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OpenTelemetry

Terragrunt can be configured to emit telemetry in OpenTelemetry format, traces and metrics.

OpenTelemetry tracing is frequently used in Terragrunt to collect traces to analyze performance. For more details on analyzing and optimizing performance, read the dedicated Performance documentation.

High-level overview

The following are concepts and technologies that are important to be aware of when using OpenTelemetry with Terragrunt.

Tracing configuration:

  • TG_TELEMETRY_TRACE_EXPORTER - traces exporter type to be used. Currently supported values are:
    • none - no trace exporting, default value.
    • console - to export traces to console as JSON
    • otlpHttp - to export traces to an OpenTelemetry collector over HTTP otlptracehttp
    • otlpGrpc - to export traces over gRPC otlptracegrpc
    • http - to export traces to a custom HTTP endpoint using otlptracehttp
  • TG_TELEMETRY_TRACE_EXPORTER_HTTP_ENDPOINT - in case of http exporter, this is the endpoint to which traces will be sent.
  • TG_TELEMETRY_TRACE_EXPORTER_INSECURE_ENDPOINT - if set to true, the exporter will not validate the server’s certificate, helpful for local traces collection.
  • TRACEPARENT - if set, the value will be used as a parent trace context, format TRACEPARENT=00-<hex_trace_id>-<hex_span_id>-<trace_flags>, example: TRACEPARENT=00-xxx-yyy-01

Metrics configuration:

  • TG_TELEMETRY_METRIC_EXPORTER - metrics exporter type to be used. Currently supported values are:
    • none - no metric exporting, default value.
    • console - write metrics to console as JSONs.
    • otlpHttp - export metrics to an OpenTelemetry collector over HTTP otlpmetrichttp
    • grpcHttp - export metrics to an OpenTelemetry collector over gRPC otlpmetricgrpc
  • TG_TELEMETRY_METRIC_EXPORTER_INSECURE_ENDPOINT - if set to true, the exporter will not validate the server’s certificate, helpful for local metrics collection.

Example configurations for trace collection

Collection of examples how to configure Terragrunt to emit traces and metrics in OpenTelemetry format.

Example traces collection with Jaeger

  • Start a Jaeger instance with docker:
Terminal window
docker run --rm --name jaeger -e COLLECTOR_OTLP_ENABLED=true -p 16686:16686 -p 4317:4317 -p 4318:4318 jaegertracing/all-in-one:1.54.0
  • Verify that UI is available at http://localhost:16686/
  • Define environment variables for Terragrunt to report traces to Jaeger:
Terminal window
export TG_TELEMETRY_TRACE_EXPORTER=http
export TG_TELEMETRY_TRACE_EXPORTER_HTTP_ENDPOINT=localhost:4318
export TG_TELEMETRY_TRACE_EXPORTER_INSECURE_ENDPOINT=true
  • Run terragrunt
  • Verify that traces are available in Jaeger UI

Configurations to collect traces in Grafana Tempo

  • Start a Grafana Tempo instance example
  • Define environment variables for Terragrunt to report traces to Tempo:
Terminal window
export TG_TELEMETRY_TRACE_EXPORTER=otlpHttp
# Replace with your tempo instance
export OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4318
export TG_TELEMETRY_TRACE_EXPORTER_INSECURE_ENDPOINT=true
  • Run terragrunt
  • Check for traces in Tempo UI for service “terragrunt”

Example traces collection in console

  • Set env variable to enable telemetry:
Terminal window
export TG_TELEMETRY_TRACE_EXPORTER=console
  • Run terragrunt
  • Check produced traces in console, like:
{"Name":"run_bash","SpanContext":{"TraceID":"bdf3cb9078706b7f0b4f1d92428eedc0","SpanID":"f91587247524593b","TraceFlags":"01","TraceState":"","Remote":false},"Parent":{"TraceID":"bdf3cb9078706b7f0b4f1d92428eedc0","SpanID":"b0b007770f852066","TraceFlags":"01","TraceState":"","Remote":false},"SpanKind":1,"StartTime":"2024-02-08T12:32:30.564217484Z","EndTime":"2024-02-08T12:32:31.570666395Z","Attributes":[{"Key":"command","Value":{"Type":"STRING","Value":"bash"}},{"Key":"args","Value":{"Type":"STRING","Value":"[-c sleep 1]"}},{"Key":"dir","Value":{"Type":"STRING","Value":"/projects/gruntwork/terragrunt-tests/trace-test/mod2"}}],"Events":null,"Links":null,"Status":{"Code":"Unset","Description":""},"DroppedAttributes":0,"DroppedEvents":0,"DroppedLinks":0,"ChildSpanCount":0,"Resource":[{"Key":"service.name","Value":{"Type":"STRING","Value":"terragrunt"}},{"Key":"service.version","Value":{"Type":"STRING","Value":"v0.55.0-29-g66bfa07b756e-dirty"}},{"Key":"telemetry.sdk.language","Value":{"Type":"STRING","Value":"go"}},{"Key":"telemetry.sdk.name","Value":{"Type":"STRING","Value":"opentelemetry"}},{"Key":"telemetry.sdk.version","Value":{"Type":"STRING","Value":"1.23.0"}}],"InstrumentationLibrary":{"Name":"terragrunt","Version":"","SchemaURL":""}}
{"Name":"parse_config_file","SpanContext":{"TraceID":"bdf3cb9078706b7f0b4f1d92428eedc0","SpanID":"d2823047fb469bdf","TraceFlags":"01","TraceState":"","Remote":false},"Parent":{"TraceID":"bdf3cb9078706b7f0b4f1d92428eedc0","SpanID":"b0b007770f852066","TraceFlags":"01","TraceState":"","Remote":false},"SpanKind":1,"StartTime":"2024-02-08T12:32:30.380054129Z","EndTime":"2024-02-08T12:32:31.570899286Z","Attributes":[{"Key":"config_path","Value":{"Type":"STRING","Value":"/projects/gruntwork/terragrunt-tests/trace-test/mod2/terragrunt.hcl"}}],"Events":null,"Links":null,"Status":{"Code":"Unset","Description":""},"DroppedAttributes":0,"DroppedEvents":0,"DroppedLinks":0,"ChildSpanCount":0,"Resource":[{"Key":"service.name","Value":{"Type":"STRING","Value":"terragrunt"}},{"Key":"service.version","Value":{"Type":"STRING","Value":"v0.55.0-29-g66bfa07b756e-dirty"}},{"Key":"telemetry.sdk.language","Value":{"Type":"STRING","Value":"go"}},{"Key":"telemetry.sdk.name","Value":{"Type":"STRING","Value":"opentelemetry"}},{"Key":"telemetry.sdk.version","Value":{"Type":"STRING","Value":"1.23.0"}}],"InstrumentationLibrary":{"Name":"terragrunt","Version":"","SchemaURL":""}}
{"Name":"run_terraform","SpanContext":{"TraceID":"bdf3cb9078706b7f0b4f1d92428eedc0","SpanID":"152d873a18559f07","TraceFlags":"01","TraceState":"","Remote":false},"Parent":{"TraceID":"bdf3cb9078706b7f0b4f1d92428eedc0","SpanID":"b0b007770f852066","TraceFlags":"01","TraceState":"","Remote":false},"SpanKind":1,"StartTime":"2024-02-08T12:32:31.57161757Z","EndTime":"2024-02-08T12:32:31.688157882Z","Attributes":[{"Key":"command","Value":{"Type":"STRING","Value":"tofu"}},{"Key":"args","Value":{"Type":"STRING","Value":"[init]"}},{"Key":"dir","Value":{"Type":"STRING","Value":"/projects/gruntwork/terragrunt-tests/trace-test/mod2"}}],"Events":null,"Links":null,"Status":{"Code":"Unset","Description":""},"DroppedAttributes":0,"DroppedEvents":0,"DroppedLinks":0,"ChildSpanCount":0,"Resource":[{"Key":"service.name","Value":{"Type":"STRING","Value":"terragrunt"}},{"Key":"service.version","Value":{"Type":"STRING","Value":"v0.55.0-29-g66bfa07b756e-dirty"}},{"Key":"telemetry.sdk.language","Value":{"Type":"STRING","Value":"go"}},{"Key":"telemetry.sdk.name","Value":{"Type":"STRING","Value":"opentelemetry"}},{"Key":"telemetry.sdk.version","Value":{"Type":"STRING","Value":"1.23.0"}}],"InstrumentationLibrary":{"Name":"terragrunt","Version":"","SchemaURL":""}}
{"Name":"run_terraform","SpanContext":{"TraceID":"bdf3cb9078706b7f0b4f1d92428eedc0","SpanID":"29341bdb65f66b1e","TraceFlags":"01","TraceState":"","Remote":false},"Parent":{"TraceID":"bdf3cb9078706b7f0b4f1d92428eedc0","SpanID":"b0b007770f852066","TraceFlags":"01","TraceState":"","Remote":false},"SpanKind":1,"StartTime":"2024-02-08T12:32:31.688240673Z","EndTime":"2024-02-08T12:32:31.793377642Z","Attributes":[{"Key":"command","Value":{"Type":"STRING","Value":"tofu"}},{"Key":"args","Value":{"Type":"STRING","Value":"[apply -auto-approve -input=false]"}},{"Key":"dir","Value":{"Type":"STRING","Value":"/projects/gruntwork/terragrunt-tests/trace-test/mod2"}}],"Events":null,"Links":null,"Status":{"Code":"Unset","Description":""},"DroppedAttributes":0,"DroppedEvents":0,"DroppedLinks":0,"ChildSpanCount":0,"Resource":[{"Key":"service.name","Value":{"Type":"STRING","Value":"terragrunt"}},{"Key":"service.version","Value":{"Type":"STRING","Value":"v0.55.0-29-g66bfa07b756e-dirty"}},{"Key":"telemetry.sdk.language","Value":{"Type":"STRING","Value":"go"}},{"Key":"telemetry.sdk.name","Value":{"Type":"STRING","Value":"opentelemetry"}},{"Key":"telemetry.sdk.version","Value":{"Type":"STRING","Value":"1.23.0"}}],"InstrumentationLibrary":{"Name":"terragrunt","Version":"","SchemaURL":""}}
{"Name":"run_module","SpanContext":{"TraceID":"bdf3cb9078706b7f0b4f1d92428eedc0","SpanID":"8a01522bc65e0f1b","TraceFlags":"01","TraceState":"","Remote":false},"Parent":{"TraceID":"bdf3cb9078706b7f0b4f1d92428eedc0","SpanID":"b0b007770f852066","TraceFlags":"01","TraceState":"","Remote":false},"SpanKind":1,"StartTime":"2024-02-08T12:32:30.290680776Z","EndTime":"2024-02-08T12:32:31.793392803Z","Attributes":[{"Key":"path","Value":{"Type":"STRING","Value":"/projects/gruntwork/terragrunt-tests/trace-test/mod2"}},{"Key":"terraformCommand","Value":{"Type":"STRING","Value":"apply"}}],"Events":null,"Links":null,"Status":{"Code":"Unset","Description":""},"DroppedAttributes":0,"DroppedEvents":0,"DroppedLinks":0,"ChildSpanCount":0,"Resource":[{"Key":"service.name","Value":{"Type":"STRING","Value":"terragrunt"}},{"Key":"service.version","Value":{"Type":"STRING","Value":"v0.55.0-29-g66bfa07b756e-dirty"}},{"Key":"telemetry.sdk.language","Value":{"Type":"STRING","Value":"go"}},{"Key":"telemetry.sdk.name","Value":{"Type":"STRING","Value":"opentelemetry"}},{"Key":"telemetry.sdk.version","Value":{"Type":"STRING","Value":"1.23.0"}}],"InstrumentationLibrary":{"Name":"terragrunt","Version":"","SchemaURL":""}}
{"Name":"run-all apply","SpanContext":{"TraceID":"bdf3cb9078706b7f0b4f1d92428eedc0","SpanID":"b0b007770f852066","TraceFlags":"01","TraceState":"","Remote":false},"Parent":{"TraceID":"00000000000000000000000000000000","SpanID":"0000000000000000","TraceFlags":"00","TraceState":"","Remote":false},"SpanKind":1,"StartTime":"2024-02-08T12:32:26.388519019Z","EndTime":"2024-02-08T12:32:31.793405603Z","Attributes":[{"Key":"terraformCommand","Value":{"Type":"STRING","Value":"apply"}},{"Key":"args","Value":{"Type":"STRING","Value":"[apply]"}},{"Key":"dir","Value":{"Type":"STRING","Value":"/projects/gruntwork/terragrunt-tests/trace-test"}}],"Events":null,"Links":null,"Status":{"Code":"Unset","Description":""},"DroppedAttributes":0,"DroppedEvents":0,"DroppedLinks":0,"ChildSpanCount":28,"Resource":[{"Key":"service.name","Value":{"Type":"STRING","Value":"terragrunt"}},{"Key":"service.version","Value":{"Type":"STRING","Value":"v0.55.0-29-g66bfa07b756e-dirty"}},{"Key":"telemetry.sdk.language","Value":{"Type":"STRING","Value":"go"}},{"Key":"telemetry.sdk.name","Value":{"Type":"STRING","Value":"opentelemetry"}},{"Key":"telemetry.sdk.version","Value":{"Type":"STRING","Value":"1.23.0"}}],"InstrumentationLibrary":{"Name":"terragrunt","Version":"","SchemaURL":""}}

Collection of metrics with OpenTelemetry collector and Prometheus

  • Start OpenTelemetry collector with Prometheus receiver.

    Example setup through docker-compose.yml:

    version: '3'
    services:
      otel-collector:
        image: otel/opentelemetry-collector:0.94.0
        volumes:
          - ./otel-collector-config.yaml:/etc/otelcol/config.yaml
        ports:
          - "4317:4317" # OTLP gRPC receiver
          - "4318:4318" # OTLP HTTP receiver
          - "8889:8889" # Prometheus exporter
      prometheus:
        image: prom/prometheus:v2.45.3
        volumes:
          - ./prometheus.yml:/etc/prometheus/prometheus.yml
        ports:
          - "9090:9090"
        depends_on:
          - otel-collector

OpenTelemetry collector configuration otel-collector-config.yaml:

receivers:
  otlp:
    protocols:
      grpc:
      http:
processors:
  batch:
exporters:
  prometheus:
    endpoint: "0.0.0.0:8889" # Prometheus exporter endpoint
service:
  pipelines:
    metrics:
      receivers: [otlp]
      processors: [batch]
      exporters: [prometheus]

Prometheus configuration file prometheus.yml:

global:
  scrape_interval: 15s
scrape_configs:
  - job_name: 'opentelemetry'
    scrape_interval: 5s
    static_configs:
      - targets: ['otel-collector:8889']
  • Confirm that Prometheus is available at http://localhost:9090/
  • Define environment variables for Terragrunt to report metrics to OpenTelemetry collector:
Terminal window
export TG_TELEMETRY_METRIC_EXPORTER=grpcHttp
export TG_TELEMETRY_METRIC_EXPORTER_INSECURE_ENDPOINT=true
export OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4317
  • Run terragrunt
  • Verify that metrics are available in Prometheus UI

Example configuration to export metrics to console:

  • Set env variable to enable telemetry:
Terminal window
export TG_TELEMETRY_METRIC_EXPORTER=console
  • Run terragrunt
  • In output will be printed messages like:
{"Resource":[{"Key":"service.name","Value":{"Type":"STRING","Value":"terragrunt"}},{"Key":"service.version","Value":{"Type":"STRING","Value":"v0.55.0-41-g7185318bb11b"}},{"Key":"telemetry.sdk.language","Value":{"Type":"STRING","Value":"go"}},{"Key":"telemetry.sdk.name","Value":{"Type":"STRING","Value":"opentelemetry"}},{"Key":"telemetry.sdk.version","Value":{"Type":"STRING","Value":"1.23.1"}}],"ScopeMetrics":[]}
{"Resource":[{"Key":"service.name","Value":{"Type":"STRING","Value":"terragrunt"}},{"Key":"service.version","Value":{"Type":"STRING","Value":"v0.55.0-41-g7185318bb11b"}},{"Key":"telemetry.sdk.language","Value":{"Type":"STRING","Value":"go"}},{"Key":"telemetry.sdk.name","Value":{"Type":"STRING","Value":"opentelemetry"}},{"Key":"telemetry.sdk.version","Value":{"Type":"STRING","Value":"1.23.1"}}],"ScopeMetrics":[{"Scope":{"Name":"terragrunt","Version":"","SchemaURL":""},"Metrics":[{"Name":"run_bash_duration","Description":"","Unit":"","Data":{"DataPoints":[{"Attributes":[{"Key":"args","Value":{"Type":"STRING","Value":"[-c sleep 2]"}},{"Key":"command","Value":{"Type":"STRING","Value":"bash"}},{"Key":"dir","Value":{"Type":"STRING","Value":"/projects/gruntwork/terragrunt-tests/trace-test/mod3"}}],"StartTime":"2024-02-12T14:38:14.85578658Z","Time":"2024-02-12T14:38:17.853165589Z","Count":1,"Bounds":[0,5,10,25,50,75,100,250,500,750,1000,2500,5000,7500,10000],"BucketCounts":[0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0],"Min":2005,"Max":2005,"Sum":2005}],"Temporality":"CumulativeTemporality"}},{"Name":"run_bash_success_count","Description":"","Unit":"","Data":{"DataPoints":[{"Attributes":[],"StartTime":"2024-02-12T14:38:16.860878555Z","Time":"2024-02-12T14:38:17.853169359Z","Value":1}],"Temporality":"CumulativeTemporality","IsMonotonic":true}}]}]}