Use urfave/cli functionality for configuration

Instead of re-inventing the wheel regarding configuration location
handling and validation, introduce a new command flag `--config`
allowing for full flexibility of configuration filename and location.
Even environment variable overrides are used so that the custom env
lookup is unnecessary.

Signed-off-by: Steven Kriegler <sk.bunsenbrenner@gmail.com>

cmd/gitea-sonarqube-bot/main.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"log"
 	"os"
-	"path"
 
 	"gitea-sonarqube-pr-bot/internal/api"
 	giteaSdk "gitea-sonarqube-pr-bot/internal/clients/gitea"
@@ -15,23 +14,22 @@ import (
 	"github.com/urfave/cli/v2"
 )
 
-func getConfigLocation() string {
-	configPath := path.Join("config")
-	if customConfigPath, ok := os.LookupEnv("PRBOT_CONFIG_PATH"); ok {
-		configPath = customConfigPath
-	}
-
-	return configPath
-}
-
 func main() {
-	settings.Load(getConfigLocation())
-
 	app := &cli.App{
 		Name:        "gitea-sonarqube-pr-bot",
 		Usage:       "Improve your experience with SonarQube and Gitea",
 		Description: `By default, gitea-sonarqube-pr-bot will start running the webserver if no arguments are passed.`,
 		Action:      serveApi,
+		Flags: []cli.Flag{
+			&cli.PathFlag{
+				Name:      "config",
+				Aliases:   []string{"c"},
+				Value:     "./config/config.yaml",
+				Usage:     "Full path to configuration file.",
+				EnvVars:   []string{"GITEA_SQ_BOT_CONFIG_PATH"},
+				TakesFile: true,
+			},
+		},
 	}
 
 	err := app.Run(os.Args)
@@ -42,6 +40,7 @@ func main() {
 
 func serveApi(c *cli.Context) error {
 	fmt.Println("Hi! I'm the Gitea-SonarQube-PR bot. At your service.")
+	settings.Load(c.Path("config"))
 
 	giteaHandler := api.NewGiteaWebhookHandler(giteaSdk.New(), sonarQubeSdk.New())
 	sqHandler := api.NewSonarQubeWebhookHandler(giteaSdk.New(), sonarQubeSdk.New())

cmd/gitea-sonarqube-bot/main_test.go

@@ -1,22 +0,0 @@
-package main
-
-import (
-	"os"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestGetConfigLocationWithDefault(t *testing.T) {
-	assert.Equal(t, "config", getConfigLocation())
-}
-
-func TestGetConfigLocationWithEnvironmentOverride(t *testing.T) {
-	os.Setenv("PRBOT_CONFIG_PATH", "/tmp/")
-
-	assert.Equal(t, "/tmp/", getConfigLocation())
-
-	t.Cleanup(func() {
-		os.Unsetenv("PRBOT_CONFIG_PATH")
-	})
-}

internal/settings/settings.go

@@ -13,10 +13,9 @@ var (
 	Projects  []Project
 )
 
-func newConfigReader() *viper.Viper {
+func newConfigReader(configFile string) *viper.Viper {
 	v := viper.New()
-	v.SetConfigName("config.yaml")
-	v.SetConfigType("yaml")
+	v.SetConfigFile(configFile)
 	v.SetEnvPrefix("prbot")
 	v.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
 	v.AllowEmptyEnv(true)
@@ -38,9 +37,8 @@ func newConfigReader() *viper.Viper {
 	return v
 }
 
-func Load(configPath string) {
-	r := newConfigReader()
-	r.AddConfigPath(configPath)
+func Load(configFile string) {
+	r := newConfigReader(configFile)
 
 	err := r.ReadInConfig()
 	if err != nil {

internal/settings/settings_test.go

@@ -31,7 +31,7 @@ projects:
       name: pr-bot
 `)
 
-func WriteConfigFile(t *testing.T, content []byte) {
+func WriteConfigFile(t *testing.T, content []byte) string {
 	dir := os.TempDir()
 	config := path.Join(dir, "config.yaml")
 
@@ -40,21 +40,23 @@ func WriteConfigFile(t *testing.T, content []byte) {
 	})
 
 	_ = ioutil.WriteFile(config, content, 0444)
+
+	return config
 }
 
 func TestLoadWithMissingFile(t *testing.T) {
-	assert.Panics(t, func() { Load(os.TempDir()) }, "No panic while reading missing file")
+	assert.Panics(t, func() { Load(path.Join(os.TempDir(), "config.yaml")) }, "No panic while reading missing file")
 }
 
 func TestLoadWithExistingFile(t *testing.T) {
-	WriteConfigFile(t, defaultConfig)
+	c := WriteConfigFile(t, defaultConfig)
 
-	assert.NotPanics(t, func() { Load(os.TempDir()) }, "Unexpected panic while reading existing file")
+	assert.NotPanics(t, func() { Load(c) }, "Unexpected panic while reading existing file")
 }
 
 func TestLoadGiteaStructure(t *testing.T) {
-	WriteConfigFile(t, defaultConfig)
-	Load(os.TempDir())
+	c := WriteConfigFile(t, defaultConfig)
+	Load(c)
 
 	expected := GiteaConfig{
 		Url: "https://example.com/gitea",
@@ -72,8 +74,8 @@ func TestLoadGiteaStructure(t *testing.T) {
 func TestLoadGiteaStructureInjectedEnvs(t *testing.T) {
 	os.Setenv("PRBOT_GITEA_WEBHOOK_SECRET", "injected-webhook-secret")
 	os.Setenv("PRBOT_GITEA_TOKEN_VALUE", "injected-token")
-	WriteConfigFile(t, defaultConfig)
-	Load(os.TempDir())
+	c := WriteConfigFile(t, defaultConfig)
+	Load(c)
 
 	expected := GiteaConfig{
 		Url: "https://example.com/gitea",
@@ -94,8 +96,8 @@ func TestLoadGiteaStructureInjectedEnvs(t *testing.T) {
 }
 
 func TestLoadSonarQubeStructure(t *testing.T) {
-	WriteConfigFile(t, defaultConfig)
-	Load(os.TempDir())
+	c := WriteConfigFile(t, defaultConfig)
+	Load(c)
 
 	expected := SonarQubeConfig{
 		Url: "https://example.com/sonarqube",
@@ -112,7 +114,7 @@ func TestLoadSonarQubeStructure(t *testing.T) {
 }
 
 func TestLoadSonarQubeStructureWithAdditionalMetrics(t *testing.T) {
-	WriteConfigFile(t, []byte(
+	c := WriteConfigFile(t, []byte(
 		`gitea:
   url: https://example.com/gitea
   token:
@@ -129,7 +131,7 @@ projects:
       owner: example-organization
       name: pr-bot
 `))
-	Load(os.TempDir())
+	Load(c)
 
 	expected := SonarQubeConfig{
 		Url: "https://example.com/sonarqube",
@@ -152,8 +154,8 @@ projects:
 func TestLoadSonarQubeStructureInjectedEnvs(t *testing.T) {
 	os.Setenv("PRBOT_SONARQUBE_WEBHOOK_SECRET", "injected-webhook-secret")
 	os.Setenv("PRBOT_SONARQUBE_TOKEN_VALUE", "injected-token")
-	WriteConfigFile(t, defaultConfig)
-	Load(os.TempDir())
+	c := WriteConfigFile(t, defaultConfig)
+	Load(c)
 
 	expected := SonarQubeConfig{
 		Url: "https://example.com/sonarqube",
@@ -186,7 +188,7 @@ func TestLoadStructureWithFileReferenceResolving(t *testing.T) {
 	sonarqubeTokenFile := path.Join(os.TempDir(), "token-secret-sonarqube")
 	_ = ioutil.WriteFile(sonarqubeTokenFile, []byte(`a09eb5785b25bb2cbacf48808a677a0709f02d8e`), 0444)
 
-	WriteConfigFile(t, []byte(
+	c := WriteConfigFile(t, []byte(
 		`gitea:
   url: https://example.com/gitea
   token:
@@ -232,7 +234,7 @@ projects:
 		AdditionalMetrics: []string{},
 	}
 
-	Load(os.TempDir())
+	Load(c)
 	assert.EqualValues(t, expectedGitea, Gitea)
 	assert.EqualValues(t, expectedSonarQube, SonarQube)
 
@@ -249,8 +251,8 @@ projects:
 }
 
 func TestLoadProjectsStructure(t *testing.T) {
-	WriteConfigFile(t, defaultConfig)
-	Load(os.TempDir())
+	c := WriteConfigFile(t, defaultConfig)
+	Load(c)
 
 	expectedProjects := []Project{
 		{
@@ -283,7 +285,7 @@ sonarqube:
     secret: haxxor-sonarqube-secret
 projects: []
 `)
-	WriteConfigFile(t, invalidConfig)
+	c := WriteConfigFile(t, invalidConfig)
 
-	assert.Panics(t, func() { Load(os.TempDir()) }, "No panic for empty project mapping that is required")
+	assert.Panics(t, func() { Load(c) }, "No panic for empty project mapping that is required")
 }