ssh-config: handle cases where there is no IdentityFile

In some cases there may be no IdentityFile you are using to ssh into
the guest (one example is using AWS provider and the remote AMI already
has the user's SSH key embedded in it by the cloud provider). Handle
this case.

Thanks to Michael P Reilly (https://github.com/arcege) for providing
this patch in the issue (#78).

Fixes #78.

lib/vagrant-sshfs/cap/guest/linux/sshfs_forward_mount.rb

@@ -206,13 +206,18 @@ def self.sshfs_slave_mount(machine, opts, hostpath, expanded_guest_path)
           sshfs_cmd+= sshfs_opts + ' ' + sshfs_opts_append + ' '
 
           # The ssh command to connect to guest and then launch sshfs
-          # Note the backslash escapes for IdentityFile - handles spaces in key path
           ssh_opts = opts[:ssh_opts]
           ssh_opts+= ' -o User=' + machine.ssh_info[:username]
           ssh_opts+= ' -o Port=' + machine.ssh_info[:port].to_s
-          ssh_opts+= ' -o "IdentityFile=\"' + machine.ssh_info[:private_key_path][0] + '\""'
           ssh_opts+= ' -o UserKnownHostsFile=/dev/null '
           ssh_opts+= ' -F /dev/null ' # Don't pick up options from user's config
+          if machine.ssh_info.key?(:private_key_path) and
+             machine.ssh_info[:private_key_path] and
+             machine.ssh_info[:private_key_path][0]
+             # Add IdentityFile since there is one
+             # Note the backslash escapes for IdentityFile - handles spaces in key path
+            ssh_opts+= ' -o "IdentityFile=\"' + machine.ssh_info[:private_key_path][0] + '\""'
+          end
 
           # Use an SSH ProxyCommand when corresponding Vagrant setting is defined
           if machine.ssh_info[:proxy_command]

lib/vagrant-sshfs/cap/host/darwin/sshfs_reverse_mount.rb

@@ -74,6 +74,13 @@ def self.sshfs_mount(machine, opts)
           ssh_opts+= ' -o "IdentityFile=\"' + machine.ssh_info[:private_key_path][0] + '\""'
           ssh_opts+= ' -o UserKnownHostsFile=/dev/null '
           ssh_opts+= ' -F /dev/null ' # Don't pick up options from user's config
+          if machine.ssh_info.key?(:private_key_path) and
+             machine.ssh_info[:private_key_path] and
+             machine.ssh_info[:private_key_path][0]
+             # Add IdentityFile since there is one
+             # Note the backslash escapes for IdentityFile - handles spaces in key path
+            ssh_opts+= ' -o "IdentityFile=\"' + machine.ssh_info[:private_key_path][0] + '\""'
+          end
 
           ssh_opts_append = opts[:ssh_opts_append].to_s # provided by user
 

lib/vagrant-sshfs/cap/host/linux/sshfs_reverse_mount.rb

@@ -67,12 +67,17 @@ def self.sshfs_mount(machine, opts)
           opts[:ssh_opts]+= ' -o ServerAliveInterval=30 '  # send keepalives
 
           # SSH connection options
-          # Note the backslash escapes for IdentityFile - handles spaces in key path
           ssh_opts = opts[:ssh_opts]
           ssh_opts+= ' -o Port=' + machine.ssh_info[:port].to_s
-          ssh_opts+= ' -o "IdentityFile=\"' + machine.ssh_info[:private_key_path][0] + '\""'
           ssh_opts+= ' -o UserKnownHostsFile=/dev/null '
           ssh_opts+= ' -F /dev/null ' # Don't pick up options from user's config
+          if machine.ssh_info.key?(:private_key_path) and
+             machine.ssh_info[:private_key_path] and
+             machine.ssh_info[:private_key_path][0]
+             # Add IdentityFile since there is one
+             # Note the backslash escapes for IdentityFile - handles spaces in key path
+            ssh_opts+= ' -o "IdentityFile=\"' + machine.ssh_info[:private_key_path][0] + '\""'
+          end
 
           ssh_opts_append = opts[:ssh_opts_append].to_s # provided by user