info: remove printServerWarningsLegacy

Docker Engine 18.09 (API v1.39) introduced a Warnings field in the into response.
This enhancement was not gated by API version (see [moby/moby@a3d4238]), and
will be returned by Docker Engine 18.09 and up, regardless of the API version
chosen.

Likewise, the client-side code was written to prefer warnings returned by
the daemon, but to fall back on client-side detection of missing features
based on information in the Info response (see [docker/cli@3c27ce2]).

Thse warnings are purely informational, and given that Docker Engine versions
before 18.09 have reached EOL 6 Years ago, and any current version of the
Engine now returns the Warnings, it should be safe to remove the client-side
fall back logic.

This patch removes the client-side fall back code for warnings that was
added in 3c27ce21c9.

[moby/moby@a3d4238]: a3d4238b9c
[docker/cli@3c27ce2]: 3c27ce21c9

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

cli/command/system/info.go

@@ -460,10 +460,7 @@ func printServerWarnings(stdErr io.Writer, info *dockerInfo) {
 	}
 	if len(info.Warnings) > 0 {
 		fprintln(stdErr, strings.Join(info.Warnings, "\n"))
-		return
 	}
-	// daemon didn't return warnings. Fallback to old behavior
-	printServerWarningsLegacy(stdErr, *info.Info)
 }
 
 // printSecurityOptionsWarnings prints warnings based on the security options
@@ -490,48 +487,6 @@ func printSecurityOptionsWarnings(stdErr io.Writer, info system.Info) {
 	}
 }
 
-// printServerWarningsLegacy 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 printServerWarningsLegacy(stdErr io.Writer, info system.Info) {
-	if info.OSType == "windows" {
-		return
-	}
-	if !info.MemoryLimit {
-		fprintln(stdErr, "WARNING: No memory limit support")
-	}
-	if !info.SwapLimit {
-		fprintln(stdErr, "WARNING: No swap limit support")
-	}
-	if !info.OomKillDisable && info.CgroupVersion != "2" {
-		fprintln(stdErr, "WARNING: No oom kill disable support")
-	}
-	if !info.CPUCfsQuota {
-		fprintln(stdErr, "WARNING: No cpu cfs quota support")
-	}
-	if !info.CPUCfsPeriod {
-		fprintln(stdErr, "WARNING: No cpu cfs period support")
-	}
-	if !info.CPUShares {
-		fprintln(stdErr, "WARNING: No cpu shares support")
-	}
-	if !info.CPUSet {
-		fprintln(stdErr, "WARNING: No cpuset support")
-	}
-	if !info.IPv4Forwarding {
-		fprintln(stdErr, "WARNING: IPv4 forwarding is disabled")
-	}
-	if !info.BridgeNfIptables {
-		fprintln(stdErr, "WARNING: bridge-nf-call-iptables is disabled")
-	}
-	if !info.BridgeNfIP6tables {
-		fprintln(stdErr, "WARNING: bridge-nf-call-ip6tables is disabled")
-	}
-}
-
 func formatInfo(output io.Writer, info dockerInfo, format string) error {
 	if format == formatter.JSONFormatKey {
 		format = formatter.JSONFormat

cli/command/system/info_test.go

@@ -333,23 +333,6 @@ func TestPrettyPrintInfo(t *testing.T) {
 			prettyGolden: "docker-info-with-swarm",
 			jsonGolden:   "docker-info-with-swarm",
 		},
-		{
-			doc: "info with legacy warnings",
-			dockerInfo: dockerInfo{
-				Info: &infoWithWarningsLinux,
-				ClientInfo: &clientInfo{
-					clientVersion: clientVersion{
-						Platform: &platformInfo{Name: "Docker Engine - Community"},
-						Version:  "24.0.0",
-						Context:  "default",
-					},
-					Debug: true,
-				},
-			},
-			prettyGolden:   "docker-info-no-swarm",
-			warningsGolden: "docker-info-warnings",
-			jsonGolden:     "docker-info-legacy-warnings",
-		},
 		{
 			doc: "info with daemon warnings",
 			dockerInfo: dockerInfo{

cli/command/system/testdata/docker-info-legacy-warnings.json.golden

@@ -1 +0,0 @@
-{"ID":"EKHL:QDUU:QZ7U:MKGD:VDXK:S27Q:GIPU:24B7:R7VT:DGN6:QCSF:2UBX","Containers":0,"ContainersRunning":0,"ContainersPaused":0,"ContainersStopped":0,"Images":0,"Driver":"overlay2","DriverStatus":[["Backing Filesystem","extfs"],["Supports d_type","true"],["Using metacopy","false"],["Native Overlay Diff","true"]],"Plugins":{"Volume":["local"],"Network":["bridge","host","macvlan","null","overlay"],"Authorization":null,"Log":["awslogs","fluentd","gcplogs","gelf","journald","json-file","splunk","syslog"]},"MemoryLimit":false,"SwapLimit":false,"CpuCfsPeriod":false,"CpuCfsQuota":false,"CPUShares":false,"CPUSet":false,"PidsLimit":false,"IPv4Forwarding":false,"BridgeNfIptables":false,"BridgeNfIp6tables":false,"Debug":true,"NFd":33,"OomKillDisable":false,"NGoroutines":135,"SystemTime":"2017-08-24T17:44:34.077811894Z","LoggingDriver":"json-file","CgroupDriver":"cgroupfs","NEventsListener":0,"KernelVersion":"4.4.0-87-generic","OperatingSystem":"Ubuntu 16.04.3 LTS","OSVersion":"","OSType":"linux","Architecture":"x86_64","IndexServerAddress":"https://index.docker.io/v1/","RegistryConfig":{"AllowNondistributableArtifactsCIDRs":null,"AllowNondistributableArtifactsHostnames":null,"InsecureRegistryCIDRs":["127.0.0.0/8"],"IndexConfigs":{"docker.io":{"Name":"docker.io","Mirrors":null,"Secure":true,"Official":true}},"Mirrors":null},"NCPU":2,"MemTotal":2097356800,"GenericResources":null,"DockerRootDir":"/var/lib/docker","HttpProxy":"","HttpsProxy":"","NoProxy":"","Name":"system-sample","Labels":["provider=digitalocean"],"ExperimentalBuild":false,"ServerVersion":"17.06.1-ce","Runtimes":{"runc":{"path":"docker-runc"}},"DefaultRuntime":"runc","Swarm":{"NodeID":"","NodeAddr":"","LocalNodeState":"inactive","ControlAvailable":false,"Error":"","RemoteManagers":null},"LiveRestoreEnabled":false,"Isolation":"","InitBinary":"docker-init","ContainerdCommit":{"ID":"6e23458c129b551d5c9871e5174f6b1b7f6d1170","Expected":"6e23458c129b551d5c9871e5174f6b1b7f6d1170"},"RuncCommit":{"ID":"810190ceaa507aa2727d7ae6f4790c76ec150bd2","Expected":"810190ceaa507aa2727d7ae6f4790c76ec150bd2"},"InitCommit":{"ID":"949e6fa","Expected":"949e6fa"},"SecurityOptions":["name=apparmor","name=seccomp,profile=default"],"DefaultAddressPools":[{"Base":"10.123.0.0/16","Size":24}],"CDISpecDirs":["/etc/cdi","/var/run/cdi"],"Warnings":null,"ClientInfo":{"Debug":true,"Platform":{"Name":"Docker Engine - Community"},"Version":"24.0.0","Context":"default","Plugins":[],"Warnings":null}}