vorteil/vorteil

package registry

/**
 * SPDX-License-Identifier: Apache-2.0
 * Copyright 2020 vorteil.io Pty Ltd
 */

import (
    "encoding/json"
    "fmt"
    "sort"

    "github.com/vorteil/vorteil/pkg/elog"
    "github.com/vorteil/vorteil/pkg/provisioners"
    "github.com/vorteil/vorteil/pkg/provisioners/amazon"
    "github.com/vorteil/vorteil/pkg/provisioners/azure"
    "github.com/vorteil/vorteil/pkg/provisioners/google"
)

func init() {

    gcpFn := func(log elog.View, data []byte) (provisioners.Provisioner, error) {
        var cfg google.Config
        err := json.Unmarshal(data, &cfg)
        if err != nil {
            return nil, err
        }
        return google.NewProvisioner(log, &cfg)
    }

    awsFn := func(log elog.View, data []byte) (provisioners.Provisioner, error) {
        var cfg amazon.Config
        err := json.Unmarshal(data, &cfg)
        if err != nil {
            return nil, err
        }
        return amazon.NewProvisioner(log, &cfg)
    }

    azureFn := func(log elog.View, data []byte) (provisioners.Provisioner, error) {
        var cfg azure.Config
        err := json.Unmarshal(data, &cfg)
        if err != nil {
            return nil, err
        }
        return azure.NewProvisioner(log, &cfg)
    }

    err := RegisterProvisioner(google.ProvisionerType, gcpFn)
    if err != nil {
        panic(err)
    }

    err = RegisterProvisioner(amazon.ProvisionerType, awsFn)
    if err != nil {
        panic(err)
    }

    err = RegisterProvisioner(azure.ProvisionerType, azureFn)
    if err != nil {
        panic(err)
    }
}

// ProvisionerInstantiator is a function that returns a new provisioner
type ProvisionerInstantiator func(log elog.View, data []byte) (provisioners.Provisioner, error)

var registeredProvisioners map[string]ProvisionerInstantiator

// RegisterProvisioner registers a ProvisionerInstantiator with a given name.
func RegisterProvisioner(name string, fn ProvisionerInstantiator) error {

    if registeredProvisioners == nil {
        registeredProvisioners = make(map[string]ProvisionerInstantiator)
    }

    if _, exists := registeredProvisioners[name]; exists {
        return fmt.Errorf("refusing to register provisioner '%s': already registered", name)
    }

    registeredProvisioners[name] = fn
    return nil
}

// Provisioners returns an alphabetised list of all registered
// provisioners. Note that a single provisioners may appear multiple times
// in the list under different names.
func Provisioners() []string {

    var names = []string{}

    if registeredProvisioners == nil {
        return names
    }

    for k := range registeredProvisioners {
        names = append(names, k)
    }

    sort.Strings(names)
    return names

}

// DeregisterProvisioner deregisters a ProvisionerInstantiator for the
// given name.
func DeregisterProvisioner(name string) error {

    if registeredProvisioners != nil {
        if _, exists := registeredProvisioners[name]; exists {
            delete(registeredProvisioners, name)
            return nil
        }
    }

    return fmt.Errorf("provisioner '%s' not found", name)

}

// NewProvisioner returns a provisioners.Provisioner object that can be used to
// provision a vorteil buildable, if the named provisioner is registered.
func NewProvisioner(name string, log elog.View, data []byte) (provisioners.Provisioner, error) {

    fn, exists := registeredProvisioners[name]
    if !exists {
        return nil, fmt.Errorf("provisioner '%s' not found", name)
    }

    return fn(log, data)
}