Make arbitrary compression tools work

We assume that the compression tools the user supplies use stdin and
stdout for handling data, and that a switch is used to distinguish
compression from decompression. This patch introduces these constraints
by adding the invocation of these tools to the import-export daemon.
Signed-off-by: Hrvoje Ribicic <riba@google.com>
Reviewed-by: Thomas Thrainer <thomasth@google.com>

daemons/import-export

@@ -438,14 +438,6 @@ def ParseOptions():
   return (status_file_path, mode)
 
 
-# Compression utility mapping, for compression types whose name does not match
-# the name of the utility to invoke
-COMPRESSION_UTILITIES = {
-  "gzip-fast": "gzip",
-  "gzip-slow": "gzip",
-  }
-
-
 # Return code signifying that no program was found
 PROGRAM_NOT_FOUND_RCODE = 127
 
@@ -493,7 +485,8 @@ def VerifyOptions():
 
   """
   if options.compress != constants.IEC_NONE:
-    utility_name = COMPRESSION_UTILITIES.get(options.compress, options.compress)
+    utility_name = constants.IEC_COMPRESSION_UTILITIES.get(options.compress,
+                                                           options.compress)
     timed_out, rcode = \
       _RunWithTimeout([utility_name, CHECK_SWITCH], 2, silent=True)
 

lib/impexpd/__init__.py

@@ -297,10 +297,11 @@ class CommandBuilder(object):
       parts.append(socat_cmd)
 
       if compr in [constants.IEC_GZIP, constants.IEC_GZIP_FAST,
-                   constants.IEC_GZIP_SLOW]:
-        parts.append("gunzip -c")
-      elif compr == constants.IEC_LZOP:
-        parts.append("lzop -d -c")
+                   constants.IEC_GZIP_SLOW, constants.IEC_LZOP]:
+        utility_name = constants.IEC_COMPRESSION_UTILITIES.get(compr, compr)
+        parts.append("%s -d -c" % utility_name)
+      elif compr != constants.IEC_NONE:
+        parts.append("%s -d" % compr)
       else:
         # No compression
         pass
@@ -310,12 +311,13 @@ class CommandBuilder(object):
     elif self._mode == constants.IEM_EXPORT:
       parts.append(dd_cmd)
 
-      if compr == constants.IEC_GZIP_SLOW:
-        parts.append("gzip -c")
+      if compr in [constants.IEC_GZIP_SLOW, constants.IEC_LZOP]:
+        utility_name = constants.IEC_COMPRESSION_UTILITIES.get(compr, compr)
+        parts.append("%s -c" % utility_name)
       elif compr in [constants.IEC_GZIP_FAST, constants.IEC_GZIP]:
         parts.append("gzip -1 -c")
-      elif compr == constants.IEC_LZOP:
-        parts.append("lzop -c")
+      elif compr != constants.IEC_NONE:
+        parts.append(compr)
       else:
         # No compression
         pass

src/Ganeti/Constants.hs

@@ -601,6 +601,13 @@ iecNone = "none"
 iecAll :: [String]
 iecAll = [iecGzip, iecGzipFast, iecGzipSlow, iecLzop, iecNone]
 
+iecCompressionUtilities :: Map String String
+iecCompressionUtilities =
+  Map.fromList
+  [ (iecGzipFast, iecGzip)
+  , (iecGzipSlow, iecGzip)
+  ]
+
 ieCustomSize :: String
 ieCustomSize = "fd"
 

test/py/ganeti.impexpd_unittest.py

@@ -66,9 +66,9 @@ class TestCommandBuilder(unittest.TestCase):
 
     # The commands various compressions should use
     compress_import = {
-      constants.IEC_GZIP: "gunzip",
-      constants.IEC_GZIP_FAST: "gunzip",
-      constants.IEC_GZIP_SLOW: "gunzip",
+      constants.IEC_GZIP: "gzip -d",
+      constants.IEC_GZIP_FAST: "gzip -d",
+      constants.IEC_GZIP_SLOW: "gzip -d",
       constants.IEC_LZOP: "lzop -d",
       }
     compress_export = {