Move config to separate package

config/command.go

@@ -0,0 +1,19 @@
+package config
+
+import "os/exec"
+
+type Command struct {
+	Program       string
+	Arguments     []string
+	AppendPayload bool
+}
+
+func (c Command) Execute(payload string) ([]byte, error) {
+	arguments := make([]string, 0)
+	copy(c.Arguments, arguments)
+	if c.AppendPayload {
+		arguments = append(arguments, payload)
+	}
+
+	return exec.Command(c.Program, arguments...).Output()
+}

config/config.go

@@ -0,0 +1,39 @@
+package config
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+type Config struct {
+	ListenAddress string
+	Services      map[string]struct {
+		Script          Command
+		Secret          string
+		SignatureHeader string
+		Tests           []Command
+	}
+}
+
+func (c Config) Validate() error {
+	if c.ListenAddress == "" {
+		return requiredFieldError{"ListenAddress", ""}
+	}
+
+	jsonbytes, _ := json.MarshalIndent(c, "", "  ")
+	fmt.Println(string(jsonbytes))
+
+	for serviceName, service := range c.Services {
+		if service.Script.Program == "" {
+			return requiredFieldError{"Script.Program", serviceName}
+		}
+		if service.SignatureHeader == "" {
+			return requiredFieldError{"SignatureHeader", serviceName}
+		}
+		if service.Secret == "" {
+			return requiredFieldError{"Secret", serviceName}
+		}
+	}
+
+	return nil
+}

config/errors.go

@@ -0,0 +1,12 @@
+package config
+
+import "fmt"
+
+type requiredFieldError struct {
+	fieldName   string
+	serviceName string
+}
+
+func (e requiredFieldError) Error() string {
+	return fmt.Sprintf("%v cannot be empty (%v)", e.fieldName, e.serviceName)
+}