Add support for user defined mount points

Also, move swap to use this format for specifying mounts.  That way
the user can turn off swap if they want with:
 | mounts:
 | - [ swap ]

Other change wrapped in here is to have DataSourceEc2 read plain text
(evalable) text for its metadata rather than pickl.  This is really for
debuging anyway, so any speed difference is not important.

1 files changed, 113 insertions, 1 deletions

diff --git a/ec2init/CloudConfig.py b/ec2init/CloudConfig.py
index 51618943..4875e999 100644
--- a/ec2init/CloudConfig.py
+++ b/ec2init/CloudConfig.py
@@ -39,6 +39,7 @@ class CloudConfig():
         self.add_handler('apt-update-upgrade', self.h_apt_update_upgrade)
         self.add_handler('config-ssh')
         self.add_handler('disable-ec2-metadata')
+        self.add_handler('config-mounts')
 
     def get_config_obj(self,cfgfile):
         f=file(cfgfile)
@@ -189,7 +190,118 @@ class CloudConfig():
     def h_config_runurl(self,name,args):
         print "Warning, not doing anything for config %s" % name
 
-
+    def h_config_mounts(self,name,args):
+        # handle 'mounts'
+
+        # these are our default set of mounts
+        defmnts = [ [ "ephemeral0", "/mnt", "auto", "defaults", "0", "0" ],
+                    [ "swap", "none", "swap", "sw", "0", "0" ] ]
+
+        # fs_spec, fs_file, fs_vfstype, fs_mntops, fs-freq, fs_passno
+        defvals = [ None, None, "auto", "defaults", "0", "0" ]
+
+        cfgmnt = [ ]
+        if self.cfg.has_key("mounts"):
+            cfgmnt = self.cfg["mounts"]
+    
+        for i in range(len(cfgmnt)):
+            # skip something that wasn't a list
+            if not isinstance(cfgmnt[i],list): continue
+
+            # workaround, allow user to specify 'ephemeral'
+            # rather than more ec2 correct 'ephemeral0'
+            if cfgmnt[i] == "ephemeral":
+                cfgmnt[i] = "ephemeral0"
+
+            newname = cfgmnt[i][0]
+            if not newname.startswith("/"):
+                newname = self.cloud.device_name_to_device(cfgmnt[i][0])
+            if newname is not None:
+                cfgmnt[i][0] = newname
+            else:
+                # there is no good way of differenciating between
+                # a name that *couldn't* exist in the md service and
+                # one that merely didnt
+                # in order to allow user to specify 'sda3' rather
+                # than '/dev/sda3', go through some hoops
+                ok = False
+                for f in [ "/", "sd", "hd", "vd", "xvd" ]:
+                    if cfgmnt[i][0].startswith(f):
+                        ok = True
+                        break
+                if not ok:
+                    cfgmnt[i][1] = None
+    
+        for i in range(len(cfgmnt)):
+            # fill in values with 
+            for j in range(len(defvals)):
+                if len(cfgmnt[i]) <= j:
+                    cfgmnt[i].append(defvals[j])
+                elif cfgmnt[i][j] is None:
+                    cfgmnt[i][j] = defvals[j]
+    
+            if not cfgmnt[i][0].startswith("/"):
+                cfgmnt[i][0]="/dev/%s" % cfgmnt[i][0]
+    
+            # if the second entry in the list is 'None' this
+            # clears all previous entries of that same 'fs_spec'
+            # (fs_spec is the first field in /etc/fstab, ie, that device)
+            if cfgmnt[i][1] is None:
+                for j in range(i):
+                    if cfgmnt[j][0] == cfgmnt[i][0]:
+                        cfgmnt[j][1] = None
+    
+
+        # for each of the "default" mounts, add them only if no other
+        # entry has the same device name
+        for defmnt in defmnts:
+            devname = self.cloud.device_name_to_device(defmnt[0])
+            if devname is None: continue
+            if not devname.startswith("/"):
+                defmnt[0] = "/dev/%s" % devname
+
+            cfgmnt_has = False
+            for cfgm in cfgmnt:
+                if cfgm[0] == defmnt[0]:
+                    cfgmnt_has = True
+                    break
+            
+            if cfgmnt_has: continue
+            cfgmnt.append(defmnt)
+
+    
+        # now, each entry in the cfgmnt list has all fstab values
+        # if the second field is None (not the string, the value) we skip it
+        actlist = filter(lambda x: x[1] is not None, cfgmnt)
+    
+        if len(actlist) == 0: return
+    
+        needswap = False
+        dirs = [ ]
+
+        fstab=file("/etc/fstab","ab")
+        fstab.write("# cloud-config mounts\n")
+        for line in actlist:
+            fstab.write('\t'.join(line) + "\n")
+            if line[2] == "swap": needswap = True
+            if line[1].startswith("/"): dirs.append(line[1])
+        fstab.close()
+    
+        if needswap:
+            try: util.subp(("swapon", "-a"))
+            except: warn("Failed to enable swap")
+
+        for d in dirs:
+            if os.path.exists(d): continue
+            try: os.makedirs(d)
+            except: warn("Failed to make '%s' config-mount\n",d)
+
+        try: util.subp(("mount","-a"))
+        except: pass
+    
+
+
+    
 def apply_credentials(keys, user, disable_root):
     keys = set(keys)
     if user: