docker/swarmkit

// Package naming centralizes the naming of SwarmKit objects.
package naming

import (
    "errors"
    "fmt"
    "strings"

    "github.com/moby/swarmkit/v2/api"
)

var (
    errUnknownRuntime = errors.New("unrecognized runtime")
)

// Task returns the task name from Annotations.Name,
// and, in case Annotations.Name is missing, fallback
// to construct the name from other information.
func Task(t *api.Task) string {
    if t.Annotations.Name != "" {
        // if set, use the container Annotations.Name field, set in the orchestrator.
        return t.Annotations.Name
    }

    slot := fmt.Sprint(t.Slot)
    if slot == "" || t.Slot == 0 {
        // when no slot id is assigned, we assume that this is node-bound task.
        slot = t.NodeID
    }

    // fallback to service.instance.id.
    return fmt.Sprintf("%s.%s.%s", t.ServiceAnnotations.Name, slot, t.ID)
}

// TODO(stevvooe): Consolidate "Hostname" style validation here.

// Runtime returns the runtime name from a given spec.
func Runtime(t api.TaskSpec) (string, error) {
    switch r := t.GetRuntime().(type) {
    case *api.TaskSpec_Attachment:
        return "attachment", nil
    case *api.TaskSpec_Container:
        return "container", nil
    case *api.TaskSpec_Generic:
        return strings.ToLower(r.Generic.Kind), nil
    default:
        return "", errUnknownRuntime
    }
}