Use warnings provided by daemon

Warnings are now generated by the daemon, and returned as
part of the /info API response.

If warnings are returned by the daemon; use those instead
of generating them locally.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/system/info.go

@@ -206,45 +206,7 @@ func prettyPrintInfo(dockerCli command.Cli, info types.Info) error {
 	fmt.Fprintln(dockerCli.Out(), "Live Restore Enabled:", info.LiveRestoreEnabled)
 	fmt.Fprint(dockerCli.Out(), "\n")
 
-	// Only output these warnings if the server does not support these features
+	printWarnings(dockerCli, info)
-	if info.OSType != "windows" {
-		printStorageDriverWarnings(dockerCli, info)
-
-		if !info.MemoryLimit {
-			fmt.Fprintln(dockerCli.Err(), "WARNING: No memory limit support")
-		}
-		if !info.SwapLimit {
-			fmt.Fprintln(dockerCli.Err(), "WARNING: No swap limit support")
-		}
-		if !info.KernelMemory {
-			fmt.Fprintln(dockerCli.Err(), "WARNING: No kernel memory limit support")
-		}
-		if !info.OomKillDisable {
-			fmt.Fprintln(dockerCli.Err(), "WARNING: No oom kill disable support")
-		}
-		if !info.CPUCfsQuota {
-			fmt.Fprintln(dockerCli.Err(), "WARNING: No cpu cfs quota support")
-		}
-		if !info.CPUCfsPeriod {
-			fmt.Fprintln(dockerCli.Err(), "WARNING: No cpu cfs period support")
-		}
-		if !info.CPUShares {
-			fmt.Fprintln(dockerCli.Err(), "WARNING: No cpu shares support")
-		}
-		if !info.CPUSet {
-			fmt.Fprintln(dockerCli.Err(), "WARNING: No cpuset support")
-		}
-		if !info.IPv4Forwarding {
-			fmt.Fprintln(dockerCli.Err(), "WARNING: IPv4 forwarding is disabled")
-		}
-		if !info.BridgeNfIptables {
-			fmt.Fprintln(dockerCli.Err(), "WARNING: bridge-nf-call-iptables is disabled")
-		}
-		if !info.BridgeNfIP6tables {
-			fmt.Fprintln(dockerCli.Err(), "WARNING: bridge-nf-call-ip6tables is disabled")
-		}
-	}
-
 	return nil
 }
 
@@ -315,11 +277,73 @@ func printSwarmInfo(dockerCli command.Cli, info types.Info) {
 	}
 }
 
+func printWarnings(dockerCli command.Cli, info types.Info) {
+	if len(info.Warnings) > 0 {
+		fmt.Fprintln(dockerCli.Err(), strings.Join(info.Warnings, "\n"))
+		return
+	}
+	// daemon didn't return warnings. Fallback to old behavior
+	printStorageDriverWarnings(dockerCli, info)
+	printWarningsLegacy(dockerCli, info)
+}
+
+// printWarningsLegacy generates warnings based on information returned by the daemon.
+// DEPRECATED: warnings are now generated by the daemon, and returned in
+// info.Warnings. This function is used to provide backward compatibility with
+// daemons that do not provide these warnings. No new warnings should be added
+// here.
+func printWarningsLegacy(dockerCli command.Cli, info types.Info) {
+	if info.OSType == "windows" {
+		return
+	}
+	if !info.MemoryLimit {
+		fmt.Fprintln(dockerCli.Err(), "WARNING: No memory limit support")
+	}
+	if !info.SwapLimit {
+		fmt.Fprintln(dockerCli.Err(), "WARNING: No swap limit support")
+	}
+	if !info.KernelMemory {
+		fmt.Fprintln(dockerCli.Err(), "WARNING: No kernel memory limit support")
+	}
+	if !info.OomKillDisable {
+		fmt.Fprintln(dockerCli.Err(), "WARNING: No oom kill disable support")
+	}
+	if !info.CPUCfsQuota {
+		fmt.Fprintln(dockerCli.Err(), "WARNING: No cpu cfs quota support")
+	}
+	if !info.CPUCfsPeriod {
+		fmt.Fprintln(dockerCli.Err(), "WARNING: No cpu cfs period support")
+	}
+	if !info.CPUShares {
+		fmt.Fprintln(dockerCli.Err(), "WARNING: No cpu shares support")
+	}
+	if !info.CPUSet {
+		fmt.Fprintln(dockerCli.Err(), "WARNING: No cpuset support")
+	}
+	if !info.IPv4Forwarding {
+		fmt.Fprintln(dockerCli.Err(), "WARNING: IPv4 forwarding is disabled")
+	}
+	if !info.BridgeNfIptables {
+		fmt.Fprintln(dockerCli.Err(), "WARNING: bridge-nf-call-iptables is disabled")
+	}
+	if !info.BridgeNfIP6tables {
+		fmt.Fprintln(dockerCli.Err(), "WARNING: bridge-nf-call-ip6tables is disabled")
+	}
+}
+
+// printStorageDriverWarnings generates warnings based on storage-driver information
+// returned by the daemon.
+// DEPRECATED: warnings are now generated by the daemon, and returned in
+// info.Warnings. This function is used to provide backward compatibility with
+// daemons that do not provide these warnings. No new warnings should be added
+// here.
 func printStorageDriverWarnings(dockerCli command.Cli, info types.Info) {
+	if info.OSType == "windows" {
+		return
+	}
 	if info.DriverStatus == nil {
 		return
 	}
-
 	for _, pair := range info.DriverStatus {
 		if pair[0] == "Data loop file" {
 			fmt.Fprintf(dockerCli.Err(), "WARNING: %s: usage of loopback devices is "+

cli/command/system/info_test.go

@@ -207,32 +207,59 @@ func TestPrettyPrintInfo(t *testing.T) {
 	infoWithWarningsLinux.BridgeNfIptables = false
 	infoWithWarningsLinux.BridgeNfIP6tables = false
 
+	sampleInfoDaemonWarnings := sampleInfoNoSwarm
+	sampleInfoDaemonWarnings.Warnings = []string{
+		"WARNING: No memory limit support",
+		"WARNING: No swap limit support",
+		"WARNING: No kernel memory limit support",
+		"WARNING: No oom kill disable support",
+		"WARNING: No cpu cfs quota support",
+		"WARNING: No cpu cfs period support",
+		"WARNING: No cpu shares support",
+		"WARNING: No cpuset support",
+		"WARNING: IPv4 forwarding is disabled",
+		"WARNING: bridge-nf-call-iptables is disabled",
+		"WARNING: bridge-nf-call-ip6tables is disabled",
+	}
+
 	for _, tc := range []struct {
+		doc            string
 		dockerInfo     types.Info
 		expectedGolden string
 		warningsGolden string
 	}{
 		{
+			doc:            "info without swarm",
 			dockerInfo:     sampleInfoNoSwarm,
 			expectedGolden: "docker-info-no-swarm",
 		},
 		{
+			doc:            "info with swarm",
 			dockerInfo:     infoWithSwarm,
 			expectedGolden: "docker-info-with-swarm",
 		},
 		{
+			doc:            "info with legacy warnings",
 			dockerInfo:     infoWithWarningsLinux,
 			expectedGolden: "docker-info-no-swarm",
 			warningsGolden: "docker-info-warnings",
 		},
+		{
+			doc:            "info with daemon warnings",
+			dockerInfo:     sampleInfoDaemonWarnings,
+			expectedGolden: "docker-info-no-swarm",
+			warningsGolden: "docker-info-warnings",
+		},
 	} {
-		cli := test.NewFakeCli(&fakeClient{})
+		t.Run(tc.doc, func(t *testing.T) {
-		assert.NilError(t, prettyPrintInfo(cli, tc.dockerInfo))
+			cli := test.NewFakeCli(&fakeClient{})
-		golden.Assert(t, cli.OutBuffer().String(), tc.expectedGolden+".golden")
+			assert.NilError(t, prettyPrintInfo(cli, tc.dockerInfo))
-		if tc.warningsGolden != "" {
+			golden.Assert(t, cli.OutBuffer().String(), tc.expectedGolden+".golden")
-			golden.Assert(t, cli.ErrBuffer().String(), tc.warningsGolden+".golden")
+			if tc.warningsGolden != "" {
-		} else {
+				golden.Assert(t, cli.ErrBuffer().String(), tc.warningsGolden+".golden")
-			assert.Check(t, is.Equal("", cli.ErrBuffer().String()))
+			} else {
-		}
+				assert.Check(t, is.Equal("", cli.ErrBuffer().String()))
+			}
+		})
 	}
 }