Merge lp:~cbehrens/nova/lp741246 into lp:~hudson-openstack/nova/trunk

[Chris Behrens]

Fixes bug 741246. Ed Leafe's inject_file method for the agent plugin was mistakenly never committed after having to fix commits under wrong email address. vmops makes calls to this (previously) missing method.

[Ed Leafe (ed-leafe)]

The uuid module is not available in Python 2.4, which is what plugins will run under. So change the 'import uuid' line (diff #16) to 'import commands', and then change diff line #96 from:

tmp_id = str(uuid.uuid4())

to:

tmp_id = commands.getoutput("uuidgen")

review: Needs Fixing

[Ed Leafe (ed-leafe)]

lgtm

review: Approve

[Josh Kearney (jk0)]

lgtm

review: Approve

=== modified file 'plugins/xenserver/xenapi/etc/xapi.d/plugins/agent'
--- plugins/xenserver/xenapi/etc/xapi.d/plugins/agent	2011-02-17 22:09:26 +0000
+++ plugins/xenserver/xenapi/etc/xapi.d/plugins/agent	2011-03-31 16:03:33 +0000
@@ -22,6 +22,8 @@
 # XenAPI plugin for reading/writing information to xenstore
 #
 
+import base64
+import commands
 try:
     import json
 except ImportError:
@@ -66,7 +68,7 @@
     try:
         resp = _wait_for_agent(self, request_id, arg_dict)
     except TimeoutError, e:
-        raise PluginError("%s" % e)
+        raise PluginError(e)
     return resp
 
 
@@ -87,7 +89,7 @@
     try:
         resp = _wait_for_agent(self, request_id, arg_dict)
     except TimeoutError, e:
-        raise PluginError("%s" % e)
+        raise PluginError(e)
     return resp
 
 
@@ -102,6 +104,75 @@
     xenstore.write_record(self, arg_dict)
 
 
+@jsonify
+def inject_file(self, arg_dict):
+    """Expects a file path and the contents of the file to be written. Both
+    should be base64-encoded in order to eliminate errors as they are passed
+    through the stack. Writes that information to xenstore for the agent,
+    which will decode the file and intended path, and create it on the
+    instance. The original agent munged both of these into a single entry;
+    the new agent keeps them separate. We will need to test for the new agent,
+    and write the xenstore records to match the agent version. We will also
+    need to test to determine if the file injection method on the agent has
+    been disabled, and raise a NotImplemented error if that is the case.
+    """
+    b64_path = arg_dict["b64_path"]
+    b64_file = arg_dict["b64_file"]
+    request_id = arg_dict["id"]
+    if self._agent_has_method("file_inject"):
+        # New version of the agent.  Agent should receive a 'value'
+        # key whose value is a dictionary containing 'b64_path' and
+        # 'b64_file'.  See old version below.
+        arg_dict["value"] = json.dumps({"name": "file_inject",
+                "value": {"b64_path": b64_path, "b64_file": b64_file}})
+    elif self._agent_has_method("injectfile"):
+        # Old agent requires file path and file contents to be
+        # combined into one base64 value.
+        raw_path = base64.b64decode(b64_path)
+        raw_file = base64.b64decode(b64_file)
+        new_b64 = base64.b64encode("%s,%s") % (raw_path, raw_file)
+        arg_dict["value"] = json.dumps({"name": "injectfile",
+                "value": new_b64})
+    else:
+        # Either the methods don't exist in the agent, or they
+        # have been disabled.
+        raise NotImplementedError(_("NOT IMPLEMENTED: Agent does not"
+                " support file injection."))
+    arg_dict["path"] = "data/host/%s" % request_id
+    xenstore.write_record(self, arg_dict)
+    try:
+        resp = _wait_for_agent(self, request_id, arg_dict)
+    except TimeoutError, e:
+        raise PluginError(e)
+    return resp
+
+
+def _agent_has_method(self, method):
+    """Check that the agent has a particular method by checking its
+    features.  Cache the features so we don't have to query the agent
+    every time we need to check.
+    """
+    try:
+        self._agent_methods
+    except AttributeError:
+        self._agent_methods = []
+    if not self._agent_methods:
+        # Haven't been defined
+        tmp_id = commands.getoutput("uuidgen")
+        dct = {}
+        dct["value"] = json.dumps({"name": "features", "value": ""})
+        dct["path"] = "data/host/%s" % tmp_id
+        xenstore.write_record(self, dct)
+        try:
+            resp = _wait_for_agent(self, tmp_id, dct)
+        except TimeoutError, e:
+            raise PluginError(e)
+        response = json.loads(resp)
+        # The agent returns a comma-separated list of methods.
+        self._agent_methods = response.split(",")
+    return method in self._agent_methods
+
+
 def _wait_for_agent(self, request_id, arg_dict):
     """Periodically checks xenstore for a response from the agent.
     The request is always written to 'data/host/{id}', and
@@ -119,9 +190,8 @@
             # First, delete the request record
             arg_dict["path"] = "data/host/%s" % request_id
             xenstore.delete_record(self, arg_dict)
-            raise TimeoutError(
-                    "TIMEOUT: No response from agent within %s seconds." %
-                    AGENT_TIMEOUT)
+            raise TimeoutError(_("TIMEOUT: No response from agent within"
+                    " %s seconds.") % AGENT_TIMEOUT)
         ret = xenstore.read_record(self, arg_dict)
         # Note: the response for None with be a string that includes
         # double quotes.
@@ -136,4 +206,5 @@
     XenAPIPlugin.dispatch(
         {"key_init": key_init,
         "password": password,
-        "resetnetwork": resetnetwork})
+        "resetnetwork": resetnetwork,
+        "inject_file": inject_file})