Add S3 provider

Signed-off-by: Knut Ahlers <knut@ahlers.me>

cmd/cloudbox/providers.go

@@ -5,10 +5,12 @@ import (
 
 	"github.com/Luzifer/cloudbox/providers"
 	"github.com/Luzifer/cloudbox/providers/local"
+	"github.com/Luzifer/cloudbox/providers/s3"
 )
 
 var providerInitFuncs = []providers.CloudProviderInitFunc{
 	local.New,
+	s3.New,
 }
 
 func providerFromURI(uri string) (providers.CloudProvider, error) {

providers/s3/file.go

@@ -0,0 +1,61 @@
+package s3
+
+import (
+	"bytes"
+	"fmt"
+	"hash"
+	"io"
+	"time"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/service/s3"
+	"github.com/pkg/errors"
+
+	"github.com/Luzifer/cloudbox/providers"
+)
+
+type File struct {
+	key          string
+	lastModified time.Time
+	checksum     string
+	size         uint64
+
+	s3Conn *s3.S3
+	bucket string
+}
+
+func (f File) Info() providers.FileInfo {
+	return providers.FileInfo{
+		RelativeName: f.key,
+		LastModified: f.lastModified,
+		Checksum:     f.checksum,
+		Size:         f.size,
+	}
+}
+
+func (f File) Checksum(h hash.Hash) (string, error) {
+	cont, err := f.Content()
+	if err != nil {
+		return "", errors.Wrap(err, "Unable to get file content")
+	}
+	defer cont.Close()
+
+	buf := new(bytes.Buffer)
+	if _, err := io.Copy(buf, cont); err != nil {
+		return "", errors.Wrap(err, "Unable to read file content")
+	}
+
+	return fmt.Sprintf("%x", h.Sum(buf.Bytes())), nil
+}
+
+func (f File) Content() (io.ReadCloser, error) {
+	resp, err := f.s3Conn.GetObject(&s3.GetObjectInput{
+		Bucket: aws.String(f.bucket),
+		Key:    aws.String(f.key),
+	})
+	if err != nil {
+		return nil, errors.Wrap(err, "Unable to get file")
+	}
+
+	return resp.Body, nil
+}

providers/s3/provider.go

@@ -0,0 +1,134 @@
+package s3
+
+import (
+	"bytes"
+	"crypto/md5"
+	"hash"
+	"io"
+	"net/url"
+	"strings"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/credentials"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/s3"
+	"github.com/pkg/errors"
+
+	"github.com/Luzifer/cloudbox/providers"
+)
+
+type Provider struct {
+	bucket string
+	s3     *s3.S3
+}
+
+func New(uri string) (providers.CloudProvider, error) {
+	if !strings.HasPrefix(uri, "s3://") {
+		return nil, providers.ErrInvalidURI
+	}
+
+	u, err := url.Parse(uri)
+	if err != nil {
+		return nil, errors.Wrap(err, "Invalid URI specified")
+	}
+
+	cfg := aws.NewConfig()
+	if u.User != nil {
+		user := u.User.Username()
+		pass, _ := u.User.Password()
+		cfg = cfg.WithCredentials(credentials.NewStaticCredentials(user, pass, ""))
+	}
+
+	svc := s3.New(session.Must(session.NewSession(cfg)))
+
+	return &Provider{
+		bucket: u.Host,
+		s3:     svc,
+	}, nil
+}
+
+func (p *Provider) Capabilities() providers.Capability {
+	return providers.CapBasic | providers.CapAutoChecksum | providers.CapShare
+}
+func (p *Provider) Name() string                 { return "s3" }
+func (p *Provider) GetChecksumMethod() hash.Hash { return md5.New() }
+
+func (p *Provider) DeleteFile(relativeName string) error {
+	_, err := p.s3.DeleteObject(&s3.DeleteObjectInput{
+		Bucket: aws.String(p.bucket),
+		Key:    aws.String(relativeName),
+	})
+
+	return errors.Wrap(err, "Unable to delete object")
+}
+
+func (p *Provider) GetFile(relativeName string) (providers.File, error) {
+	resp, err := p.s3.HeadObject(&s3.HeadObjectInput{
+		Bucket: aws.String(p.bucket),
+		Key:    aws.String(relativeName),
+	})
+	if err != nil {
+		return nil, errors.Wrap(err, "Unable to fetch head information")
+	}
+
+	return File{
+		key:          relativeName,
+		lastModified: *resp.LastModified,
+		checksum:     strings.Trim(*resp.ETag, `"`),
+		size:         uint64(*resp.ContentLength),
+
+		s3Conn: p.s3,
+		bucket: p.bucket,
+	}, nil
+}
+
+func (p *Provider) ListFiles() ([]providers.File, error) {
+	var files []providers.File
+
+	err := p.s3.ListObjectsPages(&s3.ListObjectsInput{
+		Bucket: aws.String(p.bucket),
+	}, func(out *s3.ListObjectsOutput, lastPage bool) bool {
+		for _, obj := range out.Contents {
+			files = append(files, File{
+				key:          *obj.Key,
+				lastModified: *obj.LastModified,
+				checksum:     strings.Trim(*obj.ETag, `"`),
+				size:         uint64(*obj.Size),
+
+				s3Conn: p.s3,
+				bucket: p.bucket,
+			})
+		}
+
+		return !lastPage
+	})
+
+	return files, errors.Wrap(err, "Unable to list objects")
+}
+
+func (p *Provider) PutFile(f providers.File) (providers.File, error) {
+	body, err := f.Content()
+	if err != nil {
+		return nil, errors.Wrap(err, "Unable to get file reader")
+	}
+	defer body.Close()
+
+	buf := new(bytes.Buffer)
+	if _, err := io.Copy(buf, body); err != nil {
+		return nil, errors.Wrap(err, "Unable to read source file")
+	}
+
+	if _, err = p.s3.PutObject(&s3.PutObjectInput{
+		Body:   bytes.NewReader(buf.Bytes()),
+		Bucket: aws.String(p.bucket),
+		Key:    aws.String(f.Info().RelativeName),
+	}); err != nil {
+		return nil, errors.Wrap(err, "Unable to write file")
+	}
+
+	return p.GetFile(f.Info().RelativeName)
+}
+
+func (p *Provider) Share(relativeName string) (string, error) {
+	return "", errors.New("Not implemented")
+}