Merge 'v1.5.2' into master

docs/user-guide/cluster-docker-consul.md

@@ -94,8 +94,8 @@ services:
     image: traefik:1.5
     command:
       - "--api"
-      - "--entrypoints='Name:http Address::80 Redirect.EntryPoint:https'"
-      - "--entrypoints='Name:https Address::443 TLS'"
+      - "--entrypoints=Name:http Address::80 Redirect.EntryPoint:https"
+      - "--entrypoints=Name:https Address::443 TLS"
       - "--defaultentrypoints=http,https"
       - "--acme"
       - "--acme.storage=/etc/traefik/acme/acme.json"
@@ -204,8 +204,8 @@ services:
     command:
       - "storeconfig"
       - "--api"
-      - "--entrypoints='Name:http Address::80 Redirect.EntryPoint:https'"
-      - "--entrypoints='Name:https Address::443 TLS'"
+      - "--entrypoints=Name:http Address::80 Redirect.EntryPoint:https"
+      - "--entrypoints=Name:https Address::443 TLS"
       - "--defaultentrypoints=http,https"
       - "--acme"
       - "--acme.storage=traefik/acme/account"

docs/user-guide/cluster.md

@@ -23,3 +23,11 @@ A Træfik cluster is based on a manager/worker model.
 
 When starting, Træfik will elect a manager.
 If this instance fails, another manager will be automatically elected.
+
+## Træfik cluster and Let's Encrypt
+
+**In cluster mode, ACME certificates have to be stored in [a KV Store entry](/configuration/acme/#storage-kv-entry).**
+
+Thanks to the Træfik cluster mode algorithm (based on [the Raft Consensus Algorithm](https://raft.github.io/)), only one instance will contact Let's encrypt to solve the challenges.
+
+The others instances will get ACME certificate from the KV Store entry.