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Accepted
Alex
Asked: 2012-04-20 03:44:41 +0800 CST

Running Selenium RC Headless via init script: Can not start firefox

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I am trying to start selenium and the headless Xvfb X server using a init script and the daemon tool.

But when I start my environment using this method, Firefox fails to launch. It looks like it can not find Firefox 2 and then stops. When I start that environment normally, it also does not find Firefox 2 but then it searches for Firefox 3, finds it and starts properly.

This is my init script:

#!/bin/bash
#
# Starts a Selenium-RC headless environment
# License: https://github.com/amenk/SelfScripts/blob/master/LICENSE.md

#
# BETA
# Fixmes:
# - We should take care of running the environment under a non-priviledged user


#
# Source function library.
. /lib/lsb/init-functions


LOG=/var/log/selenium.log

DISPLAY_NO=99

JAVA=/usr/bin/java
XVFB=/usr/bin/Xvfb
SELENIUM_JAR=/opt/selenium-server-standalone-2.20.0.jar
FIREFOX_TEMPLATE=/home/amenk/.mozilla/firefox/aph73r3f.selenium/


start() {
    log_daemon_msg "Starting Xvfb"
    daemon --dbglog=$LOG --errlog=$LOG --stdout=$LOG --stderr=$LOG\
        --name Xvfb -- $XVFB :$DISPLAY_NO -ac -screen 0 1024x768x8
    log_end_msg $?
    log_daemon_msg "Starting Selenium RC"
    daemon --dbglog=$LOG --errlog=$LOG --stdout=$LOG --stderr=$LOG\
         --name Selenium-RC --env=DISPLAY=$DISPLAY_NO\
         -- java -jar $SELENIUM_JAR -log /var/log/selenium-debug.log -browserSideLog -firefoxProfileTemplate $FIREFOX_TEMPLATE
    log_end_msg $?
    return
}

stop() {
    log_daemon_msg "Stopping Selenium RC"
    daemon --stop --name Selenium-RC
    log_end_msg $?

    log_daemon_msg "Stopping Xvfb"
    daemon --stop --name Xvfb
    log_end_msg $?
    return
}

status() {
    daemon -v10 --running --name Xvfb
    daemon -v10 --running --name Selenium-RC

}

case "$1" in
    start)
    start
    ;;
    stop)
    stop
    ;;
    status)
    status
    ;;
    restart)
    stop
    start
    ;;
    *)
    echo "Usage:  {start|stop|status|reload|restart[|probe]"
    exit 1
    ;;
esac
exit $?

Starting the whole thing works fine, but when I run a selenium test on that server I get the following message in /var/log/selenium-debug.log:


13:21:29.207 DEBUG [11] org.openqa.selenium.browserlaunchers.locators.BrowserLocator - Discovering Firefox 2...
13:21:29.207 DEBUG [11] org.openqa.selenium.browserlaunchers.locators.BrowserLocator - Checking whether Firefox 2 launcher at :'/Applications/Minefield.app/Contents/MacOS/firefox-bin' is valid...
13:21:29.207 DEBUG [11] org.openqa.selenium.browserlaunchers.locators.BrowserLocator - Checking whether Firefox 2 launcher at :'/Applications/Firefox-2.app/Contents/MacOS/firefox-bin' is valid...
13:21:29.207 DEBUG [11] org.openqa.selenium.browserlaunchers.locators.BrowserLocator - Checking whether Firefox 2 launcher at :'/Applications/Firefox.app/Contents/MacOS/firefox-bin' is valid...
13:21:29.207 DEBUG [11] org.openqa.selenium.browserlaunchers.locators.BrowserLocator - Checking whether Firefox 2 launcher at :'/usr/lib/firefox/firefox-bin' is valid...
13:21:29.209 INFO [11] org.openqa.selenium.server.SeleniumDriverResourceHandler - Got result: Failed to start new browser session: java.lang.NullPointerException on session null

When I run selenium and xvfb with the same parameters under the same user, I get

...
13:31:16.413 DEBUG [11] org.openqa.selenium.browserlaunchers.locators.BrowserLocator - Checking whether Firefox 2 launcher at :'/usr/lib/firefox/firefox-bin' is valid...
13:31:16.414 DEBUG [11] org.openqa.selenium.browserlaunchers.locators.CombinedFirefoxLocator - Did not find Firefox 2, now discovering Firefox 3...
13:31:16.415 DEBUG [11] org.openqa.selenium.browserlaunchers.locators.BrowserLocator - Discovering Firefox 3...
13:31:16.433 DEBUG [11] org.openqa.selenium.browserlaunchers.locators.BrowserLocator - Checking whether Firefox 3 launcher at :'/usr/lib/firefox-addons/firefox-bin' is valid...
13:31:16.434 DEBUG [11] org.openqa.selenium.browserlaunchers.locators.BrowserLocator - Checking whether Firefox 3 launcher at :'/usr/lib/firefox-addons/firefox' is valid...
13:31:16.434 DEBUG [11] org.openqa.selenium.browserlaunchers.locators.BrowserLocator - Checking whether Firefox 3 launcher at :'/usr/lib/firefox-11.0/firefox-bin' is valid...
13:31:16.434 DEBUG [11] org.openqa.selenium.browserlaunchers.locators.BrowserLocator - Checking whether Firefox 3 launcher at :'/usr/lib/firefox-11.0/firefox' is valid...
13:31:16.434 DEBUG [11] org.openqa.selenium.browserlaunchers.locators.BrowserLocator - Discovered valid Firefox 3 launcher  : '/usr/lib/firefox-11.0/firefox'
13:31:16.435 INFO [11] org.openqa.selenium.server.BrowserSessionFactory - Allocated session cb49662833c84b6cb62fcd5a4a7e9f61 for http://example.com/foo/bar/, launching...
linux firefox selenium

3 Answers

  1. As noted in the comments above, your environment looks different when running as a daemon :)

    • 2
  2. Best Answer

    The problem was the environment inside the daemon executing. The --env cleared up the enviroment variables. You can easily see this with

    daemon -O /tmp/export --env="FOO=BAR" -- bash -c export
cat /tmp/export

    The solution is to start daemon with the "-i" switch to copy the path setting. Using this change, Firefox will be found.

    The working version of the script is available on GitHub.

    • 1

  3. The init scripts in here might be a solution.

    But Selenium is put to the background simply with the "&" operator. So I think this init script would not survive exiting the shell that it was called from.

    • 0