WAL-G backups no longer work on restored S3 cluster

[crtvmn]

I have a PostgreSQL cluster with WAL-G backup enabled on a S3 (MinIO) cluster. When I backup and restore this MinIO cluster, the WAL-G file timestamps are modified in my bucket. S3 (and MinIO here) does not allow to modify the last modified timestamp. Therefore, PostgreQL can no longer restore available WAL-G backups.

Indeed, the /scripts/clone_with_wale.py script uses the envdir /run/etc/wal-e.d/env-clone-kast-default-postgresql/ wal-g backup-list --json command and the output of the modified column (https://github.com/zalando/spilo/blob/master/postgres-appliance/bootstrap/clone_with_wale.py#L72). However, this column corresponds to the last modified date (that can be changed).

Why this script does not use the start_time information returns by the same command with the --detail option (envdir /run/etc/wal-e.d/env-clone-kast-default-postgresql/ wal-g backup-list --detail --json)?

In the example just below, WAL-G files have the same modified timestamp (because I restored my MinIO cluster) but the start_time is correct (+1 second):

$ envdir /run/etc/wal-e.d/env-clone-kast-default-postgresql/ wal-g backup-list --detail
INFO: 2025/04/22 19:30:47.175942 List backups from storages: [default]
backup_name                   modified             wal_file_name            storage_name start_time           finish_time          hostname                  data_dir                          pg_version start_lsn  finish_lsn is_permanent
base_0000000300000000000000B0 2025-04-22T19:04:52Z 0000000300000000000000B0 default      2025-04-22T09:17:50Z 2025-04-22T09:17:52Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/B0000028 0/B00215F8 false
base_0000000300000000000000B2 2025-04-22T19:04:52Z 0000000300000000000000B2 default      2025-04-22T09:30:01Z 2025-04-22T09:30:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/B2000028 0/B2020DC0 false
base_0000000300000000000000B4 2025-04-22T19:04:52Z 0000000300000000000000B4 default      2025-04-22T10:00:01Z 2025-04-22T10:00:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/B40000D8 0/B401DF98 false
base_0000000300000000000000B6 2025-04-22T19:04:52Z 0000000300000000000000B6 default      2025-04-22T10:30:01Z 2025-04-22T10:30:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/B6000028 0/B601E0C0 false
base_0000000300000000000000B8 2025-04-22T19:04:52Z 0000000300000000000000B8 default      2025-04-22T11:00:01Z 2025-04-22T11:00:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/B8000028 0/B80203E0 false
base_0000000300000000000000BA 2025-04-22T19:04:52Z 0000000300000000000000BA default      2025-04-22T11:30:01Z 2025-04-22T11:30:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/BA000028 0/BA0202F0 false
base_0000000300000000000000BC 2025-04-22T19:04:52Z 0000000300000000000000BC default      2025-04-22T12:00:01Z 2025-04-22T12:00:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/BC000028 0/BC021138 false
base_0000000300000000000000BE 2025-04-22T19:04:52Z 0000000300000000000000BE default      2025-04-22T12:30:01Z 2025-04-22T12:30:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/BE0000D8 0/BE020478 false
base_0000000300000000000000C0 2025-04-22T19:04:52Z 0000000300000000000000C0 default      2025-04-22T13:00:01Z 2025-04-22T13:00:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/C00000D8 0/C001FC30 false
base_0000000300000000000000C2 2025-04-22T19:04:52Z 0000000300000000000000C2 default      2025-04-22T13:30:01Z 2025-04-22T13:30:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/C2000028 0/C20202A8 false
base_0000000300000000000000C4 2025-04-22T19:04:52Z 0000000300000000000000C4 default      2025-04-22T14:00:01Z 2025-04-22T14:00:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/C40000D8 0/C4020408 false
base_0000000300000000000000C6 2025-04-22T19:04:52Z 0000000300000000000000C6 default      2025-04-22T14:30:01Z 2025-04-22T14:30:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/C60000D8 0/C6020310 false
base_0000000300000000000000C8 2025-04-22T19:04:52Z 0000000300000000000000C8 default      2025-04-22T15:00:01Z 2025-04-22T15:00:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/C80000D8 0/C8020248 false
base_0000000300000000000000CA 2025-04-22T19:04:52Z 0000000300000000000000CA default      2025-04-22T15:30:01Z 2025-04-22T15:30:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/CA0000D8 0/CA020260 false
base_0000000300000000000000CC 2025-04-22T19:04:52Z 0000000300000000000000CC default      2025-04-22T16:00:01Z 2025-04-22T16:00:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/CC0000D8 0/CC020280 false
base_0000000300000000000000CE 2025-04-22T19:04:52Z 0000000300000000000000CE default      2025-04-22T16:30:01Z 2025-04-22T16:30:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/CE0000D8 0/CE020390 false
base_0000000300000000000000D0 2025-04-22T19:04:52Z 0000000300000000000000D0 default      2025-04-22T17:00:01Z 2025-04-22T17:00:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/D00000D8 0/D00204F0 false
base_0000000300000000000000D2 2025-04-22T19:04:52Z 0000000300000000000000D2 default      2025-04-22T17:30:02Z 2025-04-22T17:30:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/D20000D8 0/D2020468 false
base_0000000300000000000000D4 2025-04-22T19:04:52Z 0000000300000000000000D4 default      2025-04-22T18:00:01Z 2025-04-22T18:00:03Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/D4000028 0/D401FA90 false
base_0000000300000000000000D6 2025-04-22T19:04:52Z 0000000300000000000000D6 default      2025-04-22T18:30:01Z 2025-04-22T18:30:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/D6000028 0/D601FE98 false
base_0000000300000000000000D8 2025-04-22T19:04:52Z 0000000300000000000000D8 default      2025-04-22T19:00:01Z 2025-04-22T19:00:04Z kast-default-postgresql-1 /home/postgres/pgdata/pgroot/data 150010     0/D8000028 0/D80201E8 false