Add docker containers to test services.

This commit initializes the needed services which are not mocked
so tests can be executed in any environment with docker.

Some default modifications (i.e: connection strings) were also made to
current tests to accomodate them for this setup.

A docker-compose.yml file is provided with all the necessary parameters
for this services to be initialized. Future services can be added
easily by extending this configuration file

In addition a makefile has been introduced to simplify command execution

Makefile

@@ -0,0 +1,11 @@
+prepare:
+	go get -d -v -t ./...
+	docker-compose up -d
+
+test: prepare
+	go test -short ./...
+
+update:
+	go get -u -v -d -t ./...
+
+.PHONY: test

README.md

@@ -175,3 +175,16 @@ func init() {
 }
 ```
 
+## Testing
+
+As Telegraf collects metrics from several third-party services it becomes a difficult task to mock each service as
+some of them have complicated protocols which would take some time to replicate. 
+
+To overcome this situation we've decided to use docker containers to provide a fast and reproducible environment
+to test those services which require it. For other situations (i.e: https://github.com/influxdb/telegraf/blob/master/plugins/redis/redis_test.go ) a simple mock will suffice. 
+
+To execute Telegraf tests follow this simple steps:
+
+- Install docker compose following [these](https://docs.docker.com/compose/install/) instructions
+- execute `make test`
+

docker-compose.yml

@@ -0,0 +1,16 @@
+mysql:
+    image: mysql
+    ports:
+        - "3306:3306"
+    environment:
+        MYSQL_ALLOW_EMPTY_PASSWORD: true
+
+memcached:
+    image: memcached
+    ports:
+        - "11211:11211"
+
+postgres:
+    image: postgres
+    ports:
+        - "5432:5432"

plugins/kafka_consumer/kafka_consumer_integration_test.go

@@ -14,6 +14,9 @@ import (
 )
 
 func TestReadsMetricsFromKafka(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping integration test in short mode")
+	}
 	var zkPeers, brokerPeers []string
 
 	if len(os.Getenv("ZOOKEEPER_PEERS")) == 0 {

plugins/mysql/mysql_test.go

@@ -11,7 +11,7 @@ import (
 
 func TestMysqlGeneratesMetrics(t *testing.T) {
 	m := &Mysql{
-		Servers: []string{""},
+		Servers: []string{"root@tcp(localhost:3306)/"},
 	}
 
 	var acc testutil.Accumulator
@@ -53,7 +53,9 @@ func TestMysqlGeneratesMetrics(t *testing.T) {
 }
 
 func TestMysqlDefaultsToLocal(t *testing.T) {
-	m := &Mysql{}
+	m := &Mysql{
+		Servers: []string{"root@tcp(localhost:3306)/"},
+	}
 
 	var acc testutil.Accumulator
 

plugins/postgresql/postgresql_test.go

@@ -12,7 +12,7 @@ func TestPostgresqlGeneratesMetrics(t *testing.T) {
 	p := &Postgresql{
 		Servers: []*Server{
 			{
-				Address:   "sslmode=disable",
+				Address:   "host=localhost user=postgres sslmode=disable",
 				Databases: []string{"postgres"},
 			},
 		},
@@ -57,7 +57,7 @@ func TestPostgresqlTagsMetricsWithDatabaseName(t *testing.T) {
 	p := &Postgresql{
 		Servers: []*Server{
 			{
-				Address:   "sslmode=disable",
+				Address:   "host=localhost user=postgres sslmode=disable",
 				Databases: []string{"postgres"},
 			},
 		},
@@ -78,7 +78,7 @@ func TestPostgresqlDefaultsToAllDatabases(t *testing.T) {
 	p := &Postgresql{
 		Servers: []*Server{
 			{
-				Address: "sslmode=disable",
+				Address: "host=localhost user=postgres sslmode=disable",
 			},
 		},
 	}

plugins/redis/redis_test.go

@@ -83,7 +83,7 @@ func TestRedisGeneratesMetrics(t *testing.T) {
 	}
 
 	for _, c := range checkInt {
-		assert.NoError(t, acc.ValidateValue(c.name, c.value))
+		assert.True(t, acc.CheckValue(c.name, c.value))
 	}
 
 	checkFloat := []struct {
@@ -98,7 +98,7 @@ func TestRedisGeneratesMetrics(t *testing.T) {
 	}
 
 	for _, c := range checkFloat {
-		assert.NoError(t, acc.ValidateValue(c.name, c.value))
+		assert.True(t, acc.CheckValue(c.name, c.value))
 	}
 }
 
@@ -174,7 +174,7 @@ func TestRedisCanPullStatsFromMultipleServers(t *testing.T) {
 	}
 
 	for _, c := range checkInt {
-		assert.NoError(t, acc.ValidateValue(c.name, c.value))
+		assert.True(t, acc.CheckValue(c.name, c.value))
 	}
 
 	checkFloat := []struct {
@@ -189,7 +189,7 @@ func TestRedisCanPullStatsFromMultipleServers(t *testing.T) {
 	}
 
 	for _, c := range checkFloat {
-		assert.NoError(t, acc.ValidateValue(c.name, c.value))
+		assert.True(t, acc.CheckValue(c.name, c.value))
 	}
 }