docs/backends/backends.go

77 lines
2.1 KiB
Go

package backends
import (
"fmt"
"github.com/docker/libswarm/beam"
beamutils "github.com/docker/libswarm/beam/utils"
"io"
"strings"
"time"
)
// New returns a new engine, with all backends
// registered but not activated.
// To activate a backend, call a job on the resulting
// engine, named after the desired backend.
//
// Example: `New().Job("debug").Run()`
func New() beam.Sender {
backends := beamutils.NewHub()
backends.RegisterName("cd", func(msg *beam.Message, out beam.Sender) (bool, error) {
return false, fmt.Errorf("no such backend: %s\n", strings.Join(msg.Args, " "))
})
backends.RegisterName("cd", func(msg *beam.Message, out beam.Sender) (bool, error) {
if len(msg.Args) > 0 && msg.Args[0] == "debug" {
debug, err := out.Send(&beam.Message{Name: "register", Ret: beam.RetPipe})
if err != nil {
return false, err
}
// Spawn the debug object
go func() {
for {
msg, err := debug.Receive(beam.Ret)
if err == io.EOF {
return
}
if err != nil {
return
}
fmt.Printf("[DEBUG] %s %s\n", msg.Name, strings.Join(msg.Args, " "))
if _, err := out.Send(msg); err != nil {
return
}
}
}()
return false, nil
}
return true, nil
})
backends.RegisterName("cd", func(msg *beam.Message, out beam.Sender) (bool, error) {
if len(msg.Args) > 0 && msg.Args[0] == "fakeclient" {
_, err := out.Send(&beam.Message{Name: "register", Ret: beam.NopSender{}})
if err != nil {
return false, err
}
// Spawm the fakeclient task
// FIXME: only do this after started?
go func() {
out.Send(&beam.Message{Name: "log", Args: []string{"fake client starting"}})
defer out.Send(&beam.Message{Name: "log", Args: []string{"fake client terminating"}})
for {
time.Sleep(1 * time.Second)
_, err := out.Send(&beam.Message{Name: "log", Args: []string{"fake client reporting for duty"}})
if err != nil {
return
}
if _, err := out.Send(&beam.Message{Name: "children", Ret: beam.NopSender{}}); err != nil {
return
}
}
}()
return false, nil
}
return true, nil
})
return backends
}