network ls: show networks in deterministic order

The new network backend stores the networks in a map so the returned
order is not deterministic. Lets sort the network names alphabetically
to ensure a deterministic order.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

cmd/podman/networks/list.go

@@ -3,6 +3,7 @@ package network
 import (
 	"fmt"
 	"os"
+	"sort"
 	"strings"
 
 	"github.com/containers/common/pkg/completion"
@@ -73,6 +74,11 @@ func networkList(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
+	// sort the networks to make sure the order is deterministic
+	sort.Slice(responses, func(i, j int) bool {
+		return responses[i].Name < responses[j].Name
+	})
+
 	switch {
 	// quiet means we only print the network names
 	case networkListOptions.Quiet:

test/system/500-networking.bats

@@ -16,6 +16,21 @@ load helpers
     if  [[ ${output} = ${heading} ]]; then
        die "network ls --noheading did not remove heading: $output"
     fi
+
+    # check deterministic list order
+    local net1=a-$(random_string 10)
+    local net2=b-$(random_string 10)
+    local net3=c-$(random_string 10)
+    run_podman network create $net1
+    run_podman network create $net2
+    run_podman network create $net3
+
+    run_podman network ls --quiet
+    # just check the the order of the created networks is correct
+    # we cannot do an exact match since developer and CI systems could contain more networks
+    is "$output" ".*$net1.*$net2.*$net3.*podman.*" "networks sorted alphabetically"
+
+    run_podman network rm $net1 $net2 $net3
 }
 
 # Copied from tsweeney's https://github.com/containers/podman/issues/4827