Usage confusion

[OrangeDog]

Is WAL-G supposed to be a direct replacement for WAL-E, such that the commands are the same?
If so, then the readme is very confusing, seemingly describing completely different operations and usage examples. If not, then you need to provide more details and some migration tips:

• is ~/extract/to/here intended to be PG_DATADIR?
• what's example-backup? You have to get the name from backup-list ?
• is /backup/directory/path the path to backup from (i.e. PG_DATADIR)?
• are example-archive and new-file-name the %p and %f from restore_command? Note that's the opposite way around to WAL-E
• is /path/to/archive the %p from archive_command?
• what are "deltas"? do you mean the WAL segments from wal-push? But then how can a base backup be a delta?

Either way, the readme is a confusing mess of terminology at the moment.

[x4m]

Hi! Sorry for the late reply
0. Yes, we support the transition from WAL-E. Not in every feature, but in generic case backup-fetch and wal-fetch will work with WAL-E data.

1. backup-push and backup-fetch operate with PGDATA. If you will point backup-push to not-PGDATA it will crash. It is known bug Wal-g crashes when running backup-push against empty directory #120, I hope someone will fix.
2. you can backup-fetch LATEST or something from backup-list
3. Yes....I'm starting to understand that we need serious editorialization for README...
4. I user archive_command wal-g wal-push %p and restore_command = wal-g wal-fetch "%f" "%p"
5. Deltas - is a whole new story. Delta-backup is a backup which can be applied to base backup. But much faster than WAL, because it is parallel and squashes multiple page writes into one. This topic deserve proper blog post... or at least readme section

All in all: I have a lot hardcore programmers around. Most of them can read and write somewhat consistent English. But there is an extreme shortage of people who can proofread and editorialize docs.

[OrangeDog]

If the interface is supposed to be the same as WAL-E, then you can start by copying their documentation.

[x4m]

Well, the interface is quite similar, but slightly differs. E.g. we do not support CLI keys like

wal-e                                   
  -a WABS_ACCOUNT_NAME                                        
  --wabs-prefix=wabs://some-bucket/directory/or/whatever

and only read config from env vars or config file. Yeah, we have config fine.
BTW WAL-E documentation goes into details of recovery.conf, which will be obsolete after next PG release.
We cannot just copy those docs, they cover features that we have not and do not cover features that we have.
But the idea of using WAL-E docs seems very interesting, just need adaptation. Thanks!

[OrangeDog]

Hence "start by". Then make changes from there instead of writing them all from scratch.
People will still want to recover existing and older PG releases, so recovery.conf documentation is still useful.