Channel default value by changing default logic

cmd/channels/email/main.go

@@ -95,7 +95,12 @@ func (ch *Email) Send(reversePath string, recipients []string, msg []byte) error
 }
 
 func (ch *Email) SetConfig(jsonStr json.RawMessage) error {
-	err := json.Unmarshal(jsonStr, ch)
+	err := plugin.PopulateDefaults(ch)
+	if err != nil {
+		return err
+	}
+
+	err = json.Unmarshal(jsonStr, ch)
 	if err != nil {
 		return fmt.Errorf("failed to load config: %s %w", jsonStr, err)
 	}
@@ -108,24 +113,7 @@ func (ch *Email) SetConfig(jsonStr json.RawMessage) error {
 }
 
 func (ch *Email) GetInfo() *plugin.Info {
-	elements := []*plugin.ConfigOption{
-		{
-			Name: "sender_name",
-			Type: "string",
-			Label: map[string]string{
-				"en_US": "Sender Name",
-				"de_DE": "Absendername",
-			},
-		},
-		{
-			Name: "sender_mail",
-			Type: "string",
-			Label: map[string]string{
-				"en_US": "Sender Address",
-				"de_DE": "Absenderadresse",
-			},
-			Default: "icinga@example.com",
-		},
+	configAttrs := plugin.ConfigOptions{
 		{
 			Name:     "host",
 			Type:     "string",
@@ -146,6 +134,24 @@ func (ch *Email) GetInfo() *plugin.Info {
 			Min: types.Int{NullInt64: sql.NullInt64{Int64: 1, Valid: true}},
 			Max: types.Int{NullInt64: sql.NullInt64{Int64: 65535, Valid: true}},
 		},
+		{
+			Name: "sender_name",
+			Type: "string",
+			Label: map[string]string{
+				"en_US": "Sender Name",
+				"de_DE": "Absendername",
+			},
+			Default: "Icinga",
+		},
+		{
+			Name: "sender_mail",
+			Type: "string",
+			Label: map[string]string{
+				"en_US": "Sender Address",
+				"de_DE": "Absenderadresse",
+			},
+			Default: "icinga@example.com",
+		},
 		{
 			Name: "user",
 			Type: "string",
@@ -178,11 +184,6 @@ func (ch *Email) GetInfo() *plugin.Info {
 		},
 	}
 
-	configAttrs, err := json.Marshal(elements)
-	if err != nil {
-		panic(err)
-	}
-
 	return &plugin.Info{
 		Name:             "Email",
 		Version:          internal.Version.Version,

cmd/channels/email/main_test.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"encoding/json"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestEmail_SetConfig(t *testing.T) {
+	tests := []struct {
+		name    string
+		jsonMsg string
+		want    *Email
+		wantErr bool
+	}{
+		{
+			name:    "empty-string",
+			jsonMsg: ``,
+			wantErr: true,
+		},
+		{
+			name:    "empty-json-obj-use-defaults",
+			jsonMsg: `{}`,
+			want:    &Email{SenderName: "Icinga", SenderMail: "icinga@example.com"},
+		},
+		{
+			name:    "sender-mail-null-equals-defaults",
+			jsonMsg: `{"sender_mail": null}`,
+			want:    &Email{SenderName: "Icinga", SenderMail: "icinga@example.com"},
+		},
+		{
+			name:    "sender-mail-overwrite",
+			jsonMsg: `{"sender_mail": "foo@bar"}`,
+			want:    &Email{SenderName: "Icinga", SenderMail: "foo@bar"},
+		},
+		{
+			name:    "sender-mail-overwrite-empty",
+			jsonMsg: `{"sender_mail": ""}`,
+			want:    &Email{SenderName: "Icinga", SenderMail: ""},
+		},
+		{
+			name:    "full-example-config",
+			jsonMsg: `{"sender_name":"icinga","sender_mail":"icinga@example.com","host":"smtp.example.com","port":"25","encryption":"none"}`,
+			want: &Email{
+				Host:       "smtp.example.com",
+				Port:       "25",
+				SenderName: "icinga",
+				SenderMail: "icinga@example.com",
+				User:       "",
+				Password:   "",
+				Encryption: "none",
+			},
+		},
+		{
+			name:    "user-but-missing-pass",
+			jsonMsg: `{"user": "foo"}`,
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			email := &Email{}
+			err := email.SetConfig(json.RawMessage(tt.jsonMsg))
+			assert.Equal(t, tt.wantErr, err != nil, "SetConfig() error = %v, wantErr = %t", err, tt.wantErr)
+			if err != nil {
+				return
+			}
+
+			assert.Equal(t, tt.want, email, "Email differs")
+		})
+	}
+}

cmd/channels/rocketchat/main.go

@@ -77,12 +77,16 @@ func (ch *RocketChat) SendNotification(req *plugin.NotificationRequest) error {
 }
 
 func (ch *RocketChat) SetConfig(jsonStr json.RawMessage) error {
+	err := plugin.PopulateDefaults(ch)
+	if err != nil {
+		return err
+	}
+
 	return json.Unmarshal(jsonStr, ch)
 }
 
 func (ch *RocketChat) GetInfo() *plugin.Info {
-
-	elements := []*plugin.ConfigOption{
+	configAttrs := plugin.ConfigOptions{
 		{
 			Name: "url",
 			Type: "string",
@@ -112,11 +116,6 @@ func (ch *RocketChat) GetInfo() *plugin.Info {
 		},
 	}
 
-	configAttrs, err := json.Marshal(elements)
-	if err != nil {
-		panic(err)
-	}
-
 	return &plugin.Info{
 		Name:             "Rocket.Chat",
 		Version:          internal.Version.Version,

cmd/channels/webhook/main.go

@@ -27,7 +27,7 @@ type Webhook struct {
 }
 
 func (ch *Webhook) GetInfo() *plugin.Info {
-	elements := []*plugin.ConfigOption{
+	configAttrs := plugin.ConfigOptions{
 		{
 			Name: "method",
 			Type: "string",
@@ -65,7 +65,7 @@ func (ch *Webhook) GetInfo() *plugin.Info {
 				"en_US": "Go template applied to the current plugin.NotificationRequest to create an request body.",
 				"de_DE": "Go-Template über das zu verarbeitende plugin.NotificationRequest zum Erzeugen der mitgesendeten Anfragedaten.",
 			},
-			Default: `{{json .}}`,
+			Default: "{{json .}}",
 		},
 		{
 			Name: "response_status_codes",
@@ -82,11 +82,6 @@ func (ch *Webhook) GetInfo() *plugin.Info {
 		},
 	}
 
-	configAttrs, err := json.Marshal(elements)
-	if err != nil {
-		panic(err)
-	}
-
 	return &plugin.Info{
 		Name:             "Webhook",
 		Version:          internal.Version.Version,
@@ -96,7 +91,12 @@ func (ch *Webhook) GetInfo() *plugin.Info {
 }
 
 func (ch *Webhook) SetConfig(jsonStr json.RawMessage) error {
-	err := json.Unmarshal(jsonStr, ch)
+	err := plugin.PopulateDefaults(ch)
+	if err != nil {
+		return err
+	}
+
+	err = json.Unmarshal(jsonStr, ch)
 	if err != nil {
 		return err
 	}

pkg/plugin/plugin.go

@@ -1,6 +1,7 @@
 package plugin
 
 import (
+	"database/sql/driver"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -69,13 +70,23 @@ type ConfigOption struct {
 	Max types.Int `json:"max,omitempty"`
 }
 
+// ConfigOptions describes all ConfigOption entries.
+//
+// This type became necessary to implement the database.sql.driver.Valuer to marshal it into JSON.
+type ConfigOptions []ConfigOption
+
+// Value implements database.sql's driver.Valuer to represent all ConfigOptions as a JSON array.
+func (c ConfigOptions) Value() (driver.Value, error) {
+	return json.Marshal(c)
+}
+
 // Info contains plugin information.
 type Info struct {
-	Type             string          `db:"type" json:"-"`
-	Name             string          `db:"name" json:"name"`
-	Version          string          `db:"version" json:"version"`
-	Author           string          `db:"author" json:"author"`
-	ConfigAttributes json.RawMessage `db:"config_attrs" json:"config_attrs"` // ConfigOption(s) as json-encoded list
+	Type             string        `db:"type" json:"-"`
+	Name             string        `db:"name" json:"name"`
+	Version          string        `db:"version" json:"version"`
+	Author           string        `db:"author" json:"author"`
+	ConfigAttributes ConfigOptions `db:"config_attrs" json:"config_attrs"`
 }
 
 // TableName implements the contracts.TableNamer interface.
@@ -131,6 +142,25 @@ type Plugin interface {
 	SendNotification(req *NotificationRequest) error
 }
 
+// PopulateDefaults sets the struct fields from Info.ConfigAttributes where ConfigOption.Default is set.
+//
+// It should be called from each channel plugin within its Plugin.SetConfig before doing any further configuration.
+func PopulateDefaults(typePtr Plugin) error {
+	defaults := make(map[string]any)
+	for _, confAttr := range typePtr.GetInfo().ConfigAttributes {
+		if confAttr.Default != nil {
+			defaults[confAttr.Name] = confAttr.Default
+		}
+	}
+
+	defaultConf, err := json.Marshal(defaults)
+	if err != nil {
+		return err
+	}
+
+	return json.Unmarshal(defaultConf, typePtr)
+}
+
 // RunPlugin reads the incoming stdin requests, processes and writes the responses to stdout
 func RunPlugin(plugin Plugin) {
 	encoder := json.NewEncoder(os.Stdout)