api: allow querying node name from agent

api/agent.go

@@ -8,7 +8,9 @@ import (
 // agent endpoints for a specific node.
 type Agent struct {
 	client *Client
-	node   string
+
+	// Cache static agent info
+	nodeName string
 }
 
 // Agent returns a new agent which can be used to query
@@ -30,3 +32,21 @@ func (a *Agent) Self() (map[string]map[string]interface{}, error) {
 
 	return out, nil
 }
+
+// NodeName is used to query the Nomad agent for its node name.
+func (a *Agent) NodeName() (string, error) {
+	// Return from cache if we have it
+	if a.nodeName != "" {
+		return a.nodeName, nil
+	}
+
+	// Query the node name
+	info, err := a.Self()
+	if err != nil {
+		return "", err
+	}
+	if name, ok := info["member"]["Name"]; ok {
+		a.nodeName = name.(string)
+	}
+	return a.nodeName, nil
+}

api/agent_test.go

@@ -22,3 +22,25 @@ func TestAgent_Self(t *testing.T) {
 		t.Fatalf("bad member name in response: %#v", res)
 	}
 }
+
+func TestAgent_NodeName(t *testing.T) {
+	c, s := makeClient(t, nil, nil)
+	defer s.Stop()
+	a := c.Agent()
+
+	// Query the agent for the node name
+	res, err := a.NodeName()
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Ensure we got a node name back
+	if res == "" {
+		t.Fatalf("expected node name, got nothing")
+	}
+
+	// Check that we cached the node name
+	if a.nodeName == "" {
+		t.Fatalf("should have cached node name")
+	}
+}