From ca89c329b9f0748da74d08d02a47bc494e7965e2 Mon Sep 17 00:00:00 2001
From: Qiang Huang <h.huangqiang@huawei.com>
Date: Thu, 18 Feb 2016 18:10:31 +0800
Subject: [PATCH] Add CgroupDriver to docker info

Fixes: #19539

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
---
 api/client/info.go                            | 1 +
 daemon/daemon_unix.go                         | 8 ++++++++
 daemon/daemon_windows.go                      | 4 ++++
 daemon/info.go                                | 1 +
 docs/reference/api/docker_remote_api.md       | 1 +
 docs/reference/api/docker_remote_api_v1.23.md | 1 +
 docs/reference/commandline/info.md            | 1 +
 man/docker-info.1.md                          | 1 +
 8 files changed, 18 insertions(+)

diff --git a/api/client/info.go b/api/client/info.go
index fb2bdcd730..0a55f3bd52 100644
--- a/api/client/info.go
+++ b/api/client/info.go
@@ -50,6 +50,7 @@ func (cli *DockerCli) CmdInfo(args ...string) error {
 	}
 	ioutils.FprintfIfNotEmpty(cli.out, "Execution Driver: %s\n", info.ExecutionDriver)
 	ioutils.FprintfIfNotEmpty(cli.out, "Logging Driver: %s\n", info.LoggingDriver)
+	ioutils.FprintfIfNotEmpty(cli.out, "Cgroup Driver: %s\n", info.CgroupDriver)
 
 	fmt.Fprintf(cli.out, "Plugins: \n")
 	fmt.Fprintf(cli.out, " Volume:")
diff --git a/daemon/daemon_unix.go b/daemon/daemon_unix.go
index f47e420852..d8d4e56e39 100644
--- a/daemon/daemon_unix.go
+++ b/daemon/daemon_unix.go
@@ -362,6 +362,14 @@ func verifyContainerResources(resources *containertypes.Resources, sysInfo *sysi
 	return warnings, nil
 }
 
+func (daemon *Daemon) getCgroupDriver() string {
+	cgroupDriver := "cgroupfs"
+	if daemon.usingSystemd() {
+		cgroupDriver = "systemd"
+	}
+	return cgroupDriver
+}
+
 func usingSystemd(config *Config) bool {
 	for _, option := range config.ExecOptions {
 		key, val, err := parsers.ParseKeyValueOpt(option)
diff --git a/daemon/daemon_windows.go b/daemon/daemon_windows.go
index 609506f7b1..b9aadc6b00 100644
--- a/daemon/daemon_windows.go
+++ b/daemon/daemon_windows.go
@@ -65,6 +65,10 @@ func checkKernel() error {
 	return nil
 }
 
+func (daemon *Daemon) getCgroupDriver() string {
+	return ""
+}
+
 // adaptContainerSettings is called during container creation to modify any
 // settings necessary in the HostConfig structure.
 func (daemon *Daemon) adaptContainerSettings(hostConfig *containertypes.HostConfig, adjustCPUShares bool) error {
diff --git a/daemon/info.go b/daemon/info.go
index 61eab2d7fd..e0edc2ad22 100644
--- a/daemon/info.go
+++ b/daemon/info.go
@@ -83,6 +83,7 @@ func (daemon *Daemon) SystemInfo() (*types.Info, error) {
 		SystemTime:         time.Now().Format(time.RFC3339Nano),
 		ExecutionDriver:    daemon.ExecutionDriver().Name(),
 		LoggingDriver:      daemon.defaultLogConfig.Type,
+		CgroupDriver:       daemon.getCgroupDriver(),
 		NEventsListener:    daemon.EventsService.SubscribersCount(),
 		KernelVersion:      kernelVersion,
 		OperatingSystem:    operatingSystem,
diff --git a/docs/reference/api/docker_remote_api.md b/docs/reference/api/docker_remote_api.md
index 8880975eb9..715e8fede3 100644
--- a/docs/reference/api/docker_remote_api.md
+++ b/docs/reference/api/docker_remote_api.md
@@ -121,6 +121,7 @@ This section lists each version from latest to oldest.  Each listing includes a
 * `GET /networks/(name)` now returns an `EnableIPv6` field showing whether the network has ipv6 enabled or not.
 * `POST /containers/(name)/update` now supports updating container's restart policy.
 * `POST /networks/create` now supports enabling ipv6 on the network by setting the `EnableIPv6` field (doing this with a label will no longer work).
+* `GET /info` now returns `CgroupDriver` field showing what cgroup driver the daemon is using; `cgroupfs` or `systemd`.
 
 ### v1.22 API changes
 
diff --git a/docs/reference/api/docker_remote_api_v1.23.md b/docs/reference/api/docker_remote_api_v1.23.md
index 425fe1d3ae..3617e54cff 100644
--- a/docs/reference/api/docker_remote_api_v1.23.md
+++ b/docs/reference/api/docker_remote_api_v1.23.md
@@ -2128,6 +2128,7 @@ Display system-wide information
 
     {
         "Architecture": "x86_64",
+        "CgroupDriver": "cgroupfs",
         "Containers": 11,
         "ContainersRunning": 7,
         "ContainersStopped": 3,
diff --git a/docs/reference/commandline/info.md b/docs/reference/commandline/info.md
index e3cce9bbee..06f7848d5a 100644
--- a/docs/reference/commandline/info.md
+++ b/docs/reference/commandline/info.md
@@ -33,6 +33,7 @@ For example:
      Dirperm1 Supported: true
     Execution Driver: native-0.2
     Logging Driver: json-file
+    Cgroup Driver: cgroupfs
     Plugins:
      Volume: local
      Network: bridge null host
diff --git a/man/docker-info.1.md b/man/docker-info.1.md
index 93004a83c9..1ebcd1a419 100644
--- a/man/docker-info.1.md
+++ b/man/docker-info.1.md
@@ -42,6 +42,7 @@ Here is a sample output:
      Dirs: 80
     Execution Driver: native-0.2
     Logging Driver: json-file
+    Cgroup Driver: cgroupfs
     Plugins:
      Volume: local
      Network: bridge null host