Implementation of a simple load balancer for TCP connections.
goloba is a simple example of Layer 4 balancer working in proxy mode. Each connection established with goloba process is forwarded to one of configured endpoints. Endpoint selection is made internally based on implemented balancing algorithm (currently it's only round robin).
Load balancer listening port and list of endpoints (address:port pairs) are provided in configuration file or through system environment variables. Please check Usage section for more details.
goloba is a demonstration of load balancing idea rather than complete, highly efficient solution and so it is not suggested to use it in any production environment.
Together with goloba another application, dummyserver, is provided. This app is a very simple HTTP server that prints a welcome message. Both listetening port and message printed are configurable. More information in Usage section.
GoLoBa project is created as an Go module with Makefile provided so can be downloaded by git clone to any location and compiled by simple make:
git clone github.com/markamdev/goloba
cd goloba
makeOutput binaries (goloba and dummyserver) and sample configuration file will be placed inside ./build directory. Application usage can be found in Usage section while testing process is described in Testing.
When launching goloba following commandline params and system environment variables can be specified:
| Flag | Env var | Param | Description |
|---|---|---|---|
| port | PORT | <port> | Number of GoLoBa listening port |
| servers | SERVERS | <server_list> | Comma separated list of server:port pairs for each server |
| logging-file | LOGGING_FILE | <file_path> | Path to output file for logs |
| help | - | - | Request to print help message with params description |
dummyserver can be configured using command line params and system environment variables while variables have higher priority (importance).
Accepted command line parameters and related environment variable:
| Flag | Env var | Param | Description |
|---|---|---|---|
| port | PORT | <port> | Listening port number (9000 by default) |
| message | MESSAGE | <message> | Message sent to client in HTML content |
Although this repository contains two applications there is only one docker file and one Docker image that can be built. By default image launches goloba binary but it's also possible to launch dummyserver by specifying command as /usr/bin/dummyserver.
Docker image build can be launched manually using docker tool or by running make docker command (of course Docker has to be installed on the machine). Output image will be markamdev/goloba.
There's also simple testbench prepared to be launched in Docker Compose tool. Testbench is described in docker-compose.yml and contains two dummyserver instances accessible through one goloba. After launching testbench by docker-compose up -d environment can be accessed using local port 8080.
Diagram below presents testbench configuration:
To Be Done...
Code is published under MIT License as it seems to be the most permissive license. If for some reason you need to have this code published with other license (ex. to reuse the code in your project) please contact author directly.
If you need to contact me feel free to write me an email: markamdev.84#dontwantSPAM#gmail.com