feat: expose showAdditionalCommandArgs and listAdditionalCommandArgs

An ObjectStore lets users tack extra command-line flags onto four of
the six barman-cloud-* invocations the plugin shells out to:
barman-cloud-backup (data.additionalCommandArgs), -wal-archive
(wal.archiveAdditionalCommandArgs), -wal-restore
(wal.restoreAdditionalCommandArgs), and -restore (data.restoreAdditionalCommandArgs,
PR #914).

The remaining two -- barman-cloud-backup-show (post-write verification)
and barman-cloud-backup-list (retention pruning) -- had no equivalent,
which is the gap reported in #712. On strictly-vhost S3-compatible
endpoints (e.g. some Coreweave cwobject buckets) users need
`--addressing-style=virtual` on every cloud command, and currently those
two reject the user-provided args, marking otherwise-successful backups
as failed and silently disabling retention pruning.

The library-side change adds the two new fields and helpers (sister PR
in cloudnative-pg/barman-cloud) and threads them through GetBackupList /
GetBackupByName. This plugin commit just exposes them via the CRD and
documents the new shape.

## Sister PR (must merge first)

The CRD field schema is generated from the BarmanObjectStoreConfiguration
Go type in cloudnative-pg/barman-cloud. The sister PR there adds:

- DataBackupConfiguration.ShowAdditionalCommandArgs []string
- DataBackupConfiguration.ListAdditionalCommandArgs []string
- AppendShowAdditionalCommandArgs / AppendListAdditionalCommandArgs helpers

Once that PR merges and a barman-cloud release is cut, controller-gen
here picks up the new fields automatically. Until then a developer
running `go test ./...` against this branch needs a local replace
directive in go.mod pointing at the barman-cloud branch (omitted from
this commit).

Closes #712

Author: davidalmgren95

config/crd/bases/barmancloud.cnpg.io_objectstores.yaml

@@ -176,6 +176,37 @@ spec:
                         format: int32
                         minimum: 1
                         type: integer
+                      listAdditionalCommandArgs:
+                        description: |-
+                          ListAdditionalCommandArgs represents additional arguments that can be appended
+                          to the 'barman-cloud-backup-list' command-line invocation. This command is
+                          used internally for retention-policy enforcement; flags relevant to the
+                          underlying S3 client (e.g. `--addressing-style=virtual` for strictly
+                          virtual-hosted S3-compatible endpoints) generally belong here as well.
+
+                          Note:
+                          It's essential to ensure that the provided arguments are valid and supported
+                          by the 'barman-cloud-backup-list' command, to avoid potential errors or
+                          unintended behavior during execution.
+                        items:
+                          type: string
+                        type: array
+                      showAdditionalCommandArgs:
+                        description: |-
+                          ShowAdditionalCommandArgs represents additional arguments that can be appended
+                          to the 'barman-cloud-backup-show' command-line invocation. This command is
+                          used after a successful upload to verify and record metadata about the
+                          freshly-written backup, so flags relevant to the underlying S3 client
+                          (e.g. `--addressing-style=virtual` for strictly virtual-hosted S3-compatible
+                          endpoints) generally belong here as well.
+
+                          Note:
+                          It's essential to ensure that the provided arguments are valid and supported
+                          by the 'barman-cloud-backup-show' command, to avoid potential errors or
+                          unintended behavior during execution.
+                        items:
+                          type: string
+                        type: array
                     type: object
                   destinationPath:
                     description: |-

manifest.yaml

@@ -175,6 +175,37 @@ spec:
                         format: int32
                         minimum: 1
                         type: integer
+                      listAdditionalCommandArgs:
+                        description: |-
+                          ListAdditionalCommandArgs represents additional arguments that can be appended
+                          to the 'barman-cloud-backup-list' command-line invocation. This command is
+                          used internally for retention-policy enforcement; flags relevant to the
+                          underlying S3 client (e.g. `--addressing-style=virtual` for strictly
+                          virtual-hosted S3-compatible endpoints) generally belong here as well.
+
+                          Note:
+                          It's essential to ensure that the provided arguments are valid and supported
+                          by the 'barman-cloud-backup-list' command, to avoid potential errors or
+                          unintended behavior during execution.
+                        items:
+                          type: string
+                        type: array
+                      showAdditionalCommandArgs:
+                        description: |-
+                          ShowAdditionalCommandArgs represents additional arguments that can be appended
+                          to the 'barman-cloud-backup-show' command-line invocation. This command is
+                          used after a successful upload to verify and record metadata about the
+                          freshly-written backup, so flags relevant to the underlying S3 client
+                          (e.g. `--addressing-style=virtual` for strictly virtual-hosted S3-compatible
+                          endpoints) generally belong here as well.
+
+                          Note:
+                          It's essential to ensure that the provided arguments are valid and supported
+                          by the 'barman-cloud-backup-show' command, to avoid potential errors or
+                          unintended behavior during execution.
+                        items:
+                          type: string
+                        type: array
                     type: object
                   destinationPath:
                     description: |-

web/docs/misc.md

@@ -32,15 +32,22 @@ spec:
   [...]
 ```
 
-## Extra Options for Backup and WAL Archiving
+## Extra Options for Backup, WAL Archiving, Show, and List
 
-You can pass additional command-line arguments to `barman-cloud-backup` and
-`barman-cloud-wal-archive` using the `additionalCommandArgs` field in the
-`ObjectStore` configuration.
+You can pass additional command-line arguments to each barman-cloud
+invocation the plugin shells out to, using the matching
+`additionalCommandArgs` fields in the `ObjectStore` configuration.
 
 - `.spec.configuration.data.additionalCommandArgs`: for `barman-cloud-backup`
+- `.spec.configuration.data.showAdditionalCommandArgs`: for `barman-cloud-backup-show` (post-write verification)
+- `.spec.configuration.data.listAdditionalCommandArgs`: for `barman-cloud-backup-list` (retention pruning)
 - `.spec.configuration.wal.archiveAdditionalCommandArgs`: for `barman-cloud-wal-archive`
 
+If you need a flag that applies to every cloud command — such as
+`--addressing-style=virtual` for an S3-compatible endpoint that only
+accepts virtual-hosted-style requests — set it on all of the above so
+both writes and the post-write read-back / retention steps honor it.
+
 Each field accepts a list of string arguments. If an argument is already
 configured elsewhere in the plugin, the duplicate will be ignored.