query: begin implement query package

Signed-off-by: Bruno Schaatsbergen <[email protected]>

Author: bschaatsbergen

internal/query/query.go

@@ -0,0 +1,46 @@
+package query
+
+import (
+	"github.com/hashicorp/go-hclog"
+	"github.com/miekg/dns"
+	"os"
+)
+
+// Querier is an interface for querying DNS records
+type Querier interface {
+	Query(domain string, qtype uint16) (*dns.Msg, error)
+}
+
+// Query implements the Querier interface
+type Query struct {
+	Server string
+	hclog.Logger
+}
+
+// NewQuerier creates a new Querier with the specified server
+func NewQuerier(server string, logger hclog.Logger) Querier {
+	if logger == nil {
+		logger = hclog.New(&hclog.LoggerOptions{
+			Name:  "zns",
+			Level: hclog.LevelFromString(os.Getenv("ZNS_LOG_LEVEL")),
+			Color: hclog.AutoColor,
+            DisableTime: true,
+		})
+		logger.Warn("no logger provided, using default 'zns' logger")
+	}
+	return &Query{Server: server, Logger: logger}
+}
+
+// Query performs the DNS query and returns the response and any error encountered
+func (q *Query) Query(domain string, qtype uint16) (*dns.Msg, error) {
+	msg := new(dns.Msg)
+	msg.SetQuestion(dns.Fqdn(domain), qtype)
+
+	client := new(dns.Client)
+	resp, _, err := client.Exchange(msg, q.Server)
+	if err != nil {
+		return nil, err
+	}
+
+	return resp, nil
+}