Use libgfapi, or fall back to the gluster CLI to fetch the volfile

splitmount/rpc.py

@@ -0,0 +1,55 @@
+#!/usr/bin/python
+
+import ctypes
+import ctypes.util
+import subprocess
+
+def cli_get_volfile (host, volume):
+    res = subprocess.check_output(["/usr/sbin/gluster","--remote-host={}".format(host),
+        "system","getspec",volume])
+    return res
+
+def api_get_volfile (host, volume):
+    # This is set to a large value to exercise the "buffer not big enough"
+    # path.  More realistically, you'd just start with a huge buffer.
+    BUF_LEN = 0
+    fs = api.glfs_new(volume)
+    #api.glfs_set_logging(fs,"/dev/stderr",7)
+    api.glfs_set_volfile_server(fs,"tcp",host,24007)
+    api.glfs_init(fs)
+    vbuf = ctypes.create_string_buffer(BUF_LEN)
+    vlen = api.glfs_get_volfile(fs,vbuf,BUF_LEN)
+    if vlen < 0:
+        vlen = BUF_LEN - vlen
+        vbuf = ctypes.create_string_buffer(vlen)
+        vlen = api.glfs_get_volfile(fs,vbuf,vlen)
+    api.glfs_fini(fs)
+    if vlen <= 0:
+        return vlen
+    return vbuf.value[:vlen]
+
+api = ctypes.CDLL(ctypes.util.find_library("gfapi"))
+try:
+    api.glfs_get_volfile.argtypes = [ctypes.c_void_p,
+                                     ctypes.c_void_p,
+                                     ctypes.c_ulong]
+    api.glfs_get_volfile.restype = ctypes.c_long;
+    get_volfile = api_get_volfile
+except:
+    get_volfile = cli_get_volfile
+
+if __name__ == "__main__":
+    import sys
+
+    try:
+        res = apply(get_volfile,sys.argv[1:3])
+    except:
+        print "fetching volfile failed (volume not started?)"
+        raise
+
+    try:
+        for line in res.split('\n'):
+            print line
+    except:
+        print "bad return value %s" % res
+        raise

splitmount/splitmount.py

@@ -17,7 +17,7 @@
 #
 # Copyright 2014, Joe Julian <[email protected]>
 #
-import rpc.fetchvol
+import rpc
 import os,sys,re
 import tempfile
 import subprocess
@@ -50,7 +50,7 @@ def main():
         print 'of that directory, or choose another directory.'
         exit(1)
 
-    orig_vol = rpc.fetchvol.fetch_volfile(server, volume)
+    orig_vol = rpc.get_volfile(server, volume)
     regex = re.compile(r'(^volume\s.+?end-volume)', re.VERBOSE|re.MULTILINE|re.DOTALL)
     graph = [ x.strip("\n") for x in regex.split(orig_vol) if x.strip("\n") ]
     newgraph = []