Eu tenho um servidor docker que desejo fazer backup. Minha pasta de implantação tem propriedades e permissões muito específicas para oferecer suporte aos meus contêineres:
$ ls -lhaF /opt/docker
total 32K
drwxr-xr-x 7 devops devops 4.0K Aug 23 02:34 ./
drwxr-xr-x 6 root root 4.0K Aug 23 04:20 ../
drwxrwxr-x 2 devops devops 4.0K Aug 21 00:00 .certs/
drwxrwxr-x 2 devops devops 4.0K Aug 23 03:53 .scripts/
-rw-rw-r-- 1 devops devops 1.2K Aug 21 01:52 docker-compose.yml
drwxrwxr-x 4 1000 1000 4.0K Aug 21 02:05 minecraft/
drwxrwxr-x 4 devops devops 4.0K Aug 20 23:38 pihole/
drwx------ 19 70 70 4.0K Aug 19 01:31 postgres/
Em seguida, tento compactar esta pasta usando o seguinte comando. Pelo que li, preservar permissões/propriedade de arquivos requer execução tarcomo root/sudo:
$ sudo tar -czpf "/tmp/server-backup.tar.gz" --directory="/opt/docker" .
Este comando compacta a pasta, mas inspecionando o .tar.gz mostra que a propriedade de todas as pastas agora é root:
$ tar -tvf /tmp/server-backup.tar.gz
drwxr-xr-x root/root 0 2021-08-23 12:10 ./
drwxr-xr-x root/root 0 2021-08-23 12:10 ./minecraft/
-rw-r--r-- root/root 2 2021-08-23 12:10 ./minecraft/whitelist.json
-rw-r--r-- root/root 111 2021-08-23 12:10 ./minecraft/usercache.json
-rw-r--r-- root/root 1204 2021-08-23 12:10 ./minecraft/server.properties
-rw-r--r-- root/root 43626592 2021-08-23 12:10 ./minecraft/minecraft_server.1.17.1.jar
-rw-r--r-- root/root 68 2021-08-23 12:10 ./minecraft/eula.txt
-rw-r--r-- root/root 2 2021-08-23 12:10 ./minecraft/banned-players.json
-rw-r--r-- root/root 2 2021-08-23 12:10 ./minecraft/banned-ips.json
# -- Other minecraft files
drwxr-xr-x root/root 0 2021-08-23 12:10 ./.certs/
# -- Certs folder contents redacted
drwx------ root/root 0 2021-08-23 12:10 ./postgres/
drwx------ root/root 0 2021-08-23 12:10 ./postgres/pg_subtrans/
-rw------- root/root 8192 2021-08-23 12:10 ./postgres/pg_subtrans/0000
drwx------ root/root 0 2021-08-23 12:10 ./postgres/pg_multixact/
drwx------ root/root 0 2021-08-23 12:10 ./postgres/pg_multixact/offsets/
-rw------- root/root 8192 2021-08-23 12:10 ./postgres/pg_multixact/offsets/0000
drwx------ root/root 0 2021-08-23 12:10 ./postgres/pg_multixact/members/
-rw------- root/root 8192 2021-08-23 12:10 ./postgres/pg_multixact/members/0000
drwx------ root/root 0 2021-08-23 12:10 ./postgres/pg_xact/
-rw------- root/root 8192 2021-08-23 12:10 ./postgres/pg_xact/0000
# -- Other postgres files
drwxr-xr-x root/root 0 2021-08-23 12:10 ./pihole/
drwxr-xr-x root/root 0 2021-08-23 12:10 ./pihole/etc-pihole/
-rw-r--r-- root/root 0 2021-08-23 12:10 ./pihole/etc-pihole/custom.list
-rw-r--r-- root/root 5201920 2021-08-23 12:10 ./pihole/etc-pihole/gravity.db
-rw-r--r-- root/root 485 2021-08-23 12:10 ./pihole/etc-pihole/setupVars.conf
-rw-r--r-- root/root 0 2021-08-23 12:10 ./pihole/etc-pihole/setupVars.conf.update.bak
-rw-r--r-- root/root 1812161 2021-08-23 12:10 ./pihole/etc-pihole/list.1.raw.githubusercontent.com.domains
-rw-r--r-- root/root 73728 2021-08-23 12:10 ./pihole/etc-pihole/pihole-FTL.db
-rw-r--r-- root/root 0 2021-08-23 12:10 ./pihole/etc-pihole/pihole-FTL.conf
-rw-r--r-- root/root 37 2021-08-23 12:10 ./pihole/etc-pihole/local.list
-rw-r--r-- root/root 95 2021-08-23 12:10 ./pihole/etc-pihole/list.1.raw.githubusercontent.com.domains.sha1
-rw-r--r-- root/root 20 2021-08-23 12:10 ./pihole/etc-pihole/localbranches
drwxr-xr-x root/root 0 2021-08-23 12:10 ./pihole/etc-pihole/migration_backup/
-rw-r--r-- root/root 65 2021-08-23 12:10 ./pihole/etc-pihole/migration_backup/adlists.list
-rw-r--r-- root/root 618 2021-08-23 12:10 ./pihole/etc-pihole/dns-servers.conf
-rw-r--r-- root/root 20 2021-08-23 12:10 ./pihole/etc-pihole/GitHubVersions
-rw-r--r-- root/root 44 2021-08-23 12:10 ./pihole/etc-pihole/localversions
drwxr-xr-x root/root 0 2021-08-23 12:10 ./pihole/etc-dnsmasq.d/
-rw-r--r-- root/root 1475 2021-08-23 12:10 ./pihole/etc-dnsmasq.d/01-pihole.conf
drwxr-xr-x root/root 0 2021-08-23 12:10 ./.scripts/
-rwxr-xr-x root/root 1638 2021-08-23 12:10 ./.scripts/create-backup.sh
-rwxr-xr-x root/root 511 2021-08-23 12:10 ./.scripts/new-cert-pihole.sh
-rwxr-xr-x root/root 345 2021-08-23 12:10 ./.scripts/fix-permissions.sh
-rw-r--r-- root/root 1170 2021-08-23 12:10 ./docker-compose.yml
Se eu tentar extrair o arquivo .tar.gz, podemos confirmar que toda a propriedade foi perdida:
$ sudo mkdir /tmp/server-backup
$ sudo tar -xzpf /tmp/server-backup.tar.gz --directory=/tmp/server-backup
$ ls -lhaF /tmp/server-backup
total 32K
drwxr-xr-x 7 root root 4.0K Aug 23 12:10 ./
drwxrwxrwt 13 root root 4.0K Aug 23 12:16 ../
drwxr-xr-x 2 root root 4.0K Aug 23 12:10 .certs/
drwxr-xr-x 2 root root 4.0K Aug 23 12:10 .scripts/
-rw-r--r-- 1 root root 1.2K Aug 23 12:10 docker-compose.yml
drwxr-xr-x 4 root root 4.0K Aug 23 12:10 minecraft/
drwxr-xr-x 4 root root 4.0K Aug 23 12:10 pihole/
drwx------ 19 root root 4.0K Aug 23 12:10 postgres/
Pelo que descobri, preservar a propriedade e as permissões deve ser o comportamento padrão para arquivos tar. Há algo que estou perdendo aqui? Gostaria de poder fazer backup do estado do meu servidor sem atrapalhar a delicada propriedade de arquivos exigida por alguns dos contêineres do docker que executo.
Informação do sistema:
$ lsb_release -d
Description: Ubuntu 20.04.3 LTS
$ uname -a
Linux rpi-1 5.4.0-1042-raspi #46-Ubuntu SMP PREEMPT Fri Jul 30 00:35:40 UTC 2021 aarch64 aarch64 aarch64 GNU/Linux
Responder1
Aparentemente, tarnão é o culpado aqui. Isso fazia parte de um script maior para fazer backup da minha pasta de implantação. Eu estava copiando a pasta antes de compactar para evitar inconsistências de leitura enquanto os contêineres ainda estavam em execução. O script continha o seguinte:
cp -R "/opt/docker" "/tmp/server-backup"
tar -czf "/tmp/server-backup.tar.gz" --directory="/tmp/server-backup" .
A propriedade do arquivo estava sendo perdida durante a cópia da pasta. O -psinalizador é necessário para preservar permissões/propriedade em uma cópia de pasta. O comando correto seria este:
cp -Rp "/opt/docker" "/tmp/server-backup"
tar -czf "/tmp/server-backup.tar.gz" --directory="/tmp/server-backup" .