istio.io/istio@v0.0.0-20240520182934-d79c90f27776/istioctl/pkg/writer/compare/cluster.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  	"bytes"
    19  	"fmt"
    20  
    21  	"github.com/pmezard/go-difflib/difflib"
    22  
    23  	"istio.io/istio/pkg/util/protomarshal"
    24  )
    25  
    26  // ClusterDiff prints a diff between Istiod and Envoy clusters to the passed writer
    27  func (c *Comparator) ClusterDiff() error {
    28  	envoyBytes, istiodBytes := &bytes.Buffer{}, &bytes.Buffer{}
    29  	envoyClusterDump, err := c.envoy.GetDynamicClusterDump(true)
    30  	if err != nil {
    31  		envoyBytes.WriteString(err.Error())
    32  	} else {
    33  		envoy, err := protomarshal.ToJSONWithAnyResolver(envoyClusterDump, "    ", &envoyResolver)
    34  		if err != nil {
    35  			return err
    36  		}
    37  		envoyBytes.WriteString(envoy)
    38  	}
    39  	istiodClusterDump, err := c.istiod.GetDynamicClusterDump(true)
    40  	if err != nil {
    41  		istiodBytes.WriteString(err.Error())
    42  	} else {
    43  		istiod, err := protomarshal.ToJSONWithAnyResolver(istiodClusterDump, "    ", &envoyResolver)
    44  		if err != nil {
    45  			return err
    46  		}
    47  		istiodBytes.WriteString(istiod)
    48  	}
    49  	diff := difflib.UnifiedDiff{
    50  		FromFile: "Istiod Clusters",
    51  		A:        difflib.SplitLines(istiodBytes.String()),
    52  		ToFile:   "Envoy Clusters",
    53  		B:        difflib.SplitLines(envoyBytes.String()),
    54  		Context:  c.context,
    55  	}
    56  	text, err := difflib.GetUnifiedDiffString(diff)
    57  	if err != nil {
    58  		return err
    59  	}
    60  	if text != "" {
    61  		fmt.Fprintln(c.w, "Clusters Don't Match")
    62  		fmt.Fprintln(c.w, text)
    63  	} else {
    64  		fmt.Fprintln(c.w, "Clusters Match")
    65  	}
    66  	return nil
    67  }