config: dynamic attestation configuration through S3 backed API (#1808)

internal/api/versionsapi/imageinfo.go

@@ -0,0 +1,141 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package versionsapi
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"path"
+	"sort"
+
+	"github.com/edgelesssys/constellation/v2/internal/constants"
+	"golang.org/x/mod/semver"
+)
+
+// ImageInfo contains information about the OS images for a specific version.
+type ImageInfo struct {
+	// Ref is the reference name of the image.
+	Ref string `json:"ref,omitempty"`
+	// Stream is the stream name of the image.
+	Stream string `json:"stream,omitempty"`
+	// Version is the version of the image.
+	Version string `json:"version,omitempty"`
+	// List contains the image variants for this version.
+	List []ImageInfoEntry `json:"list,omitempty"`
+}
+
+// ImageInfoEntry contains information about a single image variant.
+type ImageInfoEntry struct {
+	CSP                string `json:"csp"`
+	AttestationVariant string `json:"attestationVariant"`
+	Reference          string `json:"reference"`
+	Region             string `json:"region,omitempty"`
+}
+
+// JSONPath returns the S3 JSON path for this object.
+func (i ImageInfo) JSONPath() string {
+	return path.Join(
+		constants.CDNAPIPrefixV2,
+		"ref", i.Ref,
+		"stream", i.Stream,
+		i.Version,
+		"image",
+		"info.json",
+	)
+}
+
+// URL returns the URL to the JSON file for this object.
+func (i ImageInfo) URL() (string, error) {
+	url, err := url.Parse(constants.CDNRepositoryURL)
+	if err != nil {
+		return "", fmt.Errorf("parsing CDN URL: %w", err)
+	}
+	url.Path = i.JSONPath()
+	return url.String(), nil
+}
+
+// ValidateRequest validates the request parameters of the list.
+// The provider specific maps must be empty.
+func (i ImageInfo) ValidateRequest() error {
+	var retErr error
+	if err := ValidateRef(i.Ref); err != nil {
+		retErr = errors.Join(retErr, err)
+	}
+	if err := ValidateStream(i.Ref, i.Stream); err != nil {
+		retErr = errors.Join(retErr, err)
+	}
+	if !semver.IsValid(i.Version) {
+		retErr = errors.Join(retErr, fmt.Errorf("version %q is not a valid semver", i.Version))
+	}
+	if len(i.List) != 0 {
+		retErr = errors.Join(retErr, errors.New("list must be empty for request"))
+	}
+
+	return retErr
+}
+
+// Validate checks if the image info is valid.
+func (i ImageInfo) Validate() error {
+	var retErr error
+	if err := ValidateRef(i.Ref); err != nil {
+		retErr = errors.Join(retErr, err)
+	}
+	if err := ValidateStream(i.Ref, i.Stream); err != nil {
+		retErr = errors.Join(retErr, err)
+	}
+	if !semver.IsValid(i.Version) {
+		retErr = errors.Join(retErr, fmt.Errorf("version %q is not a valid semver", i.Version))
+	}
+	if len(i.List) == 0 {
+		retErr = errors.Join(retErr, errors.New("one or more image variants must be specified in the list"))
+	}
+
+	return retErr
+}
+
+// MergeImageInfos combines the image info entries from multiple sources into a single
+// image info object.
+func MergeImageInfos(infos ...ImageInfo) (ImageInfo, error) {
+	if len(infos) == 0 {
+		return ImageInfo{}, errors.New("no image info objects specified")
+	}
+	if len(infos) == 1 {
+		return infos[0], nil
+	}
+	out := ImageInfo{
+		Ref:     infos[0].Ref,
+		Stream:  infos[0].Stream,
+		Version: infos[0].Version,
+		List:    []ImageInfoEntry{},
+	}
+	for _, info := range infos {
+		if info.Ref != out.Ref {
+			return ImageInfo{}, errors.New("image info objects have different refs")
+		}
+		if info.Stream != out.Stream {
+			return ImageInfo{}, errors.New("image info objects have different streams")
+		}
+		if info.Version != out.Version {
+			return ImageInfo{}, errors.New("image info objects have different versions")
+		}
+		out.List = append(out.List, info.List...)
+	}
+	sort.SliceStable(out.List, func(i, j int) bool {
+		if out.List[i].CSP != out.List[j].CSP {
+			return out.List[i].CSP < out.List[j].CSP
+		}
+		if out.List[i].AttestationVariant != out.List[j].AttestationVariant {
+			return out.List[i].AttestationVariant < out.List[j].AttestationVariant
+		}
+		if out.List[i].Region != out.List[j].Region {
+			return out.List[i].Region < out.List[j].Region
+		}
+		return out.List[i].Reference < out.List[j].Reference
+	})
+	return out, nil
+}