istio.io/istio@v0.0.0-20240520182934-d79c90f27776/istioctl/pkg/writer/compare/comparator.go (about)

     1  // Copyright Istio 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 compare
    16  
    17  import (
    18  	"encoding/json"
    19  	"fmt"
    20  	"io"
    21  	"strings"
    22  
    23  	admin "github.com/envoyproxy/go-control-plane/envoy/admin/v3"
    24  	discovery "github.com/envoyproxy/go-control-plane/envoy/service/discovery/v3"
    25  	legacyproto "github.com/golang/protobuf/proto" // nolint: staticcheck
    26  	exprpb "google.golang.org/genproto/googleapis/api/expr/v1alpha1"
    27  	"google.golang.org/protobuf/reflect/protoreflect"
    28  	"google.golang.org/protobuf/reflect/protoregistry"
    29  	"google.golang.org/protobuf/types/known/emptypb"
    30  
    31  	"istio.io/istio/istioctl/pkg/util/configdump"
    32  )
    33  
    34  // Comparator diffs between a config dump from Istiod and one from Envoy
    35  type Comparator struct {
    36  	envoy, istiod *configdump.Wrapper
    37  	w             io.Writer
    38  	context       int
    39  	location      string
    40  }
    41  
    42  // NewComparator is a comparator constructor
    43  func NewComparator(w io.Writer, istiodResponses map[string][]byte, envoyResponse []byte) (*Comparator, error) {
    44  	c := &Comparator{}
    45  	for _, resp := range istiodResponses {
    46  		istiodDump := &configdump.Wrapper{}
    47  		err := json.Unmarshal(resp, istiodDump)
    48  		if err != nil {
    49  			continue
    50  		}
    51  		c.istiod = istiodDump
    52  		break
    53  	}
    54  	if c.istiod == nil {
    55  		return nil, fmt.Errorf("unable to find config dump in Istiod responses")
    56  	}
    57  	envoyDump := &configdump.Wrapper{}
    58  	err := json.Unmarshal(envoyResponse, envoyDump)
    59  	if err != nil {
    60  		return nil, err
    61  	}
    62  	c.envoy = envoyDump
    63  	c.w = w
    64  	c.context = 7
    65  	c.location = "Local" // the time.Location for formatting time.Time instances
    66  	return c, nil
    67  }
    68  
    69  // NewXdsComparator is a comparator constructor
    70  func NewXdsComparator(w io.Writer, istiodResponses map[string]*discovery.DiscoveryResponse, envoyResponse []byte) (*Comparator, error) {
    71  	c := &Comparator{}
    72  	for _, resp := range istiodResponses {
    73  		if len(resp.Resources) > 0 {
    74  			c.istiod = &configdump.Wrapper{
    75  				ConfigDump: &admin.ConfigDump{
    76  					Configs: resp.Resources,
    77  				},
    78  			}
    79  			break
    80  		}
    81  	}
    82  	if c.istiod == nil {
    83  		return nil, fmt.Errorf("unable to find config dump in Istiod responses")
    84  	}
    85  	envoyDump := &configdump.Wrapper{}
    86  	err := json.Unmarshal(envoyResponse, envoyDump)
    87  	if err != nil {
    88  		return nil, err
    89  	}
    90  	c.envoy = envoyDump
    91  	c.w = w
    92  	c.context = 7
    93  	c.location = "Local" // the time.Location for formatting time.Time instances
    94  	return c, nil
    95  }
    96  
    97  // Diff prints a diff between Istiod and Envoy to the passed writer
    98  func (c *Comparator) Diff() error {
    99  	if err := c.ClusterDiff(); err != nil {
   100  		return err
   101  	}
   102  	if err := c.ListenerDiff(); err != nil {
   103  		return err
   104  	}
   105  	return c.RouteDiff()
   106  }
   107  
   108  // nonstrictResolver is an AnyResolver that ignores unknown proto messages
   109  type nonstrictResolver struct{}
   110  
   111  var envoyResolver nonstrictResolver
   112  
   113  func (m *nonstrictResolver) Resolve(typeURL string) (legacyproto.Message, error) {
   114  	// See https://github.com/golang/protobuf/issues/747#issuecomment-437463120
   115  	mname := typeURL
   116  	if slash := strings.LastIndex(typeURL, "/"); slash >= 0 {
   117  		mname = mname[slash+1:]
   118  	}
   119  	mt, err := protoregistry.GlobalTypes.FindMessageByName(protoreflect.FullName(mname))
   120  	if err != nil {
   121  		// istioctl should keep going if it encounters new Envoy versions; ignore unknown types
   122  		return &exprpb.Type{TypeKind: &exprpb.Type_Dyn{Dyn: &emptypb.Empty{}}}, nil
   123  	}
   124  	return legacyproto.MessageV1(mt.New().Interface()), nil
   125  }