Re: [monit] bugs&deficiencies

[Jan-Henrik Haukeland]

On 29. mai. 2008, at 10.12, deis wrote:

> I've been playing with monit for a few hours and it seems that I  
> came across a bug in it (tested recent beta and stable versions). If  
> I enter for an action exec "/bin/echo 1 >/some/destination", monit  
> would actually run /bin/echo "1 >/some/destination" causing echo to  
> throw out "1 >/some/destination" to console instead of sending 1 to  
> the destination.

Monit's exec does not start a shell, but is a standard exec. That is,  
exec takes the first argument as the command to execute and the rest  
as arguments: exec [command [arguments]]. In other words using shell  
redirects and pipe will not work. To do this you must start a shell in  
the exec command like so:

exec "/bin/bash -c '/bin/echo 1 >/some/destination'"

> Another very annoying deficiency of the tool is complete lack of  
> chaining arbitrary conditions, smth like
> if ...
>    if ...
>    then ...
> then...
>
> and lack of logical operators (AND, OR, etc) in the if statements,  
> which does not allow to make decisions based on complex conditions.  
> E.g., I want to test connectivity to two hosts and execute an action  
> only if both of them are down

Dependencies chains should handle some decision branching, though it  
is not as flexible. I agree that having nested if- statements and  
combining statements with logical operators would be very useful. I  
have been playing with the idea of building a real AST (abstract  
syntax tree) from parsing monit's small domain language and use this  
tree during validation which means that proper branching and combined  
statements can be used at validation time. But as usual time and  
resources are a constraint.