config-05

Config-05

Importing configs to a package using kubernetes and zap for logging

This config tips shows how to use conf package from ArdanLabs, extended to import configs to a package.

To run this configuration demo, you will need to set the below environment variables to the deploy/server.env. Feel free to use the server.env.example.

In additional we are passing the NewRelic configuration. Notice that we did NOT use annotations and point it to newrelic.Config which is our newrelic package which has the proper annontation with the default value.

type Config struct {
	Log      myLog.Config
	NewRelic newrelic.Config
	Port     string `conf:"default:8000"`
}

In pkg/log/log.go, we defined another config struct which is the myLog.Config in the main.go. This pkg will start the zap logger for us and set the correct log level.

type Config struct {
	Level string `conf:"default:error"`
}

In pkg/newrelic/newrelic.go, we defined another config struct which is the newrelic.Config in the main.go

type Config struct {
	AppName    string `conf:"default:appName"`
	LicenseKey string `conf:"default:LicenceKey"`
}

As we are running on top of k8s (kubernetes), we need a cluster. In order to make it easy, this repo provides a make file with some shortcuts to create your own cluster with KinD and some make commands to get the appication up and down. Please explore the Makefile.

make kind-init

kind-init will:

• create a cluster using kind;
• set the namespace in the context;
• build the image with the go app;
• load the image into k8s;
• apply kind ymls from ./k8s folder and create the kubernetes infrastructure;
• generate the secrets with your environment variables.

Note: Of course you should use some Vault techniques to store your secrets, but for this example it is set only in the kube secrets.

You can cleanup it using the below command.

make kind-clean

Alternatively you can use k9s to explore your pods, if you are not so familiar with kube ctl cmds. If you inspect Kubernetes logs you should see the below:

LogLevel: info

Using NewRelic 
AppName: colombostips
LicenseKey: REDACTED

As kubernetes uses a private network you need to do a fast-forward to expose the port so you can access your app from your terminal. You can try using make command.

make expose

curl localhost:8080

So if you hit the api with the above command, the output should be:

Hello

Note that in the logs it will shows only the logs in the log level set. In this case the debug log is not shown in the logs.

{"level":"info","timestamp":"2023-11-29T19:30:25.465Z","caller":"src/main.go:75","msg":"Hello Info","pid":1}
{"level":"warn","timestamp":"2023-11-29T19:30:25.465Z","caller":"src/main.go:76","msg":"Hello Warn","pid":1}
{"level":"error","timestamp":"2023-11-29T19:30:25.465Z","caller":"src/main.go:77","msg":"Hello Error","pid":1...
...

Note: If you change something in your go code, you must reload you app by running make kind-reload.