feat(akamai): unzip user content

internal/providers/akamai/akamai.go

@@ -86,12 +86,18 @@ func fetchConfig(f *resource.Fetcher) (types.Config, report.Report, error) {
 	// The Linode Metadata Service requires userdata to be base64-encoded
 	// when it is uploaded, so we will have to decode the response.
 	data := make([]byte, base64.StdEncoding.DecodedLen(len(encoded)))
-	n, err := base64.StdEncoding.Decode(data, encoded)
-	if err != nil {
+	if _, err := base64.StdEncoding.Decode(data, encoded); err != nil {
 		return types.Config{}, report.Report{}, fmt.Errorf("decode base64: %w", err)
 	}
 
-	return util.ParseConfig(f.Logger, data[:n])
+	// The Linode Metadata Service can compress userdata.
+	// We have to gunzip if needed.
+	unzipData, err := util.GunzipIfNeeded(data)
+	if err != nil {
+		return types.Config{}, report.Report{}, fmt.Errorf("unzip: %w", err)
+	}
+
+	return util.ParseConfig(f.Logger, unzipData)
 }
 
 // defaultTokenTTL is the time-to-live (TTL; in seconds) for an authorization

internal/providers/util/unzip.go

@@ -0,0 +1,41 @@
+// Copyright 2024 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package util
+
+import (
+	"bytes"
+	"compress/gzip"
+	"io"
+)
+
+var (
+	gzipMagic = []byte{0x1F, 0x8B, 0x08}
+)
+
+func hasGzipMagicNumber(source []byte) bool {
+	return bytes.HasPrefix(source, gzipMagic)
+}
+
+func GunzipIfNeeded(raw []byte) ([]byte, error) {
+	if hasGzipMagicNumber(raw) {
+		reader, err := gzip.NewReader(bytes.NewReader(raw))
+		if err != nil {
+			return nil, err
+		}
+		defer reader.Close()
+		return io.ReadAll(reader)
+	}
+	return raw, nil
+}