Add template variable substitution to influx queries

influx/influx.go

@@ -68,17 +68,20 @@ func (c *Client) query(u *url.URL, q chronograf.Query) (chronograf.Response, err
 		return nil, err
 	}
 	req.Header.Set("Content-Type", "application/json")
-
-	c.Logger.
+	command := q.Command
+	if len(q.TemplateVars) > 0 {
+		command = TemplateReplace(q.Command, q.TemplateVars)
+	}
+	logs := c.Logger.
 		WithField("component", "proxy").
 		WithField("host", req.Host).
-		WithField("command", q.Command).
+		WithField("command", command).
 		WithField("db", q.DB).
-		WithField("rp", q.RP).
-		Debug("query")
+		WithField("rp", q.RP)
+	logs.Debug("query")
 
 	params := req.URL.Query()
-	params.Set("q", q.Command)
+	params.Set("q", command)
 	params.Set("db", q.DB)
 	params.Set("rp", q.RP)
 	params.Set("epoch", "ms")
@@ -111,13 +114,7 @@ func (c *Client) query(u *url.URL, q chronograf.Query) (chronograf.Response, err
 
 	// If we got a valid decode error, send that back
 	if decErr != nil {
-		c.Logger.
-			WithField("component", "proxy").
-			WithField("host", req.Host).
-			WithField("command", q.Command).
-			WithField("db", q.DB).
-			WithField("rp", q.RP).
-			WithField("influx_status", resp.StatusCode).
+		logs.WithField("influx_status", resp.StatusCode).
 			Error("Error parsing results from influxdb: err:", decErr)
 		return nil, decErr
 	}
@@ -125,12 +122,7 @@ func (c *Client) query(u *url.URL, q chronograf.Query) (chronograf.Response, err
 	// If we don't have an error in our json response, and didn't get statusOK
 	// then send back an error
 	if resp.StatusCode != http.StatusOK && response.Err != "" {
-		c.Logger.
-			WithField("component", "proxy").
-			WithField("host", req.Host).
-			WithField("command", q.Command).
-			WithField("db", q.DB).
-			WithField("rp", q.RP).
+		logs.
 			WithField("influx_status", resp.StatusCode).
 			Error("Received non-200 response from influxdb")
 

influx/influx_test.go

@@ -82,6 +82,7 @@ func Test_Influx_HTTPS_Failure(t *testing.T) {
 func Test_Influx_HTTPS_InsecureSkipVerify(t *testing.T) {
 	t.Parallel()
 	called := false
+	q := ""
 	ts := httptest.NewTLSServer(http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
 		rw.WriteHeader(http.StatusOK)
 		rw.Write([]byte(`{}`))
@@ -89,6 +90,8 @@ func Test_Influx_HTTPS_InsecureSkipVerify(t *testing.T) {
 		if path := r.URL.Path; path != "/query" {
 			t.Error("Expected the path to contain `/query` but was", path)
 		}
+		values := r.URL.Query()
+		q = values.Get("q")
 	}))
 	defer ts.Close()
 
@@ -118,6 +121,34 @@ func Test_Influx_HTTPS_InsecureSkipVerify(t *testing.T) {
 	if called == false {
 		t.Error("Expected http request to Influx but there was none")
 	}
+	called = false
+	q = ""
+	query = chronograf.Query{
+		Command: "select $field from cpu",
+		TemplateVars: []chronograf.TemplateVar{
+			{
+				Var: "$field",
+				Values: []chronograf.TemplateValue{
+					{
+						Value: "usage_user",
+						Type:  "fieldKey",
+					},
+				},
+			},
+		},
+	}
+	_, err = series.Query(ctx, query)
+	if err != nil {
+		t.Fatal("Expected no error but was", err)
+	}
+
+	if called == false {
+		t.Error("Expected http request to Influx but there was none")
+	}
+
+	if q != `select "usage_user" from cpu` {
+		t.Errorf("Unexpected query: %s", q)
+	}
 }
 
 func Test_Influx_CancelsInFlightRequests(t *testing.T) {