Merge branch 'baserock/sam/deploy-kvm-check'

Reviewed-By: Lars Wirzenius <lars.wirzenius@codethink.co.uk>

4 files changed, 60 insertions, 12 deletions

diff --git a/morphlib/exts/kvm.check b/morphlib/exts/kvm.check
index be7c51c2..957d0893 100755
--- a/morphlib/exts/kvm.check
+++ b/morphlib/exts/kvm.check
@@ -17,11 +17,16 @@
 '''Preparatory checks for Morph 'kvm' write extension'''
 
 import cliapp
+import re
+import urlparse
 
 import morphlib.writeexts
 
 
 class KvmPlusSshCheckExtension(morphlib.writeexts.WriteExtension):
+
+    location_pattern = '^/(?P<guest>[^/]+)(?P<path>/.+)$'
+
     def process_args(self, args):
         if len(args) != 1:
             raise cliapp.AppException('Wrong number of command line args')
@@ -32,4 +37,46 @@ class KvmPlusSshCheckExtension(morphlib.writeexts.WriteExtension):
                 'Use the `ssh-rsync` write extension to deploy upgrades to an '
                 'existing remote system.')
 
+        location = args[0]
+        ssh_host, vm_name, vm_path = self.check_and_parse_location(location)
+
+        self.check_ssh_connectivity(ssh_host)
+        self.check_no_existing_libvirt_vm(ssh_host, vm_name)
+        self.check_extra_disks_exist(ssh_host, self.parse_attach_disks())
+
+    def check_and_parse_location(self, location):
+        '''Check and parse the location argument to get relevant data.'''
+
+        x = urlparse.urlparse(location)
+
+        if x.scheme != 'kvm+ssh':
+            raise cliapp.AppException(
+                'URL schema must be kvm+ssh in %s' % location)
+
+        m = re.match(self.location_pattern, x.path)
+        if not m:
+            raise cliapp.AppException('Cannot parse location %s' % location)
+
+        return x.netloc, m.group('guest'), m.group('path')
+
+    def check_no_existing_libvirt_vm(self, ssh_host, vm_name):
+        try:
+            cliapp.ssh_runcmd(ssh_host,
+                ['virsh', '--connect', 'qemu:///system', 'domstate', vm_name])
+        except cliapp.AppException as e:
+            pass
+        else:
+            raise cliapp.AppException(
+                'Host %s already has a VM named %s. You can use the ssh-rsync '
+                'write extension to deploy upgrades to existing machines.' %
+                (ssh_host, vm_name))
+
+    def check_extra_disks_exist(self, ssh_host, filename_list):
+        for filename in filename_list:
+            try:
+                cliapp.ssh_runcmd(ssh_host, ['ls', filename])
+            except cliapp.AppException as e:
+                raise cliapp.AppException('Did not find file %s on host %s' %
+                                          (filename, ssh_host))
+
 KvmPlusSshCheckExtension().run()
diff --git a/morphlib/exts/kvm.write b/morphlib/exts/kvm.write
index 94560972..94a55daa 100755
--- a/morphlib/exts/kvm.write
+++ b/morphlib/exts/kvm.write
@@ -50,6 +50,8 @@ class KvmPlusSshWriteExtension(morphlib.writeexts.WriteExtension):
     
     '''
 
+    location_pattern = '^/(?P<guest>[^/]+)(?P<path>/.+)$'
+
     def process_args(self, args):
         if len(args) != 2:
             raise cliapp.AppException('Wrong number of command line args')
@@ -79,14 +81,9 @@ class KvmPlusSshWriteExtension(morphlib.writeexts.WriteExtension):
 
     def parse_location(self, location):
         '''Parse the location argument to get relevant data.'''
-        
+
         x = urlparse.urlparse(location)
-        if x.scheme != 'kvm+ssh':
-            raise cliapp.AppException(
-                'URL schema must be vbox+ssh in %s' % location)
         m = re.match('^/(?P<guest>[^/]+)(?P<path>/.+)$', x.path)
-        if not m:
-            raise cliapp.AppException('Cannot parse location %s' % location)
         return x.netloc, m.group('guest'), m.group('path')
 
     def transfer(self, raw_disk, ssh_host, vm_path):
diff --git a/morphlib/exts/nfsboot.check b/morphlib/exts/nfsboot.check
index f84f187f..806e560a 100755
--- a/morphlib/exts/nfsboot.check
+++ b/morphlib/exts/nfsboot.check
@@ -56,12 +56,7 @@ class NFSBootCheckExtension(morphlib.writeexts.WriteExtension):
                 version_label, location))
 
     def test_good_server(self, server):
-        # Can be ssh'ed into
-        try:
-            cliapp.ssh_runcmd('root@%s' % server, ['true'])
-        except cliapp.AppException:
-            raise cliapp.AppException('You are unable to ssh into server %s'
-                                      % server)
+        self.check_ssh_connectivity(server)
 
         # Is an NFS server
         try:
diff --git a/morphlib/writeexts.py b/morphlib/writeexts.py
index bff21e8d..3f9c33d5 100644
--- a/morphlib/writeexts.py
+++ b/morphlib/writeexts.py
@@ -15,6 +15,7 @@
 
 
 import cliapp
+import logging
 import os
 import re
 import shutil
@@ -417,3 +418,11 @@ class WriteExtension(cliapp.Application):
         else:
             raise cliapp.AppException('Unexpected value for %s: %s' %
                                       (variable, value))
+
+    def check_ssh_connectivity(self, ssh_host):
+        try:
+            cliapp.ssh_runcmd(ssh_host, ['true'])
+        except cliapp.AppException as e:
+            logging.error("Error checking SSH connectivity: %s", str(e))
+            raise cliapp.AppException(
+                'Unable to SSH to %s: %s' % (ssh_host, e))