Fix Kernel::System::Storage::S3::DiscardObjects

[bschmalhofer]

When MinIO is used as a S3 backend that the console command Maint::Loader::CacheCleanup does not delete the files in MinIO.

TODO:

• make it work for MinIO

[bschmalhofer]

Tried to debug this. The request that should delete cached JS and CSS looks OK.

<Delete xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><Object><Key>OTOBO/var/httpd/htdocs/js/js-cache/CommonJS_0ead0e67127bed1894c4b23ffc892a1e.js</Key></Object><Object><Key>OTOBO/var/httpd/htdocs/js/js-cache/ModuleJS_499b835124455679ccbb66f93cf7cabc.js</Key></Object><Object><Key>OTOBO/var/httpd/htdocs/js/js-cache/ModuleJS_80d23e9b9b514232da457bc0092bf14c.js</Key></Object><Object><Key>OTOBO/var/httpd/htdocs/js/js-cache/ModuleJS_cc7ef0dcaf580b80218558a44c3fb8fc.js</Key></Object><Object><Key>OTOBO/var/httpd/htdocs/js/js-cache/TemplateJS_Standard_2658bd764ae451070900369acc855e32.js</Key></Object><Object><Key>OTOBO/var/httpd/htdocs/js/js-cache/TranslationJS_de_303d3d8d9a99e83beb7beae9b3f9164f.js</Key></Object><Object><Key>OTOBO/var/httpd/htdocs/skins/Agent/default/css-cache/CommonCSS_75f59159f757a591d12adaefed83dce1.css</Key></Object><Object><Key>OTOBO/var/httpd/htdocs/skins/Agent/default/css-cache/ModuleCSS_35d1d367d1cd619c28fff2b2fea1dd96.css</Key></Object><Object><Key>OTOBO/var/httpd/htdocs/skins/Agent/default/css-cache/ResponsiveCSS_05e96d82a496003a37c11cea53ba7893.css</Key></Object></Delete>
The method is POST and the query is delete. Just like it is documented in https://docs.aws.amazon.com/AmazonS3/latest/API/API_DeleteObjects.html .
But the actual request returns a HTTP status code 400. This is also visible in the Minio Trace log at http://localhost:9001/tools/trace. But the message is a not so helpful 'Bad Request'

[bschmalhofer]

Still no idea why this does not work. It's likely not a privilege issue, as MinIO should return an Error for each element it can't delete.

[bschmalhofer]

This bug has not only bad effects for the cleanup of loader files. There are also problems when dealing with encrypted emails. Because the objects are not cleared out in Kernel/Output/HTML/ArticleCheck/PGP.pm the decrypted files end up with unexpected name. E.g. file1.txt is stored as file1-1.txt .

[bschmalhofer]

Added fallback to delete the single objects in a loop. Verified manually that Maint::Loader::CacheCleanUp is sensible now.
scripts/test/PGP/EmailHandling.t is successful again. Closing this issue.