podmanv2: implement pod top

Implement `podman pod top` for podmanV2.

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

3 files changed, 66 insertions, 6 deletions

diff --git a/pkg/bindings/pods/pods.go b/pkg/bindings/pods/pods.go
index bb0abebc4..ae87c00e9 100644
--- a/pkg/bindings/pods/pods.go
+++ b/pkg/bindings/pods/pods.go
@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"github.com/containers/libpod/libpod"
+	"github.com/containers/libpod/pkg/api/handlers"
 	"github.com/containers/libpod/pkg/bindings"
 	"github.com/containers/libpod/pkg/domain/entities"
 	"github.com/containers/libpod/pkg/specgen"
@@ -213,9 +214,38 @@ func Stop(ctx context.Context, nameOrID string, timeout *int) (*entities.PodStop
 	return &report, response.Process(&report)
 }
 
-func Top() error {
-	// TODO
-	return bindings.ErrNotImplemented // nolint:typecheck
+// Top gathers statistics about the running processes in a pod. The nameOrID can be a pod name
+// or a partial/full ID.  The descriptors allow for specifying which data to collect from each process.
+func Top(ctx context.Context, nameOrID string, descriptors []string) ([]string, error) {
+	conn, err := bindings.GetClient(ctx)
+	if err != nil {
+		return nil, err
+	}
+	params := url.Values{}
+
+	if len(descriptors) > 0 {
+		// flatten the slice into one string
+		params.Set("ps_args", strings.Join(descriptors, ","))
+	}
+	response, err := conn.DoRequest(nil, http.MethodGet, "/pods/%s/top", params, nameOrID)
+	if err != nil {
+		return nil, err
+	}
+
+	body := handlers.PodTopOKBody{}
+	if err = response.Process(&body); err != nil {
+		return nil, err
+	}
+
+	// handlers.PodTopOKBody{} returns a slice of slices where each cell in the top table is an item.
+	// In libpod land, we're just using a slice with cells being split by tabs, which allows for an idiomatic
+	// usage of the tabwriter.
+	topOutput := []string{strings.Join(body.Titles, "\t")}
+	for _, out := range body.Processes {
+		topOutput = append(topOutput, strings.Join(out, "\t"))
+	}
+
+	return topOutput, err
 }
 
 // Unpause unpauses all paused containers in a Pod.
diff --git a/pkg/bindings/test/containers_test.go b/pkg/bindings/test/containers_test.go
index 9dd9cb707..a31181958 100644
--- a/pkg/bindings/test/containers_test.go
+++ b/pkg/bindings/test/containers_test.go
@@ -387,15 +387,15 @@ var _ = Describe("Podman containers ", func() {
 		Expect(err).To(BeNil())
 
 		// By name
-		output, err := containers.Top(bt.conn, name, nil)
+		_, err = containers.Top(bt.conn, name, nil)
 		Expect(err).To(BeNil())
 
 		// By id
-		output, err = containers.Top(bt.conn, cid, nil)
+		_, err = containers.Top(bt.conn, cid, nil)
 		Expect(err).To(BeNil())
 
 		// With descriptors
-		output, err = containers.Top(bt.conn, cid, []string{"user,pid,hpid"})
+		output, err := containers.Top(bt.conn, cid, []string{"user,pid,hpid"})
 		Expect(err).To(BeNil())
 		header := strings.Split(output[0], "\t")
 		for _, d := range []string{"USER", "PID", "HPID"} {
diff --git a/pkg/bindings/test/pods_test.go b/pkg/bindings/test/pods_test.go
index 0f786e341..2599ec7ef 100644
--- a/pkg/bindings/test/pods_test.go
+++ b/pkg/bindings/test/pods_test.go
@@ -2,6 +2,7 @@ package test_bindings
 
 import (
 	"net/http"
+	"strings"
 	"time"
 
 	"github.com/containers/libpod/libpod/define"
@@ -319,4 +320,33 @@ var _ = Describe("Podman pods", func() {
 		Expect(err).To(BeNil())
 		Expect(exists).To(BeTrue())
 	})
+
+	// Test validates the pod top bindings
+	It("pod top", func() {
+		var name string = "podA"
+
+		bt.Podcreate(&name)
+		_, err := pods.Start(bt.conn, name)
+		Expect(err).To(BeNil())
+
+		// By name
+		_, err = pods.Top(bt.conn, name, nil)
+		Expect(err).To(BeNil())
+
+		// With descriptors
+		output, err := pods.Top(bt.conn, name, []string{"user,pid,hpid"})
+		Expect(err).To(BeNil())
+		header := strings.Split(output[0], "\t")
+		for _, d := range []string{"USER", "PID", "HPID"} {
+			Expect(d).To(BeElementOf(header))
+		}
+
+		// With bogus ID
+		_, err = pods.Top(bt.conn, "IdoNotExist", nil)
+		Expect(err).ToNot(BeNil())
+
+		// With bogus descriptors
+		_, err = pods.Top(bt.conn, name, []string{"Me,Neither"})
+		Expect(err).ToNot(BeNil())
+	})
 })