Main function improved

- More explicit cli operation
- Using ctx and os.Args injected for eventual later testing
- Returning exit code
- Cli code moved to cli package

internal/cli/cli.go

@@ -0,0 +1,24 @@
+package cli
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/qdm12/golibs/network/connectivity"
+)
+
+func HealthCheck() error {
+	// DNS, HTTP and HTTPs check on github.com
+	connectivity := connectivity.NewConnectivity(3 * time.Second)
+	errs := connectivity.Checks("github.com")
+	if len(errs) > 0 {
+		var errsStr []string
+		for _, err := range errs {
+			errsStr = append(errsStr, err.Error())
+		}
+		return fmt.Errorf("Multiple errors: %s", strings.Join(errsStr, "; "))
+	}
+	// TODO check IP address is in the right region
+	return nil
+}