Add support for ssh keys in cloud-config. move write_file to util.

----
#cloud-config
apt_update: true
ssh_keys:
  rsa_private: |
    -----BEGIN RSA PRIVATE KEY-----
    MIIBxwIBAAJhAKD0YSHy73nUgysO13XsJmd4fHiFyQ+00R7VVu2iV9Qcon2LZS/x
    ...
    REPPOyrAspdeOAV+6VKRavstea7+2DZmSUgE
    -----END RSA PRIVATE KEY-----

  rsa_public: ssh-rsa AAAAB3NzaC1yc2E...18QJvWPocKJtlsDNi3 smoser@host

  dsa_private: |
    -----BEGIN DSA PRIVATE KEY-----
    MIIBuwIBAAKBgQDP2HLu7pTExL89USyM0264RCyWX/CMLmukxX0Jdbm29ax8FBJT
    ...
    8KucvUYbOEI+yv+5LW9u3z/BAoGBAI0q6JP+JvJmwZFaeCMMVxXUbqiSko/P1lsa
    -----END DSA PRIVATE KEY-----

  dsa_public: ssh-dss AAAAB3NzaC1kc3M...ybngIy66PMEoQ= smoser@host
----

1 files changed, 11 insertions, 4 deletions

diff --git a/ec2init/CloudConfig.py b/ec2init/CloudConfig.py
index 17a14363..d6947ce1 100644
--- a/ec2init/CloudConfig.py
+++ b/ec2init/CloudConfig.py
@@ -158,11 +158,18 @@ class CloudConfig():
             try: os.unlink(f)
             except: pass
 
-        if False:
+        if self.cfg.has_key("ssh_keys"):
             # if there are keys in cloud-config, use them
-            # TODO: need to get keys from cloud-config if present
-            # and replace those in /etc/ssh
-            pass
+            key2file = {
+                "rsa_private" : ("/etc/ssh/ssh_host_rsa_key", 0600),
+                "rsa_public"  : ("/etc/ssh/ssh_host_rsa_key.pub", 0644),
+                "dsa_private" : ("/etc/ssh/ssh_host_dsa_key", 0600),
+                "dsa_public"  : ("/etc/ssh/ssh_host_dsa_key.pub", 0644)
+            }
+
+            for key,val in self.cfg["ssh_keys"].items():
+                if key2file.has_key(key):
+                    util.write_file(key2file[key][0],val,key2file[key][1])
         else:
             # if not, generate them
             genkeys ='ssh-keygen -f /etc/ssh/ssh_host_rsa_key -t rsa -N ""; '