json ./
COPY ./tsconfig.json ./
COPY ./vite.config.ts ./
COPY . .

# Install dependencies, serve, and build
RUN npm install -g serve \
    && npm install --legacy-peer-deps \
    && npm run build --verbose \
    && echo "current location is: $(pwd)"


# -- END
# Runtime stage
FROM node:20.9.0 AS runtime_stage

WORKDIR /app
USER root

  
COPY ./package*.json ./
COPY ./tsconfig.json ./
COPY ./vite.config.ts ./

COPY --from=build_stage /app/dist /app/dist   
RUN ls /app/dist

# copy the build (dist) and install --only=production
RUN npm install --legacy-peer-deps --only=production \
    && npm install -g serve --verbose



# Expose the default port
EXPOSE 80


# Start the static server
# exec without sh
CMD ["serve", "-s", "dist", "-l", "80"]

this is the ./server/Dockerfile

# Production Dockerfile for the server
FROM node:20.9.0 AS build

# Set build-time arguments (available during build)
ARG MONGO_CONN
ARG DB_NAME
ARG JWT_SECRET
ARG ORIGIN
ARG PORT
ARG NODE_ENV=production
ARG SERVER_DOMAIN

# Set the runtime environment variables
ENV MONGO_CONN=${MONGO_CONN}
ENV DB_NAME=${DB_NAME}
ENV JWT_SECRET=${JWT_SECRET}
ENV ORIGIN=${ORIGIN}
ENV PORT=${PORT}
ENV NODE_ENV=${NODE_ENV}
ENV SERVER_DOMAIN=${SERVER_DOMAIN}

# Set the working directory
WORKDIR /app

COPY ./package*.json ./
# Copy the rest of the project
COPY . .

RUN npm install --omit=dev \
    && npm run build --verbose \
    && ls -alh /app/dist



# Expose port
EXPOSE 8000

# # Healthcheck for the server
# HEALTHCHECK CMD curl --fail http://localhost:${PORT}/health || exit 1

# Start the application

CMD ["node", "--trace-warnings", "dist/index.js"]

attempt to deploy my two images from docker-hub to fly.IO hosting. I'm receiving build error for my react Express client server application.

I suspect the issue lies with the TOML file - the [processes] imageName, but in case it's a build issue, then i can say:

• the npm serve package has been installed globally,
• run as the root user.
• All files and locations have been validated through the build log.
• package installation has been validated through the build log.