Emergence Engineering Go Service template

Features

• utilizing Go modules
• light and secure docker image based on 🏔Alpine
• multistage build
• GNU Makefiles
• based on official Go project layout by Go standards
• graceful shutdown 😇
• CLI with urfave/cli
• Logging with logrus
• Automatic reconnecting to dependent services

Module

Init new Go module

The project uses Go modules, I suggest to delete the go.mod and go.sum files in the project root and initiate your own project by the following command

go mod init github.com/account/project

Init your project

There are a few things that has to be done to take ownership of the template

• Init your brand new Go module (described above)
• Replace the text "example-service" in the Dockerfile and the Makefile
• Adjust your ldflags (LINKFLAGS) in Makefile

Build

We use Makefiles to build our project. The Makefile is located in the project root

The template has two commands:

make build

Builds the service, injects the build times constants to the binary and links the packages. The go tool will do all the above.

make test

//TODO

Build time variables

By default the following information is added build time:

• SERVICE_NAME
• GIT_COMMIT_ID
• GIT_BRANCH
• BUILD_TIMESTAMP

The above variables can be used in health-checks, microservice debugging or service discover...

Custom build time variables

You can add more build time constants in the makefile. Make sure that you are adding the build time constant to the correct file.

Multi-stage build

We are using a multistage build pattern for security and for small image size as well. Our builder image is based on golang:1.13 and our service image is alpine:latest.

Service

To run your service use:

./example-service start

To get help

./example-service --help 

Service CLI

We are using https://github.com/urfave/cli for the service CLI. CLI flags are configured in the service file.

Business logic

You can add your business logic here

Graceful shutdown

By default the service is listening for SIGTERM signals from the OS. If one occurs a graceful shutdown is initialized. You can extend the graceful shutdown process in the handleShutdownGracefully function inside the service main file.

Logging

Logging is currently done with github.com/sirupsen/logrus