Display values diff on upgrade

Only show diff if non-empty string

 - Disabled by default to prevent sensitive values from being leaked.
 - Also changed website in Chart.yaml
 - Added to readme

README.md

@@ -154,6 +154,7 @@ This will produce the following effect:
 | `googlechat.webhookUrl` | `KW_GOOGLECHAT_WEBHOOK_URL` |  | The Google Hangouts Chat URL to use. Must be provided by user. |
 | `namespaceToWatch` | `KW_NAMESPACE` | `""` | The cluster namespace to watch for Helm operations in. Leave blank to watch all namespaces. |
 | `messagePrefix` | `KW_MESSAGE_PREFIX` |  | A prefix for every notification sent. Often used to identify the cluster (production, staging etc). |
+| `chartValuesDiff.enabled` | `KW_CHART_VALUES_DIFF_ENABLED` | `false` | When `true`, KubeWise will log a diff of the chart values when a package is upgraded or rolled back. This is useful for visualizing changes between package versions. Be extremely careful with this feature as it can leak sensitive chart values. |
 | `image.repository` | | `us.gcr.io/larder-prod/kubewise` | Image repository |
 | `image.tag` | | `<VERSION>` | Image tag |
 | `replicaCount` | | `1` | Number of KubeWise pods to deploy. More than 1 is not desirable |

go.mod

@@ -3,17 +3,19 @@ module github.com/larderdev/kubewise
 go 1.14
 
 require (
-	github.com/Azure/go-autorest v14.0.0+incompatible
-	github.com/jmoiron/sqlx v1.2.0 // indirect
-	github.com/lib/pq v1.3.0 // indirect
+  github.com/Azure/go-autorest v14.0.0+incompatible
+	github.com/golang/groupcache v0.0.0-20190702054246-869f871628b6 // indirect
 	github.com/olekukonko/tablewriter v0.0.2
-	github.com/rubenv/sql-migrate v0.0.0-20200402132117-435005d389bc // indirect
+	github.com/pmezard/go-difflib v1.0.0
 	github.com/slack-go/slack v0.6.3
 	golang.org/x/lint v0.0.0-20200302205851-738671d3881b // indirect
 	golang.org/x/tools v0.0.0-20200410194907-79a7a3126eef // indirect
+	golang.org/x/net v0.0.0-20200226121028-0de0cce0169b // indirect
+	golang.org/x/sys v0.0.0-20191220142924-d4481acd189f // indirect
+	golang.org/x/time v0.0.0-20191024005414-555d28b269f0 // indirect
+	google.golang.org/appengine v1.6.5 // indirect
 	helm.sh/helm/v3 v3.1.1
 	k8s.io/api v0.17.3
 	k8s.io/apimachinery v0.17.3
 	k8s.io/client-go v0.17.2
-	k8s.io/helm v2.16.5+incompatible
 )

helm_chart/Chart.yaml

@@ -26,6 +26,6 @@ sources:
 maintainers:
   - name: davidtuite
     email: [email protected]
-    url: https://www.davidtuite.com
+    url: https://www.larder.dev/kubewise
 
 icon: https://github.com/larderdev/kubewise/blob/master/assets/kubewise-mark-blue-512x512.png

helm_chart/templates/deployment.yaml

@@ -52,3 +52,5 @@ spec:
               value: "{{ .Values.webhook.method }}"
             - name: KW_WEBHOOK_URL
               value: "{{ .Values.webhook.url }}"
+            - name: KW_CHART_VALUES_DIFF_ENABLED
+              value: "{{ .Values.chartValuesDiff.enabled }}"

helm_chart/values.yaml

@@ -27,6 +27,9 @@ webhook:
 namespaceToWatch: ""
 messagePrefix:
 
+chartValuesDiff:
+  enabled: false
+
 serviceAccount:
   # Specifies whether a service account should be created
   create: true

kwrelease/event.go

@@ -1,10 +1,13 @@
 package kwrelease
 
 import (
+	"fmt"
 	"log"
 	"strconv"
 	"strings"
 
+	"github.com/pmezard/go-difflib/difflib"
+	"helm.sh/helm/v3/pkg/chartutil"
 	rspb "helm.sh/helm/v3/pkg/release"
 	api_v1 "k8s.io/api/core/v1"
 	meta_v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -38,6 +41,8 @@ func (e *Event) Init() error {
 	e.currentRelease = e.GetRelease(e.CurrentReleaseSecret.Name)
 	e.previousRelease = e.getPreviousRelease()
 
+	e.GetConfigDiffYAML()
+
 	return nil
 }
 
@@ -137,6 +142,48 @@ func (e *Event) IsAppVersionChanged() bool {
 	return e.GetAppVersion() != e.GetPreviousAppVersion()
 }
 
+// GetConfigDiffYAML is useful to show what has changed during a chart upgrade or rollback. It
+// will show a diff of the values file in the Slack message or other notification. Be careful
+// with secrets.
+func (e *Event) GetConfigDiffYAML() string {
+	currentReleaseConfigYAML, err := chartutil.Values(e.currentRelease.Config).YAML()
+
+	if err != nil {
+		// Do NOT log the values. Could leak sensitive data.
+		log.Println("Error rendering current release config to YAML for application:", e.GetAppName())
+		return ""
+	}
+
+	if e.previousRelease == nil {
+		return fmt.Sprintf("%s\n", currentReleaseConfigYAML)
+	}
+
+	previousReleaseConfigYAML, err := chartutil.Values(e.previousRelease.Config).YAML()
+
+	if err != nil {
+		// Do NOT log the values. Could leak sensitive data.
+		log.Println("Error rendering previous release config to YAML for application:", e.GetAppName())
+		return ""
+	}
+
+	diff := difflib.UnifiedDiff{
+		A:        difflib.SplitLines(previousReleaseConfigYAML),
+		B:        difflib.SplitLines(currentReleaseConfigYAML),
+		FromFile: "Old Values",
+		ToFile:   "New Values",
+		Context:  3,
+	}
+
+	diffText, err := difflib.GetUnifiedDiffString(diff)
+
+	if err != nil {
+		log.Println("Error diffing chart for application:", e.GetAppName())
+		return ""
+	}
+
+	return diffText
+}
+
 // GetAction returns the action which is being performed in this Event. It may be an install,
 // upgrade or other Event.
 func (e *Event) GetAction() Action {

presenters/text.go

@@ -2,6 +2,7 @@ package presenters
 
 import (
 	"fmt"
+	"log"
 	"os"
 	"strconv"
 	"strings"
@@ -26,6 +27,21 @@ func getChangeInAppVersion(releaseEvent *kwrelease.Event) string {
 	return appVersion
 }
 
+func getConfigDiff(releaseEvent *kwrelease.Event) string {
+	showDiff, err := strconv.ParseBool(os.Getenv("KW_CHART_VALUES_DIFF_ENABLED"))
+
+	if err != nil {
+		log.Println("Invalid value passed for environment variable KW_CHART_VALUES_DIFF_ENABLED. Boolean required.")
+	}
+
+	configDiffYAML := releaseEvent.GetConfigDiffYAML()
+	if showDiff && configDiffYAML != "" {
+		return fmt.Sprintf("\n```%s```", configDiffYAML)
+	}
+
+	return ""
+}
+
 // PrepareMsg prepares a short, markdown-like message which is suitable for sending to chat
 // applications like Slack. Formatting like *text* us used to add emphasis. This is supported by
 // both Slack and Google Chat. Emoji are also used liberally.
@@ -51,6 +67,10 @@ func PrepareMsg(releaseEvent *kwrelease.Event) string {
 			getChangeInAppVersion(releaseEvent),
 		)
 
+		if configDiff := getConfigDiff(releaseEvent); configDiff != "" {
+			msg += configDiff
+		}
+
 	case kwrelease.ActionPreRollback:
 		msg += fmt.Sprintf("⏬ Rolling back *%s* from version %s to version *%s* in namespace *%s* via Helm. ⏳\n%s",
 			releaseEvent.GetAppName(),
@@ -60,6 +80,10 @@ func PrepareMsg(releaseEvent *kwrelease.Event) string {
 			getChangeInAppVersion(releaseEvent),
 		)
 
+		if configDiff := getConfigDiff(releaseEvent); configDiff != "" {
+			msg += configDiff
+		}
+
 	case kwrelease.ActionPreUninstall:
 		msg += fmt.Sprintf("🧼 Uninstalling *%s* from namespace *%s* via Helm. ⏳",
 			releaseEvent.GetAppName(),
@@ -75,30 +99,27 @@ func PrepareMsg(releaseEvent *kwrelease.Event) string {
 		)
 
 	case kwrelease.ActionPostUpgrade:
-		msg += fmt.Sprintf("⏫ Upgraded *%s* from version %s to version *%s* in namespace *%s* via Helm. ✅\n\n```%s```",
+		msg += fmt.Sprintf("⏫ Upgraded *%s* from version %s to version *%s* in namespace *%s* via Helm. ✅",
 			releaseEvent.GetAppName(),
 			releaseEvent.GetPreviousChartVersion(),
 			releaseEvent.GetChartVersion(),
 			releaseEvent.GetNamespace(),
-			releaseEvent.GetNotes(),
 		)
 
 	case kwrelease.ActionPostRollback:
-		msg += fmt.Sprintf("⏬ Rolled back *%s* from version %s to version *%s* in namespace *%s* via Helm. ✅\n\n```%s```",
+		msg += fmt.Sprintf("⏬ Rolled back *%s* from version %s to version *%s* in namespace *%s* via Helm. ✅",
 			releaseEvent.GetAppName(),
 			releaseEvent.GetPreviousChartVersion(),
 			releaseEvent.GetChartVersion(),
 			releaseEvent.GetNamespace(),
-			releaseEvent.GetNotes(),
 		)
 
 	case kwrelease.ActionPostReplace:
-		msg += fmt.Sprintf("Replaced *%s* version %s with version *%s* in namespace *%s* via Helm. ✅\n\n```%s```",
+		msg += fmt.Sprintf("Replaced *%s* version %s with version *%s* in namespace *%s* via Helm. ✅",
 			releaseEvent.GetAppName(),
 			releaseEvent.GetPreviousChartVersion(),
 			releaseEvent.GetChartVersion(),
 			releaseEvent.GetNamespace(),
-			releaseEvent.GetNotes(),
 		)
 
 	case kwrelease.ActionFailedInstall: