Reading kv-store-prefix from ENV

Change-Id: I50c57fc473fab0385e0ac120d03d584e97046df7
diff --git a/VERSION b/VERSION
index da6b0a8..35d16fb 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.5.6
+2.5.7
diff --git a/pyvoltha/common/tech_profile/tech_profile.py b/pyvoltha/common/tech_profile/tech_profile.py
index 162b476..706a685 100644
--- a/pyvoltha/common/tech_profile/tech_profile.py
+++ b/pyvoltha/common/tech_profile/tech_profile.py
@@ -14,6 +14,9 @@
 # limitations under the License.
 #
 from __future__ import absolute_import
+
+import os
+
 import json
 import ast
 from collections import namedtuple
@@ -127,7 +130,13 @@
     pbits = ['0b11111111']
 
     # Tech profile path prefix in kv store
-    KV_STORE_TECH_PROFILE_PATH_PREFIX = 'service/voltha/technology_profiles'
+    if "KV_STORE_DATAPATH_PREFIX" in os.environ:
+        kv_store_prefix = os.environ["KV_STORE_DATAPATH_PREFIX"]
+    else:
+        kv_store_prefix = "service/voltha"
+    KV_STORE_TECH_PROFILE_PATH_PREFIX = '%s/technology_profiles' % kv_store_prefix
+
+    log.debug("kv-store-tech-profile-prefix", kv_store_tech_profile_prefix=KV_STORE_TECH_PROFILE_PATH_PREFIX)
 
     # Tech profile path in kv store
     TECH_PROFILE_PATH = '{}/{}'  # <technology>/<table_id>
diff --git a/requirements.txt b/requirements.txt
index b49f951..67751ba 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -18,4 +18,4 @@
 structlog==19.2.0
 transitions==0.6.4
 txaioetcd==0.3.0
-voltha-protos==3.4.2
+voltha-protos==4.0.5