diff --git a/cmd/helm/show.go b/cmd/helm/show.go index c122d8476..fe5eaee26 100644 --- a/cmd/helm/show.go +++ b/cmd/helm/show.go @@ -151,6 +151,9 @@ func addShowFlags(subCmd *cobra.Command, client *action.Show) { f := subCmd.Flags() f.BoolVar(&client.Devel, "devel", false, "use development versions, too. Equivalent to version '>0.0.0-0'. If --version is set, this is ignored") + if subCmd.Name() == "values" { + f.StringVar(&client.JSONPathTemplate, "jsonpath", "", "supply a JSONPath expression to filter the output") + } addChartPathOptionsFlags(f, &client.ChartPathOptions) err := subCmd.RegisterFlagCompletionFunc("version", func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) { diff --git a/pkg/action/show.go b/pkg/action/show.go index 9baa9cf43..4eab2b4fd 100644 --- a/pkg/action/show.go +++ b/pkg/action/show.go @@ -20,6 +20,8 @@ import ( "fmt" "strings" + "github.com/pkg/errors" + "k8s.io/cli-runtime/pkg/printers" "sigs.k8s.io/yaml" "helm.sh/helm/v3/pkg/chart" @@ -52,9 +54,10 @@ func (o ShowOutputFormat) String() string { // It provides the implementation of 'helm show' and its respective subcommands. type Show struct { ChartPathOptions - Devel bool - OutputFormat ShowOutputFormat - chart *chart.Chart // for testing + Devel bool + OutputFormat ShowOutputFormat + JSONPathTemplate string + chart *chart.Chart // for testing } // NewShow creates a new Show object with the given configuration. @@ -87,9 +90,17 @@ func (s *Show) Run(chartpath string) (string, error) { if s.OutputFormat == ShowAll { fmt.Fprintln(&out, "---") } - for _, f := range s.chart.Raw { - if f.Name == chartutil.ValuesfileName { - fmt.Fprintln(&out, string(f.Data)) + if s.JSONPathTemplate != "" { + printer, err := printers.NewJSONPathPrinter(s.JSONPathTemplate) + if err != nil { + return "", errors.Wrapf(err, "error parsing jsonpath %s", s.JSONPathTemplate) + } + printer.Execute(&out, s.chart.Values) + } else { + for _, f := range s.chart.Raw { + if f.Name == chartutil.ValuesfileName { + fmt.Fprintln(&out, string(f.Data)) + } } } } diff --git a/pkg/action/show_test.go b/pkg/action/show_test.go index 7be9daaa5..a2efdc8ac 100644 --- a/pkg/action/show_test.go +++ b/pkg/action/show_test.go @@ -69,3 +69,17 @@ func TestShowNoValues(t *testing.T) { t.Errorf("expected empty values buffer, got %s", output) } } + +func TestShowValuesByJsonPathFormat(t *testing.T) { + client := NewShow(ShowValues) + client.JSONPathTemplate = "{$.nestedKey.simpleKey}" + client.chart = buildChart(withSampleValues()) + output, err := client.Run("") + if err != nil { + t.Fatal(err) + } + expect := "simpleValue" + if output != expect { + t.Errorf("Expected\n%q\nGot\n%q\n", expect, output) + } +}