Add action methods in controller

internal/pkg/controller/controller.go

@@ -3,7 +3,10 @@ package controller
 import (
 	"time"
 	"fmt"
-
+	"strings"
+	"bytes"
+	"sort"
+	
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/apimachinery/pkg/util/runtime"
 	informerruntime "k8s.io/apimachinery/pkg/runtime"
@@ -13,10 +16,13 @@ import (
 	"k8s.io/client-go/tools/cache"
 	"k8s.io/client-go/util/workqueue"
 	"github.com/sirupsen/logrus"
-	"github.com/stakater/Reloader/internal/pkg/actions"
+	"github.com/pkg/errors"
+	"k8s.io/api/core/v1"
+	meta_v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
 const (
+	updateOnChangeAnnotation = "reloader.stakater.com/update-on-change"
 	// AllNamespaces as our controller will be looking for events in all namespaces
 	AllNamespaces = "temp-reloader"
 )
@@ -36,7 +42,6 @@ type Controller struct {
 	queue         workqueue.RateLimitingInterface
 	informer      cache.Controller
 	resource	  string
-	Actions       []actions.Action
 
 	stopCh chan struct{}
 }
@@ -155,16 +160,14 @@ func (c *Controller) takeAction(event Event) error {
 	} else {
 		logrus.Infof("Detected changes in object %s", obj)
 		// process events based on its type
-		for _, action := range c.Actions {
-			logrus.Infof("Performing '%s' action for controller of type '%s'", event.eventType, c.resource)
-			switch event.eventType {
+		logrus.Infof("Performing '%s' action for controller of type '%s'", event.eventType, c.resource)
+		switch event.eventType {
 			case "create":
-				action.ObjectCreated(obj, c.client)
+				ObjectCreated(obj, c.client)
 			case "update":
-				action.ObjectUpdated(obj, c.client)
+				ObjectUpdated(obj, c.client)
 			case "delete":
-				action.ObjectDeleted(obj)
-			}
+				ObjectDeleted(obj)
 		}
 	}
 	return nil
@@ -194,4 +197,136 @@ func (c *Controller) handleErr(err error, key interface{}) {
 	// Report to an external entity that, even after several retries, we could not successfully process this key
 	runtime.HandleError(err)
 	logrus.Infof("Dropping the key %q out of the queue: %v", key, err)
+}
+
+// ObjectCreated Do nothing for default handler
+func ObjectCreated(obj interface{}, client kubernetes.Interface) {
+	message := "Configmap: `" + obj.(*v1.ConfigMap).Name + "`has been created in Namespace: `" + obj.(*v1.ConfigMap).Namespace + "`"
+	logrus.Infof(message)
+	err := rollingUpgradeDeployments(obj, client)
+	if err != nil {
+		logrus.Errorf("failed to update Deployment: %v", err)
+	}
+}
+
+// ObjectDeleted Do nothing for default handler
+func ObjectDeleted(obj interface{}) {
+
+}
+
+// ObjectUpdated Do nothing for default handler
+func ObjectUpdated(oldObj interface{}, client kubernetes.Interface) {
+	message := "Configmap: `" + oldObj.(*v1.ConfigMap).Name + "`has been updated in Namespace: `" + oldObj.(*v1.ConfigMap).Namespace + "`"
+	logrus.Infof(message)
+	err := rollingUpgradeDeployments(oldObj, client)
+	if err != nil {
+		logrus.Errorf("failed to update Deployment: %v", err)
+	}
+}
+
+// Implementation has been borrowed from fabric8io/configmapcontroller
+// Method has been modified a little to use updated liberaries.
+func rollingUpgradeDeployments(oldObj interface{}, client kubernetes.Interface) error {
+	ns := oldObj.(*v1.ConfigMap).Namespace
+	configMapName := oldObj.(*v1.ConfigMap).Name
+	configMapVersion := convertConfigMapToToken(oldObj.(*v1.ConfigMap))
+
+	deployments, err := client.Apps().Deployments(ns).List(meta_v1.ListOptions{})
+	if err != nil {
+		return errors.Wrap(err, "failed to list deployments")
+	}
+	for _, d := range deployments.Items {
+		containers := d.Spec.Template.Spec.Containers
+		// match deployments with the correct annotation
+		annotationValue, _ := d.ObjectMeta.Annotations[updateOnChangeAnnotation]
+		if annotationValue != "" {
+			values := strings.Split(annotationValue, ",")
+			matches := false
+			for _, value := range values {
+				if value == configMapName {
+					matches = true
+					break
+				}
+			}
+			if matches {
+				updateContainers(containers, annotationValue, configMapVersion)
+
+				// update the deployment
+				_, err := client.Apps().Deployments(ns).Update(&d)
+				if err != nil {
+					return errors.Wrap(err, "update deployment failed")
+				}
+				logrus.Infof("Updated Deployment %s", d.Name)
+			}
+		}
+	}
+	return nil
+}
+
+func updateContainers(containers []v1.Container, annotationValue, configMapVersion string) bool {
+	// we can have multiple configmaps to update
+	answer := false
+	configmaps := strings.Split(annotationValue, ",")
+	for _, cmNameToUpdate := range configmaps {
+		configmapEnvar := "STAKATER_" + convertToEnvVarName(cmNameToUpdate) + "_CONFIGMAP"
+
+		for i := range containers {
+			envs := containers[i].Env
+			matched := false
+			for j := range envs {
+				if envs[j].Name == configmapEnvar {
+					matched = true
+					if envs[j].Value != configMapVersion {
+						logrus.Infof("Updating %s to %s", configmapEnvar, configMapVersion)
+						envs[j].Value = configMapVersion
+						answer = true
+					}
+				}
+			}
+			// if no existing env var exists lets create one
+			if !matched {
+				e := v1.EnvVar{
+					Name:  configmapEnvar,
+					Value: configMapVersion,
+				}
+				containers[i].Env = append(containers[i].Env, e)
+				answer = true
+			}
+		}
+	}
+	return answer
+}
+
+// convertToEnvVarName converts the given text into a usable env var
+// removing any special chars with '_'
+func convertToEnvVarName(text string) string {
+	var buffer bytes.Buffer
+	lower := strings.ToUpper(text)
+	lastCharValid := false
+	for i := 0; i < len(lower); i++ {
+		ch := lower[i]
+		if (ch >= 'A' && ch <= 'Z') || (ch >= '0' && ch <= '9') {
+			buffer.WriteString(string(ch))
+			lastCharValid = true
+		} else {
+			if lastCharValid {
+				buffer.WriteString("_")
+			}
+			lastCharValid = false
+		}
+	}
+	return buffer.String()
+}
+
+// lets convert the configmap into a unique token based on the data values
+func convertConfigMapToToken(cm *v1.ConfigMap) string {
+	values := []string{}
+	for k, v := range cm.Data {
+		values = append(values, k+"="+v)
+	}
+	sort.Strings(values)
+	text := strings.Join(values, ";")
+	// we could zip and base64 encode
+	// but for now we could leave this easy to read so that its easier to diagnose when & why things changed
+	return text
 }