Merge pull request #31 from MichaelRuhwedel/fix/respect-metrics-temporality-preference

Author: dialupdisaster

README.md

@@ -90,6 +90,7 @@ All configuration is via environment variables. Set them in your shell profile (
 | `OPENCODE_DISABLE_METRICS` | _(unset)_ | Comma-separated list of metric name suffixes to disable (e.g. `cache.count,session.duration`) |
 | `OPENCODE_OTLP_HEADERS` | _(unset)_ | Comma-separated `key=value` headers added to all OTLP exports. **Keep out of version control — may contain sensitive auth tokens.** |
 | `OPENCODE_RESOURCE_ATTRIBUTES` | _(unset)_ | Comma-separated `key=value` pairs merged into the OTel resource. Example: `service.version=1.2.3,deployment.environment=production` |
+| `OPENCODE_OTLP_METRICS_TEMPORALITY` | _(unset)_ | Metrics aggregation temporality: `delta`, `cumulative`, or `lowmemory`. Required for Datadog (`delta`). Copied to `OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE`. |
 
 ### Quick start
 
@@ -150,10 +151,18 @@ export OPENCODE_DISABLE_METRICS="cache.count,session.duration,session.token.tota
 
 ```bash
 export OPENCODE_ENABLE_TELEMETRY=1
-export OPENCODE_OTLP_ENDPOINT=https://api.datadoghq.com
+export OPENCODE_OTLP_ENDPOINT=https://otlp.datadoghq.com
 export OPENCODE_OTLP_PROTOCOL=http/protobuf
+export OPENCODE_OTLP_HEADERS="dd-api-key=YOUR_DATADOG_API_KEY"
+
+# Required — Datadog's OTLP intake only accepts delta temporality
+export OPENCODE_OTLP_METRICS_TEMPORALITY=delta
 ```
 
+> **Note:** The endpoint is `otlp.datadoghq.com` (not `api.datadoghq.com`).
+> Use `otlp.datadoghq.eu` for EU, `otlp.us3.datadoghq.com` for US3, etc.
+> See [Datadog OTLP docs](https://docs.datadoghq.com/opentelemetry/setup/otlp_ingest_in_the_agent/) for all regions.
+
 ### Honeycomb example
 
 ```bash

src/config.ts

@@ -1,5 +1,10 @@
 import { LEVELS, type Level } from "./types.ts"
 
+/** Accepted values for `OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE`. */
+export type MetricsTemporality = "cumulative" | "delta" | "lowmemory"
+
+const VALID_TEMPORALITIES: ReadonlySet<MetricsTemporality> = new Set<MetricsTemporality>(["cumulative", "delta", "lowmemory"])
+
 /** Configuration values resolved from `OPENCODE_*` environment variables. */
 export type PluginConfig = {
   enabled: boolean
@@ -10,6 +15,7 @@ export type PluginConfig = {
   metricPrefix: string
   otlpHeaders: string | undefined
   resourceAttributes: string | undefined
+  metricsTemporality: MetricsTemporality | undefined
   disabledMetrics: Set<string>
   disabledTraces: Set<string>
 }
@@ -25,15 +31,31 @@ export function parseEnvInt(key: string, fallback: number): number {
 
 /**
  * Reads all `OPENCODE_*` environment variables and returns the resolved plugin config.
- * Copies `OPENCODE_OTLP_HEADERS` → `OTEL_EXPORTER_OTLP_HEADERS` and
- * `OPENCODE_RESOURCE_ATTRIBUTES` → `OTEL_RESOURCE_ATTRIBUTES` so the OTel SDK
- * picks them up automatically when initialised.
+ * Copies `OPENCODE_OTLP_HEADERS` → `OTEL_EXPORTER_OTLP_HEADERS`,
+ * `OPENCODE_RESOURCE_ATTRIBUTES` → `OTEL_RESOURCE_ATTRIBUTES`, and
+ * `OPENCODE_OTLP_METRICS_TEMPORALITY` → `OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE`
+ * so the OTel SDK picks them up automatically when initialised.
  */
 export function loadConfig(): PluginConfig {
   const otlpHeaders = process.env["OPENCODE_OTLP_HEADERS"]
   const resourceAttributes = process.env["OPENCODE_RESOURCE_ATTRIBUTES"]
+  const rawTemporality = process.env["OPENCODE_OTLP_METRICS_TEMPORALITY"]
   const protocol = process.env["OPENCODE_OTLP_PROTOCOL"]
 
+  let metricsTemporality: MetricsTemporality | undefined
+  if (rawTemporality) {
+    const normalized = rawTemporality.toLowerCase()
+    if (VALID_TEMPORALITIES.has(normalized as MetricsTemporality)) {
+      metricsTemporality = normalized as MetricsTemporality
+      process.env["OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE"] = normalized
+    } else {
+      console.warn(
+        `[opencode-plugin-otel] Invalid OPENCODE_OTLP_METRICS_TEMPORALITY="${rawTemporality}". ` +
+          `Expected one of: cumulative, delta, lowmemory. Value ignored.`,
+      )
+    }
+  }
+
   if (otlpHeaders) process.env["OTEL_EXPORTER_OTLP_HEADERS"] = otlpHeaders
   if (resourceAttributes) process.env["OTEL_RESOURCE_ATTRIBUTES"] = resourceAttributes
 
@@ -60,6 +82,7 @@ export function loadConfig(): PluginConfig {
     metricPrefix: process.env["OPENCODE_METRIC_PREFIX"] ?? "opencode.",
     otlpHeaders,
     resourceAttributes,
+    metricsTemporality,
     disabledMetrics,
     disabledTraces,
   }

tests/config.test.ts

@@ -49,10 +49,12 @@ describe("loadConfig", () => {
     "OPENCODE_OTLP_LOGS_INTERVAL",
     "OPENCODE_OTLP_HEADERS",
     "OPENCODE_RESOURCE_ATTRIBUTES",
+    "OPENCODE_OTLP_METRICS_TEMPORALITY",
     "OPENCODE_DISABLE_METRICS",
     "OPENCODE_DISABLE_TRACES",
     "OTEL_EXPORTER_OTLP_HEADERS",
     "OTEL_RESOURCE_ATTRIBUTES",
+    "OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE",
   ]
   beforeEach(() => vars.forEach((k) => delete process.env[k]))
   afterEach(() => vars.forEach((k) => delete process.env[k]))
@@ -120,6 +122,43 @@ describe("loadConfig", () => {
     expect(process.env["OTEL_EXPORTER_OTLP_HEADERS"]).toBeUndefined()
   })
 
+  test("copies OPENCODE_OTLP_METRICS_TEMPORALITY to OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE", () => {
+    process.env["OPENCODE_OTLP_METRICS_TEMPORALITY"] = "delta"
+    const cfg = loadConfig()
+    expect(process.env["OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE"]).toBe("delta")
+    expect(cfg.metricsTemporality).toBe("delta")
+  })
+
+  test("does not set OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE when OPENCODE_OTLP_METRICS_TEMPORALITY is unset", () => {
+    delete process.env["OPENCODE_OTLP_METRICS_TEMPORALITY"]
+    const cfg = loadConfig()
+    expect(process.env["OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE"]).toBeUndefined()
+    expect(cfg.metricsTemporality).toBeUndefined()
+  })
+
+  test("normalizes OPENCODE_OTLP_METRICS_TEMPORALITY to lowercase", () => {
+    process.env["OPENCODE_OTLP_METRICS_TEMPORALITY"] = "Delta"
+    const cfg = loadConfig()
+    expect(process.env["OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE"]).toBe("delta")
+    expect(cfg.metricsTemporality).toBe("delta")
+  })
+
+  test("ignores invalid OPENCODE_OTLP_METRICS_TEMPORALITY and warns", () => {
+    const warnings: string[] = []
+    const origWarn = console.warn
+    console.warn = (...args: unknown[]) => warnings.push(String(args[0]))
+    try {
+      process.env["OPENCODE_OTLP_METRICS_TEMPORALITY"] = "bogus"
+      const cfg = loadConfig()
+      expect(process.env["OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE"]).toBeUndefined()
+      expect(cfg.metricsTemporality).toBeUndefined()
+      expect(warnings.length).toBe(1)
+      expect(warnings[0]).toContain("bogus")
+    } finally {
+      console.warn = origWarn
+    }
+  })
+
   test("does not overwrite pre-existing OTEL_* vars when OPENCODE_* vars are unset", () => {
     process.env["OTEL_EXPORTER_OTLP_HEADERS"] = "existing-header=value"
     process.env["OTEL_RESOURCE_ATTRIBUTES"] = "existing=attr"