Allow users to set hdfs_namenode_principal in HDFSHook config

snakebite library just added the support to specify hdfs_namenode_principal
for Kerberos auth method, and this PR allows users to pass in this config from HDFSHook

Also bump the version of snakebite

airflow/hooks/hdfs_hook.py

@@ -47,11 +47,15 @@ class HDFSHook(BaseHook):
             if autoconfig:
                 client = AutoConfigClient(effective_user=effective_user, use_sasl=use_sasl)
             else:
+                hdfs_namenode_principal = connections[0].extra_dejson.get('hdfs_namenode_principal')
                 client = Client(connections[0].host, connections[0].port,
-                                effective_user=effective_user, use_sasl=use_sasl)
+                                effective_user=effective_user, use_sasl=use_sasl,
+                                hdfs_namenode_principal=hdfs_namenode_principal)
         elif len(connections) > 1:
+            hdfs_namenode_principal = connections[0].extra_dejson.get('hdfs_namenode_principal')
             nn = [Namenode(conn.host, conn.port) for conn in connections]
-            client = HAClient(nn, effective_user=effective_user, use_sasl=use_sasl)
+            client = HAClient(nn, effective_user=effective_user, use_sasl=use_sasl,
+                              hdfs_namenode_principal=hdfs_namenode_principal)
         else:
             raise HDFSHookException("conn_id doesn't exist in the repository")
         

setup.py

@@ -61,7 +61,7 @@ gcp_api = [
     'google-api-python-client<=1.4.2',
     'oauth2client>=1.5.2, <2.0.0',
 ]
-hdfs = ['snakebite>=2.4.13']
+hdfs = ['snakebite>=2.7.8']
 webhdfs = ['hdfs[dataframe,avro,kerberos]>=2.0.4']
 hive = [
     'hive-thrift-py>=0.0.1',
@@ -83,7 +83,10 @@ slack = ['slackclient>=1.0.0']
 statsd = ['statsd>=3.0.1, <4.0']
 vertica = ['vertica-python>=0.5.1']
 ldap = ['ldap3>=0.9.9.1']
-kerberos = ['pykerberos>=1.1.8']
+kerberos = [
+    'pykerberos>=1.1.8',
+    'snakebite[kerberos]>=2.7.8'
+]
 password = [
     'bcrypt>=2.0.0',
     'flask-bcrypt>=0.7.1',