| 1 | /** |
| 2 | * What each app on g1t.page carries for observability (services/telemetry), |
| 3 | * set as it is uploaded: |
| 4 | * |
| 5 | * - the telemetry service as its Tail Worker, so every request it answers |
| 6 | * arrives there with its logs and exceptions; |
| 7 | * - tags naming its project and deployment, which arrive with each event; |
| 8 | * - OpenTelemetry's standard variables, so an SDK in the app sends spans, |
| 9 | * logs and metrics to the project without configuration: the endpoint, |
| 10 | * the project's deployments token, the service's name and a resource |
| 11 | * naming the environment, deployment and commit. A variable the project |
| 12 | * sets itself wins: an app can send elsewhere. |
| 13 | * - under its hostname in `DOMAINS`, what the dispatcher writes on each |
| 14 | * request's line, so requests a site's files answered are filed too. |
| 15 | */ |
| 16 | import { TELEMETRY_OTLP_ENDPOINT, TELEMETRY_TAG } from "@g1t/contracts/telemetry"; |
| 17 | |
| 18 | /** The telemetry service's Worker, named as each app's Tail Worker. */ |
| 19 | export const TELEMETRY_WORKER = "g1t-telemetry"; |
| 20 | |
| 21 | export const TAIL_CONSUMERS = [{ service: TELEMETRY_WORKER }]; |
| 22 | |
| 23 | export function telemetryTags(projectId: string, deploymentId: string): string[] { |
| 24 | return [`${TELEMETRY_TAG.project}${projectId}`, `${TELEMETRY_TAG.deployment}${deploymentId}`]; |
| 25 | } |
| 26 | |
| 27 | export type AppTelemetry = { |
| 28 | project: string; |
| 29 | deployment: string; |
| 30 | environment: string; |
| 31 | service: string; |
| 32 | commit: string | null; |
| 33 | }; |
| 34 | |
| 35 | type Runtime = { secrets: Record<string, string>; variables: Record<string, string> }; |
| 36 | |
| 37 | /** OpenTelemetry's resource attributes, written as its variable takes them. */ |
| 38 | export function resourceAttributes(app: AppTelemetry): string { |
| 39 | const pairs: [string, string][] = [ |
| 40 | ["deployment.environment.name", app.environment], |
| 41 | ["g1t.deployment.id", app.deployment], |
| 42 | ["g1t.project.id", app.project], |
| 43 | ]; |
| 44 | if (app.commit) pairs.push(["vcs.ref.head.revision", app.commit]); |
| 45 | return pairs.map(([k, v]) => `${k}=${encodeURIComponent(v)}`).join(","); |
| 46 | } |
| 47 | |
| 48 | /** The app's runtime with OpenTelemetry's variables added, where the project set none of its own. */ |
| 49 | export function withOtel(runtime: Runtime, app: AppTelemetry, token: string | null): Runtime { |
| 50 | const has = (name: string) => name in runtime.variables || name in runtime.secrets; |
| 51 | const variables = { ...runtime.variables }; |
| 52 | const secrets = { ...runtime.secrets }; |
| 53 | // An app the project points elsewhere is left to it, whole. |
| 54 | if (has("OTEL_EXPORTER_OTLP_ENDPOINT") || !token) return runtime; |
| 55 | variables.OTEL_EXPORTER_OTLP_ENDPOINT = TELEMETRY_OTLP_ENDPOINT; |
| 56 | if (!has("OTEL_EXPORTER_OTLP_PROTOCOL")) variables.OTEL_EXPORTER_OTLP_PROTOCOL = "http/json"; |
| 57 | if (!has("OTEL_SERVICE_NAME")) variables.OTEL_SERVICE_NAME = app.service; |
| 58 | const resource = resourceAttributes(app); |
| 59 | variables.OTEL_RESOURCE_ATTRIBUTES = runtime.variables.OTEL_RESOURCE_ATTRIBUTES ? `${resource},${runtime.variables.OTEL_RESOURCE_ATTRIBUTES}` : resource; |
| 60 | if (!has("OTEL_EXPORTER_OTLP_HEADERS")) secrets.OTEL_EXPORTER_OTLP_HEADERS = `authorization=Bearer ${token}`; |
| 61 | return { variables, secrets }; |
| 62 | } |