skyconf

Example demonstrates how to use go-skyconf to parse configuration from AWS SSM.

This example assumes you have a working AWS session and SSM client. It also assumes that the following parameters exist in AWS SSM under the path /myapplication/:

• app/name: "MyApp"
• app/version: "1.2.3"
• db/host: "localhost"
• db/port: "5432"
• log_level: "info"

package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/service/ssm"

	sky "github.com/redmatter/go-skyconf"
)

func main() {
	// 1. Define your configuration struct.
	// Use struct tags to control how fields are populated from SSM.
	type Config struct {
		App struct {
			Name    string `sky:"name"`
			Version string `sky:"version"`
		} `sky:"app"`
		Database struct {
			Host string `sky:"host"`
			Port int    `sky:"port"`
		} `sky:"db"`
		LogLevel string `sky:"log_level,optional"`
	}

	// 2. Set up a real SSM client from the AWS SDK.
	// In a real application, you would load the default AWS config.
	awsCfg, err := config.LoadDefaultConfig(context.TODO())
	if err != nil {
		log.Printf("unable to load SDK config, %v; skipping example", err)
		return
	}
	ssmClient := ssm.NewFromConfig(awsCfg)

	// 3. Define the SSM source for your configuration.
	// This tells go-skyconf where to look for parameters.
	ssmSource := sky.SSMSource(ssmClient, "/myapplication/")

	// 4. Create an instance of your config struct and parse the configuration.
	var cfg Config
	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()

	_, err = sky.Parse(ctx, &cfg, false, ssmSource)
	if err != nil {
		// This will fail if the parameters don't exist in SSM.
		log.Printf("failed to parse configuration: %v; skipping example", err)
		return
	}

	// 5. Your config struct is now populated.
	fmt.Printf("AppName: %s\n", cfg.App.Name)
	fmt.Printf("AppVersion: %s\n", cfg.App.Version)
	fmt.Printf("DB Host: %s\n", cfg.Database.Host)
	fmt.Printf("DB Port: %d\n", cfg.Database.Port)
	fmt.Printf("Log Level: %s\n", cfg.LogLevel)

}

Output:
AppName: MyApp
AppVersion: 1.2.3
DB Host: localhost
DB Port: 5432
Log Level: info

Example demonstrates how to use go-skyconf to parse configuration from multiple hierarchical sources in AWS SSM.

This example assumes a working AWS session and that the following parameters exist in AWS SSM:

Project-level parameters under /my-project/:

• db/host: "project-db.example.com"
• db/port: "5432"

App-level parameters under /my-project/apps/my-app/:

• log_level: "debug"
• app_name: "MyAwesomeApp"

package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/service/ssm"

	sky "github.com/redmatter/go-skyconf"
)

func main() {
	// 1. Define your configuration struct with source tags.
	type Config struct {
		Database struct {
			Host string `sky:"host"`
			Port int    `sky:"port"`
		} `sky:"db,source:project"` // From project source
		App struct {
			LogLevel string `sky:"log_level"`
		} `sky:",flatten,source:app"` // From app source
		AppName string `sky:"app_name,source:app"` // From app source
	}

	// 2. Set up a real SSM client.
	awsCfg, err := config.LoadDefaultConfig(context.TODO())
	if err != nil {
		log.Printf("unable to load SDK config, %v; skipping example", err)
		return
	}
	ssmClient := ssm.NewFromConfig(awsCfg)

	// 3. Define multiple SSM sources with unique IDs.
	projectSource := sky.SSMSourceWithID(ssmClient, "/my-project/", "project")
	appSource := sky.SSMSourceWithID(ssmClient, "/my-project/apps/my-app/", "app")

	// 4. Parse the configuration using both sources.
	var cfg Config
	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()

	_, err = sky.Parse(ctx, &cfg, false, projectSource, appSource)
	if err != nil {
		log.Printf("failed to parse configuration: %v; skipping example", err)
		return
	}

	// 5. Your config struct is now populated from multiple sources.
	fmt.Printf("DB Host: %s\n", cfg.Database.Host)
	fmt.Printf("DB Port: %d\n", cfg.Database.Port)
	fmt.Printf("Log Level: %s\n", cfg.App.LogLevel)
	fmt.Printf("AppName: %s\n", cfg.AppName)

}

Output:
DB Host: project-db.example.com
DB Port: 5432
Log Level: debug
AppName: MyAwesomeApp