go-docker-initiator

Utility for starting docker containers from Go code. Useful for testing.

Image Support

This library currently supports the following services out of the box:

pubsub
mysql

Installation

Install the package with:

go get github.com/Storytel/go-docker-initiator

Once installed import it to your code:

import dockerinitiator github.com/Storytel/go-docker-initiator

Examples

This package is especially useful for testing. With go-docker-initiator the configuration for your external integrations lives in the code and not in 3rd party configuration files.

Below is a typical and simple example using go-docker-initiator in a test.

package example_test

import (
	"log"
	"testing"

	dockerinitiator "github.com/Storytel/go-docker-initiator"
	"github.com/stretchr/testify/assert"
)

// WithMySQL will clear obsolete containers an spin up a mysql container for use
func WithMySQL() *dockerinitiator.MysqlInstance {
	if err := dockerinitiator.ClearObsolete(); err != nil {
		log.Panic(err)
	}

	instance, err := dockerinitiator.Mysql(dockerinitiator.MysqlConfig{
		User:     "root",
		Password: "",
		DbName:   "testdb",
	})
	if err != nil {
		log.Panic(err)
	}

	// Set the needed environment variables
	// MYSQL_SERVER, MYSQL_USER, MYSQL_PASSWORD, MYSQL_DATABASE
	if err = instance.Setenv(); err != nil {
		log.Panic(err)
	}

	return instance
}

func TestDatabaseIntegration(t *testing.T) {
	mysqlInstance := WithMySQL()

	// Establish a database connection to the exposed environment variables
	db, err := InitAndCreateDatabase()
	assert.NoError(t, err)
	defer db.Close()

	// Run any DB seeds here

	// Setup your service and inject the database
	exampleService := ExampleService{
		Db: db,
	}

	// Test your integration
	_, err = exmapleService.Create()
	assert.NoError(t, err)
}

Notes

A single image can be easily shared between tests using techniques such as TableDrivenTests.

As is often the case, if you have tests set to automatically run on each file-save you might do best to tag the tests running with go-docker-initiator to avoid running them on-save.

Tag a file like so:

// +build <TAG>

Since the tests with the tag wont run automatically you have to manually invoke it with:

go test -tags=<TAG> ./...

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