istio.io/istio@v0.0.0-20240520182934-d79c90f27776/istioctl/pkg/xds/google.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 xds
    16  
    17  import (
    18  	"context"
    19  	"crypto/tls"
    20  	"crypto/x509"
    21  	"errors"
    22  	"fmt"
    23  	"strings"
    24  
    25  	"google.golang.org/grpc"
    26  	"google.golang.org/grpc/credentials"
    27  	"google.golang.org/grpc/credentials/oauth"
    28  	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    29  	"k8s.io/apimachinery/pkg/runtime/schema"
    30  
    31  	"istio.io/istio/pkg/kube"
    32  )
    33  
    34  type meshAuthCredentials struct {
    35  	k8sCreds credentials.PerRPCCredentials
    36  	gcpCreds credentials.PerRPCCredentials
    37  	project  string
    38  }
    39  
    40  func (c *meshAuthCredentials) GetRequestMetadata(ctx context.Context, uri ...string) (map[string]string, error) {
    41  	ret := map[string]string{
    42  		"x-goog-user-project": c.project,
    43  	}
    44  	if err := updateAuthHdrs(ctx, uri, "k8s", c.k8sCreds, ret, "x-mesh-authorization"); err != nil {
    45  		return nil, err
    46  	}
    47  	if err := updateAuthHdrs(ctx, uri, "gcp", c.gcpCreds, ret, "authorization"); err != nil {
    48  		return nil, err
    49  	}
    50  	return ret, nil
    51  }
    52  
    53  func (*meshAuthCredentials) RequireTransportSecurity() bool {
    54  	return true
    55  }
    56  
    57  func updateAuthHdrs(ctx context.Context, uri []string, kind string, creds credentials.PerRPCCredentials, dst map[string]string, dstHdr string) error {
    58  	ret, err := creds.GetRequestMetadata(ctx, uri...)
    59  	if err != nil {
    60  		return err
    61  	}
    62  	for k, v := range ret {
    63  		if !strings.EqualFold(k, "authorization") {
    64  			if _, ok := dst[k]; ok {
    65  				return fmt.Errorf("underlying %s credentials contain a %s header which is already present in the combined credentials", kind, k)
    66  			}
    67  			dst[k] = v
    68  		} else {
    69  			dst[dstHdr] = v
    70  		}
    71  	}
    72  	return nil
    73  }
    74  
    75  type hubMembership struct {
    76  	WorkloadIdentityPool string
    77  }
    78  
    79  func getHubMembership(ctx context.Context, exClient kube.CLIClient) (*hubMembership, error) {
    80  	client := exClient.Dynamic()
    81  	gvr := schema.GroupVersionResource{
    82  		Group:    "hub.gke.io",
    83  		Version:  "v1",
    84  		Resource: "memberships",
    85  	}
    86  	u, err := client.Resource(gvr).Get(ctx, "membership", metav1.GetOptions{})
    87  	if err != nil {
    88  		return nil, err
    89  	}
    90  	spec, ok := u.Object["spec"].(map[string]any)
    91  	if !ok {
    92  		return nil, errors.New(`field "spec" is not a map`)
    93  	}
    94  	var mem hubMembership
    95  	mem.WorkloadIdentityPool, ok = spec["workload_identity_pool"].(string)
    96  	if !ok {
    97  		return nil, errors.New(`field "spec.workload_identity_pool" is not a string`)
    98  	}
    99  	return &mem, nil
   100  }
   101  
   102  func mcpDialOptions(ctx context.Context, gcpProject string, k8sCreds credentials.PerRPCCredentials) ([]grpc.DialOption, error) {
   103  	systemRoots, err := x509.SystemCertPool()
   104  	if err != nil {
   105  		return nil, fmt.Errorf("failed to get system cert pool: %w", err)
   106  	}
   107  	gcpCreds, err := oauth.NewApplicationDefault(ctx)
   108  	if err != nil {
   109  		return nil, fmt.Errorf("failed to get application default credentials: %w", err)
   110  	}
   111  
   112  	return []grpc.DialOption{
   113  		grpc.WithTransportCredentials(credentials.NewTLS(&tls.Config{
   114  			RootCAs:    systemRoots,
   115  			MinVersion: tls.VersionTLS12,
   116  		})),
   117  		grpc.WithPerRPCCredentials(&meshAuthCredentials{
   118  			k8sCreds: k8sCreds,
   119  			gcpCreds: gcpCreds,
   120  			project:  gcpProject,
   121  		}),
   122  	}, nil
   123  }