content.log Tool

A reference implementation for processing the content.log files found at opendata.dwd.de/weather.

Example usage:

wget https://opendata.dwd.de/weather/nwp/content.log.bz2
bunzip2 content.log.bz2
echo "./icon-d2/grib/*/t_2m/*" > wildcards.txt
./get_updated_files.py -w wildcards.txt 2022-01-26T03:00 > updated_files.txt

The produced file updated_files.txt will hold all pathnames as given by content.log that are updated since 2022-01-26 03:00:00 UTC according to the file's modification date. Remember that those paths are relative to the directory the content.log.bz2 was in, in this case https://opendata.dwd.de/weather/nwp/.

Also mind that there are multiple servers behind https://opendata.dwd.de which might not be exactly in sync with each other regarding file modification timestamps. Look into the code of get_updated_files.py for a suggestion on how to deal with that.

While this program relies on the file modification timestamp dumped into content.log.bz2, it might be more feasible to process the data reference time that is contained in the filenames instead.

$ ./get_updated_files.py --help
usage: get_updated_files.py [-h] [--content-log CONTENT_LOG_FILE] [--wildcards WILDCARDS_FILE] [--min-delta MIN_DELTA] [--version] UPDATED_SINCE

Filters paths of a DWD Open Data content.log file for entries that have been updated.

positional arguments:
  UPDATED_SINCE         Last time files were checked for updates

optional arguments:
  -h, --help            show this help message and exit
  --content-log CONTENT_LOG_FILE, -f CONTENT_LOG_FILE
                        The decompressed content.log file (default: content.log)
  --wildcards WILDCARDS_FILE, -w WILDCARDS_FILE
                        Filter results by a set of wildcards
  --min-delta MIN_DELTA, -d MIN_DELTA
                        Minimum number of seconds a file needs to be younger than UPDATED_SINCE (default: 60)
  --version             show program's version number and exit