s1ap_proxy: use Global-ENB-ID as logging prefix

Change-Id: Ib3584237e60274c0276e750728b2bb2950f376a4
---
M src/s1ap_proxy.erl
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/s1ap_proxy.erl b/src/s1ap_proxy.erl
index bf5f849..66d558d 100644
--- a/src/s1ap_proxy.erl
+++ b/src/s1ap_proxy.erl
@@ -171,6 +171,11 @@
 %% private API
 %% ------------------------------------------------------------------
 
+-spec set_logging_prefix(string()) -> ok.
+set_logging_prefix(Prefix) when is_list(Prefix) ->
+    logger:set_process_metadata(#{prefix => Prefix}).
+
+
 -spec erab_uid(erab_id(), proxy_state()) -> erab_uid().
 erab_uid(ERABId, #proxy_state{mme_ue_id = MmeUeId,
                               enb_ue_id = EnbUeId}) ->
@@ -228,6 +233,12 @@
 parse_enb_id({'long-macroENB-ID', << ID:21 >>}) -> ID.
 
 
+-spec genb_id_str(proxy_state()) -> string().
+genb_id_str(#proxy_state{plmn_id = {MCC, MNC},
+                         enb_id = ENBId}) ->
+    MCC ++ "-" ++ MNC ++ "-" ++ integer_to_list(ENBId).
+
+
 %% Encode an S1AP PDU
 -spec encode_pdu(s1ap_pdu()) -> {ok, binary()} |
                                 {error, {asn1, tuple()}}.
@@ -586,12 +597,13 @@
           #'Global-ENB-ID'{'pLMNidentity' = PLMNId,
                            'eNB-ID' = ENBId} = C, S0) ->
     %% store PLMNId/ENBId
-    %% TODO: use that as a context for logging
     S1 = S0#proxy_state{plmn_id = parse_plmn_id(PLMNId),
                         enb_id = parse_enb_id(ENBId)},
     ?LOG_INFO("Global-ENB-ID: PLMN-ID=~p, eNB-ID=~p",
               [S1#proxy_state.plmn_id,
                S1#proxy_state.enb_id]),
+    %% use that as a context for logging
+    set_logging_prefix("eNB " ++ genb_id_str(S1)),
     {{ok, C}, S1};
 
 %% E-RAB SETUP REQUEST related IEs

