previewctl up

Usage

previewctl up [flags]

Description

Reads .previewctl/preview.yml, resolves service dependencies, and starts the preview stack in Docker.

The up command will:

1. Validate the config file
2. Detect the current Git branch (used for naming)
3. Resolve the service dependency graph (DAG)
4. Build services (Dockerfile, Nixpacks, or Railpack)
5. Create the Docker network
6. Deploy all services in dependency order

Flags

Flag	Type	Default	Description
--preview-id	string	generated	Preview ID to deploy
--secret	string[]	—	Secret in KEY=VALUE format (repeatable)
--env-file	string	.env	Path to .env file

Examples

Basic usage:

previewctl up

With secrets:

previewctl up --secret STRIPE_KEY=sk_test_abc --secret DB_PASSWORD=hunter2

With a custom env file:

previewctl up --env-file .env.staging

With a specific preview ID:

previewctl up --preview-id my-feature-preview

How it works

PreviewCtl reads the depends_on fields in your config to build a directed acyclic graph (DAG) of service dependencies. Services with no dependencies start first, and dependent services wait until their requirements are ready.

Environment variables support templating:

• ${services.<name>.host} — resolves to the container hostname
• ${services.<name>.port} — resolves to the service port
• ${services.<name>.env.<VAR>} — references another service’s env var
• ${secrets.<KEY>} — injects a secret from --secret or --env-file
• ${Generate(n)} — generates a random string of length n