Return title fields as a list

Podman is attempting to split the headers returned by the ps
command into a list of headers. Problem is that some headers
are multi-word, and headers are not guaranteed to be split via
a tab. This PR splits the headers bases on white space, and for
the select group of CAPS headers which are multi-word, combines
them back together.

Fixes: https://github.com/containers/podman/issues/17524

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

pkg/api/handlers/compat/containers_top.go

@@ -63,7 +63,7 @@ loop: // break out of for/select infinite` loop
 		case <-r.Context().Done():
 			break loop
 		default:
-			output, err := c.Top([]string{query.PsArgs})
+			output, err := c.Top(strings.Split(query.PsArgs, ","))
 			if err != nil {
 				logrus.Infof("Error from %s %q : %v", r.Method, r.URL, err)
 				break loop
@@ -71,7 +71,8 @@ loop: // break out of for/select infinite` loop
 
 			if len(output) > 0 {
 				body := handlers.ContainerTopOKBody{}
-				body.Titles = strings.Split(output[0], "\t")
+				body.Titles = utils.PSTitles(output[0])
+
 				for i := range body.Titles {
 					body.Titles[i] = strings.TrimSpace(body.Titles[i])
 				}

pkg/api/handlers/libpod/pods.go

@@ -413,7 +413,7 @@ loop: // break out of for/select infinite` loop
 
 			if len(output) > 0 {
 				body := handlers.PodTopOKBody{}
-				body.Titles = strings.Split(output[0], "\t")
+				body.Titles = utils.PSTitles(output[0])
 				for i := range body.Titles {
 					body.Titles[i] = strings.TrimSpace(body.Titles[i])
 				}

pkg/api/handlers/utils/containers.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"net/http"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/containers/podman/v4/libpod/events"
@@ -238,3 +239,23 @@ func containerExists(ctx context.Context, name string) (bool, error) {
 	}
 	return ctrExistRep.Value, nil
 }
+
+// PSTitles merges CAPS headers from ps output. All PS headers are single words, except for
+// CAPS. Function compines CAP Headers into single field separated by a space.
+func PSTitles(output string) []string {
+	var titles []string
+
+	for _, title := range strings.Fields(output) {
+		switch title {
+		case "AMBIENT", "INHERITED", "PERMITTED", "EFFECTIVE", "BOUNDING":
+			{
+				titles = append(titles, title+" CAPS")
+			}
+		case "CAPS":
+			continue
+		default:
+			titles = append(titles, title)
+		}
+	}
+	return titles
+}

test/apiv2/20-containers.at

@@ -121,6 +121,14 @@ if root; then
     .memory_stats.limit=536870912 \
     .id~[0-9a-f]\\{64\\}
 
+    t GET containers/$CTRNAME/top?stream=false 200 \
+      .Titles='[
+  "PID",
+  "USER",
+  "TIME",
+  "COMMAND"
+]'
+
     podman rm -f $CTRNAME
 fi