Getting Started

Check Types

Checkers provides two main types of checks, built-in and custom. Built-in checks are pre-defined checks that are included in the library, while custom checks allow you to write your own checks using any programming language.

Built-in Library Checks

Checkers comes with several built-in checks for common development environment validations:

• os.file_exists: Verify that a file exists
• cloud.aws_s3_access: Verify read/write access to an AWS S3 bucket
• cloud.aws_authentication: Verify AWS authentication and identity
• k8s.namespace_access: Verify access to a Kubernetes namespace

For a complete list of all available built-in checks, see the Built-in Checks section of the documentation.

Command Checks

Command checks allow you to run shell commands and validate their output. They are defined using the command type in your configuration. The command must output a JSON with the following schema:

{
  "status": "success|warning|failure|error",
  "output": "string describing the result"
}

Example configuration:

checks:
  - name: Check Go version
    type: command
    command: 'go version | grep -q "go1.21" && echo "{\"status\":\"success\",\"output\":\"Go 1.21 is installed\"}" || echo "{\"status\":\"failure\",\"output\":\"Wrong Go version\"}"'

The command must return a valid JSON output matching the schema above. The status field can be:

• success: The check passed successfully
• warning: The check passed but with warnings
• failure: The check failed
• error: An error occurred while running the check

Custom Checks

You can extend the checkers library by writing your own checks in Go. For details read Writing Your Own Checks

Output Formats

Checkers supports two output formats: pretty (default) and JSON.

Pretty Format

The pretty format provides a human-readable, hierarchical view of check results:

$ checkers
CLOUD
└── ✅ Check S3 access (cloud.aws_s3_access)

K8S
└── ✅ Check access to production K8s namespace (k8s.namespace_access)

OS
└── ❌ Check if .env file exists (os.file_exists)

JSON Format

The JSON format provides a machine-readable output, useful for automation and integration with other tools:

$ checkers --output json
{
  "results": [
    {
      "name": "Check S3 access",
      "type": "cloud.aws_s3_access",
      "status": "Success",
      "output": "Successfully verified write access to bucket 'my-bucket'"
    }
  ],
  "metadata": {
    "datetime": "2025-02-13T15:50:36+02:00",
    "version": "v0.5.1",
    "os": "darwin/arm64"
  }
}

The JSON output includes:

• results: Array of check results, each containing:
  • name: Check name
  • type: Check type
  • status: Check status (Success, Warning, Failure, Error)
  • output: Check output message
• metadata: Additional information about the execution:
  • datetime: Timestamp of the execution in RFC3339 format
  • version: Version of the Checkers CLI (includes git details for development builds)
  • os: Operating system and architecture

To use JSON output, pass the --output json flag:

checkers --output json

The JSON output is particularly useful for sharing the results with your team in order to get support.

For detailed information about the configuration options, see the Configuration section of the documentation.