go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/milo/internal/git/gerrit.go (about)

     1  // Copyright 2018 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package git
    16  
    17  import (
    18  	"context"
    19  	"encoding/json"
    20  	"fmt"
    21  	"time"
    22  
    23  	"google.golang.org/grpc/codes"
    24  	"google.golang.org/grpc/status"
    25  
    26  	gerritpb "go.chromium.org/luci/common/proto/gerrit"
    27  	"go.chromium.org/luci/milo/internal/utils"
    28  	"go.chromium.org/luci/server/caching/layered"
    29  )
    30  
    31  // errGRPCNotFound is what gRPC API would have returned for NotFound error.
    32  var errGRPCNotFound = status.Errorf(codes.NotFound, "not found")
    33  
    34  // CLEmail implements Client interface.
    35  func (p *implementation) CLEmail(c context.Context, host string, changeNumber int64) (email string, err error) {
    36  	defer func() { err = utils.TagGRPC(c, err) }()
    37  	changeInfo, err := p.clEmailAndProjectNoACLs(c, host, changeNumber)
    38  	if err != nil {
    39  		return
    40  	}
    41  	allowed, err := p.acls.IsAllowed(c, host, changeInfo.Project)
    42  	switch {
    43  	case err != nil:
    44  		return
    45  	case allowed:
    46  		email = changeInfo.GetOwner().GetEmail()
    47  	default:
    48  		err = errGRPCNotFound
    49  	}
    50  	return
    51  }
    52  
    53  var gerritChangeInfoCache = layered.RegisterCache(layered.Parameters[*gerritpb.ChangeInfo]{
    54  	ProcessCacheCapacity: 4096,
    55  	GlobalNamespace:      "gerrit-change-info",
    56  	Marshal: func(item *gerritpb.ChangeInfo) ([]byte, error) {
    57  		return json.Marshal(item)
    58  	},
    59  	Unmarshal: func(blob []byte) (*gerritpb.ChangeInfo, error) {
    60  		changeInfo := &gerritpb.ChangeInfo{}
    61  		err := json.Unmarshal(blob, changeInfo)
    62  		return changeInfo, err
    63  	},
    64  })
    65  
    66  // clEmailAndProjectNoACLs fetches and caches change owner email and project.
    67  //
    68  // Gerrit change owner and project are deemed immutable.
    69  // Caveat: technically only owner's account id is immutable. Owner's email
    70  // associated with this account id may change, but this is rare.
    71  func (p *implementation) clEmailAndProjectNoACLs(c context.Context, host string, changeNumber int64) (*gerritpb.ChangeInfo, error) {
    72  	key := fmt.Sprintf("%s/%d", host, changeNumber)
    73  	return gerritChangeInfoCache.GetOrCreate(c, key, func() (v *gerritpb.ChangeInfo, exp time.Duration, err error) {
    74  		client, err := p.gerritClient(c, host)
    75  		if err != nil {
    76  			return nil, 0, err
    77  		}
    78  
    79  		info, err := client.GetChange(c, &gerritpb.GetChangeRequest{
    80  			Number: changeNumber,
    81  			Options: []gerritpb.QueryOption{
    82  				gerritpb.QueryOption_DETAILED_ACCOUNTS,
    83  				gerritpb.QueryOption_SKIP_MERGEABLE,
    84  			},
    85  		})
    86  		// We can't cache outcome of not found CL because
    87  		//  * Milo may not at first have access to a CL, say while CL was hidden or
    88  		//    because of bad ACLs.
    89  		//  * Gerrit is known to return 404 flakes.
    90  		if err != nil {
    91  			return nil, 0, err
    92  		}
    93  
    94  		// Cache and return only email and project.
    95  		ret := &gerritpb.ChangeInfo{
    96  			Project: info.Project,
    97  			Owner:   &gerritpb.AccountInfo{Email: info.GetOwner().GetEmail()},
    98  		}
    99  
   100  		return ret, 0, nil
   101  	})
   102  }