Add backup and restore with pg_dumpall

[eduardoteles17]

Hello, This project has helped me a lot!

In my environments I need to back up more than one database. But there is no possibility to use pg_dumpall so I decided to implement it.

I added a new variable BACKUP_ALL to switch between pg_dump and pg_dumpall. I also made the variable POSTGRES_DATABASE optional if BACKUP_ALL is true. And I added the option to restore the backup containing all banks

Thank you very much for this project and I hope this PR can help to improve even more

[eeshugerman]

Thanks for the PR! I hope to take a closer look and test later this week.

One minor reservation I have is that, best I can tell, pg_dumpall does not compress the archive? Can you confirm, and/or do you see a way to enable compression? We use -F custom with pg_dump, which is compressed, and still people ask about adding gzip, so I'm sure it will come up soon with pg_dumpall.

[eduardoteles17]

As you pointed out, pg_dumpall still doesn't have the compression function built in, but I can implement it using gzip as a way around the lack of that function for now

[eeshugerman]

OK, great, please do!

[eduardoteles17]

Done, I added compression using gzip

[eeshugerman]

Done, I added compression using gzip

Thank you! I do intend to merge this, but I'm afraid it might be a bit (a few weeks perhaps) before I get to it. There are many combos of options to test, especially now with BACKUP_ALL -- I really need to look into automating that. Also I'm a little concerned about how messy/complicated the filename/tempfile handling is becoming (not your fault!), so I may experiment with mktemp or something to see if that can be cleaned up. Anyway, thanks for your patience and thanks again for the PR!

[sitole]

Wow, iam doing apps with database-per-tenant and this is what I am missing!

Btw Iam already user of this tool

[schonert]

@eeshugerman anything we can do to help push this forward?

[greenscientist]

Maybe we want to pipe directly to gzip here?
| gzip > db.dump.gz