BackstopJS (Docker) will randomly hang during execution

I have been experiencing this issue where a command such as reference or test would just hang an not complete execution when run in docker.

$backstop reference
BackstopJS v3.1.19
Loading config:  /src/backstop.json 

COMMAND | Executing core for `reference`
  clean | tests/visual/backstop_data/bitmaps_reference was cleaned.
createBitmaps | Selected 1 of 1 scenarios.
searching for 4 available ports.
These ports will be used: [9222,9223,9224,9225]
Starting Chromy: {"chromeFlags":["--disable-gpu","--force-device-scale-factor=1","--disable-infobars=true","--window-size=320,480"],"port":9222,"waitTimeout":30000,"visible":false}
CREATING NEW REFERENCE FILES
Cookie state restored with: [
  {
    "path": "/",
    "name": "yourCookieName",
    "value": "yourCookieValue",
    "expirationDate": 1798790400,
    "hostOnly": false,
    "httpOnly": false,
    "secure": false,
    "session": false,
    "sameSite": "no_restriction",
    "url": "https://.www.yourdomain.com"
  }
]
SCENARIO > patterns_section-1
Starting Chromy: {"chromeFlags":["--disable-gpu","--force-device-scale-factor=1","--disable-infobars=true","--window-size=600,960"],"port":9223,"waitTimeout":30000,"visible":false}
CREATING NEW REFERENCE FILES
Cookie state restored with: [
  {
    "path": "/",
    "name": "yourCookieName",
    "value": "yourCookieValue",
    "expirationDate": 1798790400,
    "hostOnly": false,
    "httpOnly": false,
    "secure": false,
    "session": false,
    "sameSite": "no_restriction",
    "url": "https://.www.yourdomain.com"
  }
]
SCENARIO > patterns_section-1
Starting Chromy: {"chromeFlags":["--disable-gpu","--force-device-scale-factor=1","--disable-infobars=true","--window-size=1008,1920"],"port":9224,"waitTimeout":30000,"visible":false}
CREATING NEW REFERENCE FILES
Cookie state restored with: [
  {
    "path": "/",
    "name": "yourCookieName",
    "value": "yourCookieValue",
    "expirationDate": 1798790400,
    "hostOnly": false,
    "httpOnly": false,
    "secure": false,
    "session": false,
    "sameSite": "no_restriction",
    "url": "https://.www.yourdomain.com"
  }
]
SCENARIO > patterns_section-1
Starting Chromy: {"chromeFlags":["--disable-gpu","--force-device-scale-factor=1","--disable-infobars=true","--window-size=1366,2048"],"port":9225,"waitTimeout":30000,"visible":false}
CREATING NEW REFERENCE FILES
Cookie state restored with: [
  {
    "path": "/",
    "name": "yourCookieName",
    "value": "yourCookieValue",
    "expirationDate": 1798790400,
    "hostOnly": false,
    "httpOnly": false,
    "secure": false,
    "session": false,
    "sameSite": "no_restriction",
    "url": "https://.www.yourdomain.com"
  }
]
SCENARIO > patterns_section-1
9224 Chrome v64 detected.
9225 Chrome v64 detected.
9223 Chrome v64 detected.
9222 Chrome v64 detected.
9224 INFO >  BackstopTools have been installed.
9222 INFO >  BackstopTools have been installed.
9223 INFO >  BackstopTools have been installed.
9225 INFO >  BackstopTools have been installed.

Even if I log into the container with the provided debugging command and run the “reference” command its will intermittently just hang and not complete. I monitored the processes in that docker instance then I ran backstop and as expected a bunch of chrome processes appeared and most of them closed again almost immediately, but a few just remained open forever. This is what I get:

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND     
    1 root      20   0   20248   3212   2732 S   0.0  0.2   0:00.04 bash        
 1117 root      20   0   20248   2988   2696 S   0.0  0.1   0:00.02 bash        
 1122 root      20   0   21920   2320   1992 R   0.0  0.1   0:00.18 top         
 1687 root      20   0 1226124  51448  24688 S   0.0  2.5   0:00.92 node        
 1862 root      20   0  597420  82508  58824 S   0.0  4.0   0:00.27 chrome      
 1884 root      20   0    4392    704    620 S   0.0  0.0   0:00.00 cat         
 1885 root      20   0    4392    720    636 S   0.0  0.0   0:00.00 cat         
 1887 root      20   0  350692  40076  31860 S   0.0  2.0   0:00.01 chrome      
 1934 root      20   0  403824  46936  37968 S   0.0  2.3   0:00.03 chrome  

Does this happen for anyone else?

[cactusa]

Yup the hang was totally cause by this memory issue, thanks for that. I guess it’s my fault for not reading the readme properly …

[garris]

Yes. these are good points. One thing I am suspecting, there are some relative paths in your config – could there be a directory mapping issue there? Again, my docker experience is very limited – so I don’t really know if this is an issue – just a guess. Good luck!