Move auto-registration to explicit install packages, register plugin interfaces

cadvisor.go

@@ -34,6 +34,9 @@ import (
 	"github.com/google/cadvisor/utils/sysfs"
 	"github.com/google/cadvisor/version"
 
+	// Register container providers
+	_ "github.com/google/cadvisor/container/install"
+
 	// Register CloudProviders
 	_ "github.com/google/cadvisor/utils/cloudinfo/aws"
 	_ "github.com/google/cadvisor/utils/cloudinfo/azure"

container/containerd/install/install.go

@@ -12,21 +12,17 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package containerd
+// The install package registers containerd.NewPlugin() as the "containerd" container provider when imported
+package install
 
 import (
 	"github.com/google/cadvisor/container"
-	"github.com/google/cadvisor/fs"
-	info "github.com/google/cadvisor/info/v1"
-	"github.com/google/cadvisor/watcher"
+	"github.com/google/cadvisor/container/containerd"
 	"k8s.io/klog"
 )
 
 func init() {
-	err := container.RegisterPlugin("containerd", func(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includedMetrics container.MetricSet) (watcher.ContainerWatcher, error) {
-		err := Register(factory, fsInfo, includedMetrics)
-		return nil, err
-	})
+	err := container.RegisterPlugin("containerd", containerd.NewPlugin())
 	if err != nil {
 		klog.Fatalf("Failed to register containerd plugin: %v", err)
 	}

container/containerd/plugin.go

@@ -0,0 +1,34 @@
+// Copyright 2019 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package containerd
+
+import (
+	"github.com/google/cadvisor/container"
+	"github.com/google/cadvisor/fs"
+	info "github.com/google/cadvisor/info/v1"
+	"github.com/google/cadvisor/watcher"
+)
+
+// NewPlugin returns an implementation of container.Plugin suitable for passing to container.RegisterPlugin()
+func NewPlugin() container.Plugin {
+	return &plugin{}
+}
+
+type plugin struct{}
+
+func (p *plugin) Register(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includedMetrics container.MetricSet) (watcher.ContainerWatcher, error) {
+	err := Register(factory, fsInfo, includedMetrics)
+	return nil, err
+}

container/crio/install/install.go

@@ -12,21 +12,17 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package crio
+// The install package registers crio.NewPlugin() as the "crio" container provider when imported
+package install
 
 import (
 	"github.com/google/cadvisor/container"
-	"github.com/google/cadvisor/fs"
-	info "github.com/google/cadvisor/info/v1"
-	"github.com/google/cadvisor/watcher"
+	"github.com/google/cadvisor/container/crio"
 	"k8s.io/klog"
 )
 
 func init() {
-	err := container.RegisterPlugin("crio", func(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includedMetrics container.MetricSet) (watcher.ContainerWatcher, error) {
-		err := Register(factory, fsInfo, includedMetrics)
-		return nil, err
-	})
+	err := container.RegisterPlugin("crio", crio.NewPlugin())
 	if err != nil {
 		klog.Fatalf("Failed to register crio plugin: %v", err)
 	}

container/crio/plugin.go

@@ -0,0 +1,34 @@
+// Copyright 2019 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package crio
+
+import (
+	"github.com/google/cadvisor/container"
+	"github.com/google/cadvisor/fs"
+	info "github.com/google/cadvisor/info/v1"
+	"github.com/google/cadvisor/watcher"
+)
+
+// NewPlugin returns an implementation of container.Plugin suitable for passing to container.RegisterPlugin()
+func NewPlugin() container.Plugin {
+	return &plugin{}
+}
+
+type plugin struct{}
+
+func (p *plugin) Register(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includedMetrics container.MetricSet) (watcher.ContainerWatcher, error) {
+	err := Register(factory, fsInfo, includedMetrics)
+	return nil, err
+}

container/docker/install/install.go

@@ -12,21 +12,17 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package docker
+// The install package registers docker.NewPlugin() as the "docker" container provider when imported
+package install
 
 import (
 	"github.com/google/cadvisor/container"
-	"github.com/google/cadvisor/fs"
-	info "github.com/google/cadvisor/info/v1"
-	"github.com/google/cadvisor/watcher"
+	"github.com/google/cadvisor/container/docker"
 	"k8s.io/klog"
 )
 
 func init() {
-	err := container.RegisterPlugin("docker", func(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includedMetrics container.MetricSet) (watcher.ContainerWatcher, error) {
-		err := Register(factory, fsInfo, includedMetrics)
-		return nil, err
-	})
+	err := container.RegisterPlugin("docker", docker.NewPlugin())
 	if err != nil {
 		klog.Fatalf("Failed to register docker plugin: %v", err)
 	}

container/docker/plugin.go

@@ -0,0 +1,34 @@
+// Copyright 2019 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package docker
+
+import (
+	"github.com/google/cadvisor/container"
+	"github.com/google/cadvisor/fs"
+	info "github.com/google/cadvisor/info/v1"
+	"github.com/google/cadvisor/watcher"
+)
+
+// NewPlugin returns an implementation of container.Plugin suitable for passing to container.RegisterPlugin()
+func NewPlugin() container.Plugin {
+	return &plugin{}
+}
+
+type plugin struct{}
+
+func (p *plugin) Register(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includedMetrics container.MetricSet) (watcher.ContainerWatcher, error) {
+	err := Register(factory, fsInfo, includedMetrics)
+	return nil, err
+}

container/factory.go

@@ -73,13 +73,17 @@ func (ms MetricSet) Add(mk MetricKind) {
 	ms[mk] = struct{}{}
 }
 
-type Register func(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includedMetrics MetricSet) (watcher.ContainerWatcher, error)
-
 // All registered auth provider plugins.
 var pluginsLock sync.Mutex
-var plugins = make(map[string]Register)
+var plugins = make(map[string]Plugin)
 
-func RegisterPlugin(name string, plugin Register) error {
+type Plugin interface {
+	// Register is invoked when starting a manager. It can optionally return a container watcher.
+	// A returned error is logged, but is not fatal.
+	Register(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includedMetrics MetricSet) (watcher.ContainerWatcher, error)
+}
+
+func RegisterPlugin(name string, plugin Plugin) error {
 	pluginsLock.Lock()
 	defer pluginsLock.Unlock()
 	if _, found := plugins[name]; found {
@@ -95,8 +99,8 @@ func InitializePlugins(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includ
 	defer pluginsLock.Unlock()
 
 	containerWatchers := []watcher.ContainerWatcher{}
-	for name, register := range plugins {
-		watcher, err := register(factory, fsInfo, includedMetrics)
+	for name, plugin := range plugins {
+		watcher, err := plugin.Register(factory, fsInfo, includedMetrics)
 		if err != nil {
 			klog.V(5).Infof("Registration of the %s container factory failed: %v", name, err)
 		}

container/install/install.go

@@ -0,0 +1,25 @@
+// Copyright 2019 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// The install package registers all included container providers when imported
+package install
+
+import (
+	_ "github.com/google/cadvisor/container/containerd/install"
+	_ "github.com/google/cadvisor/container/crio/install"
+	_ "github.com/google/cadvisor/container/docker/install"
+	_ "github.com/google/cadvisor/container/mesos/install"
+	_ "github.com/google/cadvisor/container/rkt/install"
+	_ "github.com/google/cadvisor/container/systemd/install"
+)

container/mesos/install/install.go

@@ -12,21 +12,17 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package mesos
+// The install package registers mesos.NewPlugin() as the "mesos" container provider when imported
+package install
 
 import (
 	"github.com/google/cadvisor/container"
-	"github.com/google/cadvisor/fs"
-	info "github.com/google/cadvisor/info/v1"
-	"github.com/google/cadvisor/watcher"
+	"github.com/google/cadvisor/container/mesos"
 	"k8s.io/klog"
 )
 
 func init() {
-	err := container.RegisterPlugin("mesos", func(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includedMetrics container.MetricSet) (watcher.ContainerWatcher, error) {
-		err := Register(factory, fsInfo, includedMetrics)
-		return nil, err
-	})
+	err := container.RegisterPlugin("mesos", mesos.NewPlugin())
 	if err != nil {
 		klog.Fatalf("Failed to register mesos plugin: %v", err)
 	}

container/mesos/plugin.go

@@ -0,0 +1,34 @@
+// Copyright 2019 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mesos
+
+import (
+	"github.com/google/cadvisor/container"
+	"github.com/google/cadvisor/fs"
+	info "github.com/google/cadvisor/info/v1"
+	"github.com/google/cadvisor/watcher"
+)
+
+// NewPlugin returns an implementation of container.Plugin suitable for passing to container.RegisterPlugin()
+func NewPlugin() container.Plugin {
+	return &plugin{}
+}
+
+type plugin struct{}
+
+func (p *plugin) Register(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includedMetrics container.MetricSet) (watcher.ContainerWatcher, error) {
+	err := Register(factory, fsInfo, includedMetrics)
+	return nil, err
+}

container/rkt/install/install.go

@@ -12,24 +12,17 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package rkt
+// The install package registers rkt.NewPlugin() as the "rkt" container provider when imported
+package install
 
 import (
 	"github.com/google/cadvisor/container"
-	"github.com/google/cadvisor/fs"
-	info "github.com/google/cadvisor/info/v1"
-	"github.com/google/cadvisor/watcher"
+	"github.com/google/cadvisor/container/rkt"
 	"k8s.io/klog"
 )
 
 func init() {
-	err := container.RegisterPlugin("rkt", func(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includedMetrics container.MetricSet) (watcher.ContainerWatcher, error) {
-		err := Register(factory, fsInfo, includedMetrics)
-		if err != nil {
-			return nil, err
-		}
-		return NewRktContainerWatcher()
-	})
+	err := container.RegisterPlugin("rkt", rkt.NewPlugin())
 	if err != nil {
 		klog.Fatalf("Failed to register rkt plugin: %v", err)
 	}

container/rkt/plugin.go

@@ -0,0 +1,37 @@
+// Copyright 2019 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rkt
+
+import (
+	"github.com/google/cadvisor/container"
+	"github.com/google/cadvisor/fs"
+	info "github.com/google/cadvisor/info/v1"
+	"github.com/google/cadvisor/watcher"
+)
+
+// NewPlugin returns an implementation of container.Plugin suitable for passing to container.RegisterPlugin()
+func NewPlugin() container.Plugin {
+	return &plugin{}
+}
+
+type plugin struct{}
+
+func (p *plugin) Register(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includedMetrics container.MetricSet) (watcher.ContainerWatcher, error) {
+	err := Register(factory, fsInfo, includedMetrics)
+	if err != nil {
+		return nil, err
+	}
+	return NewRktContainerWatcher()
+}

container/systemd/install/install.go

@@ -12,21 +12,17 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package systemd
+// The install package registers systemd.NewPlugin() as the "systemd" container provider when imported
+package install
 
 import (
 	"github.com/google/cadvisor/container"
-	"github.com/google/cadvisor/fs"
-	info "github.com/google/cadvisor/info/v1"
-	"github.com/google/cadvisor/watcher"
+	"github.com/google/cadvisor/container/systemd"
 	"k8s.io/klog"
 )
 
 func init() {
-	err := container.RegisterPlugin("systemd", func(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includedMetrics container.MetricSet) (watcher.ContainerWatcher, error) {
-		err := Register(factory, fsInfo, includedMetrics)
-		return nil, err
-	})
+	err := container.RegisterPlugin("systemd", systemd.NewPlugin())
 	if err != nil {
 		klog.Fatalf("Failed to register systemd plugin: %v", err)
 	}

container/systemd/plugin.go

@@ -0,0 +1,34 @@
+// Copyright 2019 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package systemd
+
+import (
+	"github.com/google/cadvisor/container"
+	"github.com/google/cadvisor/fs"
+	info "github.com/google/cadvisor/info/v1"
+	"github.com/google/cadvisor/watcher"
+)
+
+// NewPlugin returns an implementation of container.Plugin suitable for passing to container.RegisterPlugin()
+func NewPlugin() container.Plugin {
+	return &plugin{}
+}
+
+type plugin struct{}
+
+func (p *plugin) Register(factory info.MachineInfoFactory, fsInfo fs.FsInfo, includedMetrics container.MetricSet) (watcher.ContainerWatcher, error) {
+	err := Register(factory, fsInfo, includedMetrics)
+	return nil, err
+}

manager/manager_test.go

@@ -35,6 +35,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	clock "k8s.io/utils/clock/testing"
+
+	_ "github.com/google/cadvisor/container/install"
 )
 
 // TODO(vmarmol): Refactor these tests.