slogo

slogo

Go utilities for working with OpenSLO (Service Level Objectives) specifications.

Overview

slogo is a Go library that provides convenient utilities for reading, writing, and validating OpenSLO specification files. It builds on top of the OpenSLO Go SDK to provide a simpler interface for working with SLO definitions in JSON and YAML formats.

Features

• Read OpenSLO objects from files or readers (auto-detects JSON/YAML format)
• Write OpenSLO objects to files in JSON or YAML format
• Validate SLO definitions against the OpenSLO specification
• Type-safe Go representations of SLO objects
• Predefined severity and attribute constants

Installation

go get github.com/grokify/slogo

Usage

Reading SLO Files

import "github.com/grokify/slogo"

// Read from file (auto-detects JSON or YAML)
objs, err := slogo.ReadFile("slo-definition.yaml")
if err != nil {
    log.Fatal(err)
}

// Read from io.Reader
objs, err := slogo.Read(reader)
if err != nil {
    log.Fatal(err)
}

Validating SLO Objects

// Validate all objects
if err := objs.Validate(); err != nil {
    log.Fatal(err)
}

Writing SLO Files

// Write as YAML
err := objs.WriteFileYAML("output.yaml")
if err != nil {
    log.Fatal(err)
}

// Write as JSON
err := objs.WriteFileJSON("output.json")
if err != nil {
    log.Fatal(err)
}

Using Predefined Constants

import "github.com/grokify/slogo"

// Severity levels
severity := slogo.SeverityCritical // "critical"
severity := slogo.SeverityHigh     // "high"
severity := slogo.SeverityMedium   // "medium"
severity := slogo.SeverityLow      // "low"
severity := slogo.SeverityInfo     // "info"

// Attributes
attr := slogo.AttrQuery // "query"

Examples

The examples directory contains real-world examples of SLO definitions with detailed explanations:

Budgeting Methods

Compares different budgeting methods (Occurrences, Timeslices, and RatioTimeslices) with practical examples:

• Availability SLO (timeslices-slo.go) - Reflects an SLA for internet provider availability (99% uptime)
• Occurrences SLO (occurences-slo.go) - Measures search latency treating all searches equally
• Ratio Timeslices SLO (ratio-timeslices.go) - Tracks main page availability based on response codes

Treat Low Traffic as Equally Important

Demonstrates how to maintain high reliability regardless of traffic volume, ensuring that services with low usage receive the same attention as high-traffic services.

Each example includes:

• Complete, working Go code
• Detailed descriptions of what is being measured
• Explanations of why specific budgeting methods are chosen
• Automated tests to validate the SLO definitions

Dependencies

• github.com/OpenSLO/go-sdk - OpenSLO Go SDK
• github.com/grokify/mogo - Go utilities

License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Resources

• OpenSLO Specification
• OpenSLO Go SDK
• Site Reliability Engineering (SRE) Book