cutie-logs

cutie-logs is a very simple and minimal server for receiving OpenTelemetry logs, storing them in a PostgreSQL database and providing a simple web interface for querying and analysing them.

The goal of this project is to be very lightweight and it is meant mostly for small deployments (e.g. my K8s cluster made out of SBCs), for which will OpenTelemetry stacks would be excessive.

The project is written mostly in modern C++ (even the web UI thanks so WebAssembly!) and compiles into a single executable only requiring a few system dependencies which are available as Ubuntu packages.

Features

• displaying and downloading logs as text with customizable formats using powerful stencils
• displaying logs in a dynamic adjustable table with support for custom columns
• support for multiple resources (with included information) and scopes
• type-safe "stencil functions" for transforming attributes available on frontend and backend, for example:
  • basic string manipulation
  • basic mathematical functions
  • JSON support
  • padding & trimming text
  • transforming timestamps into different formats
  • looking up IP addresses in MaxMind's GeoLite2 databases
• profiles for easily working with different log formats and attributes for different resources and scopes

Planned Features

• rule-based automatic cleanup of old logs (work in progress)
• server-side custom columns (calculated & created before a log line is written to the database)
• server-side rules for redacting information before a log line is written to the database
• aggregation and analysis of logs
• rule-based alerts (i.e. send an email when an error log of a specifc server arrives) (work in progress)

Warnings

The project is currently in heavy development and does not have a stable release yet. It is therefore not suited for production yet and features might rapidly change.

The frontend and API also do not employ any kind of authentication and therefore must be run behind a proxy handling authentication.

Running

Docker

The easiest way to run the application is using the automatically built Docker image:

docker run -p 4318:4318 -p 8080:8080 -e CUTIE_LOGS_DATABASE_URL=postgres://... ghcr.io/jncrmx/cutie-logs:latest

Command Line Options

Usage: cutie-logs [--help] [--version] [--otel-address ADDRESS] [--web-address ADDRESS] [--web-dev-path PATH] [--skip-database-consistency] [--disable-web] [--geoip-country-url URL] [--geoip-asn-url URL] [--geoip-city-url URL] --database-url CONNECTION_STRING

Optional arguments:
  -h, --help                                    shows help message and exits
  -v, --version                                 prints version information and exits
  --otel-address ADDRESS                        Address to listen for OpenTelemetry requests on (env: CUTIE_LOGS_OTEL_ADDRESS) [default: "0.0.0.0:4318"]
  --web-address ADDRESS                         Address to serve web interface on (env: CUTIE_LOGS_WEB_ADDRESS) [default: "127.0.0.1:8080"]
  --web-dev-path PATH                           Path to serve static files from in development mode (env: CUTIE_LOGS_WEB_DEV_PATH)
  --skip-database-consistency                   Skip database consistency check (env: CUTIE_LOGS_SKIP_DATABASE_CONSISTENCY)
  --disable-web                                 Disable the web interface (env: CUTIE_LOGS_DISABLE_WEB)
  --geoip-country-url URL                       URL to download GeoLite2-Country database from (env: CUTIE_LOGS_GEOIP_COUNTRY_URL)
  --geoip-asn-url URL                           URL to download GeoLite2-ASN database from (env: CUTIE_LOGS_GEOIP_ASN_URL)
  --geoip-city-url URL                          URL to download GeoLite2-City database from (env: CUTIE_LOGS_GEOIP_CITY_URL)
  --database, --database-url CONNECTION_STRING  Database connection string (env: CUTIE_LOGS_DATABASE_URL) [required]