Move workflow to plugins

Makefile

@@ -5,6 +5,10 @@ EXECUTABLE_CLI := airshipctl
 
 SCRIPTS_DIR    := scripts
 
+PLUGIN_DIR     := plugins
+PLUGIN_SOURCES := $(wildcard $(PLUGIN_DIR)/*/*.go)
+PLUGIN_OBJECTS := $(PLUGIN_SOURCES:%.go=%.so)
+
 # linting
 LINTER_CMD     := "github.com/golangci/golangci-lint/cmd/golangci-lint" run
 ADDTL_LINTERS  := goconst,gofmt,lll,unparam
@@ -61,3 +65,9 @@ update-golden: TESTFLAGS += -update -v
 update-golden: PKG = github.com/ian-howell/airshipctl/cmd
 update-golden:
 	@go test $(PKG) $(TESTFLAGS)
+
+.PHONY: plugin
+plugin: $(PLUGIN_OBJECTS)
+
+%.so: %.go
+	@go build -buildmode=plugin -o $@ $<

cmd/root.go

@@ -9,6 +9,8 @@ import (
 	"github.com/ian-howell/airshipctl/pkg/environment"
 	"github.com/ian-howell/airshipctl/pkg/kube"
 	"github.com/ian-howell/airshipctl/pkg/log"
+	"github.com/ian-howell/airshipctl/pkg/plugin"
+
 	"github.com/spf13/cobra"
 )
 
@@ -34,8 +36,11 @@ func NewRootCmd(out io.Writer, client *kube.Client, args []string) (*cobra.Comma
 
 	rootCmd.AddCommand(NewVersionCommand(out, client))
 
-	// Compound commands
-	rootCmd.AddCommand(NewWorkflowCommand(out))
+	workflowPlugin := "plugins/internal/workflow.so"
+	if _, err := os.Stat(workflowPlugin); err == nil {
+		rootCmd.AddCommand(plugin.CreateCommandFromPlugin(workflowPlugin, out, settings.KubeConfigFilePath))
+	}
+
 	return rootCmd, nil
 }
 

cmd/workflow.go

@@ -1,19 +0,0 @@
-package cmd
-
-import (
-	"io"
-
-	"github.com/spf13/cobra"
-)
-
-func NewWorkflowCommand(out io.Writer) *cobra.Command {
-	workflowRootCmd := &cobra.Command{
-		Use:     "workflow",
-		Short:   "access to workflows",
-		Aliases: []string{"workflows", "wf"},
-	}
-
-	workflowRootCmd.AddCommand(NewWorkflowListCommand(out))
-
-	return workflowRootCmd
-}

pkg/environment/settings.go

@@ -1,5 +1,9 @@
 package environment
 
+import (
+	restclient "k8s.io/client-go/rest"
+)
+
 // AirshipCTLSettings is a container for all of the settings needed by airshipctl
 type AirshipCTLSettings struct {
 	// KubeConfigFilePath is the path to the kubernetes configuration file.
@@ -7,6 +11,10 @@ type AirshipCTLSettings struct {
 	// out-of-cluster
 	KubeConfigFilePath string
 
+	// KubeConfig contains the configuration details needed for interacting
+	// with the cluster
+	KubeConfig *restclient.Config
+
 	// Debug is used for verbose output
 	Debug bool
 }

pkg/plugin/plugin.go

@@ -0,0 +1,25 @@
+package plugin
+
+import (
+	"io"
+	"plugin"
+
+	"github.com/spf13/cobra"
+)
+
+func CreateCommandFromPlugin(pluginPath string, out io.Writer, configPath string) *cobra.Command {
+	//TODO(howell): Remove these panics
+	plug, err := plugin.Open(pluginPath)
+	if err != nil {
+		panic(err.Error())
+	}
+	cmdSym, err := plug.Lookup("NewCommand")
+	if err != nil {
+		panic(err.Error())
+	}
+	command, ok := cmdSym.(func(io.Writer, string) *cobra.Command)
+	if !ok {
+		panic("NewCommand does not meet the interface.")
+	}
+	return command(out, configPath)
+}

plugins/internal/workflow.go

@@ -1,12 +1,10 @@
-package cmd
+package main
 
 import (
 	"fmt"
 	"io"
 	"text/tabwriter"
 
-	"github.com/ian-howell/airshipctl/pkg/log"
-
 	"github.com/argoproj/argo/pkg/apis/workflow/v1alpha1"
 	"github.com/spf13/cobra"
 	"k8s.io/apimachinery/pkg/runtime/serializer"
@@ -15,11 +13,23 @@ import (
 	"k8s.io/client-go/tools/clientcmd"
 )
 
-func NewWorkflowListCommand(out io.Writer) *cobra.Command {
+func NewCommand(out io.Writer, configPath string) *cobra.Command {
+	workflowRootCmd := &cobra.Command{
+		Use:     "workflow",
+		Short:   "access to workflows",
+		Aliases: []string{"workflows", "wf"},
+	}
 
-	config, err := clientcmd.BuildConfigFromFlags("", settings.KubeConfigFilePath)
+	workflowRootCmd.AddCommand(NewWorkflowListCommand(out, configPath))
+
+	return workflowRootCmd
+}
+
+func NewWorkflowListCommand(out io.Writer, configPath string) *cobra.Command {
+
+	config, err := clientcmd.BuildConfigFromFlags("", configPath)
 	if err != nil {
-		log.Fatal(err.Error())
+		panic(err.Error())
 	}
 
 	v1alpha1.AddToScheme(scheme.Scheme)
@@ -53,7 +63,7 @@ func NewWorkflowListCommand(out io.Writer) *cobra.Command {
 			w := tabwriter.NewWriter(out, 0, 0, 5, ' ', 0)
 			defer w.Flush()
 			fmt.Fprintf(w, "%s\t%s\n", "NAME", "PHASE")
-			for _, wf := range(wflist.Items) {
+			for _, wf := range wflist.Items {
 				fmt.Fprintf(w, "%s\t%s\n", wf.Name, wf.Status.Phase)
 			}
 		},