[Pacemaker] Stonith setup hostname params

[Pavel Levshin]

29.03.2011 17:28, Dejan Muhamedagic:


> The fact that the shell has this feature doesn't mean that it
> should be misused. It was meant mainly for one-off management
> commands (such as "resource stop" or "node standby") and only
> very seldom for one-off configuration commands.

Sounds reasonable.

If you think that the feature should not be misused, there must be 
something enforcing your intention. Unfortunately, it's almost late to 
restrict command line arguments usage, as it will broke backward 
compatibility.

>> But, unfortunately, the feature is not uniform with interactive shell.
> How's that now? I know that many people don't understand how
> shell (as in bash) work, but don't understand how crm shell can
> work around that. If you have an idea, please speak up.

I'm not very familiar with crm shell internals, so it's raw idea only. 
But, as I've said before, this kind of mistake can be detected. Look at 
what we have seen in the very start of the thread:

 >crm configure primitive rsa-fencing stonith:external/ibmrsa params 
hostname="alpha1 alpha2" ipaddr=192.168.75.178 userid=USR passwd=PWD 
type=ibm op monitor interval="60s"

>  The console print the ERROR message: "ERROR: rsa-fencing: parameter 
alpha2 does not exist"


The shell does not give you meaningful explanation of what has happened. 
Most nonintrusive change I can imagine would be to print actual crm 
command which has caused the error. For example:

ERROR: rsa-fencing: parameter alpha2 does not exist
The command was: configure primitive rsa-fencing stonith:external/ibmrsa 
params hostname=alpha1 alpha2 ipaddr=192.168.75.178 userid=USR 
passwd=PWD type=ibm op monitor interval=60s


Hopefully the user will quickly notice the difference between his 
command and shell's variant.

The shell can also analyze command line parameters and note that one of 
them contains space. It would then suggest user to do proper shell 
escaping. But there may be false positives.


The shell can go one step further and analyze it's arguments to repair 
lost quotes. If there are many arguments, and there is an argument 
without quotes and with space inside, quotes can be inserted right after 
first '=' character (if any) and at the end of the argument. The result 
may be unreliable, though. So it's up to you to rate this quirk.


--
Pavel Levshin

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