new: [monujo] make relation to ``odoo-server`` optional

Signed-off-by: Valentin Lab <valentin.lab@kalysto.org>

monujo/hooks/pre_deploy

@@ -5,6 +5,7 @@
 
 set -e
 
+if service:traverse "${SERVICE_NAME}":odoo-server >/dev/null; then
     if ! url=$(relation:get "${SERVICE_NAME}":odoo-server:web-proxy url); then
         err "Monujo doesn't support odoo-server not having a web-proxy yet."
         exit 1
@@ -13,11 +14,12 @@ if ! dbname=$(relation:get "${SERVICE_NAME}":odoo-server:postgres-database dbnam
         err "Can't find db name of our odoo-server relation."
         exit 1
     fi
-
     monujo:config_merge "{
       \"lokapiHost\": \"$url\",
       \"lokapiDb\": \"$dbname\"
     }"
+fi
+
 
 
 if map_url=$(relation:get "${SERVICE_NAME}":map-server:publish-dir url); then

monujo/metadata.yml

@@ -18,7 +18,7 @@ uses:
   odoo-server:
     #constraint: required | recommended | optional
     #auto: pair | summon | none ## default: pair
-    constraint: required
+    constraint: optional
     auto: pair
     solves:
       container: "LCC API provider"