Update backup compression options that call pg_basebackup.

add `backup_compression=none` to create an uncompressed archive
that only supports `backup_compression_level=0`.
for pg >= 15:
update `zstd` compression level range from `-131072` to `22`
update `lz4` compression level range from `0` to `12`

For PG < 15:
Allow using `backup_compression_level=0` with `backup_compression=gzip` algorithm.

In configuration 'none' can be used as value and not identified as None value.

barman/command_wrappers.py

@@ -1010,9 +1010,16 @@ def _get_compression_args(self, version, compression):
                 compression_args.append(compress_arg)
             # For clients < 15 we use the old style argument format
             else:
-                compression_args.append("--%s" % compression.config.type)
-                if compression.config.level:
-                    compression_args.append("--compress=%d" % compression.config.level)
+                if compression.config.type == "none":
+                    compression_args.append("--compress=0")
+                else:
+                    if compression.config.level is not None:
+                        compression_args.append(
+                            "--compress=%d" % compression.config.level
+                        )
+                    # --gzip must be positioned after --compress when compression level=0
+                    # so `base.tar.gz` can be created. Otherwise `.gz` won't be added.
+                    compression_args.append("--%s" % compression.config.type)
         return compression_args
 
 

barman/compression.py

@@ -467,36 +467,41 @@ def get_pg_basebackup_compression(server):
         server.config.backup_compression_location,
         server.config.backup_compression_workers,
     )
-
+    base_backup_compression_option = None
+    compression = None
     if server.config.backup_compression == GZipCompression.name:
         # Create PgBaseBackupCompressionOption
         base_backup_compression_option = GZipPgBaseBackupCompressionOption(
             pg_base_backup_cfg
         )
         compression = GZipCompression(unix_command_factory())
-        return PgBaseBackupCompression(
-            pg_base_backup_cfg, base_backup_compression_option, compression
-        )
+
     if server.config.backup_compression == LZ4Compression.name:
         base_backup_compression_option = LZ4PgBaseBackupCompressionOption(
             pg_base_backup_cfg
         )
         compression = LZ4Compression(unix_command_factory())
-        return PgBaseBackupCompression(
-            pg_base_backup_cfg, base_backup_compression_option, compression
-        )
+
     if server.config.backup_compression == ZSTDCompression.name:
         base_backup_compression_option = ZSTDPgBaseBackupCompressionOption(
             pg_base_backup_cfg
         )
         compression = ZSTDCompression(unix_command_factory())
-        return PgBaseBackupCompression(
-            pg_base_backup_cfg, base_backup_compression_option, compression
+
+    if server.config.backup_compression == NoneCompression.name:
+        base_backup_compression_option = NonePgBaseBackupCompressionOption(
+            pg_base_backup_cfg
         )
-    # We got to the point where the compression is not handled
-    raise CompressionException(
-        "Barman does not support pg_basebackup compression: %s"
-        % server.config.backup_compression
+        compression = NoneCompression(unix_command_factory())
+
+    if base_backup_compression_option is None or compression is None:
+        # We got to the point where the compression is not handled
+        raise CompressionException(
+            "Barman does not support pg_basebackup compression: %s"
+            % server.config.backup_compression
+        )
+    return PgBaseBackupCompression(
+        pg_base_backup_cfg, base_backup_compression_option, compression
     )
 
 
@@ -574,13 +579,32 @@ def validate(self, pg_server_version, remote_status):
         issues = super(GZipPgBaseBackupCompressionOption, self).validate(
             pg_server_version, remote_status
         )
-        if self.config.level is not None and (
-            self.config.level < 1 or self.config.level > 9
+        levels = list(range(1, 10))
+        levels.append(-1)
+        if self.config.level is not None and remote_status[
+            "pg_basebackup_version"
+        ] < Version("15"):
+            # version prior to 15 allowed gzip compression 0
+            levels.append(0)
+            if self.config.level not in levels:
+                issues.append(
+                    "backup_compression_level %d unsupported by compression algorithm."
+                    " %s expects a compression level between -1 and 9 (-1 will use default compression level)."
+                    % (self.config.level, self.config.type)
+                )
+        if (
+            self.config.level is not None
+            and remote_status["pg_basebackup_version"] >= Version("15")
+            and self.config.level not in levels
         ):
-            issues.append(
-                "backup_compression_level %d unsupported by "
-                "pg_basebackup compression %s" % (self.config.level, self.config.type)
+            msg = (
+                "backup_compression_level %d unsupported by compression algorithm."
+                " %s expects a compression level between 1 and 9 (-1 will use default compression level)."
+                % (self.config.level, self.config.type)
             )
+            if self.config.level == 0:
+                msg += "\nIf you need to create an uncompress archive, you should set `backup_compression = none`."
+            issues.append(msg)
         if self.config.workers is not None:
             issues.append(
                 "backup_compression_workers is not compatible with compression %s"
@@ -610,15 +634,16 @@ def validate(self, pg_server_version, remote_status):
             )
 
         if self.config.level is not None and (
-            self.config.level < 1 or self.config.level > 12
+            self.config.level < 0 or self.config.level > 12
         ):
             issues.append(
-                "backup_compression_level %d unsupported by "
-                "pg_basebackup compression %s" % (self.config.level, self.config.type)
+                "backup_compression_level %d unsupported by compression algorithm."
+                " %s expects a compression level between 1 and 12 (0 will use default compression level)."
+                % (self.config.level, self.config.type)
             )
         if self.config.workers is not None:
             issues.append(
-                "backup_compression_workers is not compatible with compression %s"
+                "backup_compression_workers is not compatible with compression %s."
                 % self.config.type
             )
         return issues
@@ -644,21 +669,50 @@ def validate(self, pg_server_version, remote_status):
                 "pg_basebackup 15 or greater" % self.config.type
             )
 
+        # Minimal config level comes from zstd library `STD_minCLevel()` and is
+        # commonly set to -131072.
         if self.config.level is not None and (
-            self.config.level < 1 or self.config.level > 22
+            self.config.level < -131072 or self.config.level > 22
         ):
             issues.append(
-                "backup_compression_level %d unsupported by "
-                "pg_basebackup compression %s" % (self.config.level, self.config.type)
+                "backup_compression_level %d unsupported by compression algorithm."
+                " '%s' expects a compression level between -131072 and 22 (3 will use default compression level)."
+                % (self.config.level, self.config.type)
             )
         if self.config.workers is not None and (
             type(self.config.workers) is not int or self.config.workers < 0
         ):
             issues.append(
-                "backup_compression_workers should be a positive integer: '%s' is invalid"
+                "backup_compression_workers should be a positive integer: '%s' is invalid."
                 % self.config.workers
             )
+        return issues
+
+
+class NonePgBaseBackupCompressionOption(PgBaseBackupCompressionOption):
+    def validate(self, pg_server_version, remote_status):
+        """
+        Validate none compression specific options.
 
+        :param pg_server_version int: the server for which the
+          compression options should be validated.
+        :param dict remote_status: the status of the pg_basebackup command
+        :return List: List of Issues (str) or empty list
+        """
+        issues = super(NonePgBaseBackupCompressionOption, self).validate(
+            pg_server_version, remote_status
+        )
+
+        if self.config.level is not None and (self.config.level != 0):
+            issues.append(
+                "backup_compression %s only supports backup_compression_level 0."
+                % self.config.type
+            )
+        if self.config.workers is not None:
+            issues.append(
+                "backup_compression_workers is not compatible with compression '%s'."
+                % self.config.type
+            )
         return issues
 
 
@@ -972,3 +1026,70 @@ def get_file_content(self, filename, archive):
                 )
         else:
             return out
+
+
+class NoneCompression(Compression):
+    name = "none"
+    file_extension = "tar"
+
+    def __init__(self, command):
+        """
+
+        :param command: barman.fs.UnixLocalCommand
+        """
+        self.command = command
+
+    def uncompress(self, src, dst, exclude=None, include_args=None):
+        """
+
+        :param src: source file path without compression extension
+        :param dst: destination path
+        :param exclude: list of filepath in the archive to exclude from the extraction
+        :param include_args: list of filepath in the archive to extract.
+        :return:
+        """
+        if src is None or src == "":
+            raise ValueError("Source path should be a string")
+        if dst is None or dst == "":
+            raise ValueError("Destination path should be a string")
+        exclude = [] if exclude is None else exclude
+        exclude_args = []
+        for name in exclude:
+            exclude_args.append("--exclude")
+            exclude_args.append(name)
+        include_args = [] if include_args is None else include_args
+        args = ["-xf", src, "--directory", dst]
+        args.extend(exclude_args)
+        args.extend(include_args)
+        ret = self.command.cmd("tar", args=args)
+        out, err = self.command.get_last_output()
+        if ret != 0:
+            raise CommandFailedException(
+                "Error decompressing %s into %s: %s" % (src, dst, err)
+            )
+        else:
+            return self.command.get_last_output()
+
+    def get_file_content(self, filename, archive):
+        """
+
+        :param filename: str file to search for in the archive (requires its full path within the archive)
+        :param archive: str archive path/name without extension
+        :return: string content
+        """
+        full_archive_name = "%s.%s" % (archive, self.file_extension)
+        args = ["-xf", full_archive_name, "-O", filename, "--occurrence"]
+        ret = self.command.cmd("tar", args=args)
+        out, err = self.command.get_last_output()
+        if ret != 0:
+            if "Not found in archive" in err:
+                raise FileNotFoundException(
+                    err + "archive name: %s" % full_archive_name
+                )
+            else:
+                raise CommandFailedException(
+                    "Error reading %s into archive %s: (%s)"
+                    % (filename, full_archive_name, err)
+                )
+        else:
+            return out

barman/config.py

@@ -71,7 +71,7 @@
 CREATE_SLOT_VALUES = ["manual", "auto"]
 
 # Config values relating to pg_basebackup compression
-BASEBACKUP_COMPRESSIONS = ["gzip", "lz4", "zstd"]
+BASEBACKUP_COMPRESSIONS = ["gzip", "lz4", "zstd", "none"]
 
 
 class CsvOption(set):
@@ -294,8 +294,6 @@ def parse_backup_compression(value):
     """
     Parse a string to a valid backup_compression value.
 
-    Valid values are contained in compression.basebackup_compressions list
-
     :param str value: backup_compression value
     :raises ValueError: if the value is invalid
     """
@@ -304,7 +302,7 @@ def parse_backup_compression(value):
     if value.lower() in BASEBACKUP_COMPRESSIONS:
         return value.lower()
     raise ValueError(
-        "Invalid value (must be one in: '%s')" % ("', '".join(BASEBACKUP_COMPRESSIONS))
+        "Invalid value '%s'(must be one in: %s)" % (value, BASEBACKUP_COMPRESSIONS)
     )
 
 
@@ -862,7 +860,7 @@ def get(self, section, option, defaults=None, none_value=None):
             return None
         try:
             value = self._config.get(section, option, raw=False, vars=defaults)
-            if value.lower() == "none":
+            if value == "None":
                 value = none_value
             if value is not None:
                 value = self._QUOTE_RE.sub(lambda m: m.group(2), value)

barman/recovery_executor.py

@@ -52,7 +52,7 @@
     RecoveryPreconditionException,
     SnapshotBackupException,
 )
-from barman.compression import GZipCompression, LZ4Compression, ZSTDCompression
+from barman.compression import GZipCompression, LZ4Compression, ZSTDCompression, NoneCompression
 import barman.fs as fs
 from barman.infofile import BackupInfo, LocalBackupInfo
 from barman.utils import force_str, mkpath
@@ -1803,7 +1803,8 @@ def recovery_executor_factory(backup_manager, command, backup_info):
         return TarballRecoveryExecutor(backup_manager, LZ4Compression(command))
     if compression == ZSTDCompression.name:
         return TarballRecoveryExecutor(backup_manager, ZSTDCompression(command))
-
+    if compression == NoneCompression.name:
+        return TarballRecoveryExecutor(backup_manager, NoneCompression(command))
     raise AttributeError("Unexpected compression format: %s" % compression)