initial commit [ci skip]

internal/platform/platform.go

@@ -0,0 +1,177 @@
+// Copyright 2019 Drone.IO Inc. All rights reserved.
+// Use of this source code is governed by the Polyform License
+// that can be found in the LICENSE file.
+
+// Package platform contains code to provision and destroy server
+// instances on the Digital Ocean cloud platform.
+package platform
+
+import (
+	"context"
+	"time"
+
+	"github.com/drone/runner-go/logger"
+
+	"github.com/digitalocean/godo"
+	"golang.org/x/oauth2"
+)
+
+type (
+	// RegisterArgs provides arguments to register the SSH
+	// public key with the account.
+	RegisterArgs struct {
+		Fingerprint string
+		Name        string
+		Data        string
+		Token       string
+	}
+
+	// DestroyArgs provides arguments to destroy the server
+	// instance.
+	DestroyArgs struct {
+		ID    int
+		IP    string
+		Token string
+	}
+
+	// ProvisionArgs provides arguments to provision instances.
+	ProvisionArgs struct {
+		Key    string
+		Image  string
+		Name   string
+		Region string
+		Size   string
+		Token  string
+	}
+
+	// Instance represents a provisioned server instance.
+	Instance struct {
+		ID int
+		IP string
+	}
+)
+
+// Provision provisions the server instance.
+func Provision(ctx context.Context, args ProvisionArgs) (Instance, error) {
+	res := Instance{}
+	req := &godo.DropletCreateRequest{
+		Name:   args.Name,
+		Region: args.Region,
+		Size:   args.Size,
+		Tags:   []string{"drone"},
+		IPv6:   false,
+		SSHKeys: []godo.DropletCreateSSHKey{
+			{Fingerprint: args.Key},
+		},
+		Image: godo.DropletCreateImage{
+			Slug: args.Image,
+		},
+	}
+
+	logger := logger.FromContext(ctx).
+		WithField("region", req.Region).
+		WithField("image", req.Image.Slug).
+		WithField("size", req.Size).
+		WithField("name", req.Name)
+
+	logger.Debug("instance create")
+
+	client := newClient(ctx, args.Token)
+	droplet, _, err := client.Droplets.Create(ctx, req)
+	if err != nil {
+		logger.WithError(err).Error("cannot create instance")
+		return res, err
+	}
+
+	// record the droplet ID
+	res.ID = droplet.ID
+
+	logger.WithField("name", req.Name).
+		Info("instance created")
+
+	// poll the digitalocean endpoint for server updates
+	// and exit when a network address is allocated.
+	interval := time.Duration(0)
+poller:
+	for {
+		select {
+		case <-ctx.Done():
+			logger.WithField("name", req.Name).
+				Debug("cannot ascertain network")
+
+			return res, ctx.Err()
+		case <-time.After(interval):
+			interval = time.Second * 30
+
+			logger.WithField("name", req.Name).
+				Debug("find instance network")
+
+			droplet, _, err = client.Droplets.Get(ctx, res.ID)
+			if err != nil {
+				logger.WithError(err).
+					Error("cannot find instance")
+				return res, err
+			}
+
+			for _, network := range droplet.Networks.V4 {
+				if network.Type == "public" {
+					res.IP = network.IPAddress
+				}
+			}
+
+			if res.IP != "" {
+				break poller
+			}
+		}
+	}
+
+	logger.WithField("name", req.Name).
+		WithField("ip", res.IP).
+		WithField("id", res.ID).
+		Debug("instance network ready")
+
+	return res, nil
+}
+
+// Destroy destroys the server instance.
+func Destroy(ctx context.Context, args DestroyArgs) error {
+	client := newClient(ctx, args.Token)
+	_, err := client.Droplets.Delete(ctx, args.ID)
+	if err != nil {
+		logger.FromContext(ctx).
+			WithError(err).
+			WithField("id", args.ID).
+			WithField("ip", args.IP).
+			Error("cannot terminate server")
+	}
+	return err
+}
+
+// RegisterKey registers the ssh public key with the account if
+// it is not already registered.
+func RegisterKey(ctx context.Context, args RegisterArgs) error {
+	client := newClient(ctx, args.Token)
+	_, _, err := client.Keys.GetByFingerprint(ctx, args.Fingerprint)
+	if err == nil {
+		return nil
+	}
+
+	// if the ssh key does not exists we attempt to register
+	// with the digital ocean account.
+	_, _, err = client.Keys.Create(ctx, &godo.KeyCreateRequest{
+		Name:      args.Name,
+		PublicKey: args.Data,
+	})
+	return err
+}
+
+// helper function returns a new docker client.
+func newClient(ctx context.Context, token string) *godo.Client {
+	return godo.NewClient(
+		oauth2.NewClient(ctx, oauth2.StaticTokenSource(
+			&oauth2.Token{
+				AccessToken: token,
+			},
+		)),
+	)
+}