[bug] restic backup fail when website has already existed

[ponsfrilus]

If a web site has been delete and the recreated, the restic backup fails with Fatal: create key in repository at s3:https://s3.epfl.ch/svc0041-123456789/backup/path/file failed: repository master key and config already initialized

Steps to reproduce:

1. Create a new web site (wp-veritas + ansible)
2. Run ansible -t wp.backup
3. Wipe the website
4. Remove the website from wp-veritas
5. Then, restore the website from the wp-veritas's trash
6. Re-run the website creation with ansible
7. Run any task related to a backup (wipe or backup)

expand error message

fatal: [www__campus__services__website__canari2]: FAILED! => {"changed": true, "cmd": "set -o pipefail
set -e -x
echo \"restic_start{url=\\\"https://www.epfl.ch/campus/services/website/canari2/\\\", wp_env=\\\"www\\\"} $(date +%s)\" \\
| curl -X POST -H \"Content-Type: text/plain\" --data-binary @- http://pushgateway.wwp-infra:9091/metrics/job/backup/instance/www__campus__services__website__canari2
for repo in \"s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/files\" \"s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/sql\"; do
[...]

\r  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0\r100    98    0     0  100    98      0   2969 --:--:-- --:--:-- --:--:--  2969

+ for repo in "s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/files\\" "s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/sql\"

+ restic -r s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/files init
Fatal: create key in repository at s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/files failed: repository master key and config already initialized
+ true

+ restic -r s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/files unlock

+ for repo in "s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/fil\es\" "s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/sql\"

+ restic -r s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/sql init
Fatal: create key in repository at s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/sql failed: repository master key and config already initialized
+ true

+ restic -r s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/sql unlock

+ cd /srv/www/www.epfl.ch/htdocs/campus/services/website/canari2/

+ declare -a excludes

++ find . -mindepth 2 -maxdepth 2 -name wp-config.php

++ set -o pipefail

++ set -e -x

++ restic -r s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/files backup --json .

++ jq -r -s 'last(.[] | select(.message_type == "summary")) | .snapshot_id'
Fatal: unable to save snapshot: snapshot is empty
+ files_snapshot_id=null", "stderr_lines": ["+ curl -X POST -H 'Content-Type: text/plain' --data-binary @- http://pushgateway.wwp-infra:9091/metrics/job/backup/instance/www__campus__services__website__canari2", "++ date +%s", "+ echo 'restic_start{url="https://www.epfl.ch/campus/services/website/canari2/", wp_env="www"} 1613557480'", "  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current", "                                 Dload  Upload   Total   Spent    Left  Speed", "", "  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0", "100    98    0     0  100    98      0   2969 --:--:-- --:--:-- --:--:--  2969", "+ for repo in "s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/files" "s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/sql"", "+ restic -r s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/files init", "Fatal: create key in repository at s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/files failed: repository master key and config already initialized", "", "+ true", "+ restic -r s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/files unlock", "+ for repo in "s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/files" "s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/sql"", "+ restic -r s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/sql init", "Fatal: create key in repository at s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/sql failed: repository master key and config already initialized", "", "+ true", "+ restic -r s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/sql unlock", "+ cd /srv/www/www.epfl.ch/htdocs/campus/services/website/canari2/", "+ declare -a excludes", "++ find . -mindepth 2 -maxdepth 2 -name wp-config.php", "++ set -o pipefail", "++ set -e -x", "++ restic -r s3:https://s3.epfl.ch/svc0041-123456789/backup/wordpresses/www__campus__services__website__canari2/files backup --json .", "++ jq -r -s 'last(.[] | select(.message_type == "summary")) | .snapshot_id'",

"Fatal: unable to save snapshot: snapshot is empty", "+ files_snapshot_id=null"], "stdout": "created new cache in /var/www/.cache/restic

successfully removed locks

created new cache in /var/www/.cache/restic

successfully removed locks", "stdout_lines": ["created new cache in /var/www/.cache/restic", "successfully removed locks", "created new cache in /var/www/.cache/restic", "successfully removed locks"]}