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|
package connectors
import (
"context"
"io"
"github.com/mimecast/dtail/internal/clients/handlers"
"github.com/mimecast/dtail/internal/config"
"github.com/mimecast/dtail/internal/io/dlog"
serverHandlers "github.com/mimecast/dtail/internal/server/handlers"
user "github.com/mimecast/dtail/internal/user/server"
)
// Serverless creates a server object directly without TCP.
type Serverless struct {
handler handlers.Handler
commands []string
userName string
}
// NewServerless starts a new serverless session.
func NewServerless(userName string, handler handlers.Handler,
commands []string) *Serverless {
dlog.Client.Debug("Creating new serverless connector", handler, commands)
return &Serverless{
userName: userName,
handler: handler,
commands: commands,
}
}
// Server returns serverless server indicator.
func (s *Serverless) Server() string {
return "local(serverless)"
}
// Handler returns the handler used for the serverless connection.
func (s *Serverless) Handler() handlers.Handler {
return s.handler
}
// Start the serverless connection.
func (s *Serverless) Start(ctx context.Context, cancel context.CancelFunc,
throttleCh, statsCh chan struct{}) {
dlog.Client.Debug("Starting serverless connector")
go func() {
defer cancel()
if err := s.handle(ctx, cancel); err != nil {
dlog.Client.Warn(err)
}
}()
<-ctx.Done()
}
func (s *Serverless) handle(ctx context.Context, cancel context.CancelFunc) error {
dlog.Client.Debug("Creating server handler for a serverless session")
user, err := user.New(s.userName, s.Server())
if err != nil {
return err
}
var serverHandler serverHandlers.Handler
switch s.userName {
case config.HealthUser:
dlog.Client.Debug("Creating serverless health handler")
serverHandler = serverHandlers.NewHealthHandler(user)
default:
dlog.Client.Debug("Creating serverless server handler")
serverHandler = serverHandlers.NewServerHandler(
user,
make(chan struct{}, config.Server.MaxConcurrentCats),
make(chan struct{}, config.Server.MaxConcurrentTails),
)
}
terminate := func() {
dlog.Client.Debug("Terminating serverless connection")
serverHandler.Shutdown()
cancel()
}
go func() {
defer terminate()
if _, err := io.Copy(serverHandler, s.handler); err != nil {
dlog.Client.Trace(err)
}
dlog.Client.Trace("io.Copy(serverHandler, s.handler) => done")
}()
go func() {
defer terminate()
if _, err := io.Copy(s.handler, serverHandler); err != nil {
dlog.Client.Trace(err)
}
dlog.Client.Trace("io.Copy(s.handler, serverHandler) => done")
}()
go func() {
defer terminate()
select {
case <-s.handler.Done():
dlog.Client.Trace("<-s.handler.Done()")
case <-ctx.Done():
dlog.Client.Trace("<-ctx.Done()")
}
}()
// Send all commands to client.
for _, command := range s.commands {
dlog.Client.Debug("Sending command to serverless server", command)
if err := s.handler.SendMessage(command); err != nil {
dlog.Client.Debug(err)
}
}
<-ctx.Done()
dlog.Client.Trace("s.handler.Shutdown()")
s.handler.Shutdown()
return nil
}
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