72 lines
1.8 KiB
Go
72 lines
1.8 KiB
Go
// Copyright (c) HashiCorp, Inc.
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// SPDX-License-Identifier: MPL-2.0
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package consul
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import (
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"encoding/json"
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"io"
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"os"
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"time"
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)
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// ServerMetadataFile is the name of the file on disk that server metadata
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// should be written to.
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const ServerMetadataFile = "server_metadata.json"
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// ServerMetadata represents specific metadata about a running server.
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type ServerMetadata struct {
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// LastSeenUnix is the timestamp a server was last seen, in Unix format.
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LastSeenUnix int64 `json:"last_seen_unix"`
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}
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// IsLastSeenStale checks whether the last seen timestamp is older than a given duration.
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func (md *ServerMetadata) IsLastSeenStale(d time.Duration) bool {
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lastSeen := time.Unix(md.LastSeenUnix, 0)
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maxAge := time.Now().Add(-d)
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return lastSeen.Before(maxAge)
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}
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// OpenServerMetadata is a helper function for opening the server metadata file
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// with the correct permissions.
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func OpenServerMetadata(filename string) (io.WriteCloser, error) {
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return os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
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}
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type ServerMetadataReadFunc func(filename string) (*ServerMetadata, error)
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// ReadServerMetadata is a helper function for reading the contents of a server
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// metadata file and unmarshaling the data from JSON.
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func ReadServerMetadata(filename string) (*ServerMetadata, error) {
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b, err := os.ReadFile(filename)
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if err != nil {
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return nil, err
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}
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var md ServerMetadata
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if err := json.Unmarshal(b, &md); err != nil {
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return nil, err
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}
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return &md, nil
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}
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// WriteServerMetadata writes server metadata to a file in JSON format.
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func WriteServerMetadata(w io.Writer) error {
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md := &ServerMetadata{
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LastSeenUnix: time.Now().Unix(),
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}
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b, err := json.Marshal(md)
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if err != nil {
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return err
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}
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if _, err := w.Write(b); err != nil {
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return err
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}
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return nil
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}
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