v2 api: implement pods top endpoint

Note that this commit does not add tests for the pod-top endpoint.
They will be added in a later change.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

pkg/api/handlers/libpod/pods.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"strings"
 
 	"github.com/containers/libpod/libpod"
 	"github.com/containers/libpod/libpod/define"
@@ -287,6 +288,48 @@ func PodUnpause(w http.ResponseWriter, r *http.Request) {
 	utils.WriteResponse(w, http.StatusOK, &report)
 }
 
+func PodTop(w http.ResponseWriter, r *http.Request) {
+	runtime := r.Context().Value("runtime").(*libpod.Runtime)
+	decoder := r.Context().Value("decoder").(*schema.Decoder)
+
+	query := struct {
+		PsArgs string `schema:"ps_args"`
+	}{
+		PsArgs: "",
+	}
+	if err := decoder.Decode(&query, r.URL.Query()); err != nil {
+		utils.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest,
+			errors.Wrapf(err, "Failed to parse parameters for %s", r.URL.String()))
+		return
+	}
+
+	name := utils.GetName(r)
+	pod, err := runtime.LookupPod(name)
+	if err != nil {
+		utils.ContainerNotFound(w, name, err)
+		return
+	}
+
+	args := []string{}
+	if query.PsArgs != "" {
+		args = append(args, query.PsArgs)
+	}
+	output, err := pod.GetPodPidInformation(args)
+	if err != nil {
+		utils.InternalServerError(w, err)
+		return
+	}
+
+	var body = handlers.PodTopOKBody{}
+	if len(output) > 0 {
+		body.Titles = strings.Split(output[0], "\t")
+		for _, line := range output[1:] {
+			body.Processes = append(body.Processes, strings.Split(line, "\t"))
+		}
+	}
+	utils.WriteJSON(w, http.StatusOK, body)
+}
+
 func PodKill(w http.ResponseWriter, r *http.Request) {
 	var (
 		runtime = r.Context().Value("runtime").(*libpod.Runtime)