[augeas-devel] Adding error handling

[Graham Leggett]

Hi all,

After making a first attempt at getting augeas to work together with puppet, I found myself in a situation where postfix's main.cf configuration file would work, but included ldap templates wouldn't. Augeas+puppet went through all the motions, but made no changes to the ldap templates, even though the main.cf file substitution worked fine.

Eventually, after much reverse engineering of puppet and of augeas, I discovered that augeas is only able to discover which lens maps to what file by looking up hard coded file locations in each lens. If no lens matches, augeas silently succeeds, leaving the end user none the wiser as to what was wrong and why nothing is happening.

An attempt to use augtool to eliminate puppet from the equation showed the same problem - the attempt to edit would silently succeed, the attempt to list would silently list nothing.

Ideally augeas should return some kind of error code to indicate why a particular failure has occured.

At the same time, it would be ideal if augeas could accept the name of the lens to use as a parameter, so that any file can be edited, not just specific well known files. This limitation significantly reduces the usefulness of the software, as it can only be used for simple config files in well known places, not more complex ones that might be structured in a directory tree using an "include" concept.

Regards,
Graham
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