Strip trailing period from hostname generated from weavedns domain.

We strip at the calling point rather than in the server, because DNS
servers do see the domain as ending with a '.'  representing the root.

proxy/create_container_interceptor.go

@@ -94,7 +94,8 @@ func (i *createContainerInterceptor) setWeaveDNS(container *createContainerReque
 	name := r.URL.Query().Get("name")
 	if container.Hostname == "" && name != "" {
 		container.Hostname = name
-		container.Domainname = i.getDNSDomain()
+		// Strip trailing period because it's unusual to see it used on the end of a host name
+		container.Domainname = strings.TrimSuffix(i.getDNSDomain(), ".")
 	}
 
 	return nil

test/270_use_name_as_hostname_test.sh

@@ -3,7 +3,7 @@
 . ./config.sh
 
 NAME=c1
-DOMAIN=weave.local.
+DOMAIN=weave.local
 HOSTNAME=$NAME-hostname.$DOMAIN
 
 # Docker inspect hostname + domainname of container $2 on host $1

weave

@@ -660,7 +660,8 @@ dns_args() {
     DNS_ARGS="$DNS_ARG $DNS_SEARCH_ARG"
     if [ -n "$NAME_ARG" -a -z "$HOSTNAME_SPECIFIED" ] ; then
         DOMAIN=$(call_dns GET /domain 2>/dev/null) || DOMAIN=weave.local.
-        DNS_ARGS="$DNS_ARGS --hostname=$NAME_ARG.$DOMAIN"
+        # Strip trailing period off DNS domain to reduce surprise
+        DNS_ARGS="$DNS_ARGS --hostname=$NAME_ARG.${DOMAIN%.}"
     fi
 }