Merge pull request #4673 from jacksontj/helpful_dns_error

More helpful dns error

rootfs/etc/nginx/lua/test/util/dns_test.lua

@@ -40,38 +40,37 @@ describe("dns.lookup", function()
     it("returns host when the query returns nil", function()
       helpers.mock_resty_dns_query(nil, nil, "oops!")
       assert.are.same({ "example.com" }, dns_lookup("example.com"))    
-      assert.spy(spy_ngx_log).was_called_with(ngx.ERR, "failed to query the DNS server:\noops!\noops!")
+      assert.spy(spy_ngx_log).was_called_with(ngx.ERR, "failed to query the DNS server for ", "example.com", ":\n", "oops!\noops!")
     end)
 
     it("returns host when the query returns empty answer", function()
       helpers.mock_resty_dns_query(nil, {})
       assert.are.same({ "example.com" }, dns_lookup("example.com"))
-      assert.spy(spy_ngx_log).was_called_with(ngx.ERR, "failed to query the DNS server:\nno A record resolved\nno AAAA record resolved")
+      assert.spy(spy_ngx_log).was_called_with(ngx.ERR, "failed to query the DNS server for ", "example.com", ":\n", "no A record resolved\nno AAAA record resolved")
     end)
 
     it("returns host when there's answer but with error", function()
       helpers.mock_resty_dns_query(nil, { errcode = 1, errstr = "format error" })
       assert.are.same({ "example.com" }, dns_lookup("example.com"))
-      assert.spy(spy_ngx_log).was_called_with(ngx.ERR, "failed to query the DNS server:\n" ..
-        "server returned error code: 1: format error\nserver returned error code: 1: format error")
+      assert.spy(spy_ngx_log).was_called_with(ngx.ERR, "failed to query the DNS server for ", "example.com", ":\n", "server returned error code: 1: format error\nserver returned error code: 1: format error")
     end)
 
     it("retuns host when there's answer but no A/AAAA record in it", function()
       helpers.mock_resty_dns_query(nil, { { name = "example.com", cname = "sub.example.com", ttl = 60 } })
       assert.are.same({ "example.com" }, dns_lookup("example.com"))
-      assert.spy(spy_ngx_log).was_called_with(ngx.ERR, "failed to query the DNS server:\nno A record resolved\nno AAAA record resolved")
+      assert.spy(spy_ngx_log).was_called_with(ngx.ERR, "failed to query the DNS server for ", "example.com", ":\n", "no A record resolved\nno AAAA record resolved")
     end)
 
     it("returns host when the query returns nil and number of dots is not less than configured ndots", function()
       helpers.mock_resty_dns_query(nil, nil, "oops!")
       assert.are.same({ "a.b.c.d.example.com" }, dns_lookup("a.b.c.d.example.com"))    
-      assert.spy(spy_ngx_log).was_called_with(ngx.ERR, "failed to query the DNS server:\noops!\noops!")
+      assert.spy(spy_ngx_log).was_called_with(ngx.ERR, "failed to query the DNS server for ", "a.b.c.d.example.com", ":\n", "oops!\noops!")
     end)
 
     it("returns host when the query returns nil for a fully qualified domain", function()
       helpers.mock_resty_dns_query("example.com.", nil, "oops!")
       assert.are.same({ "example.com." }, dns_lookup("example.com."))
-      assert.spy(spy_ngx_log).was_called_with(ngx.ERR, "failed to query the DNS server:\noops!\noops!")
+      assert.spy(spy_ngx_log).was_called_with(ngx.ERR, "failed to query the DNS server for ", "example.com.", ":\n", "oops!\noops!")
     end)
   end)
 

rootfs/etc/nginx/lua/util/dns.lua

@@ -118,7 +118,7 @@ function _M.lookup(host)
       return addresses
     end
 
-    ngx_log(ngx_ERR, "failed to query the DNS server:\n" .. table_concat(dns_errors, "\n"))
+    ngx_log(ngx_ERR, "failed to query the DNS server for ", host, ":\n", table_concat(dns_errors, "\n"))
 
     return { host }
   end
@@ -147,7 +147,7 @@ function _M.lookup(host)
   end
 
   if #dns_errors > 0 then
-    ngx_log(ngx_ERR, "failed to query the DNS server:\n" .. table_concat(dns_errors, "\n"))
+    ngx_log(ngx_ERR, "failed to query the DNS server for ", host, ":\n", table_concat(dns_errors, "\n"))
   end
 
   return { host }