debian/cloud-tools/hv_set_ifconfig

   1 #!/usr/bin/python3
   2 #
   3 # hv_set_ifconfig <config> -- take the hv_kvp_daemon generated configuration
   4 #                             file and apply it to the Ubuntu configuration.
   5 #
   6
   7 # CONFIG example:
   8 # HWADDR=11:22:33:44:55:66
   9 # DEVICE=foo1
  10 # DHCP=yes
  11
  12 # CONFIG example:
  13 # HWADDR=11:22:33:44:55:66
  14 # DEVICE=foo1
  15 # IPADDR=192.168.99.10
  16 # GATEWAY=192.168.99.1
  17 # DNS1=192.168.88.250
  18 # IPADDR2=192.168.99.11
  19 # IPV6ADDR=2001:DB8:99::10
  20 # IPV6NETMASK=64
  21 # IPV6_DEFAULTGW=2001:DB8:99::10
  22
  23 # set interfaces in hv_kvp_daemon style
  24 import fileinput
  25 import sys
  26 import errno
  27 import os
  28 import shutil
  29 import tempfile
  30 import subprocess
  31
  32 if_filename="/etc/network/interfaces"
  33
  34 # Drop our output (XXX?)
  35 sys.stdout = open(os.devnull, 'w')
  36 sys.stderr = open(os.devnull, 'w')
  37
  38 # Confirm we can open the network configuration.
  39 try:
  40     if_file=open(if_filename,"r+")
  41 except IOError as e:
  42     exit(e.errno)
  43 else:
  44     if_file.close()
  45
  46 # Usage: hv_set_ifconfig <config>
  47 if len(sys.argv) != 2 :
  48     exit(errno.EINVAL)
  49
  50 #
  51 # Here is the format of the ip configuration file:
  52 #
  53 # HWADDR=macaddr
  54 # DEVICE=interface name
  55 # BOOTPROTO=<protocol> (where <protocol> is "dhcp" if DHCP is configured
  56 #                       or "none" if no boot-time protocol should be used)
  57 #
  58 kvp=dict(line.strip().split("=") for line in fileinput.input())
  59
  60 # Setting the hwaddress to something azure is not expecting is fatal
  61 # to networking.
  62 if not "HWADDR" in kvp :
  63     exit(errno.EPROTO)
  64
  65 # Confirm we have a device specified.
  66 if not "DEVICE" in kvp :
  67     exit(1)
  68
  69 output=[]
  70 basename=kvp["DEVICE"]
  71
  72 if "DHCP" in kvp and kvp["DHCP"]=="yes" :
  73     output += ["auto " + basename]
  74     output += ["iface " + basename  + " inet dhcp"]
  75     output += [""]
  76 else:
  77     # Matchup the interface specific lines
  78
  79     # DNS entries will go with the first interface
  80     # and there can be a max of three
  81     autolist=[]
  82     dns=[]
  83     if "DNS1" in kvp :
  84         dns+=[kvp["DNS1"]]
  85         if "DNS2" in kvp :
  86             dns+=[kvp["DNS2"]]
  87             if "DNS3" in kvp :
  88                 dns+=[kvp["DNS3"]]
  89
  90
  91     # No real max for the number of interface + aliases ...
  92     # only required is the address (but mate everything up that comes in.
  93
  94     # IPv4
  95     v4names=[name for name in kvp.keys() if name.startswith("IPADDR")]
  96     v4names.sort()
  97
  98     if_count=0
  99     for v4 in v4names:
 100         ifname=basename
 101         suffix=""
 102         if if_count :
 103             ifname+=":" + str(if_count)
 104             suffix="_"+str(if_count)
 105         if not ifname in autolist:
 106             autolist += [ifname]
 107         output += [ "iface " + ifname + " inet static"]
 108         output += [ "\t" + "address " + kvp[v4]]
 109         if "NETMASK"+suffix in kvp.keys():
 110             output += ["\tnetmask " + kvp["NETMASK"+suffix]]
 111         if "GATEWAY"+suffix in kvp.keys():
 112             output += ["\tgateway " + kvp["GATEWAY"+suffix]]
 113         if not if_count :
 114             output += ["\tdns-nameservers " + ' '.join(dns)]
 115         output += [""]
 116         if_count+=1
 117
 118
 119     # IPv6 requires a netmask
 120     # If an ipv6 exists, you'll want to turn off /proc/sys/net/ipv6/conf/all/autoconf with
 121     # echo 0 > /proc/sys/net/ipv6/conf/all/autoconf
 122     v6names=[name for name in kvp.keys() if name.startswith("IPV6ADDR")]
 123     v6names.sort()
 124
 125     if6_count=0
 126     if6_used=0
 127     for v6 in v6names:
 128         ifname=basename
 129         suffix=""
 130         if if6_used :
 131             ifname+=":" + str(if6_used)
 132         if if6_count :
 133             suffix="_" + str(if6_count)
 134         if not ifname in autolist:
 135             autolist += [ifname]
 136         if "IPV6NETMASK"+suffix in kvp.keys():
 137             output += [ "iface " + ifname + " inet6 static"]
 138             output += [ "\taddress " + kvp[v6]]
 139             output += [ "\tnetmask " + kvp["IPV6NETMASK"+suffix]]
 140             if "IPV6_DEFAULTGW"+suffix in kvp.keys():
 141                 output += [ "\tgateway " + kvp["IPV6_DEFAULTGW"+suffix] ]
 142             if not if_count :
 143                 output += ["\tdns-nameservers " + ' '.join(dns)]
 144             output += [""]
 145             if_count += 1
 146             if6_used += 1
 147         if6_count += 1
 148
 149     # Mark this new interface for automatic up.
 150     output = ["auto "+" ".join(autolist)] + output
 151
 152 print("===================================")
 153 print(output)
 154 print("===================================")
 155
 156
 157 ''' Time to clean out the existing interface file'''
 158
 159 # Markers.
 160 start_mark = "# The following stanza(s) added by hv_set_ifconfig"
 161 end_mark = "#End of hv_set_ifconfig stanzas"
 162
 163 f=open(if_filename,"r")
 164 flines=f.readlines()
 165 f.close()
 166 newfile=[]
 167 pitchstanza=0
 168 inastanza=0
 169 stanza=[]
 170 prev_line=None
 171 for line in flines:
 172     if line.startswith("auto"):
 173         if inastanza:
 174             if not pitchstanza:
 175                 newfile.extend(stanza)
 176             stanza=[]
 177         inastanza=0
 178         newline=""
 179         autoline=line.strip().split(" ")
 180         for word in autoline:
 181             if (not word == basename) and (not word.startswith(basename+":")):
 182                 newline+=word + " "
 183         newline = newline.strip()
 184         if not newline == "auto":
 185             newfile += [newline.strip()]
 186     elif line.startswith(("iface","mapping","source")):
 187         '''Read a stanza'''
 188         '''A Stanza can also start with allow- ie allow-hotplug'''
 189         if inastanza:
 190             if not pitchstanza:
 191                 newfile.extend(stanza)
 192             stanza=[]
 193         inastanza=1
 194         pitchstanza=0
 195         autoline=line.strip().split(" ")
 196         for word in autoline:
 197             if (word == basename) or (word.startswith(basename+":")):
 198                 pitchstanza=1
 199         if not pitchstanza:
 200             stanza+=[line.strip()]
 201     elif line.strip() in (start_mark, end_mark):
 202         if inastanza:
 203             if not pitchstanza:
 204                 newfile.extend(stanza)
 205             stanza=[]
 206         inastanza = 0
 207         pitchstanza = 0
 208         # Deduplicate markers.
 209         if line != prev_line:
 210             newfile += [line.strip()]
 211     else:
 212         if inastanza:
 213             if not pitchstanza:
 214                 stanza+=[line.strip()]
 215         else:
 216             if not pitchstanza:
 217                 newfile += [line.strip()]
 218     prev_line=line
 219
 220
 221
 222 def emit(line):
 223     print(line)
 224     output = line + "\n"
 225     os.write(fd, output.encode('utf-8'))
 226
 227 # Insert the new output at the end and inside the existing markers if found.
 228 emitted = False
 229 fd, path = tempfile.mkstemp()
 230 for line in newfile:
 231     if line == end_mark:
 232         emit("\n".join(output))
 233         emitted = True
 234     emit(line)
 235 if not emitted:
 236     emit(start_mark)
 237     emit("\n".join(output))
 238     emit(end_mark)
 239 os.close(fd)
 240
 241 shutil.copy(path,if_filename)
 242 os.chmod(if_filename,0o644)
 243
 244 #print("TMPFILE is at: " + path)
 245 #print("Copied file is at: " + if_filename)
 246
 247 try:
 248     retcode = subprocess.call("ifdown "+basename , shell=True)
 249     if retcode < 0:
 250         print("Child was terminated by signal", -retcode, file=sys.stderr)
 251     else:
 252         print("Child returned", retcode, file=sys.stderr)
 253 except OSError as e:
 254     print("Execution failed:", e, file=sys.stderr)
 255
 256 try:
 257     retcode = subprocess.call("ifup "+basename , shell=True)
 258     if retcode < 0:
 259         print("Child was terminated by signal", -retcode, file=sys.stderr)
 260     else:
 261         print("Child returned", retcode, file=sys.stderr)
 262 except OSError as e:
 263     print("Execution failed:", e, file=sys.stderr)