Allow passing environment variables into config

Signed-off-by: Steven Kriegler <61625851+justusbunsi@users.noreply.github.com>

internal/settings/settings.go

@@ -2,6 +2,7 @@ package settings
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/spf13/viper"
 )
@@ -22,27 +23,35 @@ var (
 	Gitea GiteaConfig
 )
 
-func Load(configPath string) {
+func init() {
 	viper.SetConfigName("config.yaml")
 	viper.SetConfigType("yaml")
+	viper.SetEnvPrefix("prbot")
+	viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
+	viper.AllowEmptyEnv(true)
+	viper.AutomaticEnv()
+}
+
+func Load(configPath string) {
 	viper.AddConfigPath(configPath)
 
 	err := viper.ReadInConfig()
-
 	if err != nil {
 		panic(fmt.Errorf("Fatal error while reading config file: %w \n", err))
 	}
 
-	var giteaConfig GiteaConfig
-
-	if viper.Sub("gitea") == nil {
+	if viper.IsSet("gitea") == false {
 		panic("Gitea not configured")
 	}
 
-	err = viper.UnmarshalKey("gitea", &giteaConfig)
-	if err != nil {
-		panic(fmt.Errorf("Unable to decode into struct, %v", err))
+	var fullConfig struct {
+		Gitea GiteaConfig
 	}
 
-	Gitea = giteaConfig
+	err = viper.Unmarshal(&fullConfig)
+	if err != nil {
+		panic(fmt.Errorf("Unable to load config into struct, %v", err))
+	}
+
+	Gitea = fullConfig.Gitea
 }

internal/settings/settings_test.go

@@ -12,13 +12,13 @@ import (
 var defaultConfigInlineSecrets []byte = []byte(
 `gitea:
   url: https://example.com/gitea
-  token: 1337
-  webhookSecret: ""
+  token: d0fcdeb5eaa99c506831f9eb4e63fc7cc484a565
+  webhookSecret: "haxxor"
   repositories: []
 sonarqube:
   url: https://example.com/sonarqube
-  token: 42
-  webhookSecret: ""
+  token: a09eb5785b25bb2cbacf48808a677a0709f02d8e
+  webhookSecret: "haxxor"
   projects: []
 `)
 
@@ -53,12 +53,33 @@ func TestLoadGiteaStructure(t *testing.T) {
 	WriteConfigFile(t, defaultConfigInlineSecrets)
 	Load(os.TempDir())
 
-	expected := &GiteaConfig{
+	expected := GiteaConfig{
 		Url: "https://example.com/gitea",
-		Token: "1337",
-		WebhookSecret: "",
+		Token: "d0fcdeb5eaa99c506831f9eb4e63fc7cc484a565",
+		WebhookSecret: "haxxor",
 		Repositories: []GiteaRepository{},
 	}
 
-	assert.True(t, assert.ObjectsAreEqualValues(&Gitea, expected))
+	assert.EqualValues(t, expected, Gitea)
+}
+
+func TestLoadGiteaStructureWithEnvInjectedWebhookSecret(t *testing.T) {
+	os.Setenv("PRBOT_GITEA_WEBHOOKSECRET", "injected-secret")
+	os.Setenv("PRBOT_GITEA_TOKEN", "injected-token")
+	WriteConfigFile(t, defaultConfigInlineSecrets)
+	Load(os.TempDir())
+
+	expected := GiteaConfig{
+		Url: "https://example.com/gitea",
+		Token: "injected-token",
+		WebhookSecret: "injected-secret",
+		Repositories: []GiteaRepository{},
+	}
+
+	assert.EqualValues(t, expected, Gitea)
+
+	t.Cleanup(func() {
+		os.Unsetenv("PRBOT_GITEA_WEBHOOKSECRET")
+		os.Unsetenv("PRBOT_GITEA_TOKEN")
+	})
 }