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| 1 | +package chstatsreceiver |
| 2 | + |
| 3 | +import ( |
| 4 | + "bytes" |
| 5 | + "context" |
| 6 | + "fmt" |
| 7 | + "text/template" |
| 8 | + "time" |
| 9 | + |
| 10 | + "github.com/ClickHouse/clickhouse-go/v2" |
| 11 | + "go.opentelemetry.io/collector/component" |
| 12 | + "go.opentelemetry.io/collector/consumer" |
| 13 | + "go.opentelemetry.io/collector/pdata/pcommon" |
| 14 | + "go.opentelemetry.io/collector/pdata/pmetric" |
| 15 | + "go.uber.org/zap" |
| 16 | +) |
| 17 | + |
| 18 | +type chReceiver struct { |
| 19 | + cfg *Config |
| 20 | + db clickhouse.Conn |
| 21 | + consumer consumer.Metrics |
| 22 | + templates []*template.Template |
| 23 | + logger *zap.Logger |
| 24 | + cancel context.CancelFunc |
| 25 | + ticker *time.Ticker |
| 26 | +} |
| 27 | + |
| 28 | +func (r *chReceiver) Start(ctx context.Context, _ component.Host) error { |
| 29 | + opts, err := clickhouse.ParseDSN(r.cfg.DSN) |
| 30 | + if err != nil { |
| 31 | + return err |
| 32 | + } |
| 33 | + db, err := clickhouse.Open(opts) |
| 34 | + if err != nil { |
| 35 | + return err |
| 36 | + } |
| 37 | + r.db = db |
| 38 | + r.templates = make([]*template.Template, len(r.cfg.Queries)) |
| 39 | + for i, query := range r.cfg.Queries { |
| 40 | + r.templates[i], err = template.New(fmt.Sprintf("tpl-%d", i)).Parse(query) |
| 41 | + if err != nil { |
| 42 | + return err |
| 43 | + } |
| 44 | + } |
| 45 | + |
| 46 | + _ctx, cancel := context.WithCancel(ctx) |
| 47 | + r.cancel = cancel |
| 48 | + |
| 49 | + r.ticker = time.NewTicker(r.cfg.Timeout) |
| 50 | + |
| 51 | + go r.mainLoop(_ctx) |
| 52 | + return nil |
| 53 | +} |
| 54 | + |
| 55 | +func (r *chReceiver) mainLoop(ctx context.Context) { |
| 56 | + for { |
| 57 | + r.logger.Info("tick start") |
| 58 | + select { |
| 59 | + case <-ctx.Done(): |
| 60 | + fmt.Println("tick stop") |
| 61 | + return |
| 62 | + case <-r.ticker.C: |
| 63 | + err := r.GetMetrics(ctx) |
| 64 | + if err != nil { |
| 65 | + r.logger.Error("failed to get metrics", zap.Error(err)) |
| 66 | + } |
| 67 | + } |
| 68 | + r.logger.Info("tick end") |
| 69 | + } |
| 70 | +} |
| 71 | + |
| 72 | +func (r *chReceiver) GetMetrics(ctx context.Context) error { |
| 73 | + for _, tpl := range r.templates { |
| 74 | + err := r.getMetricsTemplate(ctx, tpl) |
| 75 | + if err != nil { |
| 76 | + return err |
| 77 | + } |
| 78 | + } |
| 79 | + return nil |
| 80 | +} |
| 81 | + |
| 82 | +func (r *chReceiver) getMetricsTemplate(ctx context.Context, tpl *template.Template) error { |
| 83 | + queryBuf := bytes.Buffer{} |
| 84 | + params := map[string]any{ |
| 85 | + "timestamp_ns": time.Now().UnixNano(), |
| 86 | + "timestamp_ms": time.Now().UnixMilli(), |
| 87 | + "timestamp_s": time.Now().Unix(), |
| 88 | + } |
| 89 | + err := tpl.Execute(&queryBuf, params) |
| 90 | + wrapErr := func(err error) error { |
| 91 | + return fmt.Errorf("failed to execute. Query: %s; error: %w", queryBuf.String(), err) |
| 92 | + } |
| 93 | + if err != nil { |
| 94 | + return wrapErr(err) |
| 95 | + } |
| 96 | + rows, err := r.db.Query(ctx, queryBuf.String()) |
| 97 | + if err != nil { |
| 98 | + return wrapErr(err) |
| 99 | + } |
| 100 | + defer rows.Close() |
| 101 | + for rows.Next() { |
| 102 | + var ( |
| 103 | + labels [][]string |
| 104 | + value float64 |
| 105 | + ) |
| 106 | + err = rows.Scan(&labels, &value) |
| 107 | + if err != nil { |
| 108 | + return wrapErr(err) |
| 109 | + } |
| 110 | + metrics := pmetric.NewMetrics() |
| 111 | + res := metrics.ResourceMetrics().AppendEmpty() |
| 112 | + res.Resource().Attributes() |
| 113 | + metric := res.ScopeMetrics().AppendEmpty().Metrics().AppendEmpty() |
| 114 | + data := metric.SetEmptyGauge().DataPoints().AppendEmpty() |
| 115 | + for _, label := range labels { |
| 116 | + if label[0] == "__name__" { |
| 117 | + metric.SetName(label[1]) |
| 118 | + continue |
| 119 | + } |
| 120 | + data.Attributes().PutStr(label[0], label[1]) |
| 121 | + } |
| 122 | + data.SetTimestamp(pcommon.NewTimestampFromTime(time.Now())) |
| 123 | + data.SetDoubleValue(value) |
| 124 | + select { |
| 125 | + case <-ctx.Done(): |
| 126 | + return nil |
| 127 | + default: |
| 128 | + err = r.consumer.ConsumeMetrics(ctx, metrics) |
| 129 | + if err != nil { |
| 130 | + return wrapErr(err) |
| 131 | + } |
| 132 | + } |
| 133 | + } |
| 134 | + return nil |
| 135 | +} |
| 136 | + |
| 137 | +func (r *chReceiver) Shutdown(_ context.Context) error { |
| 138 | + fmt.Println("shutting down") |
| 139 | + r.cancel() |
| 140 | + r.ticker.Stop() |
| 141 | + _ = r.db.Close() |
| 142 | + return nil |
| 143 | +} |
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