Setting BACKUP_CRON_EXPRESSION in env produces a parse error on latest version

[eselskas]

  db-backup:
    image: offen/docker-volume-backup:v2.25.1
    restart: always
    environment:
      - BACKUP_CRON_EXPRESSION="*/5 * * * *"
    volumes:
      - db:/backup/db-backup:ro
      - /var/docker/db_backups:/archive

Starting the container produces:

# docker-compose up db-backup
Starting e_db-backup_1 ... done
Attaching to e_db-backup_1
db-backup_1  | Installing cron.d entry with expression "*/5 * * * *".
db-backup_1  | Starting cron in foreground.
db-backup_1  | crond: crond (busybox 1.35.0) started, log level 8
db-backup_1  | crond: user root: parse error at "*/5
db-backup_1  | crond: user root: parse error at *"

Downgraded to v2.0.0 and it works fine

Status: Downloaded newer image for offen/docker-volume-backup:v2.0.0
db-backup_1  | Installing cron.d entry with expression "*/5 * * * *".
db-backup_1  | Starting cron in foreground.

[m90]

I did not confirm this, but I think what you are seeing is just a change in log verbosity (introduced in #120) and not a change in cron expression parsing. Does v2.0.0 even run backups on the given schedule?

I'm no expert in cron expressions but a good start would probably checking the limitations of BusyBox's cron implementation and whether it allows the expression you are passing here.

[m90]

You need to unquote the expression string, something like this:

db-backup:
  image: offen/docker-volume-backup:v2.25.1
  restart: always
  environment:
    BACKUP_CRON_EXPRESSION: */5 * * * *
  volumes:
    - db:/backup/db-backup:ro
    - /var/docker/db_backups:/archive

to make sure you are not bitten by docker-compose passing the quoted string: docker/compose#2854

[m90]

Closing this, as it seems to be a duplicate of #117 - if this is not the case, feel free to reopen.

[m90]

v2.37.0 brought a new cron scheduler so this might well be supported now