ftp: retry connections and logins on 421 errors #3984

Before this we just failed if the ftp connection or login failed.

This change adds a pacer just for the ftp connect and retries if the
connection failed to Dial or the login returns a 421 error.
This commit is contained in:
Nick Craig-Wood 2020-03-03 11:07:03 +00:00
parent df451e1e70
commit d72d9e591a
1 changed files with 40 additions and 11 deletions

View File

@ -21,6 +21,7 @@ import (
"github.com/rclone/rclone/fs/config/configmap"
"github.com/rclone/rclone/fs/config/configstruct"
"github.com/rclone/rclone/fs/config/obscure"
"github.com/rclone/rclone/fs/fserrors"
"github.com/rclone/rclone/fs/fshttp"
"github.com/rclone/rclone/fs/hash"
"github.com/rclone/rclone/lib/encoder"
@ -33,6 +34,12 @@ var (
currentUser = env.CurrentUser()
)
const (
minSleep = 10 * time.Millisecond
maxSleep = 2 * time.Second
decayConstant = 2 // bigger for slower decay, exponential
)
// Register with Fs
func init() {
fs.Register(&fs.RegInfo{
@ -157,6 +164,7 @@ type Fs struct {
drain *time.Timer // used to drain the pool when we stop using the connections
tokens *pacer.TokenDispenser
tlsConf *tls.Config
pacer *fs.Pacer // pacer for FTP connections
}
// Object describes an FTP file
@ -250,8 +258,24 @@ func (d *dialCtx) dial(network, address string) (net.Conn, error) {
return conn, err
}
// shouldRetry returns a boolean as to whether this err deserve to be
// retried. It returns the err as a convenience
func shouldRetry(ctx context.Context, err error) (bool, error) {
if fserrors.ContextError(ctx, &err) {
return false, err
}
switch errX := err.(type) {
case *textproto.Error:
switch errX.Code {
case ftp.StatusNotAvailable:
return true, err
}
}
return fserrors.ShouldRetry(err), err
}
// Open a new connection to the FTP server.
func (f *Fs) ftpConnection(ctx context.Context) (*ftp.ServerConn, error) {
func (f *Fs) ftpConnection(ctx context.Context) (c *ftp.ServerConn, err error) {
fs.Debugf(f, "Connecting to FTP server")
dCtx := dialCtx{f, ctx}
ftpConfig := []ftp.DialOption{ftp.DialWithDialFunc(dCtx.dial)}
@ -273,18 +297,22 @@ func (f *Fs) ftpConnection(ctx context.Context) (*ftp.ServerConn, error) {
if f.ci.Dump&(fs.DumpHeaders|fs.DumpBodies|fs.DumpRequests|fs.DumpResponses) != 0 {
ftpConfig = append(ftpConfig, ftp.DialWithDebugOutput(&debugLog{auth: f.ci.Dump&fs.DumpAuth != 0}))
}
c, err := ftp.Dial(f.dialAddr, ftpConfig...)
err = f.pacer.Call(func() (bool, error) {
c, err = ftp.Dial(f.dialAddr, ftpConfig...)
if err != nil {
return shouldRetry(ctx, err)
}
err = c.Login(f.user, f.pass)
if err != nil {
_ = c.Quit()
return shouldRetry(ctx, err)
}
return false, nil
})
if err != nil {
fs.Errorf(f, "Error while Dialing %s: %s", f.dialAddr, err)
return nil, errors.Wrap(err, "ftpConnection Dial")
err = errors.Wrapf(err, "failed to make FTP connection to %q", f.dialAddr)
}
err = c.Login(f.user, f.pass)
if err != nil {
_ = c.Quit()
fs.Errorf(f, "Error while Logging in into %s: %s", f.dialAddr, err)
return nil, errors.Wrap(err, "ftpConnection Login")
}
return c, nil
return c, err
}
// Get an FTP connection from the pool, or open a new one
@ -417,6 +445,7 @@ func NewFs(ctx context.Context, name, root string, m configmap.Mapper) (ff fs.Fs
dialAddr: dialAddr,
tokens: pacer.NewTokenDispenser(opt.Concurrency),
tlsConf: tlsConfig,
pacer: fs.NewPacer(ctx, pacer.NewDefault(pacer.MinSleep(minSleep), pacer.MaxSleep(maxSleep), pacer.DecayConstant(decayConstant))),
}
f.features = (&fs.Features{
CanHaveEmptyDirectories: true,