image: implement idempotent upload of os images

internal/osimage/archive/archive.go

@@ -0,0 +1,68 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+// package archive is used to archive OS images in S3.
+package archive
+
+import (
+	"context"
+	"io"
+	"net/url"
+
+	awsconfig "github.com/aws/aws-sdk-go-v2/config"
+	s3manager "github.com/aws/aws-sdk-go-v2/feature/s3/manager"
+	"github.com/aws/aws-sdk-go-v2/service/s3"
+	s3types "github.com/aws/aws-sdk-go-v2/service/s3/types"
+	"github.com/edgelesssys/constellation/v2/internal/logger"
+	"github.com/edgelesssys/constellation/v2/internal/versionsapi"
+)
+
+// Archivist uploads OS images to S3.
+type Archivist struct {
+	uploadClient uploadClient
+	// bucket is the name of the S3 bucket to use.
+	bucket string
+
+	log *logger.Logger
+}
+
+// New creates a new Archivist.
+func New(ctx context.Context, region, bucket string, log *logger.Logger) (*Archivist, error) {
+	cfg, err := awsconfig.LoadDefaultConfig(ctx, awsconfig.WithRegion(region))
+	if err != nil {
+		return nil, err
+	}
+	s3client := s3.NewFromConfig(cfg)
+	uploadClient := s3manager.NewUploader(s3client)
+
+	return &Archivist{
+		uploadClient: uploadClient,
+		bucket:       bucket,
+		log:          log,
+	}, nil
+}
+
+// Archive reads the OS image in img and uploads it as key.
+func (a *Archivist) Archive(ctx context.Context, version versionsapi.Version, csp, variant string, img io.Reader) (string, error) {
+	key, err := url.JoinPath(version.ArtifactPath(), version.Kind.String(), "csp", csp, variant, "image.raw")
+	if err != nil {
+		return "", err
+	}
+	a.log.Debugf("Archiving OS image %s %s %v to s3://%v/%v", csp, variant, version.ShortPath(), a.bucket, key)
+	_, err = a.uploadClient.Upload(ctx, &s3.PutObjectInput{
+		Bucket:            &a.bucket,
+		Key:               &key,
+		Body:              img,
+		ChecksumAlgorithm: s3types.ChecksumAlgorithmSha256,
+	})
+	return baseURL + key, err
+}
+
+type uploadClient interface {
+	Upload(ctx context.Context, input *s3.PutObjectInput, opts ...func(*s3manager.Uploader)) (*s3manager.UploadOutput, error)
+}
+
+const baseURL = "https://cdn.confidential.cloud/"