Remove deprecated --enable-api-cors flag

The `--enable-api-cors` flag was deprecated in f3dd2db4ff,
and marked for removal in docker 17.09 through 85f92ef359.

This patch removes the deprecated flag.

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

api/server/server.go

@@ -23,7 +23,6 @@ const versionMatcher = "/v{version:[0-9.]+}"
 // Config provides the configuration for the API server
 type Config struct {
 	Logging     bool
-	EnableCors  bool
 	CorsHeaders string
 	Version     string
 	SocketGroup string

cmd/dockerd/config_unix.go

@@ -33,8 +33,6 @@ func installConfigFlags(conf *config.Config, flags *pflag.FlagSet) {
 	flags.StringVar(&conf.BridgeConfig.FixedCIDRv6, "fixed-cidr-v6", "", "IPv6 subnet for fixed IPs")
 	flags.BoolVar(&conf.BridgeConfig.EnableUserlandProxy, "userland-proxy", true, "Use userland proxy for loopback traffic")
 	flags.StringVar(&conf.BridgeConfig.UserlandProxyPath, "userland-proxy-path", "", "Path to the userland proxy binary")
-	flags.BoolVar(&conf.EnableCors, "api-enable-cors", false, "Enable CORS headers in the Engine API, this is deprecated by --api-cors-header")
-	flags.MarkDeprecated("api-enable-cors", "Please use --api-cors-header")
 	flags.StringVar(&conf.CgroupParent, "cgroup-parent", "", "Set parent cgroup for all containers")
 	flags.StringVar(&conf.RemappedRoot, "userns-remap", "", "User/Group setting for user namespaces")
 	flags.StringVar(&conf.ContainerdAddr, "containerd", "", "Path to containerd socket")

cmd/dockerd/daemon.go

@@ -132,7 +132,6 @@ func (cli *DaemonCli) start(opts *daemonOptions) (err error) {
 		Logging:     true,
 		SocketGroup: cli.Config.SocketGroup,
 		Version:     dockerversion.Version,
-		EnableCors:  cli.Config.EnableCors,
 		CorsHeaders: cli.Config.CorsHeaders,
 	}
 
@@ -548,7 +547,7 @@ func (cli *DaemonCli) initMiddlewares(s *apiserver.Server, cfg *apiserver.Config
 	vm := middleware.NewVersionMiddleware(v, api.DefaultVersion, api.MinVersion)
 	s.UseMiddleware(vm)
 
-	if cfg.EnableCors || cfg.CorsHeaders != "" {
+	if cfg.CorsHeaders != "" {
 		c := middleware.NewCORSMiddleware(cfg.CorsHeaders)
 		s.UseMiddleware(c)
 	}

daemon/config/config.go

@@ -103,7 +103,6 @@ type CommonConfig struct {
 	Root                 string                    `json:"data-root,omitempty"`
 	SocketGroup          string                    `json:"group,omitempty"`
 	CorsHeaders          string                    `json:"api-cors-header,omitempty"`
-	EnableCors           bool                      `json:"api-enable-cors,omitempty"`
 
 	// TrustKeyPath is used to generate the daemon ID and for signing schema 1 manifests
 	// when pushing to a registry which does not support schema 2. This field is marked as