compose2nix supports the Compose build spec.

• Default behavior: A one-shot systemd service is generated for each container build. You must manually start this service to build the image before the container can run:

  sudo systemctl start podman-build-my-service.service

- **Auto-build**: If you run `compose2nix` with the `-build=true` flag, the build service is marked as a dependency for the container service. This ensures the build runs automatically before the container starts. 

**Warning**: Using `-build=true` means the build will be re-run on every restart of the root target or the system, which may update the image.

Manual build

sudo systemctl start podman-build-my-service.service

CLI flag for auto-build

compose2nix -build=true

You can extend the generated systemd services by providing additional systemd service and unit options directly within your Docker Compose file using labels.

Use the compose2nix.systemd. prefix for these labels to pass configuration through to the generated NixOS systemd units.

To update secrets within the nixos-test/sops directory, use sops edit inside a nix-shell environment with the SOPS_AGE_KEY_FILE environment variable pointing to your age key file. This allows you to edit secrets.yaml using your system's preferred editor while ensuring the sops dependency is available.

cd nixos-test/sops
nix-shell -p sops --run "SOPS_AGE_KEY_FILE=age-key.txt sops edit secrets.yaml"

You can install compose2nix using several methods:

1. Nix shell: Run it without permanent installation using:

   nix shell github:aksiksi/compose2nix

2. **Go install**: If you have Go installed:
   ```bash
go install github.com/aksiksi/compose2nix

3. Build from source: Clone the repository and use make:

   make build

By default, all generated services are set to start automatically on boot via systemd. You can change this behavior in two ways:

1. Global setting: Re-generate your Nix configuration using the -auto_start=false CLI flag.
2. Per-service setting: Add a Compose label to specific services to enable or disable auto-start.

services:
  my-service:
    labels:
      - "compose2nix.settings.autoStart=false"

# Disable globally via CLI
compose2nix -auto_start=false

# Disable per service in docker-compose.yml
services:
  my-service:
    labels:
      - "compose2nix.settings.autoStart=false"

To reference secrets already configured in your NixOS system via sops-nix, follow these steps:

1. Add a compose2nix.settings.sops.secrets label to your Compose services with a comma-separated list of secret names.
2. Run compose2nix and point to your encrypted secrets YAML file using the --sops_file flag.

This generates a NixOS configuration that appends the sops-nix secret paths to the container's environmentFiles.

# In your docker-compose.yml
services:
  webapp:
    image: nginx:latest
    labels:
      - "compose2nix.settings.sops.secrets=example.env,some-folder/example-2.env"

# Run the command
compose2nix \
  --inputs docker-compose.yml \
  --sops_file ./secrets/secrets.yaml

To generate a NixOS configuration from an existing Docker Compose project, run the compose2nix command.

Requirements:

• The project must either be passed via the -project flag or have its name defined in the top-level name field of the Compose file.
• By default, the tool searches for docker-compose.yml in the current working directory.

Output:

• The generated NixOS configuration is saved to docker-compose.nix by default.

Mapping Logic:

• Each YAML service definition is converted into a oci-container configuration.
• Systemd services are automatically set up to manage networks and volumes defined in the Compose project.
• Each Compose service maps to a native NixOS-managed systemd service.

compose2nix -project=myproject

agenix decrypts secrets into /run/agenix/. To include these in your Nix configuration via compose2nix:

1. Place secret environment variables in an encrypted file (e.g., my-env-file.env).
2. Ensure the decrypted file is readable by the user running compose2nix.
3. Run compose2nix using the --env_files flag and set --include_env_files=true.

If you want the output Nix config to only contain environment files (and not the container definitions themselves), add the --env_files_only=true flag.

compose2nix --env_files=/run/agenix/my-env-file.env --include_env_files=true
# To include ONLY env files:
compose2nix --env_files=/run/agenix/my-env-file.env --include_env_files=true --env_files_only=true