Add support for --dry-run in Helm Client

pkg/app/cassandra.go

@@ -92,7 +92,7 @@ func (cas *CassandraInstance) Install(ctx context.Context, namespace string) err
 	if err != nil {
 		return err
 	}
-	err = cli.Install(ctx, fmt.Sprintf("%s/%s", cas.chart.RepoName, cas.chart.Chart), cas.chart.Version, cas.chart.Release, cas.namespace, cas.chart.Values, true)
+	_, err = cli.Install(ctx, fmt.Sprintf("%s/%s", cas.chart.RepoName, cas.chart.Chart), cas.chart.Version, cas.chart.Release, cas.namespace, cas.chart.Values, true, false)
 	if err != nil {
 		return err
 	}

pkg/app/cockroachdb.go

@@ -70,7 +70,7 @@ func (c *CockroachDB) Install(ctx context.Context, namespace string) error { //n
 		return errors.Wrapf(err, "Failed to install helm repo. app=%s repo=%s", c.name, c.chart.RepoName)
 	}
 
-	err = cli.Install(ctx, fmt.Sprintf("%s/%s", c.chart.RepoName, c.chart.Chart), c.chart.Version, c.chart.Release, c.namespace, c.chart.Values, false)
+	_, err = cli.Install(ctx, fmt.Sprintf("%s/%s", c.chart.RepoName, c.chart.Chart), c.chart.Version, c.chart.Release, c.namespace, c.chart.Values, false, false)
 	return errors.Wrapf(err, "Failed to install helm chart. app=%s chart=%s release=%s", c.name, c.chart.Chart, c.chart.Release)
 }
 

pkg/app/couchbase.go

@@ -96,7 +96,7 @@ func (cb *CouchbaseDB) Install(ctx context.Context, ns string) error { //nolint:
 	}
 
 	// Install cb operator, admission controller and cluster
-	err = cli.Install(ctx, fmt.Sprintf("%s/%s", cb.chart.RepoName, cb.chart.Chart), cb.chart.Version, cb.chart.Release, cb.namespace, cb.chart.Values, true)
+	_, err = cli.Install(ctx, fmt.Sprintf("%s/%s", cb.chart.RepoName, cb.chart.Chart), cb.chart.Version, cb.chart.Release, cb.namespace, cb.chart.Values, true, false)
 	return errors.Wrapf(err, "Failed to install helm chart. app=%s chart=%s release=%s", cb.name, cb.chart.Chart, cb.chart.Release)
 }
 

pkg/app/elasticsearch.go

@@ -99,7 +99,7 @@ func (esi *ElasticsearchInstance) Install(ctx context.Context, namespace string)
 		return err
 	}
 
-	err = cli.Install(ctx, fmt.Sprintf("%s/%s", esi.chart.RepoName, esi.chart.Chart), esi.chart.Version, esi.chart.Release, esi.namespace, esi.chart.Values, true)
+	_, err = cli.Install(ctx, fmt.Sprintf("%s/%s", esi.chart.RepoName, esi.chart.Chart), esi.chart.Version, esi.chart.Release, esi.namespace, esi.chart.Values, true, false)
 	if err != nil {
 		return err
 	}

pkg/app/kafka.go

@@ -132,7 +132,7 @@ func (kc *KafkaCluster) Install(ctx context.Context, namespace string) error {
 		return errors.Wrapf(err, "Error adding helm repo for app %s.", kc.name)
 	}
 	log.Print("Installing kafka operator using helm.", field.M{"app": kc.name})
-	err = cli.Install(ctx, kc.chart.RepoName+"/"+kc.chart.Chart, kc.chart.Version, kc.chart.Release, kc.namespace, kc.chart.Values, true)
+	_, err = cli.Install(ctx, kc.chart.RepoName+"/"+kc.chart.Chart, kc.chart.Version, kc.chart.Release, kc.namespace, kc.chart.Values, true, false)
 	if err != nil {
 		return errors.Wrapf(err, "Error installing operator %s through helm.", kc.name)
 	}

pkg/app/mariadb.go

@@ -87,7 +87,7 @@ func (m *MariaDB) Install(ctx context.Context, namespace string) error { //nolin
 	}
 
 	log.Print("Installing maria instance using helm.", field.M{"app": m.name})
-	err = cli.Install(ctx, m.chart.RepoName+"/"+m.chart.Chart, m.chart.Version, m.chart.Release, m.namespace, m.chart.Values, true)
+	_, err = cli.Install(ctx, m.chart.RepoName+"/"+m.chart.Chart, m.chart.Version, m.chart.Release, m.namespace, m.chart.Values, true, false)
 	if err != nil {
 		return errors.Wrapf(err, "Error intalling application %s through helm.", m.name)
 	}

pkg/app/mongodb.go

@@ -102,7 +102,7 @@ func (mongo *MongoDB) Install(ctx context.Context, namespace string) error {
 	}
 
 	log.Print("Installing application using helm.", field.M{"app": mongo.name})
-	err = cli.Install(ctx, fmt.Sprintf("%s/%s", mongo.chart.RepoName, mongo.chart.Chart), mongo.chart.Version, mongo.chart.Release, mongo.namespace, mongo.chart.Values, true)
+	_, err = cli.Install(ctx, fmt.Sprintf("%s/%s", mongo.chart.RepoName, mongo.chart.Chart), mongo.chart.Version, mongo.chart.Release, mongo.namespace, mongo.chart.Values, true, false)
 	if err != nil {
 		return err
 	}

pkg/app/mysql.go

@@ -96,7 +96,7 @@ func (mdb *MysqlDB) Install(ctx context.Context, namespace string) error { //nol
 	}
 
 	log.Print("Installing mysql instance using helm.", field.M{"app": mdb.name})
-	err = cli.Install(ctx, mdb.chart.RepoName+"/"+mdb.chart.Chart, mdb.chart.Version, mdb.chart.Release, mdb.namespace, mdb.chart.Values, true)
+	_, err = cli.Install(ctx, mdb.chart.RepoName+"/"+mdb.chart.Chart, mdb.chart.Version, mdb.chart.Release, mdb.namespace, mdb.chart.Values, true, false)
 	if err != nil {
 		return errors.Wrapf(err, "Error intalling application %s through helm.", mdb.name)
 	}

pkg/app/postgresql.go

@@ -95,7 +95,8 @@ func (pdb *PostgresDB) Install(ctx context.Context, ns string) error {
 		return err
 	}
 	// Install helm chart
-	return cli.Install(ctx, fmt.Sprintf("%s/%s", pdb.chart.RepoName, pdb.chart.Chart), pdb.chart.Version, pdb.chart.Release, pdb.namespace, pdb.chart.Values, true)
+	_, err = cli.Install(ctx, fmt.Sprintf("%s/%s", pdb.chart.RepoName, pdb.chart.Chart), pdb.chart.Version, pdb.chart.Release, pdb.namespace, pdb.chart.Values, true, false)
+	return err
 }
 
 func (pdb *PostgresDB) IsReady(ctx context.Context) (bool, error) {

pkg/helm/client.go

@@ -128,8 +128,10 @@ func (h CliClient) UpdateRepo(ctx context.Context) error {
 	return nil
 }
 
-// Install installs helm chart with given release name
-func (h CliClient) Install(ctx context.Context, chart, version, release, namespace string, values map[string]string, wait bool) error {
+// Install installs helm chart with given release name.
+// The output string is to check the generated manifests of a release without installing the chart when ‘dryRun’ flags combined.
+// For normal installation, this output string is blank.
+func (h CliClient) Install(ctx context.Context, chart, version, release, namespace string, values map[string]string, wait, dryRun bool) (string, error) {
 	log.Debug().Print("Installing helm chart", field.M{"chart": chart, "version": version, "release": release, "namespace": namespace})
 	var setVals string
 	for k, v := range values {
@@ -140,14 +142,24 @@ func (h CliClient) Install(ctx context.Context, chart, version, release, namespa
 	if wait {
 		cmd = append(cmd, "--wait")
 	}
-
+	if !dryRun {
+		out, err := RunCmdWithTimeout(ctx, h.helmBin, cmd)
+		if err != nil {
+			log.Error().Print("Error installing helm chart", field.M{"output": out})
+			return "", err
+		}
+		log.Debug().Print("Result", field.M{"output": out})
+		return out, nil
+	}
+	cmd = append(cmd, "--dry-run")
+	log.Debug().Print("Executing helm install command with dry-run enabled to capture rendered manifests:")
 	out, err := RunCmdWithTimeout(ctx, h.helmBin, cmd)
 	if err != nil {
-		log.Error().Print("Error installing helm chart", field.M{"output": out})
-		return err
+		log.Error().Print("Error capturing output during Helm dry-run", field.M{"output": out, "error": err})
+		return "", err
 	}
-	log.Debug().Print("Result", field.M{"output": out})
-	return nil
+	log.Debug().Print("Helm dry-run output:", field.M{"command": h.helmBin, "args": cmd, "output": out})
+	return out, nil
 }
 
 func (h CliClient) Upgrade(ctx context.Context, chart, version, release, namespace string, values map[string]string) error {

pkg/helm/helm.go

@@ -27,7 +27,7 @@ type Client interface {
 	RemoveRepo(ctx context.Context, name string) error
 	// Install installs helm chart with given release name in the namespace
 	// wait argument enables/disables --wait flag in 'helm install' command
-	Install(ctx context.Context, chart, version, release, namespace string, values map[string]string, wait bool) error
+	Install(ctx context.Context, chart, version, release, namespace string, values map[string]string, wait, dryRun bool) (string, error)
 	// Uninstall deletes helm release from the given namespace
 	Uninstall(ctx context.Context, release, namespace string) error
 	// Upgrade upgrades an installed helm release

pkg/helm/helm_helpers.go

@@ -0,0 +1,96 @@
+// Copyright 2022 The Kanister Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package helm
+
+import (
+	"regexp"
+	"strings"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"sigs.k8s.io/yaml"
+
+	"github.com/kanisterio/kanister/pkg/field"
+	"github.com/kanisterio/kanister/pkg/log"
+)
+
+type k8sObj struct {
+	ObjKind  string            `json:"kind"`
+	MetaData metav1.ObjectMeta `json:"metadata"`
+}
+
+type K8sObjectType string
+
+type Component struct {
+	k8sType K8sObjectType
+	name    string
+}
+
+// ReleaseNameFromRenderedOutput takes as input the rendered output from a dry-run enabled HelmApp Install and tries to
+// extract the release name from it for validation.
+func ReleaseNameFromRenderedOutput(helmStatus string) string {
+	re := regexp.MustCompile(`.*NAME:\s+(.*)\n`)
+	withNameRE := regexp.MustCompile(`^Release\s+"(.*)"\s+`)
+	tmpRelease := re.FindAllStringSubmatch(helmStatus, -1)
+	log.Debug().Print("Parsed output for generate name install")
+	if len(tmpRelease) < 1 {
+		tmpRelease = withNameRE.FindAllStringSubmatch(helmStatus, -1)
+		log.Debug().Print("Parsed output for specified name install/upgrade")
+		if len(tmpRelease) < 1 {
+			return ""
+		}
+	}
+	if len(tmpRelease[0]) == 2 {
+		return tmpRelease[0][1]
+	}
+	return ""
+}
+
+// ComponentsFromManifest is helper utility function that takes input the rendered output from dry-run enabled HelmApp Install and
+// return a slice of struct Component. This struct holds basic information about all the resources that are going to be deployed when
+// helm install is run in actual.
+func ComponentsFromManifest(manifest string) []Component {
+	var ret []Component
+	// Get rid of the notes section
+	parts := strings.Split(manifest, "NOTES:")
+	// Now only take the resources to be deployed
+	parts = strings.Split(parts[0], "---")
+	/*
+		Ignore the part that includes:
+		  NAME: something
+
+		  LAST DEPLOYED: something
+
+		  NAMESPACE: something
+
+		  STATUS: something
+
+		  REVISION: something
+
+		  TEST SUITE: something
+
+		  HOOKS:
+
+		  MANIFEST:
+	*/
+	for _, objYaml := range parts[1:] {
+		tmpK8s := k8sObj{}
+		if err := yaml.Unmarshal([]byte(objYaml), &tmpK8s); err != nil {
+			log.Error().Print("failed to Unmarshal k8s obj", field.M{"Error": err})
+			continue
+		}
+		ret = append(ret, Component{k8sType: K8sObjectType(strings.ToLower(tmpK8s.ObjKind)), name: tmpK8s.MetaData.Name})
+	}
+	return ret
+}

pkg/testing/helm/helm_app.go

@@ -50,9 +50,9 @@ func (h *HelmApp) AddRepo(name, url string) error {
 	return h.client.AddRepo(context.Background(), name, url)
 }
 
-func (h *HelmApp) Install() error {
+func (h *HelmApp) Install() (string, error) {
 	ctx := context.Background()
-	return h.client.Install(ctx, h.chart, "", h.name, h.namespace, h.helmValues, true)
+	return h.client.Install(ctx, h.chart, "", h.name, h.namespace, h.helmValues, true, h.dryRun)
 }
 
 func (h *HelmApp) Upgrade(chart string, updatedValues map[string]string) error {

pkg/testing/helm/helm_test.go

@@ -23,6 +23,7 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes"
 
+	"github.com/kanisterio/kanister/pkg/helm"
 	"github.com/kanisterio/kanister/pkg/kube"
 )
 
@@ -72,9 +73,9 @@ func (h *HelmTestSuite) TestUpgrade(c *C) {
 
 	// install released version of kanister
 	c.Log("Installing kanister release")
-	err := h.helmApp.Install()
+	// TODO: Use manifests to test the helm charts
+	_, err := h.helmApp.Install()
 	c.Assert(err, IsNil)
-
 	// wait for kanister deployment to be ready
 	err = kube.WaitOnDeploymentReady(ctx, h.kubeClient, h.helmApp.namespace, h.deploymentName)
 	c.Assert(err, IsNil)
@@ -92,6 +93,40 @@ func (h *HelmTestSuite) TestUpgrade(c *C) {
 	c.Assert(err, IsNil)
 }
 
+func (h *HelmTestSuite) TestDryRunInstall(c *C) {
+	defer func() {
+		h.helmApp.dryRun = false
+	}()
+	c.Log("Installing kanister release - Dry run")
+	h.helmApp.dryRun = true
+	out, err := h.helmApp.Install()
+	c.Assert(err, IsNil)
+	releaseName := helm.ReleaseNameFromRenderedOutput(out)
+	c.Assert(releaseName, Equals, kanisterName)
+}
+
+func (h *HelmTestSuite) TestComponentsFromManifestAfterDryRunHelmInstall(c *C) {
+	defer func() {
+		h.helmApp.dryRun = false
+	}()
+	c.Log("Installing kanister release - Dry run")
+	h.helmApp.dryRun = true
+	out, err := h.helmApp.Install()
+	c.Assert(err, IsNil)
+	components := helm.ComponentsFromManifest(out)
+	/*
+		Following are components from kanister include :
+		1. kanister-kanister-operator (serviceaccount)
+		2. kanister-kanister-operator-cluster-role (clusterrole)
+		3. kanister-kanister-operator-edit-role (clusterrolebinding)
+		4. kanister-kanister-operator-cr-role (clusterrolebinding)
+		5. kanister-kanister-operator-pv-provisioner (clusterrolebinding)
+		6. kanister-kanister-operator (service)
+		7. kanister-kanister-operator (deployment)
+	*/
+	c.Assert(len(components), Equals, 7)
+}
+
 func (h *HelmTestSuite) TearDownSuite(c *C) {
 	c.Log("Uninstalling chart")
 	err := h.helmApp.Uninstall()