add webhook spec to Terminator

src/api/v1alpha1/terminator_logging.go

@@ -57,3 +57,22 @@ func (e EventsSpec) MarshalLogObject(enc zapcore.ObjectEncoder) error {
 	enc.AddString("stateChange", e.StateChange)
 	return nil
 }
+
+func (w WebhookSpec) MarshalLogObject(enc zapcore.ObjectEncoder) error {
+	enc.AddString("url", w.URL)
+	enc.AddString("proxyURL", w.ProxyURL)
+
+	enc.AddArray("headers", zapcore.ArrayMarshalerFunc(func(enc zapcore.ArrayEncoder) error {
+		for _, header := range w.Headers {
+			enc.AppendObject(zapcore.ObjectMarshalerFunc(func(enc zapcore.ObjectEncoder) error {
+				enc.AddString("name", header.Name)
+				enc.AddString("value", header.Value)
+				return nil
+			}))
+		}
+		return nil
+	}))
+
+	enc.AddString("template", w.Template)
+	return nil
+}

src/api/v1alpha1/terminator_types.go

@@ -34,6 +34,7 @@ type TerminatorSpec struct {
 	SQS         SQSSpec           `json:"sqs,omitempty"`
 	Drain       DrainSpec         `json:"drain,omitempty"`
 	Events      EventsSpec        `json:"events,omitempty"`
+	Webhook     WebhookSpec       `json:"webhook,omitempty"`
 }
 
 // SQSSpec defines inputs to SQS "receive messages" requests.
@@ -73,6 +74,20 @@ type EventsSpec struct {
 	StateChange             Action `json:"stateChange,omitempty"`
 }
 
+// HeaderSpec defines the HTTP headers to include with webhook notifications.
+type HeaderSpec struct {
+	Name  string `json:"name,omitempty"`
+	Value string `json:"value,omitempty"`
+}
+
+// WebhookSpec defines the configuration of webhook notifications to send when events are handled.
+type WebhookSpec struct {
+	URL      string       `json:"url,omitempty"`
+	ProxyURL string       `json:"proxyURL,omitempty"`
+	Headers  []HeaderSpec `json:"headers,omitempty"`
+	Template string       `json:"template,omitempty"`
+}
+
 // TerminatorStatus defines the observed state of Terminator
 type TerminatorStatus struct {
 	// INSERT ADDITIONAL STATUS FIELD - define observed state of cluster

src/api/v1alpha1/terminator_validation.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"fmt"
 	"net/url"
+	"text/template"
 
 	"k8s.io/apimachinery/pkg/util/sets"
 
@@ -44,6 +45,7 @@ func (t *TerminatorSpec) validate() (errs *apis.FieldError) {
 		t.validateMatchLabels().ViaField("matchLabels"),
 		t.SQS.validate().ViaField("sqs"),
 		t.Events.validate().ViaField("events"),
+		t.Webhook.validate().ViaField("webhook"),
 	)
 }
 
@@ -78,3 +80,28 @@ func (e *EventsSpec) validate() (errs *apis.FieldError) {
 	}
 	return errs
 }
+
+func (w *WebhookSpec) validate() (errs *apis.FieldError) {
+	if _, err := url.Parse(w.URL); err != nil {
+		errs = errs.Also(apis.ErrInvalidValue(w.URL, "url", err.Error()))
+	}
+
+	if _, err := url.Parse(w.ProxyURL); err != nil && w.ProxyURL != "" {
+		errs = errs.Also(apis.ErrInvalidValue(w.ProxyURL, "proxyURL", "must be a valid URL"))
+	}
+
+	for i, h := range w.Headers {
+		if h.Name != "" {
+			continue
+		}
+		errs = errs.Also(apis.ErrInvalidValue(h.Name, "name", "must not be empty").ViaFieldIndex("headers", i))
+	}
+
+	if w.Template == "" {
+		errs = errs.Also(apis.ErrInvalidValue(w.Template, "template", "must not be empty"))
+	} else if _, err := template.New("Validate").Parse(w.Template); err != nil {
+		errs = errs.Also(apis.ErrInvalidValue(w.Template, "template", err.Error()))
+	}
+
+	return errs
+}