rclone/cmd/backend/backend.go
Nick Craig-Wood e43b5ce5e5 Remove github.com/pkg/errors and replace with std library version
This is possible now that we no longer support go1.12 and brings
rclone into line with standard practices in the Go world.

This also removes errors.New and errors.Errorf from lib/errors and
prefers the stdlib errors package over lib/errors.
2021-11-07 11:53:30 +00:00

178 lines
4.4 KiB
Go

package backend
import (
"context"
"encoding/json"
"fmt"
"os"
"sort"
"github.com/rclone/rclone/cmd"
"github.com/rclone/rclone/cmd/rc"
"github.com/rclone/rclone/fs"
"github.com/rclone/rclone/fs/config/flags"
"github.com/rclone/rclone/fs/operations"
"github.com/spf13/cobra"
)
var (
options []string
useJSON bool
)
func init() {
cmd.Root.AddCommand(commandDefinition)
cmdFlags := commandDefinition.Flags()
flags.StringArrayVarP(cmdFlags, &options, "option", "o", options, "Option in the form name=value or name")
flags.BoolVarP(cmdFlags, &useJSON, "json", "", useJSON, "Always output in JSON format")
}
var commandDefinition = &cobra.Command{
Use: "backend <command> remote:path [opts] <args>",
Short: `Run a backend-specific command.`,
Long: `
This runs a backend-specific command. The commands themselves (except
for "help" and "features") are defined by the backends and you should
see the backend docs for definitions.
You can discover what commands a backend implements by using
rclone backend help remote:
rclone backend help <backendname>
You can also discover information about the backend using (see
[operations/fsinfo](/rc/#operations/fsinfo) in the remote control docs
for more info).
rclone backend features remote:
Pass options to the backend command with -o. This should be key=value or key, e.g.:
rclone backend stats remote:path stats -o format=json -o long
Pass arguments to the backend by placing them on the end of the line
rclone backend cleanup remote:path file1 file2 file3
Note to run these commands on a running backend then see
[backend/command](/rc/#backend/command) in the rc docs.
`,
RunE: func(command *cobra.Command, args []string) error {
cmd.CheckArgs(2, 1e6, command, args)
name, remote := args[0], args[1]
cmd.Run(false, false, command, func() error {
// show help if remote is a backend name
if name == "help" {
fsInfo, err := fs.Find(remote)
if err == nil {
return showHelp(fsInfo)
}
}
// Create remote
fsInfo, configName, fsPath, config, err := fs.ConfigFs(remote)
if err != nil {
return err
}
f, err := fsInfo.NewFs(context.Background(), configName, fsPath, config)
if err != nil {
return err
}
// Run the command
var out interface{}
switch name {
case "help":
return showHelp(fsInfo)
case "features":
out = operations.GetFsInfo(f)
default:
doCommand := f.Features().Command
if doCommand == nil {
return fmt.Errorf("%v: doesn't support backend commands", f)
}
arg := args[2:]
opt := rc.ParseOptions(options)
out, err = doCommand(context.Background(), name, arg, opt)
}
if err != nil {
return fmt.Errorf("command %q failed: %w", name, err)
}
// Output the result
writeJSON := false
if useJSON {
writeJSON = true
} else {
switch x := out.(type) {
case nil:
case string:
fmt.Println(out)
case []string:
for _, line := range x {
fmt.Println(line)
}
default:
writeJSON = true
}
}
if writeJSON {
// Write indented JSON to the output
enc := json.NewEncoder(os.Stdout)
enc.SetIndent("", "\t")
err = enc.Encode(out)
if err != nil {
return fmt.Errorf("failed to write JSON: %w", err)
}
}
return nil
})
return nil
},
}
// show help for a backend
func showHelp(fsInfo *fs.RegInfo) error {
cmds := fsInfo.CommandHelp
name := fsInfo.Name
if len(cmds) == 0 {
return fmt.Errorf("%s backend has no commands", name)
}
fmt.Printf("## Backend commands\n\n")
fmt.Printf(`Here are the commands specific to the %s backend.
Run them with
rclone backend COMMAND remote:
The help below will explain what arguments each command takes.
See [the "rclone backend" command](/commands/rclone_backend/) for more
info on how to pass options and arguments.
These can be run on a running backend using the rc command
[backend/command](/rc/#backend/command).
`, name)
for _, cmd := range cmds {
fmt.Printf("### %s\n\n", cmd.Name)
fmt.Printf("%s\n\n", cmd.Short)
fmt.Printf(" rclone backend %s remote: [options] [<arguments>+]\n\n", cmd.Name)
if cmd.Long != "" {
fmt.Printf("%s\n\n", cmd.Long)
}
if len(cmd.Opts) != 0 {
fmt.Printf("Options:\n\n")
ks := []string{}
for k := range cmd.Opts {
ks = append(ks, k)
}
sort.Strings(ks)
for _, k := range ks {
v := cmd.Opts[k]
fmt.Printf("- %q: %s\n", k, v)
}
fmt.Printf("\n")
}
}
return nil
}