chore(deps) Update dns dependency and options

updates the dns lib to 0.6.0, adds the new `dns_stale_ttl` and `dns_no_sync` options.
Kong · Jun 17, 2017 · 7b36454 · 7b36454
1 parent 61444ec
commit 7b36454
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Showing 5 changed files with 25 additions and 4 deletions.
diff --git a/kong-0.10.3-0.rockspec b/kong-0.10.3-0.rockspec
@@ -28,7 +28,7 @@ dependencies = {
   "luacrypto == 0.3.2",
   "luasyslog == 1.0.0",
   "lua_pack == 1.0.4",
-  "lua-resty-dns-client == 0.5.0",
+  "lua-resty-dns-client == 0.6.0",
   "lua-resty-worker-events == 0.3.0",
   "lua-resty-mediador == 0.1.2",
 }

diff --git a/kong.conf.default b/kong.conf.default
@@ -452,16 +452,31 @@
                                  # To read the file again after modifying it,
                                  # Kong must be reloaded.
 
-#dns_order = LAST,SRV,A,CNAME    # the order in which to resolve different
+#dns_order = LAST,SRV,A,CNAME    # The order in which to resolve different
                                  # record types. The `LAST` type means the
                                  # type of the last successful lookup (for the
                                  # specified name). The format is a (case
                                  # insensitive) comma separated list.
 
-#dns_not_found_ttl = 30.0        # ttl in seconds for empty DNS responses and
+#dns_stale_ttl = 4               # Once a record expires, how much longer (in
+                                 # seconds) may the current stale record be 
+                                 # used while the refresh query is executed in
+                                 # the background.
+                                 # Stale data will be used from expiry of a
+                                 # record until either the refresh query
+                                 # completes, or the `dns_stale_ttl` number of
+                                 # seconds have passed.
+
+#dns_not_found_ttl = 30          # Ttl in seconds for empty DNS responses and
                                  # "(3) name error" responses.
 
-#dns_error_ttl = 1.0             # ttl in seconds for error responses.
+#dns_error_ttl = 1               # Ttl in seconds for error responses.
+
+#dns_no_sync = off               # If enabled, then upon a cache-miss every
+                                 # request will trigger its own dns query.
+                                 # When disabled multiple requests for the
+                                 # same name/type will be synchronised to a
+                                 # single query.
 
 #------------------------------------------------------------------------------
 # DEVELOPMENT & MISCELLANEOUS

diff --git a/kong/conf_loader.lua b/kong/conf_loader.lua
@@ -105,8 +105,10 @@ local CONF_INFERENCES = {
   dns_resolver = {typ = "array"},
   dns_hostsfile = {typ = "string"},
   dns_order = {typ = "array"},
+  dns_stale_ttl = {typ = "number"},
   dns_not_found_ttl = {typ = "number"},
   dns_error_ttl = {typ = "number"},
+  dns_no_sync = {typ = "boolean"},
 
   ssl = {typ = "boolean"},
   client_ssl = {typ = "boolean"},

diff --git a/kong/templates/kong_defaults.lua b/kong/templates/kong_defaults.lua
@@ -73,8 +73,10 @@ cluster_ttl_on_failure = 3600
 dns_resolver = NONE
 dns_hostsfile = /etc/hosts
 dns_order = LAST,SRV,A,CNAME
+dns_stale_ttl = 4.0
 dns_not_found_ttl = 30.0
 dns_error_ttl = 1.0
+dns_no_sync = off
 
 lua_code_cache = on
 lua_socket_pool_size = 30

diff --git a/kong/tools/dns.lua b/kong/tools/dns.lua
@@ -27,7 +27,9 @@ local setup_client = function(conf)
     timeout = nil,                   -- taken from system resolv.conf; timeout
     badTtl = conf.dns_not_found_ttl, -- ttl in seconds for dns error responses (except 3 - name error)
     emptyTtl = conf.dns_error_ttl,   -- ttl in seconds for empty and "(3) name error" dns responses
+    staleTtl = conf.dns_stale_ttl,   -- ttl in seconds for records once they become stale
     order = conf.dns_order,          -- order of trying record types
+    noSynchronisation = conf.dns_no_sync,
   }
 
   assert(dns_client.init(opts))