Add Docker Compose for integration tests (#228)

* Add Docker Compose for integration tests.

Closes #223.

* Add very basic integration test as an example.

* Remove `-v`.

* Remove duplicate line.

.travis.yml

@@ -1,11 +1,28 @@
-sudo: false
-
+dist: trusty
+sudo: required
 language: go
+
 go:
 - 1.8.x
 - tip
 
+env:
+- MYSQL_IMAGE=mysql/mysql-server:5.5
+- MYSQL_IMAGE=mysql/mysql-server:5.6
+- MYSQL_IMAGE=mysql/mysql-server:5.7
+- MYSQL_IMAGE=mysql/mysql-server:8.0
+
+services:
+- docker
+
 go_import_path: github.com/prometheus/mysqld_exporter
 
+before_script:
+- sudo service mysql stop
+- docker --version
+- docker-compose --version
+- docker-compose up -d
+
 script:
 - make
+- make test

CONTRIBUTING.md

@@ -16,3 +16,14 @@ Prometheus uses GitHub to manage reviews of pull requests.
   and the _Formatting and style_ section of Peter Bourgon's [Go: Best
   Practices for Production
   Environments](http://peter.bourgon.org/go-in-production/#formatting-and-style).
+
+
+## Local setup
+
+The easiest way to make a local development setup is to use Docker Compose.
+
+```
+docker-compose up
+make
+make test
+```

Makefile

@@ -22,15 +22,19 @@ DOCKER_IMAGE_NAME   ?= mysqld-exporter
 DOCKER_IMAGE_TAG    ?= $(subst /,-,$(shell git rev-parse --abbrev-ref HEAD))
 
 
-all: format build test
+all: format build test-short
 
 style:
 	@echo ">> checking code style"
 	@! gofmt -d $(shell find . -path ./vendor -prune -o -name '*.go' -print) | grep '^'
 
+test-short:
+	@echo ">> running short tests"
+	@$(GO) test -short -race $(pkgs)
+
 test:
 	@echo ">> running tests"
-	@$(GO) test -short -race $(pkgs)
+	@$(GO) test -race $(pkgs)
 
 format:
 	@echo ">> formatting code"

collector/exporter_test.go

@@ -0,0 +1,47 @@
+package collector
+
+import (
+	"testing"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/model"
+	"github.com/smartystreets/goconvey/convey"
+)
+
+const dsn = "root@/mysql"
+
+func TestExporter(t *testing.T) {
+	if testing.Short() {
+		t.Skip("-short is passed, skipping test")
+	}
+
+	exporter := New(dsn, Collect{
+		GlobalStatus: true,
+	})
+
+	convey.Convey("Metrics describing", t, func() {
+		ch := make(chan *prometheus.Desc)
+		go func() {
+			exporter.Describe(ch)
+			close(ch)
+		}()
+
+		for range ch {
+		}
+	})
+
+	convey.Convey("Metrics collection", t, func() {
+		ch := make(chan prometheus.Metric)
+		go func() {
+			exporter.Collect(ch)
+			close(ch)
+		}()
+
+		for m := range ch {
+			got := readMetric(m)
+			if got.labels[model.MetricNameLabel] == "mysql_up" {
+				convey.So(got.value, convey.ShouldEqual, 1)
+			}
+		}
+	})
+}

docker-compose.yml

@@ -0,0 +1,11 @@
+# see CONTRIBUTING.md
+---
+version: '3'
+services:
+  mysql:
+    image: ${MYSQL_IMAGE:-mysql/mysql-server:5.7}
+    environment:
+      - MYSQL_ALLOW_EMPTY_PASSWORD=yes
+      - MYSQL_ROOT_HOST=%
+    ports:
+      - 127.0.0.1:3306:3306