Cosmos-Compose files are a derivative of Docker-Compose. They can be described as both JSON or YML. They are used to describe the services that Cosmos will manage. They are very similar to Docker-Compose files, but with some Cosmos specific extensions, as well as some unsupported features removed.

The main difference is the addition of the routes section which is used to describe the reverse proxy configuration. The routes section is a list of route objects, which is the exact same than the one you will find in the configuration file.

Another difference, when using Links, Cosmos does not actually create docker links but instead creates a network and adds the containers to it. This is because docker links are deprecated and will be removed in the future.

Finally, cosmos-compose support an entire templating system called Whiskers. It is used to generate the final cosmos-compose file. You can see many examples of this in the marketplace repository

Here's the complete description of Cosmos-Compose, and all supported parameters:

type DockerServiceCreateRequest struct {
    Services map[string]ContainerCreateRequestContainer `json:"services"`
    Volumes []ContainerCreateRequestVolume `json:"volumes"`
    Networks map[string]ContainerCreateRequestNetwork `json:"networks"`

type ContainerCreateRequestContainer struct {
    Name            string            `json:"container_name"`
    Image       string            `json:"image"`
    Environment []string `json:"environment"`
    Labels      map[string]string `json:"labels"`
    Ports       []string          `json:"ports"`
    Volumes     []mount.Mount          `json:"volumes"`
    Networks    map[string]struct {
        Aliases []string `json:"aliases,omitempty"`
        IPV4Address string `json:"ipv4_address,omitempty"`
        IPV6Address string `json:"ipv6_address,omitempty"`
    } `json:"networks"`
    Routes             []utils.ProxyRouteConfig          `json:"routes"`

    RestartPolicy  string            `json:"restart,omitempty"`
    Devices        []string          `json:"devices"`
    Expose           []string          `json:"expose"`
    DependsOn      []string          `json:"depends_on"`
    Tty            bool              `json:"tty,omitempty"`
    StdinOpen      bool              `json:"stdin_open,omitempty"`

    Command string `json:"command,omitempty"`
    Entrypoint string `json:"entrypoint,omitempty"`
    WorkingDir string `json:"working_dir,omitempty"`
    User string `json:"user,omitempty"`
    Hostname string `json:"hostname,omitempty"`
    Domainname string `json:"domainname,omitempty"`
    MacAddress string `json:"mac_address,omitempty"`
    Privileged bool `json:"privileged,omitempty"`
    NetworkMode string `json:"network_mode,omitempty"`
    StopSignal string `json:"stop_signal,omitempty"`
    StopGracePeriod int `json:"stop_grace_period,omitempty"`
    HealthCheck struct {
        Test []string `json:"test"`
        Interval int `json:"interval"`
        Timeout int `json:"timeout"`
        Retries int `json:"retries"`
        StartPeriod int `json:"start_period"`
    } `json:"healthcheck,omitempty"`
    DNS []string `json:"dns,omitempty"`
    DNSSearch []string `json:"dns_search,omitempty"`
    ExtraHosts []string `json:"extra_hosts,omitempty"`
    Links []string `json:"links,omitempty"`
    SecurityOpt []string `json:"security_opt,omitempty"`
    StorageOpt map[string]string `json:"storage_opt,omitempty"`
    Sysctls map[string]string `json:"sysctls,omitempty"`
    Isolation string `json:"isolation,omitempty"`

    CapAdd []string `json:"cap_add,omitempty"`
    CapDrop []string `json:"cap_drop,omitempty"`
    SysctlsMap map[string]string `json:"sysctls,omitempty"`

type ContainerCreateRequestVolume struct {
    // name must be unique
    Name string `json:"name"`
    Driver string `json:"driver"`
    Source string `json:"source"`
    Target string `json:"target"`

type ContainerCreateRequestNetwork struct {
    // name must be unique
    Name string `json:"name"`
    Driver string `json:"driver"`
    Attachable bool `json:"attachable"`
    Internal bool `json:"internal"`
    EnableIPv6 bool `json:"enable_ipv6"`
    IPAM struct {
        Driver string `json:"driver"`
        Config []struct {
            Subnet string `json:"subnet"`
        } `json:"config"`
    } `json:"ipam"`