(feat)helm: Allow dynamic dependency override (#2205)

Add the --requirements flag to install and upgrade commands

Signed-off-by: Fuxin Hao <haofxpro@gmail.com>

cmd/helm/install.go

@@ -114,6 +114,7 @@ type installCmd struct {
 	name           string
 	namespace      string
 	valueFiles     valueFiles
+	reqFile        string
 	chartPath      string
 	dryRun         bool
 	disableHooks   bool
@@ -195,6 +196,7 @@ func newInstallCmd(c helm.Interface, out io.Writer) *cobra.Command {
 	f := cmd.Flags()
 	settings.AddFlagsTLS(f)
 	f.VarP(&inst.valueFiles, "values", "f", "specify values in a YAML file or a URL(can specify multiple)")
+	f.StringVarP(&inst.reqFile, "requirements", "r", "", "specify a yaml file to override dependencies(specify 'none' to remove all dependencies)")
 	f.StringVarP(&inst.name, "name", "n", "", "release name. If unspecified, it will autogenerate one for you")
 	f.StringVar(&inst.namespace, "namespace", "", "namespace to install the release into. Defaults to the current kube config namespace.")
 	f.BoolVar(&inst.dryRun, "dry-run", false, "simulate an install")
@@ -254,6 +256,18 @@ func (i *installCmd) run() error {
 		return prettyError(err)
 	}
 
+	// Override the requirements
+	if i.reqFile != "" {
+		if err := chartutil.SetRequirements(chartRequested, i.reqFile); err != nil {
+			return prettyError(err)
+		}
+
+		// Run `helm dependency update` to update dependencies
+		i.depUp = true
+		// Ignore the existing dependencies
+		chartRequested.Dependencies = nil
+	}
+
 	if req, err := chartutil.LoadRequirements(chartRequested); err == nil {
 		// If checkDependencies returns an error, we have unfulfilled dependencies.
 		// As of Helm 2.4.0, this is treated as a stopping condition:
@@ -268,6 +282,9 @@ func (i *installCmd) run() error {
 					SkipUpdate: false,
 					Getters:    getter.All(settings),
 				}
+				if i.reqFile != "" {
+					man.Requirements = req
+				}
 				if err := man.Update(); err != nil {
 					return prettyError(err)
 				}
@@ -277,10 +294,18 @@ func (i *installCmd) run() error {
 				if err != nil {
 					return prettyError(err)
 				}
+
+				if i.reqFile != "" {
+					if err := chartutil.SetRequirements(chartRequested, i.reqFile); err != nil {
+						return prettyError(err)
+					}
+					if err := chartutil.RemoveDependenciesNotPresent(chartRequested); err != nil {
+						return prettyError(err)
+					}
+				}
 			} else {
 				return prettyError(err)
 			}
-
 		}
 	} else if err != chartutil.ErrRequirementsNotFound {
 		return fmt.Errorf("cannot load requirements: %v", err)

cmd/helm/upgrade.go

@@ -24,6 +24,8 @@ import (
 	"github.com/spf13/cobra"
 
 	"k8s.io/helm/pkg/chartutil"
+	"k8s.io/helm/pkg/downloader"
+	"k8s.io/helm/pkg/getter"
 	"k8s.io/helm/pkg/helm"
 	"k8s.io/helm/pkg/renderutil"
 	storageerrors "k8s.io/helm/pkg/storage/errors"
@@ -96,6 +98,7 @@ type upgradeCmd struct {
 	values       []string
 	stringValues []string
 	fileValues   []string
+	reqFile      string
 	verify       bool
 	keyring      string
 	install      bool
@@ -149,6 +152,7 @@ func newUpgradeCmd(client helm.Interface, out io.Writer) *cobra.Command {
 	f := cmd.Flags()
 	settings.AddFlagsTLS(f)
 	f.VarP(&upgrade.valueFiles, "values", "f", "specify values in a YAML file or a URL(can specify multiple)")
+	f.StringVarP(&upgrade.reqFile, "requirements", "r", "", "specify a yaml file to override dependencies(specify 'none' to remove all dependencies)")
 	f.BoolVar(&upgrade.dryRun, "dry-run", false, "simulate an upgrade")
 	f.BoolVar(&upgrade.recreate, "recreate-pods", false, "performs pods restart for the resource if applicable")
 	f.BoolVar(&upgrade.force, "force", false, "force resource update through delete/recreate if needed")
@@ -219,6 +223,7 @@ func (u *upgradeCmd) run() error {
 				out:          u.out,
 				name:         u.release,
 				valueFiles:   u.valueFiles,
+				reqFile:      u.reqFile,
 				dryRun:       u.dryRun,
 				verify:       u.verify,
 				disableHooks: u.disableHooks,
@@ -240,22 +245,60 @@ func (u *upgradeCmd) run() error {
 		return err
 	}
 
+	ch, err := chartutil.Load(chartPath)
+	if err != nil {
+		return prettyError(err)
+	}
+
+	// Override requirements
+	if u.reqFile != "" {
+		if err = chartutil.SetRequirements(ch, u.reqFile); err != nil {
+			return prettyError(err)
+		}
+
+		// Ignore existing dependencies
+		ch.Dependencies = nil
+	}
+
 	// Check chart requirements to make sure all dependencies are present in /charts
-	if ch, err := chartutil.Load(chartPath); err == nil {
-		if req, err := chartutil.LoadRequirements(ch); err == nil {
-			if err := renderutil.CheckDependencies(ch, req); err != nil {
-				return err
+	if req, err := chartutil.LoadRequirements(ch); err == nil {
+		if err := renderutil.CheckDependencies(ch, req); err != nil {
+			if u.reqFile != "" {
+				man := &downloader.Manager{
+					Out:          u.out,
+					ChartPath:    chartPath,
+					HelmHome:     settings.Home,
+					Keyring:      defaultKeyring(),
+					SkipUpdate:   false,
+					Getters:      getter.All(settings),
+					Requirements: req,
+				}
+				if err := man.Update(); err != nil {
+					return prettyError(err)
+				}
+
+				// Update all dependencies which are present in /charts.
+				ch, err = chartutil.Load(chartPath)
+				if err != nil {
+					return prettyError(err)
+				}
+				if err := chartutil.SetRequirements(ch, u.reqFile); err != nil {
+					return prettyError(err)
+				}
+				if err := chartutil.RemoveDependenciesNotPresent(ch); err != nil {
+					return prettyError(err)
+				}
+			} else {
+				return prettyError(err)
 			}
-		} else if err != chartutil.ErrRequirementsNotFound {
-			return fmt.Errorf("cannot load requirements: %v", err)
 		}
-	} else {
-		return prettyError(err)
+	} else if err != chartutil.ErrRequirementsNotFound {
+		return fmt.Errorf("cannot load requirements: %v", err)
 	}
 
-	resp, err := u.client.UpdateRelease(
+	resp, err := u.client.UpdateReleaseFromChart(
 		u.release,
-		chartPath,
+		ch,
 		helm.UpdateValueOverrides(rawVals),
 		helm.UpgradeDryRun(u.dryRun),
 		helm.UpgradeRecreate(u.recreate),

docs/helm/helm_install.md

@@ -95,6 +95,7 @@ helm install [CHART] [flags]
       --password string          chart repository password where to locate the requested chart
       --replace                  re-use the given name, even if that name is already used. This is unsafe in production
       --repo string              chart repository url where to locate the requested chart
+  -r, --requirements string      specify a yaml file to override dependencies(specify 'none' to remove all dependencies)
       --set stringArray          set values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
       --set-file stringArray     set values from respective files specified via the command line (can specify multiple or separate values with commas: key1=path1,key2=path2)
       --set-string stringArray   set STRING values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
@@ -128,4 +129,4 @@ helm install [CHART] [flags]
 
 * [helm](helm.md)	 - The Helm package manager for Kubernetes.
 
-###### Auto generated by spf13/cobra on 10-Aug-2018
+###### Auto generated by spf13/cobra on 16-Oct-2018

docs/helm/helm_upgrade.md

@@ -80,6 +80,7 @@ helm upgrade [RELEASE] [CHART] [flags]
       --password string          chart repository password where to locate the requested chart
       --recreate-pods            performs pods restart for the resource if applicable
       --repo string              chart repository url where to locate the requested chart
+  -r, --requirements string      specify a yaml file to override dependencies(specify 'none' to remove all dependencies)
       --reset-values             when upgrading, reset the values to the ones built into the chart
       --reuse-values             when upgrading, reuse the last release's values and merge in any overrides from the command line via --set and -f. If '--reset-values' is specified, this is ignored.
       --set stringArray          set values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
@@ -115,4 +116,4 @@ helm upgrade [RELEASE] [CHART] [flags]
 
 * [helm](helm.md)	 - The Helm package manager for Kubernetes.
 
-###### Auto generated by spf13/cobra on 24-Aug-2018
+###### Auto generated by spf13/cobra on 16-Oct-2018

pkg/chartutil/requirements.go

@@ -17,6 +17,8 @@ package chartutil
 
 import (
 	"errors"
+	"fmt"
+	"io/ioutil"
 	"log"
 	"strings"
 	"time"
@@ -27,8 +29,9 @@ import (
 )
 
 const (
-	requirementsName = "requirements.yaml"
-	lockfileName     = "requirements.lock"
+	requirementsName       = "requirements.yaml"
+	lockfileName           = "requirements.lock"
+	removeRequirementsName = "none"
 )
 
 var (
@@ -123,6 +126,46 @@ func LoadRequirementsLock(c *chart.Chart) (*RequirementsLock, error) {
 	return r, yaml.Unmarshal(data, r)
 }
 
+// SetRequirements sets a requirements file from an in-memory chart.
+func SetRequirements(c *chart.Chart, filename string) error {
+	var data []byte
+
+	if filename == removeRequirementsName {
+		data = []byte("dependencies:")
+	} else {
+		var err error
+		data, err = ioutil.ReadFile(filename)
+		if err != nil {
+			return fmt.Errorf("error reading %s: %s", filename, err)
+		}
+	}
+	for _, f := range c.Files {
+		if f.TypeUrl == requirementsName {
+			f.Value = data
+		}
+	}
+
+	return nil
+}
+
+// RemoveDependenciesNotPresent removes the charts not present in requirements
+func RemoveDependenciesNotPresent(c *chart.Chart) error {
+	var deps []*chart.Chart
+	req, err := LoadRequirements(c)
+	if err != nil {
+		return err
+	}
+	for _, depInRequestments := range req.Dependencies {
+		for _, dep := range c.Dependencies {
+			if depInRequestments.Name == dep.Metadata.Name {
+				deps = append(deps, dep)
+			}
+		}
+	}
+	c.Dependencies = deps
+	return nil
+}
+
 // ProcessRequirementsConditions disables charts based on condition path value in values
 func ProcessRequirementsConditions(reqs *Requirements, cvals Values) {
 	var cond string

pkg/downloader/manager.go

@@ -57,6 +57,8 @@ type Manager struct {
 	SkipUpdate bool
 	// Getter collection for the operation
 	Getters []getter.Provider
+	// Requirements is the requirements override
+	Requirements *chartutil.Requirements
 }
 
 // Build rebuilds a local charts directory from a lockfile.
@@ -113,15 +115,20 @@ func (m *Manager) Update() error {
 		return err
 	}
 
-	// If no requirements file is found, we consider this a successful
-	// completion.
-	req, err := chartutil.LoadRequirements(c)
-	if err != nil {
-		if err == chartutil.ErrRequirementsNotFound {
-			fmt.Fprintf(m.Out, "No requirements found in %s/charts.\n", m.ChartPath)
-			return nil
+	var req *chartutil.Requirements
+	if m.Requirements == nil {
+		// If no requirements file is found, we consider this a successful
+		// completion.
+		req, err = chartutil.LoadRequirements(c)
+		if err != nil {
+			if err == chartutil.ErrRequirementsNotFound {
+				fmt.Fprintf(m.Out, "No requirements found in %s/charts.\n", m.ChartPath)
+				return nil
+			}
+			return err
 		}
-		return err
+	} else {
+		req = m.Requirements
 	}
 
 	// Hash requirements.yaml