validator

OpenTelemetry SDK Configuration Validator

This application will replace environment variables in values of valid yaml files, following the rules of file configuration environment variable substitution, before validating that result against a version of the OpenTelemetry SDK Configuration schema and optionally outputting to a yaml or json file.

NOTE: All make commands are run from the root of the repository.

Build

Requirements:

• Go 1.20 or above

The schema directory is required to be in the directory of the Go file that embeds it, so a go build alone will fail, instead run make which will copy the schema:

$ make validator

Same is true for building the docker image:

$ make validator-docker-image

The schema in the schema directory is the default that will be used when running the validator. To use a different schema a directory containing the schema can be passed with -s/--schema.

Usage

The command otel_config_validator takes one argument, the path to the yaml file and optionally the path to a file to output the configuration after environment variable expansion and validation has been done. The format (json or yaml) of the output is based on the extension (.json or yml/.yaml) of the output file name.

$ ./otel_config_validator -o out.json ../examples/sdk-config.yaml

The docker image creates a directory /opt/otel_config_validator and sets it to the WORKDIR, meaning you can mount your current directory to /opt/otel_config_validator and then read/write from ./ in the arguments to docker run:

$ docker run -v $(pwd):/opt/otel_config_validator otel_config_validator:current -o out.yaml examples/sdk-config.yaml

With the above docker command the output file, out.yaml, will be owned by root:root but be readable by any user.

Environment variable substitution is supported with the syntax ${VARIABLE} or ${env:VARIABLE}. Default values are supported in the form ${VARIABLE:-default}. The full specification for variable substitution can be found in the opentelemetry-specification.

Using a Different Schema Version

To use a version of of the schema other than the one builtin to the otel_config_validator executable pass the -s <directory> option:

$ ./otel_config_validator -o out.json -s .../some/path/opentelemetry-configuration-0.1.0/ ../examples/sdk-config.yaml

Testing

Run the Go unit tests:

$ go test .

Running the tests of the compiled CLI requires shelltest, jq and yq and setting the $PATH to include otel_config_validator, but you can just use the Makefile target validator-run-shelltests to run them in Docker:

$ make validator-run-shelltests

Releasing

To release a new version of otel_config_validator the version in dist.toml and the Version property of cli.Comamnd in main.go must be bumped. Next, a tag prefixed with validator- must be created and pushed to the repository, for example validator-0.1.0. Then, the cargo-dist Github Action will create a Github release, build binaries for multiple platforms and publish them to the new release.

Docker image are published on merge to main.