sourcy / kotlin-backup-retention

Small tool to delete old backups based on filenames. Written in Kotlin with love, because it's awesome.

kotlin-backup-retention

Small tool to delete old backups based on filenames.

Written in Kotlin with love, because it's awesome.

Use with caution, although the code has close to 100% test coverage, there might be bugs. I recommend to only run it manually and with --dry to check what would happen. You've been warned.

application.properties

Below are currently supported retention settings with their default values. As with every spring-boot application, there are multiple ways to override those.

See Spring Boot Documentation for details.

# regex that is used to extract the date from filenames
retention.date-regex-pattern = .*_(\d{4}-\d{2}-\d{2})_.*
    
# java date format that is used to parse the extracted date (has to match the regex)
retention.date-format = yyyy-MM-dd
     
# number of daily backups to keep
retention.daily.keep = 7
    
# number of weekly backups to keep
retention.weekly.keep = 8
    
# day of week for weekly backups
retention.weekly.day-of-week = SUNDAY
    
# number of monthly backups to keep
retention.monthly.keep = 36
    
# day of month for monthly backups
retention.monthly.day-of-month = 1
    
# maximum percentage of files allowed to delete without --force 
retention.files.max-percent-delete = 10
    
# minimum number of files to keep per directory (this counts per subdirectory)
# this keeps files if no other rule applies (e.g a directory that only contains very old backups)
retention.files.min-keep-per-directory = 10
    
# list of regex patterns for files that should be processed
# all files that match at least one of those patterns are taken into consideration
retention.files.file-name-regex-patterns = 

Most settings have useful defaults, but for safety reasons retention.files.file-name-regex-patterns has none. You need to set this, otherwise no files will be processed.

An application.properties file with

retention.files.file-name-regex-patterns = .*\\.zip,.*\\.tgz,.*\\.tar\\.gz,.*\\.tar\\.bz2

should be enough to get you started if you are fine with the other defaults.

usage

You can either run via gradle or directly with java. After gradle build, the jar can be copied from build/libs.

gradle bootRun [OPTION]... DIRECTORY...        
    
OR    
    
java -jar kotlin-backup-retention-1.0.jar [OPTION]... DIRECTORY...
    
Options
    --verbose                   output more info      
    --dry                       dry run (don't delete anything)
    --force                     force deletion even if max-percent-delete is reached  
                                (take care, use together with --dry first!)
    --fake-date=DATE            use DATE instead of current date 
                                (take care, use together with --dry first)
    --property=VALUE            use VALUE for specified property from application.properties                            

Any property from application.properties can also be provided via command-line.

retention.files.min-keep-per-directory = 20

becomes

--retention-files-minKeepPerDirectory=20

As mentioned, please read Spring Boot Documentation for details on the many possible ways to set property values.