diff options
| -rw-r--r-- | plugin/loadbalance/README.md | 6 | ||||
| -rw-r--r-- | plugin/loadbalance/loadbalance.go | 14 | ||||
| -rw-r--r-- | plugin/loadbalance/setup.go | 24 | ||||
| -rw-r--r-- | plugin/loadbalance/setup_test.go | 43 |
4 files changed, 71 insertions, 16 deletions
diff --git a/plugin/loadbalance/README.md b/plugin/loadbalance/README.md index 4c075bb9d..fed9c906f 100644 --- a/plugin/loadbalance/README.md +++ b/plugin/loadbalance/README.md @@ -2,12 +2,12 @@ ## Name -*loadbalance* - randomize the order of A and AAAA records. +*loadbalance* - randomize the order of A, AAAA and MX records. ## Description -The *loadbalance* will act as a round-robin DNS loadbalancer by randomizing the order of A and AAAA -records in the answer. +The *loadbalance* will act as a round-robin DNS loadbalancer by randomizing the order of A, AAAA, +and MX records in the answer. See [Wikipedia](https://en.wikipedia.org/wiki/Round-robin_DNS) about the pros and cons on this setup. It will take care to sort any CNAMEs before any address records, because some stub resolver diff --git a/plugin/loadbalance/loadbalance.go b/plugin/loadbalance/loadbalance.go index 031f841f4..39e70368d 100644 --- a/plugin/loadbalance/loadbalance.go +++ b/plugin/loadbalance/loadbalance.go @@ -1,14 +1,12 @@ -// Package loadbalance shuffles A and AAAA records. +// Package loadbalance shuffles A, AAAA and MX records. package loadbalance import ( "github.com/miekg/dns" ) -// RoundRobinResponseWriter is a response writer that shuffles A and AAAA records. -type RoundRobinResponseWriter struct { - dns.ResponseWriter -} +// RoundRobinResponseWriter is a response writer that shuffles A, AAAA and MX records. +type RoundRobinResponseWriter struct{ dns.ResponseWriter } // WriteMsg implements the dns.ResponseWriter interface. func (r *RoundRobinResponseWriter) WriteMsg(res *dns.Msg) error { @@ -77,9 +75,3 @@ func (r *RoundRobinResponseWriter) Write(buf []byte) (int, error) { n, err := r.ResponseWriter.Write(buf) return n, err } - -// Hijack implements the dns.ResponseWriter interface. -func (r *RoundRobinResponseWriter) Hijack() { - r.ResponseWriter.Hijack() - return -} diff --git a/plugin/loadbalance/setup.go b/plugin/loadbalance/setup.go index 38dce6308..9d52a3cbe 100644 --- a/plugin/loadbalance/setup.go +++ b/plugin/loadbalance/setup.go @@ -1,6 +1,8 @@ package loadbalance import ( + "fmt" + "github.com/coredns/coredns/core/dnsserver" "github.com/coredns/coredns/plugin" clog "github.com/coredns/coredns/plugin/pkg/log" @@ -18,8 +20,9 @@ func init() { } func setup(c *caddy.Controller) error { - for c.Next() { - // TODO(miek): block and option parsing + err := parse(c) + if err != nil { + return plugin.Error("loadbalance", err) } dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler { @@ -28,3 +31,20 @@ func setup(c *caddy.Controller) error { return nil } + +func parse(c *caddy.Controller) error { + for c.Next() { + args := c.RemainingArgs() + switch len(args) { + case 0: + return nil + case 1: + if args[0] != "round_robin" { + return fmt.Errorf("unknown policy: %s", args[0]) + + } + return nil + } + } + return c.ArgErr() +} diff --git a/plugin/loadbalance/setup_test.go b/plugin/loadbalance/setup_test.go new file mode 100644 index 000000000..67673a72c --- /dev/null +++ b/plugin/loadbalance/setup_test.go @@ -0,0 +1,43 @@ +package loadbalance + +import ( + "strings" + "testing" + + "github.com/mholt/caddy" +) + +func TestSetup(t *testing.T) { + tests := []struct { + input string + shouldErr bool + expectedPolicy string + expectedErrContent string // substring from the expected error. Empty for positive cases. + }{ + // positive + {`loadbalance`, false, "round_robin", ""}, + {`loadbalance round_robin`, false, "round_robin", ""}, + // negative + {`loadbalance fleeb`, true, "", "unknown policy"}, + {`loadbalance a b`, true, "", "argument count or unexpected line"}, + } + + for i, test := range tests { + c := caddy.NewTestController("dns", test.input) + err := parse(c) + + if test.shouldErr && err == nil { + t.Errorf("Test %d: Expected error but found %s for input %s", i, err, test.input) + } + + if err != nil { + if !test.shouldErr { + t.Errorf("Test %d: Expected no error but found one for input %s. Error was: %v", i, test.input, err) + } + + if !strings.Contains(err.Error(), test.expectedErrContent) { + t.Errorf("Test %d: Expected error to contain: %v, found error: %v, input: %s", i, test.expectedErrContent, err, test.input) + } + } + } +} |