OpenTelemetry Collector Service

How to provide configuration?

The --config flag accepts either a file path or values in the form of a config URI "<scheme>:<opaque_data>". Currently, the OpenTelemetry Collector supports the following providers scheme:

• file - Reads configuration from a file. E.g. file:path/to/config.yaml.
• env - Reads configuration from an environment variable. E.g. env:MY_CONFIG_IN_AN_ENVVAR.
• yaml - Reads configuration from yaml bytes. E.g. yaml:exporters::debug::verbosity: detailed.
• http - Reads configuration from a HTTP URI. E.g. http://www.example.com

For more technical details about how configuration is resolved you can read the configuration resolving design.

Single Config Source

1. Simple local file:

   ./otelcorecol --config=examples/local/otel-config.yaml

2. Simple local file using the new URI format:

   ./otelcorecol --config=file:examples/local/otel-config.yaml

3. Config provided via an environment variable:

   ./otelcorecol --config=env:MY_CONFIG_IN_AN_ENVVAR

Multiple Config Sources

1. Merge a otel-config.yaml file with the content of an environment variable MY_OTHER_CONFIG and use the merged result as the config:

   ./otelcorecol --config=file:examples/local/otel-config.yaml --config=env:MY_OTHER_CONFIG

2. Merge a config.yaml file with the content of a yaml bytes configuration (overwrites the exporters::debug::verbosity config) and use the content as the config:

   ./otelcorecol --config=file:examples/local/otel-config.yaml --config="yaml:exporters::debug::verbosity: normal"

Embedding other configuration providers

One configuration provider can also make references to other config providers, like the following:

receivers:
  otlp:
    protocols:
      grpc:

exporters: ${file:otlp-exporter.yaml}

service:
  extensions: [ ]
  pipelines:
    traces:
      receivers:  [ otlp ]
      processors: [  ]
      exporters:  [ otlp ]

How to override config properties?

The --set flag allows to set arbitrary config property. The --set values are merged into the final configuration after all the sources specified by the --config are resolved and merged.

The Format and Limitations of --set

Simple property

The --set option takes always one key/value pair, and it is used like this: --set key=value. The YAML equivalent of that is:

key: value

Complex nested keys

Use dot (.) in the pair's name as key separator to reference nested map values. For example, --set outer.inner=value is translated into this:

outer:
  inner: value

Multiple values

To set multiple values specify multiple --set flags, so --set a=b --set c=d becomes:

a: b
c: d

Array values

Arrays can be expressed by enclosing values in []. For example, --set "key=[a, b, c]" translates to:

key:
  - a
  - b
  - c

Map values

Maps can be expressed by enclosing values in {}. For example, "--set "key={a: c}" translates to:

key:
  a: c

Limitations

1. Does not support setting a key that contains a dot ..
2. Does not support setting a key that contains a equal sign =.
3. The configuration key separator inside the value part of the property is “::”. For example --set "name={a::b: c}" is equivalent with --set name.a.b=c.

How to check components available in a distribution

Use the sub command build-info. Below is an example:

   ./otelcorecol components

Sample output:

buildinfo:
   command: otelcorecol
   description: Local OpenTelemetry Collector binary, testing only.
   version: 0.62.1-dev
receivers:
   - otlp
processors:
   - memory_limiter
   - batch
exporters:
   - otlp
   - otlphttp
   - debug
extensions:
   - zpages

How to validate configuration file and return all errors without running collector

   ./otelcorecol validate --config=file:examples/local/otel-config.yaml