Vibeham Docs

Rock8Cloud deploys any application that has a valid Dockerfile. Here's what you need.

Requirements

Your Dockerfile must:

Build successfully - docker build . works without errors
Expose a port - Use EXPOSE <port> instruction
Start automatically - Use CMD or ENTRYPOINT

Example

Here's a real-world example from astro-rocketship:

# Build stage
FROM oven/bun:1.3.4-alpine AS builder
WORKDIR /app

COPY package.json bun.lock ./
RUN bun install --frozen-lockfile

COPY . .
RUN bun run build

# Production stage
FROM nginx:alpine
COPY --from=builder /app/dist /usr/share/nginx/html

EXPOSE 80
CMD ["nginx", "-g", "daemon off;"]

This multi-stage build:

Builds the app with Bun
Serves static files with nginx
Results in a small, production-ready image

Port Configuration

The port in your Dockerfile must match what you configure in Rock8Cloud:

Dockerfile:

EXPOSE 3000

Rock8Cloud service settings:

Port: 3000

If they don't match, health checks will fail.

Test Locally First

Before deploying, verify your Dockerfile works:

# Build
docker build -t my-app .

# Run
docker run -p 3000:3000 my-app

# Test
curl http://localhost:3000

If it works locally, it'll work on Rock8Cloud.

Monorepo Setup

If your Dockerfile is in a subdirectory, you have two options for build context:

Option 1: Build from repository root (default)

Your Dockerfile references paths from the repo root:

# backend/Dockerfile
FROM node:20-alpine
WORKDIR /app

# Copy from repo root
COPY backend/package.json backend/package-lock.json ./
RUN npm install

COPY backend/ .
RUN npm run build

EXPOSE 3000
CMD ["node", "dist/index.js"]

Option 2: Build from Dockerfile directory

Enable "Use Dockerfile directory as build context" in service settings. Your Dockerfile uses relative paths:

# backend/Dockerfile
FROM node:20-alpine
WORKDIR /app

# Copy from backend/ directory
COPY package.json package-lock.json ./
RUN npm install

COPY . .
RUN npm run build

EXPOSE 3000
CMD ["node", "dist/index.js"]

This option is useful when:

Each service is self-contained in its folder
You want faster builds (smaller context)
Your Dockerfile already uses COPY . .

Common Issues

Problem	Solution
Build fails	Run `docker build .` locally to see errors
App not accessible	Check your app binds to the correct port
Health check fails	Ensure port matches between Dockerfile and settings
Missing files	Check all `COPY` paths exist and aren't in `.dockerignore`
Wrong files copied	Check build context setting matches your Dockerfile's COPY paths

See FAQ for more help.

Dockerfile Requirements