refactor: split into modules

main.go

@@ -2,6 +2,10 @@ package main
 
 import (
 	"github.com/spf13/cobra"
+	"log"
+
+	service "spud/service"
+	service_definition "spud/service_definition"
 )
 
 var cli = &cobra.Command{
@@ -14,8 +18,13 @@ var start = &cobra.Command{
 	Short: "Creates or updates a service based on the provided definition.",
 	Run: func(cmd *cobra.Command, args []string) {
 		pathProvided := args[0]
-		def := GetServiceDefinitionFromFile(pathProvided)
-		CreateService(def)
+		def, err := service_definition.GetServiceDefinitionFromFile(pathProvided)
+
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		service.CreateService(def)
 	},
 }
 

podman/main.go

@@ -1,8 +1,10 @@
-package main
+package podman
 
 import (
 	"log"
 	"os/exec"
+
+	"spud/service_definition"
 )
 
 /*
@@ -53,7 +55,7 @@ func CreatePod(name string) error {
 /*
  * Creates individual containers.
  */
-func CreateContainer(definition ContainerDefinition, knownVolumes map[string]string, service string) error {
+func CreateContainer(definition service_definition.ContainerDefinition, knownVolumes map[string]string, service string) error {
 	namespacedContainerName := service + "_" + definition.Name
 
 	args := []string{

service/service.go

@@ -0,0 +1,32 @@
+package service
+
+import (
+	"log"
+
+	podman "spud/podman"
+	service_definition "spud/service_definition"
+)
+
+func CreateService(definition service_definition.ServiceDefinition) {
+	var err error
+
+	err = podman.CreatePod(definition.Name)
+
+	if err != nil {
+		log.Fatalf("%s", err)
+	}
+
+	knownVolumes := map[string]string{}
+
+	for _, volume := range definition.Volumes {
+		namespacedName := definition.Name + "_" + volume.Name
+		podman.CreateVolume(namespacedName, true)
+		knownVolumes[volume.Name] = namespacedName
+	}
+
+	for _, container := range definition.Containers {
+		if err = podman.CreateContainer(container, knownVolumes, definition.Name); err != nil {
+			log.Fatalf("%s", err)
+		}
+	}
+}

service_definition/errors.go

@@ -0,0 +1,24 @@
+package service_definition
+
+type FileDoesNotExistError struct {
+	Message      string
+	ExpectedPath string
+}
+
+func (r *FileDoesNotExistError) Error() string {
+	prefix := "File not found"
+
+	if r.Message != "" {
+		prefix = r.Message
+	}
+
+	return prefix + ": " + r.ExpectedPath
+}
+
+type InvalidServiceDefinitionError struct {
+	Path string
+}
+
+func (r *InvalidServiceDefinitionError) Error() string {
+	return "Service definition does not satisfy expected schema: " + r.Path
+}

service_definition/main.go

@@ -1,9 +1,9 @@
-package main
+package service_definition
 
 import (
-	"github.com/goccy/go-yaml"
-	"log"
 	"os"
+
+	"github.com/goccy/go-yaml"
 )
 
 type VolumeDefinition struct {
@@ -29,43 +29,18 @@ type ServiceDefinition struct {
 	Containers []ContainerDefinition `yaml:"containers"`
 }
 
-func GetServiceDefinitionFromFile(path string) ServiceDefinition {
+func GetServiceDefinitionFromFile(path string) (ServiceDefinition, error) {
 	var definition ServiceDefinition
 
 	defData, err := os.ReadFile(path)
 
-	// TODO: Bubble up error?
 	if err != nil {
-		log.Fatalf("Could not parse service configuration at %s: %s", path, err)
+		return ServiceDefinition{}, &FileDoesNotExistError{Message: "Could not find service configuration file", ExpectedPath: path}
 	}
 
 	if err = yaml.Unmarshal(defData, &definition); err != nil {
-		log.Fatalf("Could not unpack service configuration: %s", err)
+		return ServiceDefinition{}, &InvalidServiceDefinitionError{Path: path}
 	}
 
-	return definition
-}
-
-func CreateService(definition ServiceDefinition) {
-	var err error
-
-	err = CreatePod(definition.Name)
-
-	if err != nil {
-		log.Fatalf("%s", err)
-	}
-
-	knownVolumes := map[string]string{}
-
-	for _, volume := range definition.Volumes {
-		namespacedName := definition.Name + "_" + volume.Name
-		CreateVolume(namespacedName, true)
-		knownVolumes[volume.Name] = namespacedName
-	}
-
-	for _, container := range definition.Containers {
-		if err = CreateContainer(container, knownVolumes, definition.Name); err != nil {
-			log.Fatalf("%s", err)
-		}
-	}
+	return definition, nil
 }

service_definition/service_definition_test.go

@@ -0,0 +1,13 @@
+package service_definition
+
+import (
+	"testing"
+)
+
+func TestGetServiceDefinitionFromFileDoesNotExist(t *testing.T) {
+	_, err := GetServiceDefinitionFromFile(t.TempDir() + "/not-a-file.yml")
+
+	if err == nil {
+		t.Errorf("Expected error, got nil.")
+	}
+}