containerd/plugin/plugin.go
Stephen J Day 193abed96e
content: unify provider and ingester
The split between provider and ingester was a long standing division
reflecting the client-side use cases. For the most part, we were
differentiating these for the algorithms that operate them, but it made
instantation and use of the types challenging. On the server-side, this
distinction is generally less important. This change unifies these types
and in the process we get a few benefits.

The first is that we now completely access the content store over GRPC.
This was the initial intent and we have now satisfied this goal
completely. There are a few issues around listing content and getting
status, but we resolve these with simple streaming and regexp filters.
More can probably be done to polish this but the result is clean.

Several other content-oriented methods were polished in the process of
unification. We have now properly seperated out the `Abort` method to
cancel ongoing or stalled ingest processes. We have also replaced the
`Active` method with a single status method.

The transition went extremely smoothly. Once the clients were updated to
use the new methods, every thing worked as expected on the first
compile.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2017-05-10 17:05:53 -07:00

82 lines
1.6 KiB
Go

package plugin
import (
"fmt"
"sync"
"github.com/boltdb/bolt"
"github.com/containerd/containerd"
"github.com/containerd/containerd/content"
"github.com/containerd/containerd/snapshot"
"golang.org/x/net/context"
"google.golang.org/grpc"
)
type PluginType int
const (
RuntimePlugin PluginType = iota + 1
GRPCPlugin
SnapshotPlugin
ContainerMonitorPlugin
)
type Registration struct {
Type PluginType
Config interface{}
Init func(*InitContext) (interface{}, error)
}
// TODO(@crosbymichael): how to we keep this struct from growing but support dependency injection for loaded plugins?
type InitContext struct {
Root string
State string
Runtimes map[string]containerd.Runtime
Content content.Store
Meta *bolt.DB
Snapshotter snapshot.Snapshotter
Config interface{}
Context context.Context
Monitor ContainerMonitor
}
type Service interface {
Register(*grpc.Server) error
}
var register = struct {
sync.Mutex
r map[string]*Registration
}{
r: make(map[string]*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(name string, r *Registration) error {
register.Lock()
defer register.Unlock()
if _, ok := register.r[name]; ok {
return fmt.Errorf("plugin already registered as %q", name)
}
register.r[name] = r
return nil
}
func Registrations() map[string]*Registration {
return register.r
}