Bug 534611 (RHQ-1391)

Summary:	Can't run rhq-agent-wrapper.sh as a service if it is symlinked.
Product:	[Other] RHQ Project	Reporter:	Corey Welton <cwelton>
Component:	Agent	Assignee:	John Mazzitelli <mazz>
Status:	CLOSED NEXTRELEASE	QA Contact:	Corey Welton <cwelton>
Severity:	medium	Docs Contact:
Priority:	high
Version:	1.2	Flags:	cwelton: archived+
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	All
URL:	http://jira.rhq-project.org/browse/RHQ-1391
Whiteboard:
Fixed In Version:	1.2	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:	Red Hat Enterprise Linux Server release 5.2 (Tikanga) Kernel \r on an \m Linux rlx-0-12.rhndev.redhat.com 2.6.18-92.1.22.el5 #1 SMP Fri Dec 5 09:29:46 EST 2008 i686 i686 i386 GNU/Linux
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Corey Welton 2009-01-22 18:27:00 UTC

Per new behaviour for rhq-agent, config for running agent as a service includes symlinking to the actual location of the rhq-agent-wrapper.sh script.  Agent fails to launch, however, after doing this.

Steps to repro.

1.  `ln -s /root/rhq-agent/bin/rhq-agent-wrapper.sh  /etc/init.d/rhq-agent-wrapper.sh`
2. `service rhq-agent-wrapper.sh`
3.  optional:  enable debug (add  export RHQ_AGENT_DEBUG=true to top of  rhq-agent-wrapper.sh)
4. View results

Current result.
[root@rlx-0-12 ]# service rhq-agent-wrapper.sh start
Starting RHQ Agent...
ERROR! Cannot find the RHQ Agent start script
Not found: /etc/bin/rhq-agent.sh

If debug enabled:
[root@rlx-0-12 ]# service rhq-agent-wrapper.sh start
rhq-agent-wrapper.sh: RHQ_AGENT_WRAPPER_BIN_DIR_PATH=/etc/init.d
rhq-agent-wrapper.sh: pidfile will be located at /etc/bin/rhq-agent.pid
ERROR! Cannot find the RHQ Agent start script
Not found: /etc/bin/rhq-agent.sh


Expected result:
Agent launches.

Comment 1 John Mazzitelli 2009-01-22 18:31:38 UTC

the problem is this line in rhq-agent-wrapper.sh:

RHQ_AGENT_WRAPPER_BIN_DIR_PATH=`dirname "$0"`

$0 is the value of the sym link, not the real script itself.

Will need to use "readlink" here - need to example $0 and if its a symlink, use "readlink" to get the "real" file that the link points to.

Comment 2 John Mazzitelli 2009-01-22 19:18:12 UTC

Now using the following to follow symlinks - if the script isn't a symlink, it still works:

_DOLLARZERO=`readlink "$0" || echo "$0"`

So, we can now use "$_DOLLARZERO" for the "real" script path, e.g.:

RHQ_AGENT_WRAPPER_BIN_DIR_PATH=`dirname "$_DOLLARZERO"`

Comment 3 Charles Crouch 2009-01-22 23:22:56 UTC

How many flavors of *nix has this been tested on ?

Comment 4 John Mazzitelli 2009-01-22 23:31:48 UTC

This will work on all UNIX's that have "readlink" available and in the path, which from what it looks like is all the ones we care about (I see this working on solaris, rhel and fedora - unsure if readlink is available on aix, hpux, macos - but workaround is simple - provide readlink access to the user running the agent :)

Comment 5 Corey Welton 2009-01-26 18:13:55 UTC

QA Verified.

Comment 6 Red Hat Bugzilla 2009-11-10 20:31:57 UTC

This bug was previously known as http://jira.rhq-project.org/browse/RHQ-1391
This bug relates to RHQ-1752