web-app configuration error handling

I suggest for DocumentStore.setOutDir checking if the out directory exists and throwing an error if not.

In (the very likely) case that someone doesn't follow the INSTALL file suggestion to use '/srv/onionoo' as working directory, the missing folder is reported immediatly.

And, maybe add some hint about changing 'etc/web.xml.template' to the top of INSTALL? Like "If you choose a different working directory make sure its path is reflected in the following files: ..."

added component::metrics/onionoo priority::low resolution::fixed status::closed type::enhancement labels

Replying to iwakeh:

I suggest for DocumentStore.setOutDir checking if the out directory exists and throwing an error if not.

In (the very likely) case that someone doesn't follow the INSTALL file suggestion to use '/srv/onionoo' as working directory, the missing folder is reported immediatly.

Yes, good idea. Want to submit a patch for this?

And, maybe add some hint about changing 'etc/web.xml.template' to the top of INSTALL? Like "If you choose a different working directory make sure its path is reflected in the following files: ..."

Or should we take this parameter out of etc/web.xml.template? We could default to out/ in the current working directory, and accept a command-line parameter to override that default similar to the logging directory. Does that make sense?

I think it is most useful that the setOutdir method just verifies the path and throws FileNotFoundEx. if there is no directory. The callers have to deal with that. Currently, only NodeIndexer is affected and an informative message should be logged and the web application should exit.

A patch is attached, which exits the web application and logs an error message and a hint about where to fix the path, i.e.

        Out-dir not found! Expected directory: /srv/onionoo.torproject.org/onionoo/out
        Verify the configuration in ./etc/web.xml.template

I think it might be better to keep real application configuration in files rather than on the command line. That way it'll be easier to determine runtime parameters during trouble-shooting. Command lines can be ephemeral sometimes.

If the location of the outdir configuration is changed in future, the error handling is close to the affected code and can be easily adapted.

Trac:
0001-task-14024-adding-dramatic-error-message-for-missing.patch

Trac:
Status: new to needs_review

Patch looks good. Merged to master. Thanks!

I'm yet undecided if we should find a better solution than defining the directory in etc/web.xml which is then included in the .war file. If we ever want to give out binaries, which include the .war file, people wouldn't be able to change the path to their out/ directory. If command-line parameters are not the way to go, how about we use something else for config files? (I vaguely remember that you suggested something on a different ticket, but I don't remember the details.)

Trac:
Status: needs_review to new

You're right web.xml is an odd place for setting the out dir path.

In #13600 (moved) I mentioned commons-configuration (but there too a config file would be better than command line, I think). User docs are here Commons Configuration User Guide

Without an additional lib reference, why not use a plain old java properties file? Have useful defaults for everything and write the properties file, if the app could not find one initially?

This ought to be a new issue.

Either commons-configuration or properties file works for me. And yes, new ticket makes sense. Want to create one and ideally submit a patch? Resolving this issue as implemented. Thanks!

Trac:
Resolution: N/A to fixed
Status: new to closed

Created #14201 (moved) for configuring the out/ directory path.

closed

mentioned in issue #14201 (moved)