feat(pkg/cmd): get subcommand

Author: leodido

pkg/cmd/get.go

@@ -0,0 +1,115 @@
+package cmd
+
+import (
+	"fmt"
+
+	"github.com/fntlnz/kubectl-trace/factory"
+	"github.com/spf13/cobra"
+	"k8s.io/cli-runtime/pkg/genericclioptions"
+	// "k8s.io/kubernetes/pkg/kubectl/util/templates"
+)
+
+var (
+	getCommand = "get"
+	getShort   = `Get the running traces` // Wrap with i18n.T()
+	getLong    = getShort + `
+	
+...`
+
+	getExamples = `
+  # Get all traces in a namespace
+  %[1]s trace get -n myns
+
+  # Get only a specific trace
+  %[1]s trace get 656ee75a-ee3c-11e8-9e7a-8c164500a77e
+
+  # Get only a specific trace in a specific namespace
+  %[1]s trace get 656ee75a-ee3c-11e8-9e7a-8c164500a77e -n myns
+
+  # Get all traces in all namespaces
+  %[1]s trace get --all-namespaces`
+
+	argumentsErr     = fmt.Sprintf("at most one argument for %s command", getCommand)
+	missingTargetErr = fmt.Sprintf("specify either a TRACE_ID or a namespace or all namespaces")
+)
+
+// GetOptions ...
+type GetOptions struct {
+	genericclioptions.IOStreams
+	ResourceBuilderFlags *genericclioptions.ResourceBuilderFlags
+
+	namespace         string
+	explicitNamespace bool
+
+	// Local to this command
+	allNamespaces bool
+	traceArg      string
+}
+
+// NewGetOptions provides an instance of GetOptions with default values.
+func NewGetOptions(streams genericclioptions.IOStreams) *GetOptions {
+	rbFlags := &genericclioptions.ResourceBuilderFlags{}
+	rbFlags.WithAllNamespaces(false)
+
+	return &GetOptions{
+		ResourceBuilderFlags: rbFlags,
+		IOStreams:            streams,
+	}
+}
+
+// NewGetCommand provides the get command wrapping GetOptions.
+func NewGetCommand(factory factory.Factory, streams genericclioptions.IOStreams) *cobra.Command {
+	o := NewGetOptions(streams)
+
+	cmd := &cobra.Command{
+		Use:          fmt.Sprintf("%s [TRACE_ID]", getCommand),
+		Short:        getShort,
+		Long:         getLong,                             // wrap with templates.LongDesc()
+		Example:      fmt.Sprintf(getExamples, "kubectl"), // wrap with templates.Examples()
+		SilenceUsage: true,
+		PreRunE: func(c *cobra.Command, args []string) error {
+			return o.Validate(c, args)
+		},
+		RunE: func(c *cobra.Command, args []string) error {
+			if err := o.Complete(factory, c, args); err != nil {
+				return err
+			}
+			return nil
+		},
+	}
+
+	o.ResourceBuilderFlags.AddFlags(cmd.Flags())
+
+	return cmd
+}
+
+// Validate validates the arguments and flags populating GetOptions accordingly.
+func (o *GetOptions) Validate(cmd *cobra.Command, args []string) error {
+	switch len(args) {
+	case 0:
+		break
+	case 1:
+		o.traceArg = args[0]
+		break
+	default:
+		return fmt.Errorf(argumentsErr)
+	}
+
+	return nil
+}
+
+// Complete completes the setup of the command.
+func (o *GetOptions) Complete(factory factory.Factory, cmd *cobra.Command, args []string) error {
+	o.namespace, o.explicitNamespace, _ = factory.ToRawKubeConfigLoader().Namespace()
+
+	if cmd.Flag("all-namespaces").Changed {
+		o.allNamespaces = *o.ResourceBuilderFlags.AllNamespaces
+		o.explicitNamespace = false
+		o.namespace = ""
+	}
+	if o.traceArg == "" && !o.allNamespaces && !o.explicitNamespace {
+		return fmt.Errorf(missingTargetErr)
+	}
+
+	return nil
+}