README
¶
Config-02
How to import environment variables into a package.
This config tip shows how to use the conf/v3 package from ArdanLabs, which is extended to import configs to a package.
To run this configuration demo, you must set the environment variables below or use the below command to run.
NEW_RELIC_LICENSE_KEY=some_valid_licence_key \
NEW_RELIC_APP_NAME=colombostips \
LOG_LEVEL=info \
go run app/example/main.go
Notice that we used a local config type to get environment variables and are passing the values using the newrelic.Config type explicitly to keep the code easy to understand. In addition to that, we are not exposing the main Config, avoiding passing it along to the application.
... //main.go
var cfg struct {
Log struct {
Level string `conf:"default:error"`
}
NewRelic struct {
AppName string `conf:"default:appName"`
LicenseKey string `conf:"default:LicenceKey"`
}
}
...
/foundation
In this section we are going to start to use the foundation folder to save the packages for loggin and metrics, since it does not belongs to the business layer.
In foundation/log/log.go, we defined another config struct which will be explicitly filled in the main.go.
... // main.go
logCfg := logger.Config{
Level: cfg.Log.Level,
}
logger := logger.New(logCfg)
...
In foundation/newrelic/newrelic.go, we defined another config struct which will be explicitly filled in the main.go. In this case, you are not hiding the configuration but setting it explicitly.
... //main.go
nrCfg := newrelic.Config{
AppName: cfg.NewRelic.AppName,
LicenseKey: cfg.NewRelic.LicenseKey,
}
// skipping the newrelic return for this demo
if _, err = newrelic.New(nrCfg); err != nil {
return fmt.Errorf("starting newrelic: %w", err)
}
...
So if you run this app with the above command, the output should be:
Using Log Level: info
Using NewRelic
AppName: colombostips
LicenseKey: REDACTED
But you can see that it is printing the environment variable set.
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