extended

Golang Extended Cli Boilerplate Example

Using spf13/viper to gather parameters from various sources can be tricky. You will probably run into the problem of having to redefine default parameters for each means of input. This example shows how to to load parameters from different sources without having to define them multiple times. The common priority for input methods is this:

1. CLI parameters
2. Environment variables
3. Config file
4. Default values

Checkout the cli package on how to setup this config.

Also included in this example is adding Version and CommitHash to your application through ld flags. Checkout the Makefile on how to load them during build from git tags and git commit hash.

It is often useful to get performance insights from your application. That is when you want to add pprof to your application. When doing this from the start of your project you're more likely to find bottlenecks or memory leaks earlier. The rampup and -down of the profiling is handled in /cli/profiling.go

Usage

Build the application

make build

Parameters can be passed into the application in these 4 ways:

config.yaml:

param1: "param from config"

defaultConfig in config.go:

var defaultConfig = config{
    Param2: "param with default value",
}

Environment variable

PARAM1="param from env" ./our_app

Cli parameter

./our_app --param1="param from cli"

For profiling just add the parameters cpuprofile and/or memprofile to the application call. This will generate the profiling files cpuprofile.pprof and memprofile.pprof which can be inspected with github.com/google/pprof