feat(cmd/get): basic get command

Signed-off-by: Lorenzo Fontana <lo@linux.com>

README.md

@@ -39,7 +39,7 @@ Some of them will not yet work because we don't attach with a TTY already, sorry
 To consider this project (ready) the goals are:
 
 - [x] basic program run and attach
-- [ ] list command to list running traces - command: `kubectl trace ls`
+- [x] list command to list running traces - command: `kubectl trace get`
 - [x] delete running traces
 - [ ] run without attach
 - [ ] attach command to attach only - command: `kubectl trace attach <program>`

cmd/kubectl-trace/delete.go

@@ -10,13 +10,13 @@ import (
 )
 
 var deleteCmd = &cobra.Command{
-	Use:   "delete TRACEID",
+	Use:   "delete NAME",
 	Short: "Delete a trace execution from your system",
-	Long: `Delete all the running pods that are collecting your trace data using bpftrace for a given TRACEID
+	Long: `Delete all the running pods that are collecting your trace data using bpftrace for a given NAME
 
 Example:
   # Delete a specific trace
-  kubectl trace delete 656ee75a-ee3c-11e8-9e7a-8c164500a77e
+  kubectl trace delete kubectl-trace-d5314890-ee4f-11e8-9684-8c164500a77e-sm4t2<Paste>
 
 Limitations:
   This command does not implement yet a way to bulk delete traces.
@@ -29,9 +29,9 @@ func delete(cmd *cobra.Command, args []string) {
 	defer log.Sync()
 
 	if len(args) == 0 {
-		log.Fatal("TRACEID not provided")
+		log.Fatal("NAME not provided")
 	}
-	uuid := args[0]
+	name := args[0]
 
 	kubeconfig := viper.GetString("kubeconfig")
 	config, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
@@ -45,18 +45,19 @@ func delete(cmd *cobra.Command, args []string) {
 		log.Fatal("cannot create kubernetes config from provider KUBECONFIG", zap.Error(err))
 	}
 
+	namespace := viper.GetString("namespace")
 	jobsClient := clientset.BatchV1().Jobs(namespace)
 
 	tc := &tracejob.TraceJobClient{
 		JobClient:    jobsClient,
 		ConfigClient: clientset.CoreV1().ConfigMaps(namespace),
 	}
 
-	tj := tracejob.TraceJob{
-		ID: uuid,
+	tf := tracejob.TraceJobFilter{
+		Name: &name,
 	}
 
-	err = tc.DeleteJob(tj)
+	err = tc.DeleteJob(tf)
 
 	if err != nil {
 		log.Fatal("error deleting trace execution from cluster", zap.Error(err))

cmd/kubectl-trace/get.go

@@ -0,0 +1,103 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"text/tabwriter"
+
+	"github.com/fntlnz/kubectl-trace/pkg/tracejob"
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+	"go.uber.org/zap"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/tools/clientcmd"
+)
+
+var getCmd = &cobra.Command{
+	Use:   "get [TRACEID] [-n NAMESPACE]",
+	Short: "Get all the running traces in a kubernetes cluster",
+	Long: `Get all the running traces in a kubernetes cluster
+
+Examples:
+	# Get all traces in a namespace
+	kubectl trace get -n mynamespace
+
+	# Get only a specific trace
+	kubectl trace get 656ee75a-ee3c-11e8-9e7a-8c164500a77e
+
+	# Get only a specific trace in a specific namespace
+	kubectl trace get 656ee75a-ee3c-11e8-9e7a-8c164500a77e -n mynamespace
+
+Limitations:
+  - Currently work only with a single namespace at time
+	- It does not contain yet status and age for the trace
+`,
+	Run: get,
+}
+
+func get(cmd *cobra.Command, args []string) {
+	log, _ := zap.NewProduction()
+	defer log.Sync()
+
+	kubeconfig := viper.GetString("kubeconfig")
+	config, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
+
+	if err != nil {
+		log.Fatal("cannot create kubernetes client from provider KUBECONFIG", zap.Error(err))
+	}
+
+	var uuid *string
+	if len(args) > 0 {
+		uuid = &args[0]
+	}
+
+	namespace := viper.GetString("namespace")
+
+	clientset, err := kubernetes.NewForConfig(config)
+	if err != nil {
+		log.Fatal("cannot create kubernetes config from provider KUBECONFIG", zap.Error(err))
+	}
+
+	jobsClient := clientset.BatchV1().Jobs(namespace)
+
+	tc := &tracejob.TraceJobClient{
+		JobClient:    jobsClient,
+		ConfigClient: clientset.CoreV1().ConfigMaps(namespace),
+	}
+
+	tf := tracejob.TraceJobFilter{
+		ID: uuid,
+	}
+
+	jobs, err := tc.GetJob(tf)
+
+	if err != nil {
+		log.Fatal("error getting jobs with provided filter", zap.Error(err), zap.Any("filter", tf))
+	}
+
+	jobsTablePrint(jobs)
+
+}
+
+// TODO(fntlnz): This needs better printing, perhaps we could use the humanreadable table from k8s itself
+// to be consistent with the main project.
+func jobsTablePrint(jobs []tracejob.TraceJob) {
+	format := "%s\t%s\t%s\t%s\t%s\t"
+	if len(jobs) == 0 {
+		fmt.Println("No resources found.")
+		return
+	}
+	// initialize tabwriter
+	w := new(tabwriter.Writer)
+	// minwidth, tabwidth, padding, padchar, flags
+	w.Init(os.Stdout, 8, 8, 0, '\t', 0)
+	defer w.Flush()
+
+	// TODO(fntlnz): Do the status and age fields, we don't have a way to get them now, so reporting
+	// them as missing.
+	fmt.Fprintf(w, format, "NAMESPACE", "NAME", "STATUS", "AGE", "HOSTNAME")
+	for _, j := range jobs {
+		fmt.Fprintf(w, "\n"+format, j.Namespace, j.Name, "<missing>", "<missing>", j.Hostname)
+	}
+}

cmd/kubectl-trace/root.go

@@ -7,13 +7,12 @@ import (
 	homedir "github.com/mitchellh/go-homedir"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
+	apiv1 "k8s.io/api/core/v1"
 	//"k8s.io/cli-runtime/pkg/genericclioptions"
 )
 
 var cfgFile string
 
-//var parentConfigFlags genericclioptions.ConfigFlags
-
 var rootCmd = &cobra.Command{
 	Use:   "trace",
 	Short: "Execute and manage bpftrace programs on your kubernetes cluster",
@@ -29,21 +28,18 @@ func Execute() {
 func init() {
 	cobra.OnInitialize(initConfig)
 
-	// Here you will define your flags and configuration settings.
-	// Cobra supports persistent flags, which, if defined here,
-	// will be global for your application.
 	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.kubectl-trace.yaml)")
 
-	// TODO(leodido): figure out how to use the flag from the main kubectl
-	// instead of having to recreate them like below
-	//parentConfigFlags = genericclioptions.ConfigFlags{}
-	//parentConfigFlags.AddFlags(rootCmd.PersistentFlags())
-
 	rootCmd.PersistentFlags().String("kubeconfig", "", "Path to the kubeconfig file to use for CLI requests.")
 	viper.BindPFlag("kubeconfig", rootCmd.PersistentFlags().Lookup("kubeconfig"))
 	viper.BindEnv("kubeconfig", "KUBECONFIG")
+
+	rootCmd.PersistentFlags().StringP("namespace", "n", apiv1.NamespaceDefault, "If present, the namespace scope for this CLI request")
+	viper.BindPFlag("namespace", rootCmd.PersistentFlags().Lookup("namespace"))
+
 	rootCmd.AddCommand(runCmd)
 	rootCmd.AddCommand(deleteCmd)
+	rootCmd.AddCommand(getCmd)
 }
 
 // initConfig reads in config file and ENV variables if set.

cmd/kubectl-trace/run.go

@@ -13,7 +13,6 @@ import (
 	"go.uber.org/zap"
 	"k8s.io/apimachinery/pkg/util/uuid"
 
-	apiv1 "k8s.io/api/core/v1"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/tools/clientcmd"
 )
@@ -29,18 +28,22 @@ Examples:
 
   # Execute a program from file on a specific node
   kubectl trace run kubernetes-node-emt8.c.myproject.internal -f read.bt
+
+Limitations:
+  1. Right now this command lets you run bpftrace commands only on a specific node in your cluster,
+     the plan is to have this working for a node, a pod, a deployment, a statefulset.
+  2. Since there's no TTY attach (yet) it is not possible to run bpftrace commands that need an input
+     from the user in order to complete, like histograms, working on this is a priority for this project.
 `,
 	Run: run,
 }
 
 var program string
 var programfile string
-var namespace string
 
 func init() {
 	runCmd.Flags().StringVarP(&program, "program-literal", "e", "", "Literal string containing a bpftrace program")
 	runCmd.Flags().StringVarP(&programfile, "program-file", "f", "", "File containing a bpftrace program")
-	runCmd.Flags().StringVarP(&namespace, "namespace", "n", apiv1.NamespaceDefault, "Name of the node where to do the trace")
 }
 
 func run(cmd *cobra.Command, args []string) {
@@ -63,6 +66,8 @@ func run(cmd *cobra.Command, args []string) {
 	}
 	node := args[0]
 
+	namespace := viper.GetString("namespace")
+
 	ctx := context.Background()
 	ctx = signals.WithStandardSignals(ctx)