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50 lines
971 B
Go
50 lines
971 B
Go
8 years ago
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package store
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import (
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"bytes"
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"encoding/json"
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"io/ioutil"
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"os"
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"path/filepath"
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)
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const (
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jsonPeerPath = "peers.json"
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)
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// NumPeers returns the number of peers indicated by the config files
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// within raftDir.
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//
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// This code makes assumptions about how the Raft module works.
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func NumPeers(raftDir string) (int, error) {
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// Read the file
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buf, err := ioutil.ReadFile(filepath.Join(raftDir, jsonPeerPath))
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if err != nil && !os.IsNotExist(err) {
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return 0, err
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}
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// Check for no peers
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if len(buf) == 0 {
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return 0, nil
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}
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// Decode the peers
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var peerSet []string
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dec := json.NewDecoder(bytes.NewReader(buf))
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if err := dec.Decode(&peerSet); err != nil {
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return 0, err
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}
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return len(peerSet), nil
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}
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// JoinAllowed returns whether the config files within raftDir indicate
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// that the node can join a cluster.
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func JoinAllowed(raftDir string) (bool, error) {
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n, err := NumPeers(raftDir)
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if err != nil {
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return false, err
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}
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return n <= 1, nil
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}
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