github.com/imran-kn/cilium-fork@v1.6.9/pkg/envoy/xds/node.go (about)

     1  // Copyright 2018 Authors of Cilium
     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 xds
    16  
    17  import (
    18  	"errors"
    19  	"fmt"
    20  	"net"
    21  	"strings"
    22  
    23  	envoy_api_v2_core "github.com/cilium/proxy/go/envoy/api/v2/core"
    24  )
    25  
    26  // NodeToIDFunc extracts a string identifier from an Envoy Node identifier.
    27  type NodeToIDFunc func(node *envoy_api_v2_core.Node) (string, error)
    28  
    29  // IstioNodeToIP extract the IP address from an Envoy node identifier
    30  // configured by Istio's pilot-agent.
    31  //
    32  // Istio's pilot-agent structures the node.id as the concatenation of the
    33  // following parts separated by ~:
    34  //
    35  // - node type: one of "sidecar", "ingress", or "router"
    36  // - node IP address
    37  // - node ID: the unique platform-specific sidecar proxy ID
    38  // - node domain: the DNS domain suffix for short hostnames, e.g. "default.svc.cluster.local"
    39  //
    40  // For instance:
    41  //
    42  //    "sidecar~10.1.1.0~v0.default~default.svc.cluster.local"
    43  func IstioNodeToIP(node *envoy_api_v2_core.Node) (string, error) {
    44  	if node == nil {
    45  		return "", errors.New("node is nil")
    46  	}
    47  	if node.GetId() == "" {
    48  		return "", errors.New("node.id is empty")
    49  	}
    50  
    51  	parts := strings.Split(node.Id, "~")
    52  	if len(parts) != 4 {
    53  		return "", fmt.Errorf("node.id is invalid: %s", node.Id)
    54  	}
    55  
    56  	ip := parts[1]
    57  
    58  	if net.ParseIP(ip) == nil {
    59  		return "", fmt.Errorf("node.id contains an invalid node IP address: %s", node.Id)
    60  	}
    61  
    62  	return ip, nil
    63  }