Paste a Dockerfile or Compose file

Open the Dockerfile tab

The card is titled Deploy from a Dockerfile ("Write or paste a Dockerfile. Synq builds the image and runs it."). The editor starts with a small working example:

FROM nginx:alpine
RUN echo '<h1>Hello from Synq</h1>' > /usr/share/nginx/html/index.html
EXPOSE 80

Write or paste your Dockerfile

Replace the example with your own. It needs at least one FROM line ("The Dockerfile needs a FROM instruction."). Remember that the Dockerfile is the whole build context: there are no other files next to it, so COPY and ADD have nothing local to copy. Fetch the code inside the build instead:

FROM node:22-alpine
RUN apk add --no-cache git
WORKDIR /app
# Fetch the app's code during the build
RUN git clone --depth 1 https://github.com/acme/hello-node.git . \
 && npm ci --omit=dev
ENV NODE_ENV=production
EXPOSE 3000
CMD ["node", "server.js"]

ADD https://... (a remote URL) and RUN curl ... work too. COPY --from=<image> works for copying out of another image.

Name it and check the port

• Project name: required, and unique in your organization.
• Container port: the port the app listens on inside the container. It follows the Dockerfile's last EXPOSE line as you type (80 when there is none), until you change it by hand.

Pick the server and add variables

• Server: which server builds and runs it.
• Environment variables (optional): one KEY=value per line. They are set on the running container and passed to the build as build arguments, so a Dockerfile ARG APP_VERSION receives the value of an APP_VERSION=... line.

Press Build and deploy

Synq uploads the Dockerfile ("Uploading…"), creates the project, and starts the first build ("Deploying…"). You land on the build screen with the live docker build output. When it is live, add a domain on the project's Domains & Routes tab.

Open the Compose tab

The card is titled Deploy from a Compose file ("Paste a docker-compose.yml. Synq deploys each of its services."). The editor starts with a one-service example:

services:
  web:
    image: nginx:alpine
    ports:
      - "80"
    restart: unless-stopped

Paste your docker-compose.yml

The file needs a top-level services: block with at least one service. Under the editor, Synq lists the services it found ("Services: web, db") as you type. Two rules:

• Every service uses image:. A service with build: has no files to build from here, because only the Compose file is uploaded. Push the image to a registry first, or use a repository instead.
• Indent with spaces. YAML does not allow tabs ("YAML cannot be indented with tabs. Use spaces.").

A typical stack:

services:
  app:
    image: ghcr.io/acme/app:2.3.0
    environment:
      DATABASE_URL: postgres://app:${DB_PASSWORD}@db:5432/app
    ports:
      - "3000"
    depends_on:
      - db
  db:
    image: postgres:16-alpine
    environment:
      POSTGRES_USER: app
      POSTGRES_PASSWORD: ${DB_PASSWORD}
      POSTGRES_DB: app
    volumes:
      - db_data:/var/lib/postgresql/data
volumes:
  db_data: {}

Services reach each other by service name (db above), never localhost.

Add the .env values

Environment variables (.env) takes one KEY=value per line:

DB_PASSWORD=change-me-to-something-long

Synq saves them twice: as a .env file next to the Compose file, so ${VAR} references and env_file: .env resolve, and as project variables you can edit later on the Environment tab.

Name it, pick the server, press Deploy stack

Enter a Project name (required, unique), choose the Server, and press Deploy stack. Synq uploads the file, parses it on the server ("No services were found in this Compose file." means the server could not read any service), creates the project, and deploys every service. You land on the build screen.