Mittens is a tool that can be used to warm up an http application over REST or gRPC. For a more detailed overview and the background behind this project you can read our blogpost.
Mittens can run as a standalone command-line tool, as a linked Docker container, or even as a sidecar in Kubernetes.
Its main features are summarised below:
- Sends requests continuously for X seconds
- Supports REST and gRPC
- Supports HTTP/1.1, HTTP/2 and HTTP/2 Cleartext protocol for REST
- Supports placeholders for random elements in requests
- Supports concurrent requests
- Provides files or/and endpoints that can be used as liveness/readiness probes in Kubernetes
- Allows readiness to fail if unable to warm up target app
The application receives a number of command-line flags. Read the documentation for more context.
Mittens is written in Go and the simplest way to run it is as a cmd application. It receives a number of command line arguments (see Flags).
The project uses Go Modules. We provide a Makefile which can be used to generate an executable binary and a Dockerfile if you prefer to run using Docker.
To build the binary make sure you've installed Go 1.21.
To build the project run the following:
make testThis will run the unit tests and generate a binary executable.
To run the binary:
./mittens -target-readiness-http-path=/health -target-grpc-port=6565 -max-duration-seconds=60 -concurrency=3 -http-requests=get:/hotel/potatoes -grpc-requests=service/method:"{\"foo\":\"bar\",\"bar\":\"foo\"}"To build a Docker image named mittens:
make dockerTo run the container:
docker run mittens:latest -target-readiness-http-path=/health -target-grpc-port=6565 -max-duration-seconds=60 -concurrency=3 -http-requests=get:/hotel/potatoes -grpc-requests=service/method:"{\"foo\":\"bar\",\"bar\":\"foo\"}"Note: If you use Docker for Mac/Windows you might need to set the target host (target-http-host, target-grpc-host) to host.docker.internal so that your container can resolve localhost. If you use an older version of Docker (< 18.03), the value will depend on your Operating System, e.g. docker.for.mac.host.internal or docker.for.win.host.internal. For target-http-host, you need to prefix the host with the scheme, e.g. http://host.docker.internal.
Please refer to our CONTRIBUTING file.
- Hotels.com - Used in the production environment as a linked Docker container and as a Kubernetes sidecar to eliminate cold starts.
- Expedia Group - Used in the production environment as a Kubernetes sidecar to eliminate cold starts.
This project is available under the Apache 2.0 License.
Copyright 2024 Expedia, Inc.