Fix tags not being applied on AWS EBS Snapshots

[ruimarinho]

This PR resolves an issue where tags specified via command-line arguments were not being correctly applied to snapshots.

Consider the following example:

/usr/bin/barman-cloud-backup --cloud-provider aws-s3 \
--aws-region us-east-1 \
--tags environment,production project,my-project service,barman \
--snapshot-disk $VOLUME_ID \
--snapshot-instance $INSTANCE_ID \
s3://test/barman postgres

Previously, the tags environment, project and service were not included in the snapshot tags; only a single tag (Name) was set by default. This omission made it difficult to filter snapshots based on tags, which is crucial for maintaining security and managing resources effectively.

[diogotorres97]

Tested alongside #1005 and is working as expected!

[diogotorres97]

ping

[gustabowill]

Thanks for the patch. There's a small fix which needs to be addressed as it's currently breaking snapshot backups via standard barman server.

Besides that, this looks good in general. I would just suggest a few things so it gets more in accordance with the standards:

• Write a commit body message detailing the issue a little bit more.
• Run black on the changed files to have them well-formatted.

The code works as expected when run with the barman-cloud-backup script:

1. Using the modified code.

$ which barman-cloud-backup
~/barman/venv/bin/barman-cloud-backup

2. Do a snapshot backup with barman-cloud-backup passing some tags.

$ barman-cloud-backup -h 127.0.0.1 -d postgres -U postgres --snapshot-instance=test-snapshot-tags --snapshot-disk=test-snapshot-tags-non-root --tags environment,production project,my-project service,barman --aws-region us-east-1 s3://barman-testing-snapshot-tags pg-server

3. The tags are available in the snapshot created.

$ aws ec2 describe-snapshots --owner <account-id>
{
  "Snapshots": [
    {
      "Tags": [
        {
          "Key": "Name",
          "Value": "test-snapshot-tags-non-root-20241022t124114"
        },
        {
          "Key": "environment",
          "Value": "production"
        },
        {
          "Key": "project",
          "Value": "my-project"
        },
        {
          "Key": "service",
          "Value": "barman"
        }
      ],
      "StorageTier": "standard",
      "SnapshotId": "snap-08ac5e6b84264cdd8",
      "VolumeId": "vol-0e4fc46b267a3ecce",
      "State": "completed",
      "StartTime": "2024-10-22T12:41:14.813000+00:00",
      "Progress": "100%",
      "OwnerId": "account-id",
      "Description": "",
      "VolumeSize": 10,
      "Encrypted": false
    }
  ]
}

It will still not be possible to use tags when doing snapshot backups via standard barman server, but we will work on that internally.

[gustabowill]

This needs to be removed. This is the server config object and there's currently no tags option available in the server parameters. This function is used in the context of snapshot backups via the barman standard server (when backup_method = snapshot) and there's currently no way to pass tags in there.

You indeed get an error when attempting a snapshot backup via barman server with your code:

$ barman backup snapshot-server
WARNING: No backup strategy set for server 'snapshot-server' (using default 'concurrent_backup').
ERROR: Error initialising snapshot provider aws: 'ServerConfig' object has no attribute 'tags' 

[gcalacoci]

Suggested change

server_config.tags,

[barthisrael]

Let's also add a description for tags in the docstring.