Fetch

Common file download operations.

Supports http, https, and file URLs, along with the following non-standard URL formats:

• Ceph ceph://[<user>@][<cluster>]/<pool>[;ns=<namespace>]/<objectkey>. If the user is not specified it will be set to the value of the RADOS_USER environment variable, if set. Otherwise, not user will be used, which defaults to requesting admin permissions.

• S3 TLS: s3://[<endpoint>]/<bucket>/<key> and non-TLS s3+http://[<endpoint>]/<bucket>/<key>. It is assumed credentials are available via standard AWS configuration files or environment variables.

• Relative File: file:<relpath>?volume=<name>

  Where there must exist a FETCH_FILE_VOLUME_<uppername>_ROOT environment variable to specify the root directory for volume name.