otel-ottl

# OpenTelemetry Transformation Language (OTTL) ## Components that use OTTL OTTL is not limited to the transform and filter processors. Processors (transform, filter, attributes, span, tailsampling, cumulativetodelta, logdedup, lookup), connectors (routing, count, sum, signaltometrics), and the hostmetrics receiver all accept OTTL expressions. See [components](./rules/components.md) for the full list with use cases. ## OTTL syntax ### Path expressions Navigate telemetry data using dot notation: ``` span.name span.attributes["http.method"] resource.attributes["service.name"] ``` **Contexts** (first path segment): `resource`, `scope`, `span`, `spanevent`, `metric`, `datapoint`, `log`. ### Enumerations Use int64 constants for enumeration fields: ``` span.status.code == STATUS_CODE_ERROR span.kind == SPAN_KIND_SERVER ``` ### Operators Assignment: `=` — Comparison: `==`, `!=`, `>`, `<`, `>=`, `<=` — Logical: `and`, `or`, `not` ### Functions **Converters** (uppercase, return values): ``` ToUpperCase(span.attributes["http.request.method"]) Substring(log.body.string, 0, 1024) Concat(["prefix", span.attributes["request.id"]], "-") IsMatch(metric.name, "^k8s\\..*$") ``` **Editors** (lowercase, modify data in-place): ``` set(span.attributes["region"], "us-east-1") delete_key(resource.attributes, "internal.key") limit(log.attributes, 10, []) ``` See [function-reference](./rules/function-reference.md) for the full list of editors and converters. ### Conditional statement...