Combine flags from other package

[justintv90]

Hi

Is there any solutaion for combining flags from other package. For example, glog package requires flag.Parse for using his flags but when i put the flag.Parse(), his flag overrided whole my cli flags. What should i do if i want to use both glog flags and my cli flags ?

[ashw7n]

+1

[ashw7n]

I needed this and the following seems to be work. I of course had to vendor the cli package and add the following file

package cli
import (
    "flag"
    "fmt"
)

type FlagsFlag struct {
    *flag.Flag
}

func (f FlagsFlag) Apply(flag *flag.FlagSet) {
    flag.Var(f.Flag.Value, f.Name, f.Usage)
}

func (f FlagsFlag) getName() string {
    return f.Name
}

func (f FlagsFlag) String() string {
    return fmt.Sprintf("%s \"%v\"\t%v", prefixedNames(f.Flag.Name), f.Flag.Value, f.Flag.Usage)
}

and then add the following to my app

func addDefault(app *cli.App) {
    app.HideVersion=true
    flag.CommandLine.VisitAll(func(f *flag.Flag) {
        app.Flags = append(app.Flags, cli.FlagsFlag{f})
    })
}

Seems to print the logs, not clean but unblock for now.

[decker502]

+1

[johnweldon]

That workaround doesn't work for the v2 branch

[carlverge]

Managed to get it going in the v1 branch without vendoring (though it's certainly pretty janky):

func glogFlagShim(fakeVals map[string]string) {
    flag.VisitAll(func(fl *flag.Flag) {
        if val, ok := fakeVals[fl.Name]; ok {
            fl.Value.Set(val)
        }
    })
}

func glogGangstaShim(c *cli.Context) {
    _ = flag.CommandLine.Parse([]string{})
    glogFlagShim(map[string]string{
        "v":                fmt.Sprint(c.Int("v")),
        "logtostderr":      fmt.Sprint(c.Bool("logtostderr")),
        "stderrthreshold":  fmt.Sprint(c.Int("stderrthreshold")),
        "alsologtostderr":  fmt.Sprint(c.Bool("alsologtostderr")),
        "vmodule":          c.String("vmodule"),
        "log_dir":          c.String("log_dir"),
        "log_backtrace_at": c.String("log_backtrace_at"),
    })
}

var glogGangstaFlags = []cli.Flag{
    cli.IntFlag{
        Name: "v", Value: 0, Usage: "log level for V logs",
    },
    cli.BoolFlag{
        Name: "logtostderr", Usage: "log to standard error instead of files",
    },
    cli.IntFlag{
        Name:  "stderrthreshold",
        Usage: "logs at or above this threshold go to stderr",
    },
    cli.BoolFlag{
        Name: "alsologtostderr", Usage: "log to standard error as well as files",
    },
    cli.StringFlag{
        Name:  "vmodule",
        Usage: "comma-separated list of pattern=N settings for file-filtered logging",
    },
    cli.StringFlag{
        Name: "log_dir", Usage: "If non-empty, write log files in this directory",
    },
    cli.StringFlag{
        Name:  "log_backtrace_at",
        Usage: "when logging hits line file:N, emit a stack trace",
        Value: ":0",
    },
}

func main() {
    cli.VersionFlag = cli.BoolFlag{
        Name:  "version",
        Usage: "print the version",
    }
    app := cli.NewApp()
    app.Flags = []cli.Flag{
        cli.StringFlag{Name: "config", Value: "config.json"},
    }
    app.Flags = append(app.Flags, glogGangstaFlags...)

    app.Action = func(c *cli.Context) error {
        glogGangstaShim(c)
        return nil
    }
    app.Run(os.Args)
}

[silentred]

+1, consider solving the problem in this tool?

[coilysiren]

I'm not 100% sure what the request is here - as far as I can tell @carlverge has a solution above? Given that, I think I'm gonna close this. Let me know if it should be re-opened, though!

[coilysiren]

Created a stand-alone feature request for this => https://github.com/urfave/cli/issues/948. I'm going to close this one as a duplicate now

[coilysiren]

re-opening this b/c there wasn't any movement on https://github.com/urfave/cli/issues/948, anyone that's available please do pick up the work here

[stale[bot]]

This issue or PR has been automatically marked as stale because it has not had recent activity. Please add a comment bumping this if you're still interested in it's resolution! Thanks for your help, please let us know if you need anything else.

[stale[bot]]

Closing this as it has become stale.

[ricardokirkner]

This is breaking code that already defined flags that external packages are also defining. How can this behaviour be made optional? I think this behaviour should be configurable and opt-in, instead of opt-out.