3db8adc5d7
Allow plugins to be mapped and returned by their ID. Add skip plugin to allow plugins to decide whether they should be loaded. Signed-off-by: Derek McGowan <derek@mcgstyle.net>
114 lines
2.3 KiB
Go
114 lines
2.3 KiB
Go
package plugin
|
|
|
|
import (
|
|
"fmt"
|
|
"sync"
|
|
|
|
"github.com/pkg/errors"
|
|
"google.golang.org/grpc"
|
|
)
|
|
|
|
var (
|
|
ErrNoPluginType = errors.New("plugin: no type")
|
|
ErrNoPluginID = errors.New("plugin: no id")
|
|
|
|
// SkipPlugin is used when a plugin is not initialized and should not be loaded,
|
|
// this allows the plugin loader differentiate between a plugin which is configured
|
|
// not to load and one that fails to load.
|
|
SkipPlugin = errors.New("skip plugin")
|
|
)
|
|
|
|
// IsSkipPlugin returns true if the error is skipping the plugin
|
|
func IsSkipPlugin(err error) bool {
|
|
if errors.Cause(err) == SkipPlugin {
|
|
return true
|
|
}
|
|
return false
|
|
}
|
|
|
|
type PluginType string
|
|
|
|
const (
|
|
RuntimePlugin PluginType = "io.containerd.runtime.v1"
|
|
GRPCPlugin PluginType = "io.containerd.grpc.v1"
|
|
SnapshotPlugin PluginType = "io.containerd.snapshotter.v1"
|
|
TaskMonitorPlugin PluginType = "io.containerd.monitor.v1"
|
|
DiffPlugin PluginType = "io.containerd.differ.v1"
|
|
MetadataPlugin PluginType = "io.containerd.metadata.v1"
|
|
ContentPlugin PluginType = "io.containerd.content.v1"
|
|
)
|
|
|
|
type Registration struct {
|
|
Type PluginType
|
|
ID string
|
|
Config interface{}
|
|
Requires []PluginType
|
|
Init func(*InitContext) (interface{}, error)
|
|
|
|
added bool
|
|
}
|
|
|
|
func (r *Registration) URI() string {
|
|
return fmt.Sprintf("%s.%s", r.Type, r.ID)
|
|
}
|
|
|
|
type Service interface {
|
|
Register(*grpc.Server) error
|
|
}
|
|
|
|
var register = struct {
|
|
sync.Mutex
|
|
r []*Registration
|
|
}{}
|
|
|
|
// Load loads all plugins at the provided path into containerd
|
|
func Load(path string) (err error) {
|
|
defer func() {
|
|
if v := recover(); v != nil {
|
|
rerr, ok := v.(error)
|
|
if !ok {
|
|
rerr = fmt.Errorf("%s", v)
|
|
}
|
|
err = rerr
|
|
}
|
|
}()
|
|
return loadPlugins(path)
|
|
}
|
|
|
|
func Register(r *Registration) {
|
|
register.Lock()
|
|
defer register.Unlock()
|
|
if r.Type == "" {
|
|
panic(ErrNoPluginType)
|
|
}
|
|
if r.ID == "" {
|
|
panic(ErrNoPluginID)
|
|
}
|
|
register.r = append(register.r, r)
|
|
}
|
|
|
|
func Graph() (ordered []*Registration) {
|
|
for _, r := range register.r {
|
|
children(r.Requires, &ordered)
|
|
if !r.added {
|
|
ordered = append(ordered, r)
|
|
r.added = true
|
|
}
|
|
}
|
|
return ordered
|
|
}
|
|
|
|
func children(types []PluginType, ordered *[]*Registration) {
|
|
for _, t := range types {
|
|
for _, r := range register.r {
|
|
if r.Type == t {
|
|
children(r.Requires, ordered)
|
|
if !r.added {
|
|
*ordered = append(*ordered, r)
|
|
r.added = true
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|