Service Types

Vessl supports a variety of service types to accommodate any application architecture.

Source Services

Source services are built directly from your code using Railpack or a standard Dockerfile.

Source Options

• GitHub repository: Browse repositories available to the connected GitHub App, choose a branch, and select a root directory.
• Git URL: Enter an HTTPS or SSH Git URL manually, then provide the branch and root directory.

Use GitHub repositories when you want push-triggered deployments. Use direct Git URLs when the repository is public or uses SSH. Vessl supports custom install, build, and start command overrides for source services if auto-detection (Railpack) is insufficient.

Docker Compose Support

Vessl supports natively deploying applications defined via standard docker-compose.yml files.

vessld deploy --compose ./docker-compose.yml

When Vessl detects a docker-compose.yml file, it parses the file:

1. Services: Iterates over the services block and registers each as an individual App Service.
2. Environment Variables: Values in environment or env_file are imported as Vessl Secrets.
3. Ports & Volumes: Port mappings are honored and dynamically wired to Traefik. Volumes are mounted as persistent directories.

Docker Image Services

Docker image services skip the source build. Vessl pulls the configured image and runs it directly on the server. Use this when:

• CI already builds and publishes images.
• You want to deploy a service from GHCR, Docker Hub, or another registry.
• You are running third-party software.

Private images use the host Docker daemon’s registry login. For a web image, Vessl starts a temporary container, probes the port, and only switches traffic after the container is reachable (zero-downtime hot swap).

Static Sites

A static site is a web service with a Static output directory defined.

Vessl builds the source service, creates an image, copies the static output directory from that image into a static volume, and serves the files directly through Traefik.

Set Static output to the directory created by your build (e.g., dist, build, .output/public). Leave it blank if you are running a server-rendered application (like Next.js or Nuxt).

Background Workers

Workers run background processes without public traffic. Use workers for queues, schedulers, job processors, or event consumers.

Worker services:

• Do not need an internal port.
• Do not receive generated public web routes.
• Are considered healthy when the container stays running.

Serverless Functions

Vessl supports serverless function deployment for lightweight, event-driven workloads directly from the dashboard using the in-browser Monaco editor.

• Supported Runtimes: Node.js, Python, Go
• Environment Variables: Full access to project secrets and auto-linked databases.

Functions are deployed as lightweight containers with fast cold-start times whenever you click Save & Deploy.