vitess.io/vitess@v0.16.2/go/vt/topo/external_vitess_cluster.go (about)

     1  /*
     2  Copyright 2019 The Vitess Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package topo
    18  
    19  import (
    20  	"context"
    21  	"path"
    22  
    23  	"google.golang.org/protobuf/proto"
    24  
    25  	"vitess.io/vitess/go/event"
    26  	topodatapb "vitess.io/vitess/go/vt/proto/topodata"
    27  	"vitess.io/vitess/go/vt/topo/events"
    28  	"vitess.io/vitess/go/vt/vterrors"
    29  )
    30  
    31  // ExternalVitessClusterInfo is a meta struct that contains metadata to give the
    32  // data more context and convenience. This is the main way we interact
    33  // with a vitess cluster stored in the topo.
    34  type ExternalVitessClusterInfo struct {
    35  	ClusterName string
    36  	version     Version
    37  	*topodatapb.ExternalVitessCluster
    38  }
    39  
    40  // GetExternalVitessClusterDir returns node path containing external vitess clusters
    41  func GetExternalVitessClusterDir() string {
    42  	return path.Join(ExternalClustersFile, ExternalClusterVitess)
    43  }
    44  
    45  // GetExternalVitessClusterPath returns node path containing external clusters
    46  func GetExternalVitessClusterPath(clusterName string) string {
    47  	return path.Join(GetExternalVitessClusterDir(), clusterName)
    48  }
    49  
    50  // CreateExternalVitessCluster creates a topo record for the passed vitess cluster
    51  func (ts *Server) CreateExternalVitessCluster(ctx context.Context, clusterName string, value *topodatapb.ExternalVitessCluster) error {
    52  	data, err := proto.Marshal(value)
    53  	if err != nil {
    54  		return err
    55  	}
    56  
    57  	if _, err := ts.globalCell.Create(ctx, GetExternalVitessClusterPath(clusterName), data); err != nil {
    58  		return err
    59  	}
    60  
    61  	event.Dispatch(&events.ExternalVitessClusterChange{
    62  		ClusterName:           clusterName,
    63  		ExternalVitessCluster: value,
    64  		Status:                "created",
    65  	})
    66  	return nil
    67  }
    68  
    69  // GetExternalVitessCluster returns a topo record for the named vitess cluster
    70  func (ts *Server) GetExternalVitessCluster(ctx context.Context, clusterName string) (*ExternalVitessClusterInfo, error) {
    71  	data, version, err := ts.globalCell.Get(ctx, GetExternalVitessClusterPath(clusterName))
    72  	switch {
    73  	case IsErrType(err, NoNode):
    74  		return nil, nil
    75  	case err == nil:
    76  	default:
    77  		return nil, err
    78  	}
    79  	vc := &topodatapb.ExternalVitessCluster{}
    80  	if err = proto.Unmarshal(data, vc); err != nil {
    81  		return nil, vterrors.Wrap(err, "bad vitess cluster data")
    82  	}
    83  
    84  	return &ExternalVitessClusterInfo{
    85  		ClusterName:           clusterName,
    86  		version:               version,
    87  		ExternalVitessCluster: vc,
    88  	}, nil
    89  }
    90  
    91  // UpdateExternalVitessCluster updates the topo record for the named vitess cluster
    92  func (ts *Server) UpdateExternalVitessCluster(ctx context.Context, vc *ExternalVitessClusterInfo) error {
    93  	//FIXME: check for cluster lock
    94  	data, err := proto.Marshal(vc.ExternalVitessCluster)
    95  	if err != nil {
    96  		return err
    97  	}
    98  	version, err := ts.globalCell.Update(ctx, GetExternalVitessClusterPath(vc.ClusterName), data, vc.version)
    99  	if err != nil {
   100  		return err
   101  	}
   102  	vc.version = version
   103  
   104  	event.Dispatch(&events.ExternalVitessClusterChange{
   105  		ClusterName:           vc.ClusterName,
   106  		ExternalVitessCluster: vc.ExternalVitessCluster,
   107  		Status:                "updated",
   108  	})
   109  	return nil
   110  }
   111  
   112  // DeleteExternalVitessCluster deletes the topo record for the named vitess cluster
   113  func (ts *Server) DeleteExternalVitessCluster(ctx context.Context, clusterName string) error {
   114  	if err := ts.globalCell.Delete(ctx, GetExternalVitessClusterPath(clusterName), nil); err != nil {
   115  		return err
   116  	}
   117  
   118  	event.Dispatch(&events.ExternalVitessClusterChange{
   119  		ClusterName:           clusterName,
   120  		ExternalVitessCluster: nil,
   121  		Status:                "deleted",
   122  	})
   123  	return nil
   124  }
   125  
   126  // GetExternalVitessClusters returns the list of external vitess clusters in the topology.
   127  func (ts *Server) GetExternalVitessClusters(ctx context.Context) ([]string, error) {
   128  	children, err := ts.globalCell.ListDir(ctx, GetExternalVitessClusterDir(), false /*full*/)
   129  	switch {
   130  	case err == nil:
   131  		return DirEntriesToStringArray(children), nil
   132  	case IsErrType(err, NoNode):
   133  		return nil, nil
   134  	default:
   135  		return nil, err
   136  	}
   137  }