panic when using Docker Cloud's web console to access influxdb container

[tevjef]

Bug report

System info: Official docker image, 1.0-alpine,
OS: debian 8

Steps to reproduce:

1. Start an influxdb Docker container from docker cloud onto a machine/node.
2. Use Docker CLoud's web terminal/console to access container
3. Use command influx to use influxdb CLI
4. Type any character

Expected behavior:

Characters are written to the CLI

Actual behavior:

panics with err: integer divide by zero

Additional info:

/ # influx                                                                                                                                                               
Visit https://enterprise.influxdata.com to register for updates, InfluxDB server management, and monitoring.                                                             
Connected to http://localhost:8086 version 1.0.0                                                                                                                         
InfluxDB shell version: 1.0.0                                                                                                                                            
> panic: runtime error: integer divide by zero                                                                                                                           
[signal 0x8 code=0x1 addr=0x61c680 pc=0x61c680]                                                                                                                          

goroutine 1 [running]:                                                                                                                                                   
panic(0x782460, 0xc82000a060)                                                                                                                                            
        /usr/local/go/src/runtime/panic.go:481 +0x3e6                                                                                                                    
github.com/peterh/liner.(*State).refreshMultiLine(0xc8200943c0, 0xc82010d3b8, 0x2, 0x2, 0xc82000a1c0, 0x1, 0x2, 0x1, 0x0, 0x0)                                           
        /root/go/src/github.com/peterh/liner/line.go:159 +0xf0                                                                                                           
github.com/peterh/liner.(*State).refresh(0xc8200943c0, 0xc82010d3b8, 0x2, 0x2, 0xc82000a1c0, 0x1, 0x2, 0x1, 0x0, 0x0)                                                    
        /root/go/src/github.com/peterh/liner/line.go:94 +0x8f                                                                                                            
github.com/peterh/liner.(*State).PromptWithSuggestion(0xc8200943c0, 0x7f2f58, 0x2, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0)                                                    
        /root/go/src/github.com/peterh/liner/line.go:822 +0x1e64                                                                                                         
github.com/peterh/liner.(*State).Prompt(0xc8200943c0, 0x7f2f58, 0x2, 0x0, 0x0, 0x0, 0x0)                                                                                 
        /root/go/src/github.com/peterh/liner/line.go:567 +0x6c                                                                                                           
github.com/influxdata/influxdb/cmd/influx/cli.(*CommandLine).mainLoop(0xc820094280, 0x0, 0x0)                                                                            
        /root/go/src/github.com/influxdata/influxdb/cmd/influx/cli/cli.go:195 +0x17e                                                                                     
github.com/influxdata/influxdb/cmd/influx/cli.(*CommandLine).Run(0xc820094280, 0x0, 0x0)                                                                                 
        /root/go/src/github.com/influxdata/influxdb/cmd/influx/cli/cli.go:181 +0x1483                                                                                    
main.main()                                                                                                                                                              
        /root/go/src/github.com/influxdata/influxdb/cmd/influx/main.go:112 +0x964                                                                                        
/ #                                                                                                                                                                      
/ #                                                                                                                                                                      

Going by the stacktrace and the vender info, I can pinpoint the location of crash in the github.com/peterh/liner library: https://github.com/peterh/liner/blob/8975875355a81d612fafb9f5a6037bdcc2d9b073/line.go#L159

[jwilder]

Not reproducible.

[ConnorNe]

@tevjef Did you find a work around for this? I'm encountering the same problem

[Soulou]

We're also having the same probleme here, any idea?

[Soulou]

The problem seems to come from here: https://github.com/peterh/liner/blob/8975875355a81d612fafb9f5a6037bdcc2d9b073/output.go#L51-L63

func (s *State) getColumns() bool {
	var ws winSize
	ok, _, _ := syscall.Syscall(syscall.SYS_IOCTL, uintptr(syscall.Stdout),
		syscall.TIOCGWINSZ, uintptr(unsafe.Pointer(&ws)))
	if int(ok) < 0 {
		return false
	}
	s.columns = int(ws.col)
	if cursorColumn && s.columns > 1 {
		s.columns--
	}
	return true
}

The ws.col must equals 0, which result in a panic

[Soulou]

Easy to reproduce:

[11:22] Scalingo ~/gopath/src/a $ stty cols 0
[11:22] Scalingo ~/gopath/src/a $ stty rows 0
[11:22] Scalingo ~/gopath/src/a $ influx
InfluxDB shell version: 1.2.0
> lpanic: runtime error: integer divide by zero

goroutine 1 [running]:
panic(0x6de060, 0xc42001e090)
	/usr/local/go/src/runtime/panic.go:500 +0x1a1
github.com/peterh/liner.(*State).refreshMultiLine(0xc42013c000, 0xc4200514a8, 0x2, 0x20, 0xc420051428, 0x1, 0x20, 0x1, 0xc42005133c, 0xc4200f606c)
	/root/go/src/github.com/peterh/liner/line.go:159 +0x5e4

[Soulou]

We can reproduce what is done by the package with this gist: https://gist.github.com/Soulou/ad9b094d3b9a56c04995405751301e1b

Result by running this in docker:

sudo docker run -v `pwd`:/mnt -it ubuntu:latest /mnt/poc
true
0

We've the 0 which creates the panic

[Soulou]

By adding a sleep in the main:

	s := State{}
	fmt.Println(s.getColumns())
	fmt.Println(s.columns)
	time.Sleep(time.Second)
	s = State{}
	fmt.Println(s.getColumns())
	fmt.Println(s.columns)

└> sudo docker run -v `pwd`:/mnt -it scalingo/builder:v24 /mnt/a
true
0
true
80

We can see that the problem comes from the delay in which docker initialize the stty of the container.

[zorro786]

Just resize the window after logging in your container/pod. And then execute influx cli.