chore: migrate to gitea

vendor/cloud.google.com/go/auth/credentials/compute.go

@@ -0,0 +1,102 @@
+// Copyright 2023 Google LLC
+//
+// 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 credentials
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/url"
+	"strings"
+	"time"
+
+	"cloud.google.com/go/auth"
+	"cloud.google.com/go/compute/metadata"
+)
+
+var (
+	computeTokenMetadata = map[string]interface{}{
+		"auth.google.tokenSource":    "compute-metadata",
+		"auth.google.serviceAccount": "default",
+	}
+	computeTokenURI = "instance/service-accounts/default/token"
+)
+
+// computeTokenProvider creates a [cloud.google.com/go/auth.TokenProvider] that
+// uses the metadata service to retrieve tokens.
+func computeTokenProvider(opts *DetectOptions, client *metadata.Client) auth.TokenProvider {
+	return auth.NewCachedTokenProvider(&computeProvider{
+		scopes:           opts.Scopes,
+		client:           client,
+		tokenBindingType: opts.TokenBindingType,
+	}, &auth.CachedTokenProviderOptions{
+		ExpireEarly:         opts.EarlyTokenRefresh,
+		DisableAsyncRefresh: opts.DisableAsyncRefresh,
+	})
+}
+
+// computeProvider fetches tokens from the google cloud metadata service.
+type computeProvider struct {
+	scopes           []string
+	client           *metadata.Client
+	tokenBindingType TokenBindingType
+}
+
+type metadataTokenResp struct {
+	AccessToken  string `json:"access_token"`
+	ExpiresInSec int    `json:"expires_in"`
+	TokenType    string `json:"token_type"`
+}
+
+func (cs *computeProvider) Token(ctx context.Context) (*auth.Token, error) {
+	tokenURI, err := url.Parse(computeTokenURI)
+	if err != nil {
+		return nil, err
+	}
+	hasScopes := len(cs.scopes) > 0
+	if hasScopes || cs.tokenBindingType != NoBinding {
+		v := url.Values{}
+		if hasScopes {
+			v.Set("scopes", strings.Join(cs.scopes, ","))
+		}
+		switch cs.tokenBindingType {
+		case MTLSHardBinding:
+			v.Set("transport", "mtls")
+			v.Set("binding-enforcement", "on")
+		case ALTSHardBinding:
+			v.Set("transport", "alts")
+		}
+		tokenURI.RawQuery = v.Encode()
+	}
+	tokenJSON, err := cs.client.GetWithContext(ctx, tokenURI.String())
+	if err != nil {
+		return nil, fmt.Errorf("credentials: cannot fetch token: %w", err)
+	}
+	var res metadataTokenResp
+	if err := json.NewDecoder(strings.NewReader(tokenJSON)).Decode(&res); err != nil {
+		return nil, fmt.Errorf("credentials: invalid token JSON from metadata: %w", err)
+	}
+	if res.ExpiresInSec == 0 || res.AccessToken == "" {
+		return nil, errors.New("credentials: incomplete token received from metadata")
+	}
+	token := &auth.Token{
+		Value:    res.AccessToken,
+		Type:     res.TokenType,
+		Expiry:   time.Now().Add(time.Duration(res.ExpiresInSec) * time.Second),
+		Metadata: computeTokenMetadata,
+	}
+	return token, nil
+}