Implement basic netplan support

Start with single links, ipv4 only for ubuntu.

confluent_osdeploy/common/profile/scripts/confignet

@@ -8,6 +8,10 @@ import sys
 import time
 import shlex
 import subprocess
+try:
+    import yaml
+except ImportError:
+    pass
 try:
     from importlib.machinery import SourceFileLoader
     def load_source(mod, path):
@@ -107,6 +111,80 @@ def get_interface_name(iname, settings):
         return iname
     return None
 
+class NetplanManager(object):
+    def __init__(self):
+        self.cfgbydev = {}
+        self.read_connections()
+
+    def read_connections(self):
+        for plan in glob.glob('/etc/netplan/*.y*ml'):
+            with open(plan) as planfile:
+                planinfo = yaml.safe_load(planfile)
+                if not planinfo:
+                    continue
+            nicinfo = planinfo.get('network', {}).get('ethernets', {})
+            for devname in nicinfo:
+                if devname == 'lo':
+                    continue
+                if 'gateway4' in nicinfo[devname]:
+                    # normalize deprecated syntax on read in
+                    gw4 = nicinfo[devname]['gateway4']
+                    del nicinfo[devname]['gateway4']
+                    routeinfo = nicinfo[devname].get('routes', [])
+                    for ri in routeinfo:
+                        if ri.get('via', None) == gw4 and ri.get('to', None) in ('default', '0.0.0.0/0', '0/0'):
+                            break
+                    else:
+                        routeinfo.append({
+                            'to': 'default',
+                            'via': gw4
+                        })
+                    nicinfo[devname]['routes'] = routeinfo
+                self.cfgbydev[devname] = nicinfo[devname]
+    
+    def apply_configuration(self, cfg):
+        devnames = cfg['interfaces']
+        if len(devnames) != 1:
+            raise Exception('Multi-nic team/bonds not yet supported')
+        stgs = cfg['settings']
+        needcfgapply = False
+        for devname in devnames:
+            needcfgwrite = False
+            if stgs['ipv4_method'] == 'static':
+                curraddr = stgs['ipv4_address']
+                currips = self.getcfgarrpath([devname, 'addresses'])
+                if curraddr not in currips:
+                    needcfgwrite = True
+                    currips.append(curraddr)
+            gwaddr = stgs.get('ipv4_gateway', None)
+            if gwaddr:
+                cfgroutes = self.getcfgarrpath([devname, 'routes'])
+                for rinfo in cfgroutes:
+                    if rinfo.get('via', None) == gwaddr:
+                        break
+                else:
+                    needcfgwrite = True
+                    cfgroutes.append({'via': gwaddr, 'to': 'default'})
+            if needcfgwrite:
+                needcfgaply = True
+                newcfg = {'network': {'version': 2, 'ethernets': {devname: self.cfgbydev[devname]}}}
+                with open('/etc/netplan/{0}-confluentcfg.yaml'.format(devname), 'w') as planout:
+                    planout.write(yaml.dump(newcfg))
+        if needcfgapply:
+            subprocess.call(['netplan', 'apply'])
+
+    def getcfgarrpath(self, devpath):
+        currptr = self.cfgbydev
+        for k in devpath[:-1]:
+            if k not in currptr:
+                currptr[k] = {}
+            currptr = currptr[k]
+        if devpath[-1] not in currptr:
+            currptr[devpath[-1]] = []
+        return currptr[devpath[-1]]
+        
+
+
 class WickedManager(object):
     def __init__(self):
         self.teamidx = 0
@@ -360,6 +438,8 @@ if __name__ == '__main__':
         if not netname_to_interfaces['default']['interfaces']:
             del netname_to_interfaces['default']
     rm_tmp_llas(tmpllas)
+    if os.path.exists('/usr/sbin/netplan'):
+        nm = NetplanManager()
     if os.path.exists('/usr/bin/nmcli'):
         nm = NetworkManager(devtypes)
     elif os.path.exists('/usr/sbin/wicked'):