Add integration test.

.travis.yml

@@ -1,13 +1,26 @@
-sudo: false
+dist: trusty
+sudo: required
 language: go
+group: edge
 
 go:
-  - 1.7.x
   - 1.8.x
   - tip
 
+env:
+  - PROXYSQL_IMAGE=percona/proxysql:1.2.1
+  - PROXYSQL_IMAGE=perconalab/proxysql:1.3.6
+
+services:
+  - docker
+
+before_script:
+  - docker --version
+  - docker-compose --version
+  - docker-compose up -d
+
 script:
-  - make
+  - make format build testall
 
 after_success:
   - bash <(curl -s https://codecov.io/bash)

CONTRIBUTING.md

@@ -6,11 +6,14 @@ The easiest way to make a local development setup is to use Docker Compose.
 
 ```
 docker-compose up
-<wait>
-mysql --host=127.0.0.1 --port=16032 --user=admin --password=admin < proxysql.sql
+make all testall
 export DATA_SOURCE_NAME='admin:admin@tcp(127.0.0.1:16032)/'
+./proxysql_exporter
 ```
 
+`testall` make target will run integration test and also leave ProxySQL inside Docker container in configured state.
+
+
 ## Vendoring
 
 We use [Glide](https://glide.sh) to vendor dependencies. Please use released version of Glide (i.e. do not `go get`

Makefile

@@ -31,7 +31,11 @@ style:
 
 test:
 	@echo ">> running tests"
-	@$(GO) test -short -race -coverprofile coverage.txt $(pkgs)
+	@$(GO) test -v -short -race -coverprofile coverage.txt $(pkgs)
+
+testall:
+	@echo ">> running all tests"
+	@$(GO) test -v -race -coverprofile coverage.txt $(pkgs)
 
 format:
 	@echo ">> formatting code"

docker-compose.yml

@@ -1,9 +1,9 @@
+# see CONTRIBUTING.md
 ---
 version: '3'
 services:
   proxysql:
-    # image: percona/proxysql
-    image: perconalab/proxysql:1.3.6
+    image: ${PROXYSQL_IMAGE:-perconalab/proxysql:1.3.6}
     environment:
       # those environment variables are not actually required by ProxySQL, but entrypoint erroneously checks them
       - CLUSTER_NAME=dummy

exporter.go

@@ -109,6 +109,14 @@ func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 	e.proxysqlUp.Collect(ch)
 }
 
+func (e *Exporter) db() (*sql.DB, error) {
+	db, err := sql.Open("mysql", e.dsn)
+	if err == nil {
+		err = db.Ping()
+	}
+	return db, err
+}
+
 func (e *Exporter) scrape(ch chan<- prometheus.Metric) {
 	e.scrapesTotal.Inc()
 	var err error
@@ -121,10 +129,7 @@ func (e *Exporter) scrape(ch chan<- prometheus.Metric) {
 		}
 	}(time.Now())
 
-	db, err := sql.Open("mysql", e.dsn)
-	if err == nil {
-		err = db.Ping()
-	}
+	db, err := e.db()
 	if err != nil {
 		log.Errorln("Error opening connection to ProxySQL:", err)
 		e.proxysqlUp.Set(0)

exporter_test.go

@@ -17,6 +17,7 @@ import (
 	"regexp"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
 	dto "github.com/prometheus/client_model/go"
@@ -107,7 +108,7 @@ func TestScrapeMySQLGlobal(t *testing.T) {
 		close(ch)
 	}()
 
-	counterExpected := []*metricResult{
+	counterExpected := []metricResult{
 		{"proxysql_mysql_status_active_transactions", labelMap{}, 3, dto.MetricType_GAUGE},
 		{"proxysql_mysql_status_backend_query_time_nsec", labelMap{}, 76355784684851, dto.MetricType_UNTYPED},
 		{"proxysql_mysql_status_client_connections_aborted", labelMap{}, 0, dto.MetricType_COUNTER},
@@ -117,7 +118,7 @@ func TestScrapeMySQLGlobal(t *testing.T) {
 	}
 	convey.Convey("Metrics comparison", t, convey.FailureContinues, func() {
 		for _, expect := range counterExpected {
-			got := readMetric(<-ch)
+			got := *readMetric(<-ch)
 			convey.So(got, convey.ShouldResemble, expect)
 		}
 	})
@@ -159,7 +160,7 @@ func TestScrapeMySQLConnectionPool(t *testing.T) {
 		close(ch)
 	}()
 
-	counterExpected := []*metricResult{
+	counterExpected := []metricResult{
 		{"proxysql_connection_pool_status", labelMap{"hostgroup": "0", "endpoint": "10.91.142.80:3306"}, 1, dto.MetricType_GAUGE},
 		{"proxysql_connection_pool_conn_used", labelMap{"hostgroup": "0", "endpoint": "10.91.142.80:3306"}, 0, dto.MetricType_GAUGE},
 		{"proxysql_connection_pool_conn_free", labelMap{"hostgroup": "0", "endpoint": "10.91.142.80:3306"}, 45, dto.MetricType_GAUGE},
@@ -202,7 +203,7 @@ func TestScrapeMySQLConnectionPool(t *testing.T) {
 	}
 	convey.Convey("Metrics comparison", t, convey.FailureContinues, func() {
 		for _, expect := range counterExpected {
-			got := readMetric(<-ch)
+			got := *readMetric(<-ch)
 			convey.So(got, convey.ShouldResemble, expect)
 		}
 	})
@@ -212,3 +213,87 @@ func TestScrapeMySQLConnectionPool(t *testing.T) {
 		t.Errorf("there were unfulfilled expectations: %s", err)
 	}
 }
+
+func TestExporter(t *testing.T) {
+	if testing.Short() {
+		t.Skip("-short is passed, skipping integration test")
+	}
+
+	// wait up to 30 seconds for ProxySQL to become available
+	exporter := NewExporter("admin:admin@tcp(127.0.0.1:16032)/", true, true)
+	for i := 0; i < 30; i++ {
+		db, err := exporter.db()
+		if err != nil {
+			time.Sleep(time.Second)
+			continue
+		}
+
+		// configure ProxySQL
+		for _, q := range strings.Split(`
+DELETE FROM mysql_servers;
+INSERT INTO mysql_servers(hostgroup_id, hostname, port) VALUES (1, 'mysql', 3306);
+INSERT INTO mysql_servers(hostgroup_id, hostname, port) VALUES (1, 'percona-server', 3306);
+LOAD MYSQL SERVERS TO RUNTIME;
+SAVE MYSQL SERVERS TO DISK;
+
+DELETE FROM mysql_users;
+INSERT INTO mysql_users(username, password, default_hostgroup) VALUES ('root', '', 1);
+INSERT INTO mysql_users(username, password, default_hostgroup) VALUES ('monitor', 'monitor', 1);
+LOAD MYSQL USERS TO RUNTIME;
+SAVE MYSQL USERS TO DISK;
+`, ";") {
+			q = strings.TrimSpace(q)
+			if q == "" {
+				continue
+			}
+			_, err = db.Exec(q)
+			if err != nil {
+				t.Fatalf("Failed to execute %q\n%s", q, err)
+			}
+		}
+		break
+	}
+
+	convey.Convey("Metrics descriptions", t, convey.FailureContinues, func() {
+		ch := make(chan *prometheus.Desc)
+		go func() {
+			exporter.Describe(ch)
+			close(ch)
+		}()
+
+		descs := make(map[string]struct{})
+		for d := range ch {
+			descs[d.String()] = struct{}{}
+		}
+
+		convey.So(descs, convey.ShouldContainKey,
+			`Desc{fqName: "proxysql_connection_pool_latency_us", help: "The currently ping time in microseconds, as reported from Monitor.", constLabels: {}, variableLabels: [hostgroup endpoint]}`)
+	})
+
+	convey.Convey("Metrics data", t, convey.FailureContinues, func() {
+		ch := make(chan prometheus.Metric)
+		go func() {
+			exporter.Collect(ch)
+			close(ch)
+		}()
+
+		var metrics []metricResult
+		for m := range ch {
+			got := *readMetric(m)
+			got.value = 0 // ignore actual values in comparison for now
+			metrics = append(metrics, got)
+		}
+
+		for _, m := range metrics {
+			convey.So(m.name, convey.ShouldEqual, strings.ToLower(m.name))
+			for k := range m.labels {
+				convey.So(k, convey.ShouldEqual, strings.ToLower(k))
+			}
+		}
+
+		convey.So(metricResult{"proxysql_connection_pool_latency_us", labelMap{"hostgroup": "1", "endpoint": "mysql:3306"}, 0, dto.MetricType_GAUGE},
+			convey.ShouldBeIn, metrics)
+		convey.So(metricResult{"proxysql_connection_pool_latency_us", labelMap{"hostgroup": "1", "endpoint": "percona-server:3306"}, 0, dto.MetricType_GAUGE},
+			convey.ShouldBeIn, metrics)
+	})
+}