openclaw-grafana-lens/dist/src/services/otlp-json-writer.js

OpenClaw plugin that gives AI agents full Grafana access — 18 composable tools for PromQL/LogQL/TraceQL queries, dashboard creation, alerting, SRE investigation, security monitoring, data collection pipeline management via Grafana Alloy (29 recipes), and

/**
 * OTLP JSON Writer
 *
 * Constructs OTLP ExportMetricsServiceRequest payloads as JSON with custom
 * timestamps and POSTs them to the OTLP HTTP endpoint. This bypasses the
 * OTel SDK (which doesn't expose timestamp control) while using the same
 * wire protocol and collector endpoint.
 *
 * Data flow:
 *   TimestampedSample[] → OTLP JSON (gauge dataPoints with timeUnixNano)
 *     → POST to :4318/v1/metrics → OTel Collector → Mimir → Grafana
 */
// ── Writer ───────────────────────────────────────────────────────────
export class OtlpJsonWriter {
    endpoint;
    headers;
    constructor(config) {
        this.endpoint = config.endpoint;
        this.headers = config.headers ?? {};
    }
    async write(samples) {
        if (samples.length === 0)
            return;
        const payload = this.buildPayload(samples);
        const res = await fetch(this.endpoint, {
            method: "POST",
            headers: {
                "Content-Type": "application/json",
                ...this.headers,
            },
            body: JSON.stringify(payload),
        });
        if (!res.ok) {
            const body = await res.text().catch(() => "");
            throw new Error(`OTLP push failed (HTTP ${res.status}): ${body || res.statusText}`);
        }
    }
    /** Visible for testing. */
    buildPayload(samples) {
        // Group samples by metric name
        const grouped = new Map();
        for (const s of samples) {
            let group = grouped.get(s.metricName);
            if (!group) {
                group = [];
                grouped.set(s.metricName, group);
            }
            group.push(s);
        }
        const metrics = [];
        for (const [name, group] of grouped) {
            metrics.push({
                name,
                description: group[0].description ?? "Custom metric",
                gauge: {
                    dataPoints: group.map((s) => ({
                        timeUnixNano: msToNanoString(s.timestampMs),
                        asDouble: s.value,
                        attributes: labelsToAttributes(s.labels),
                    })),
                },
            });
        }
        return {
            resourceMetrics: [
                {
                    resource: {
                        attributes: [
                            { key: "service.name", value: { stringValue: "openclaw" } },
                            { key: "service.namespace", value: { stringValue: "grafana-lens" } },
                        ],
                    },
                    scopeMetrics: [
                        {
                            scope: { name: "grafana-lens-custom" },
                            metrics,
                        },
                    ],
                },
            ],
        };
    }
}
// ── Helpers ──────────────────────────────────────────────────────────
/** Convert millisecond timestamp to nanosecond string (avoids Number overflow). */
export function msToNanoString(ms) {
    return `${ms}000000`;
}
export function labelsToAttributes(labels) {
    return Object.entries(labels).map(([key, val]) => ({
        key,
        value: { stringValue: val },
    }));
}