[autotest] Drop compatibility for the old dut-status.

This is the last of three stages to update the RPC API for special
tasks.  This change drops the compatibility behaviors from the
get_special_tasks() RPC call.

This change cannot be pushed to prod until all old versions of
dut-status have been updated.

BUG=None
TEST=Test dut-status on a local instance using the prod database

Change-Id: I2680f2541c363975518b0fbe33f9bc312236ec8c
Reviewed-on: https://chromium-review.googlesource.com/265575
Reviewed-by: Fang Deng <fdeng@chromium.org>
Tested-by: Richard Barnette <jrbarnette@chromium.org>
Reviewed-by: Dan Shi <dshi@chromium.org>
Reviewed-by: Mungyung Ryu <mkryu@google.com>
Commit-Queue: Richard Barnette <jrbarnette@chromium.org>
diff --git a/frontend/afe/rpc_utils.py b/frontend/afe/rpc_utils.py
index 25196e6..dafa432 100644
--- a/frontend/afe/rpc_utils.py
+++ b/frontend/afe/rpc_utils.py
@@ -1178,92 +1178,17 @@
 
 
 def get_global_afe_hostname():
-    """Reads the hostname of the global AFE from the global configuration."""
+    """Read the hostname of the global AFE from the global configuration."""
     return global_config.global_config.get_config_value(
             'SHARD', 'global_afe_hostname')
 
 
 def route_rpc_to_master(rpc_name, **kwargs):
-    """Routes RPC to master AFE.
+    """Route RPC to master AFE.
 
     @param rpc_name: The name of the rpc.
     @param **kwargs: The kwargs for the rpc.
+
     """
     master_afe = frontend.AFE(server=get_global_afe_hostname())
     return master_afe.run(rpc_name, **kwargs)
-
-
-def pack_in_list(obj, list):
-    """Packs objects into a list appropriately.
-
-    @param obj:  An object to insert into a list
-    @param list: List that will contain the input object.
-    """
-    if obj is None or not obj:
-        return
-    # In python 2.x, string does not have __iter__ attribute
-    # while it does in python 3.x.
-    # Check string type first to be safe.
-    if isinstance(obj, basestring):
-        list.append(obj)
-    elif hasattr(obj, '__iter__'):
-        list.extend(obj)
-    else:
-        list.append(obj)
-
-
-def get_from_shards(shard_hostnames, rpc_name, **kwargs):
-    """Gets data via RPC to shards.
-
-    @param shard_hostnames: Host names for shards
-    @param rpc_name:        Name of the RPC endpoint to call.
-    @param **kwargs:        Keyword arguments to pass in the RPCs.
-    @return: List of all RPC results from the shards.
-    """
-    results = list()
-    for shard in shard_hostnames:
-        afe = frontend.AFE(server=shard)
-        pack_in_list(afe.run(rpc_name, **kwargs), results)
-    return results
-
-
-def get_data(serialized_db_access_func, rpc_name, **kwargs):
-    """Gets data according to the role of a node (master/shard).
-
-    Master:
-    When |kwargs| has host_id and the host is in a shard,
-    calls |rpc_name| to the shard, and gets the result.
-    When |kwargs| doesn't have host info, contacts all shards.
-    Retrieves data from local DB and coalesces them with results
-    from shards.
-
-    Shard:
-    Retrieves data from local DB.
-
-    @param serialized_db_access_func: Function object that access local
-           DB and serialize returned records.
-    @param rpc_name: Name of the RPC endpoint to call.
-    @param **kwargs: Keyword arguments to pass in the RPCs.
-    @return: List of objects
-    """
-    results = list()
-    pack_in_list(serialized_db_access_func(**kwargs), results)
-
-    if not server_utils.is_shard():
-        shard_hostnames = list()
-
-        if 'host_id' in kwargs:
-            host_objs = [models.Host.smart_get(kwargs['host_id'])]
-            shard_host_map = bucket_hosts_by_shard(host_objs, True)
-            shard_hostnames.extend(shard_host_map.keys())
-        elif 'host_id__in' in kwargs:
-            host_objs = models.Host.smart_get_bulk(kwargs['host_id__in'])
-            shard_host_map = bucket_hosts_by_shard(host_objs, True)
-            shard_hostnames.extend(shard_host_map.keys())
-        else:
-            for shard in models.Shard.objects.all():
-                shard_hostnames.append(shard.rpc_hostname())
-
-        pack_in_list(get_from_shards(
-                shard_hostnames, rpc_name, **kwargs), results)
-    return results