Grafana is an open-source observability platform for querying, visualizing, and alerting on metrics, logs, and traces. It is a full-stack application with a Go backend and React/TypeScript frontend, featuring a plugin system for datasources, panels, and apps. The architecture is a monolith with Kubernetes-style API extensions, supporting multiple database backends (MySQL, PostgreSQL, SQLite). It includes built-in alerting, dashboard management, provisioning, and RBAC. The codebase is large and well-maintained, with high-quality UI components and data abstractions, but has some technical debt from dual build systems and generated code.

Grafana Loki is a horizontally-scalable, highly-available, multi-tenant log aggregation system inspired by Prometheus. It is designed to be cost-effective and easy to operate by indexing only log metadata (labels) rather than the log contents. The system consists of several loosely coupled services (distributor, ingester, querier, compactor, ruler) that can be deployed in a monolithic or microservices architecture. Logs are ingested via various protocols (HTTP, gRPC, Kafka) and integrations (fluent-bit, fluentd, logstash, Docker driver), stored in chunk format in object stores, and indexed by labels in a separate store. Queries are executed using LogQL, which allows filtering by label expressions and log content. The system includes a ruler for alerting and recording rules, a compactor for storage optimization, and a Kubernetes operator for deployment and management.

This repository builds and maintains the `grafana/otel-lgtm` Docker image, an all-in-one OpenTelemetry backend for development, demo, and testing. It bundles Grafana, Prometheus, Tempo, Loki, Pyroscope, and the OpenTelemetry Collector into a single container, providing a complete observability stack with a single `docker run` command. The image supports optional eBPF-based auto-instrumentation (OBI) for zero-code traces and RED metrics, and can export telemetry to external vendors via OTLP. The architecture is a multi-stage Docker build that downloads and verifies each component using checksums or cosign signatures. The container entrypoint (`run-all.sh`) starts all services in parallel, waits for health checks, and handles graceful shutdown. The OpenTelemetry Collector configuration is dynamically extended based on environment variables (debug exporter, external endpoints, custom headers). The repository also includes example applications in Java, Go, Python, .NET, and Node.js that demonstrate OpenTelemetry instrumentation, along with acceptance tests (OATS) that validate traces, metrics, logs, and profiles. CI/CD is comprehensive: automated builds, linting (flint, hadolint, shellcheck, etc.), container scanning with Trivy, CodeQL analysis, and weekly scheduled releases with immutable version tags. Container images are signed with cosign and attested via GitHub Artifact Attestations. The repository is actively maintained with Renovate for dependency updates and a well-defined release process.

This repository is the official Helm chart distribution hub for Grafana's observability stack, containing over 20 charts for deploying Loki, Tempo, Mimir, Promtail, Grafana Agent, enterprise metrics/logs, and supporting components (rollout-operator, pdc-agent, snyk-exporter, etc.) on Kubernetes. The codebase is entirely Helm templates, values files, CRDs, and CI/CD scripts—no application source code. The architecture follows standard Helm patterns with per-component subdirectories, shared helpers, and extensive use of conditional logic for enterprise features, scaling, and storage backends. Many charts are deprecated or have their source maintained in separate product repositories (e.g., grafana/loki, grafana/tempo), with releases still published here. The repository shows signs of technical drift (old API versions, duplicated template logic, legacy dependencies) but remains actively maintained for the remaining non-deprecated charts with recent CI updates and release automation. It serves as both a legacy archive and an active distribution point.

xk6 is a command-line tool and Go library for building custom k6 binaries with extensions, enabling developers to create, test, and distribute k6 extensions. The tool provides scaffolding for new extensions, a build system that integrates with k6's module system and automatically resolves the correct k6 major version, a linter for extension compliance (including security, licensing, and quality checks), a test runner for k6 scripts, and a dependency synchronizer to keep extension dependencies aligned with k6. It also ships as a Docker image and a Dev Container feature. The codebase is a well-structured Go application using cobra for CLI, with clean separation of concerns across internal packages for linting, scaffolding, sync, and testing. It demonstrates high craftsmanship with proper error handling, logging, and test coverage.