fix connection usage with containers.conf

--connection was failing due to the servicedestinations array being empty on runtime.
Fix by making sure the cached config is used

resolves #16282

Signed-off-by: Charlie Doern <cdoern@redhat.com>

cmd/podman/root.go

@@ -198,6 +198,8 @@ func persistentPreRunE(cmd *cobra.Command, args []string) error {
 		if contextConn != nil && contextConn.Changed {
 			return fmt.Errorf("use of --connection and --context at the same time is not allowed")
 		}
+		// need to give our blank containers.conf all of the service destinations if we are using one.
+		podmanConfig.ContainersConf.Engine.ServiceDestinations = podmanConfig.ContainersConfDefaultsRO.Engine.ServiceDestinations
 		podmanConfig.ContainersConf.Engine.ActiveService = conn.Value.String()
 		if err := setupConnection(); err != nil {
 			return err

test/e2e/system_connection_test.go

@@ -276,6 +276,11 @@ var _ = Describe("podman system connection", func() {
 			Expect(session.Out.Contents()).Should(BeEmpty())
 			Expect(session.Err.Contents()).Should(BeEmpty())
 
+			cmd = exec.Command(podmanTest.RemotePodmanBinary,
+				"--connection", "QA", "ps")
+			_, err = Start(cmd, GinkgoWriter, GinkgoWriter)
+			Expect(err).ToNot(HaveOccurred())
+
 			uri := url.URL{
 				Scheme: "ssh",
 				User:   url.User(u.Username),