Backup container for mongo instances to Google Storage

This image provides a cron daemon that runs daily backups from mongo (clustered or single instance) to Google Storage.

Following ENV variables must be specified:

• MONGO_URL contains the connection string for mongodump command line client (option -h)
• MONGO_USER contains the username
• MONGO_PASSWORD password of a user who has access to all dbs
• MONGO_DUMP_OPLOG - if set to any value, adds --oplog parameter
• GS_URL contains address in GS where to store backups, without the gs:// prefix
• bucket-name/directory
• CRON_SCHEDULE cron schedule string, default '0 2 * * *'