Example multitenant microservice written in golang

main.go

package main

import (
	"fmt"
	"net/http"
)

// Tenant struct to hold tenant information
type Tenant struct {
	ID          int
	Name        string
	IsActive    bool
	Configuration map[string]string
}

//Tenants map to hold all the tenants
var Tenants = map[int]Tenant{
	1: {1, "Tenant 1", true, map[string]string{"config1": "value1"}},
	2: {2, "Tenant 2", true, map[string]string{"config1": "value2"}},
}

// GetTenantConfg retrieves the config for a tenant
func GetTenantConfg(tenant int) (Tenant, error) {
	if t, ok := Tenants[tenant]; ok {
		return t, nil
	}
	return Tenant{}, fmt.Errorf("Tenant not found")
}

func handler(w http.ResponseWriter, r *http.Request) {
	tenant := r.Header.Get("tenant")
	if tenant == "" {
		http.Error(w, "Tenant header is missing", http.StatusBadRequest)
		return
	}
	// get tenant configuration
	t, err := GetTenantConfg(tenant)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	fmt.Fprintf(w, "Hello from tenant: %s with config: %v", t.Name, t.Configuration)
}

func main() {
	http.HandleFunc("/", handler)
	http.ListenAndServe(":8000", nil)
}