Go

Platform.sh supports building and deploying applications written in Go using Go modules. They are compiled during the Build hook phase, and support both committed dependencies and download-on-demand.

Supported versions

1.11
1.12

To specify a Go container, use the type property in your .platform.app.yaml.

type: 'golang:1.12'

Deprecated versions

The following container versions are also available. However, due to their lack of Go module support and the difficulties in supporting the GOPATH during the Platform.sh build they are not recommended.

1.8
1.9
1.10

Go modules

The recommended way to handle Go dependencies on Platform.sh is using Go module support in Go 1.11 and later. That allows the build process to use go build directly without any extra steps, and you can specify an output executable file of your choice. (See the examples below.)

Platform.sh variables

Platform.sh exposes relationships and other configuration as environment variables. To make them easier to access you should use the provided GoHelper library. Most notably, it allows a program to determine at runtime what HTTP port it should listen on and what the credentials are to access other services.

package main

import (
    _ "github.com/go-sql-driver/mysql"
    psh "github.com/platformsh/gohelper"
    "net/http"
)

func main() {

    p, err := psh.NewPlatformInfo()

    if err != nil {
        panic("Not in a Platform.sh Environment.")
    }

    http.HandleFunc("/bar", func(w http.ResponseWriter, r *http.Request) {
        // ...
    })

    http.ListenAndServe(":"+p.Port, nil)
}

Building and running the application

Assuming your go.mod and go.sum files are present in your repository, the application may be built with a simple go build command that will produce a working executable. You can then start it from the web.commands.start directive. Note that the start command must run in the foreground. Should the program terminate for any reason it will be automatically restarted.

The following basic .platform.app.yaml file is sufficient to run most Go applications.

name: app

type: golang:1.12

hooks:
    build: |
        # Modify this line if you want to build differently or use an alternate name for your executable.
        go build -o bin/app

web:
    upstream:
        socket_family: tcp
        protocol: http

    commands:
        # If you change the build output in the build hook above, update this line as well.
        start: ./bin/app

    locations:
        /:
            # Route all requests to the Go app, unconditionally.
            # If you want some files served directly by the web server without hitting Go, see
            # https://docs.platform.sh/configuration/app/web.html
            allow: false
            passthru: true

disk: 1024

Note that there will still be an Nginx proxy server sitting in front of your application. If desired, certain paths may be served directly by Nginx without hitting your application (for static files, primarily) or you may route all requests to the Go application unconditionally, as in the example above.

Accessing services

To access various services with Go, see the following examples. The individual service pages have more information on configuring each service.

Memcached

MongoDB

MySQL

PostgreSQL

RabbitMQ

Solr

package examples

import (
	"fmt"
	"github.com/bradfitz/gomemcache/memcache"
	psh "github.com/platformsh/config-reader-go/v2"
	gomemcache "github.com/platformsh/config-reader-go/v2/gomemcache"
)

func UsageExampleMemcached() string {

	// Create a NewRuntimeConfig object to ease reading the Platform.sh environment variables.
	// You can alternatively use os.Getenv() yourself.
	config, err := psh.NewRuntimeConfig()
	checkErr(err)

	// Get the credentials to connect to the Solr service.
	credentials, err := config.Credentials("memcached")
	checkErr(err)

	// Retrieve formatted credentials for gomemcache.
	formatted, err := gomemcache.FormattedCredentials(credentials)
	checkErr(err)

	// Connect to Memcached.
	mc := memcache.New(formatted)

	// Set a value.
	key := "Deploy_day"
	value := "Friday"

	err = mc.Set(&memcache.Item{Key: key, Value: []byte(value)})

	// Read it back.
	test, err := mc.Get(key)

	return fmt.Sprintf("Found value <strong>%s</strong> for key <strong>%s</strong>.", test.Value, key)
}

package examples

import (
	"context"
	"fmt"
	psh "github.com/platformsh/config-reader-go/v2"
	mongoPsh "github.com/platformsh/config-reader-go/v2/mongo"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
	"time"
)

func UsageExampleMongoDB() string {

	// Create a NewRuntimeConfig object to ease reading the Platform.sh environment variables.
	// You can alternatively use os.Getenv() yourself.
	config, err := psh.NewRuntimeConfig()
	checkErr(err)

	// Get the credentials to connect to the Solr service.
	credentials, err := config.Credentials("mongodb")
	checkErr(err)

	// Retrieve the formatted credentials for mongo-driver.
	formatted, err := mongoPsh.FormattedCredentials(credentials)
	checkErr(err)

	// Connect to MongoDB using the formatted credentials.
	ctx, _ := context.WithTimeout(context.Background(), 10*time.Second)
	client, err := mongo.Connect(ctx, options.Client().ApplyURI(formatted))
	checkErr(err)

	// Create a new collection.
	collection := client.Database("main").Collection("starwars")

	// Clean up after ourselves.
	err = collection.Drop(context.Background())
	checkErr(err)

	// Create an entry.
	res, err := collection.InsertOne(ctx, bson.M{"name": "Rey", "occupation": "Jedi"})
	checkErr(err)

	id := res.InsertedID

	// Read it back.
	cursor, err := collection.Find(context.Background(), bson.M{"_id": id})
	checkErr(err)

	var name string
	var occupation string

	for cursor.Next(context.Background()) {
		document := struct {
			Name       string
			Occupation string
		}{}
		err := cursor.Decode(&document)
		checkErr(err)

		name = document.Name
		occupation = document.Occupation
	}

	return fmt.Sprintf("Found %s (%s)", name, occupation)
}

package examples

import (
	"database/sql"
	"fmt"
	_ "github.com/go-sql-driver/mysql"
	psh "github.com/platformsh/config-reader-go/v2"
	sqldsn "github.com/platformsh/config-reader-go/v2/sqldsn"
)

func UsageExampleMySQL() string {

	// Create a NewRuntimeConfig object to ease reading the Platform.sh environment variables.
	// You can alternatively use os.Getenv() yourself.
	config, err := psh.NewRuntimeConfig()
	checkErr(err)

	// The 'database' relationship is generally the name of the primary SQL database of an application.
	// That's not required, but much of our default automation code assumes it.
	credentials, err := config.Credentials("database")
	checkErr(err)

	// Using the sqldsn formatted credentials package.
	formatted, err := sqldsn.FormattedCredentials(credentials)
	checkErr(err)

	db, err := sql.Open("mysql", formatted)
	checkErr(err)

	defer db.Close()

	// Force MySQL into modern mode.
	db.Exec("SET NAMES=utf8")
	db.Exec(\x60SET sql_mode = 'ANSI,STRICT_TRANS_TABLES,STRICT_ALL_TABLES,
    NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,
    NO_AUTO_CREATE_USER,ONLY_FULL_GROUP_BY'\x60)

	// Creating a table.
	sqlCreate := \x60
CREATE TABLE IF NOT EXISTS PeopleGo (
id SERIAL PRIMARY KEY,
name VARCHAR(30) NOT NULL,
city VARCHAR(30) NOT NULL)\x60

	_, err = db.Exec(sqlCreate)
	checkErr(err)

	// Insert data.
	sqlInsert := \x60
INSERT INTO PeopleGo (name, city) VALUES
('Neil Armstrong', 'Moon'),
('Buzz Aldrin', 'Glen Ridge'),
('Sally Ride', 'La Jolla');\x60

	_, err = db.Exec(sqlInsert)
	checkErr(err)

	table := \x60<table>
<thead>
<tr><th>Name</th><th>City</th></tr>
</thead>
<tbody>\x60

	var id int
	var name string
	var city string

	rows, err := db.Query("SELECT * FROM PeopleGo")
	if err != nil {
		panic(err)
	} else {
		for rows.Next() {
			err = rows.Scan(&id, &name, &city)
			checkErr(err)
			table += fmt.Sprintf("<tr><td>%s</td><td>%s</td><tr>\n", name, city)
		}
		table += "</tbody>\n</table>\n"
	}

	_, err = db.Exec("DROP TABLE PeopleGo;")
	checkErr(err)

	return table
}

package examples

import (
	"database/sql"
	"fmt"
	_ "github.com/lib/pq"
	psh "github.com/platformsh/config-reader-go/v2"
	libpq "github.com/platformsh/config-reader-go/v2/libpq"
)

func UsageExamplePostgreSQL() string {

	// Create a NewRuntimeConfig object to ease reading the Platform.sh environment variables.
	// You can alternatively use os.Getenv() yourself.
	config, err := psh.NewRuntimeConfig()
	checkErr(err)

	// The 'database' relationship is generally the name of the primary SQL database of an application.
	// It could be anything, though, as in the case here where it's called "postgresql".
	credentials, err := config.Credentials("postgresql")
	checkErr(err)

	// Retrieve the formatted credentials.
	formatted, err := libpq.FormattedCredentials(credentials)
	checkErr(err)

	// Connect.
	db, err := sql.Open("postgres", formatted)
	checkErr(err)

	defer db.Close()

	// Creating a table.
	sqlCreate := \x60
CREATE TABLE IF NOT EXISTS PeopleGo (
id SERIAL PRIMARY KEY,
name VARCHAR(30) NOT NULL,
city VARCHAR(30) NOT NULL);\x60

	_, err = db.Exec(sqlCreate)
	checkErr(err)

	// Insert data.
	sqlInsert := \x60
INSERT INTO PeopleGo(name, city) VALUES
('Neil Armstrong', 'Moon'),
('Buzz Aldrin', 'Glen Ridge'),
('Sally Ride', 'La Jolla');\x60

	_, err = db.Exec(sqlInsert)
	checkErr(err)

	table := \x60<table>
<thead>
<tr><th>Name</th><th>City</th></tr>
</thead>
<tbody>\x60

	var id int
	var name string
	var city string

	// Read it back.
	rows, err := db.Query("SELECT * FROM PeopleGo")
	if err != nil {
		panic(err)
	} else {
		for rows.Next() {
			err = rows.Scan(&id, &name, &city)
			checkErr(err)
			table += fmt.Sprintf("<tr><td>%s</td><td>%s</td><tr>\n", name, city)
		}
		table += "</tbody>\n</table>\n"
	}

	_, err = db.Exec("DROP TABLE PeopleGo;")
	checkErr(err)

	return table
}

package examples

import (
	"fmt"
	psh "github.com/platformsh/config-reader-go/v2"
	amqpPsh "github.com/platformsh/config-reader-go/v2/amqp"
	"github.com/streadway/amqp"
	"sync"
)

func UsageExampleRabbitMQ() string {

	// Create a NewRuntimeConfig object to ease reading the Platform.sh environment variables.
	// You can alternatively use os.Getenv() yourself.
	config, err := psh.NewRuntimeConfig()
	checkErr(err)

	// Get the credentials to connect to RabbitMQ.
	credentials, err := config.Credentials("rabbitmq")
	checkErr(err)

	// Use the amqp formatted credentials package.
	formatted, err := amqpPsh.FormattedCredentials(credentials)
	checkErr(err)

	// Connect to the RabbitMQ server.
	connection, err := amqp.Dial(formatted)
	checkErr(err)
	defer connection.Close()

	// Make a channel.
	channel, err := connection.Channel()
	checkErr(err)
	defer channel.Close()

	// Create a queue.
	q, err := channel.QueueDeclare(
		"deploy_days", // name
		false,         // durable
		false,         // delete when unused
		false,         // exclusive
		false,         // no-wait
		nil,           // arguments
	)

	body := "Friday"
	msg := fmt.Sprintf("Deploying on %s", body)

	// Publish a message.
	err = channel.Publish(
		"",     // exchange
		q.Name, // routing key
		false,  // mandatory
		false,  // immediate
		amqp.Publishing{
			ContentType: "text/plain",
			Body:        []byte(msg),
		})
	checkErr(err)

	outputMSG := fmt.Sprintf("[x] Sent '%s' <br>", body)

	// Consume the message.
	msgs, err := channel.Consume(
		q.Name, // queue
		"",     // consumer
		true,   // auto-ack
		false,  // exclusive
		false,  // no-local
		false,  // no-wait
		nil,    // args
	)
	checkErr(err)

	var received string
	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		for d := range msgs {
			received = fmt.Sprintf("[x] Received message: '%s' <br>", d.Body)
			wg.Done()
		}
	}()

	wg.Wait()

	outputMSG += received

	return outputMSG
}

package examples

import (
	"fmt"
	psh "github.com/platformsh/config-reader-go/v2"
	gosolr "github.com/platformsh/config-reader-go/v2/gosolr"
	solr "github.com/rtt/Go-Solr"
)

func UsageExampleSolr() string {

	// Create a NewRuntimeConfig object to ease reading the Platform.sh environment variables.
	// You can alternatively use os.Getenv() yourself.
	config, err := psh.NewRuntimeConfig()
	checkErr(err)

	// Get the credentials to connect to the Solr service.
	credentials, err := config.Credentials("solr")
	checkErr(err)

	// Retrieve Solr formatted credentials.
	formatted, err := gosolr.FormattedCredentials(credentials)
	checkErr(err)

	// Connect to Solr using the formatted credentials.
	connection := &solr.Connection{URL: formatted}

	// Add a document and commit the operation.
	docAdd := map[string]interface{}{
		"add": []interface{}{
			map[string]interface{}{"id": 123, "name": "Valentina Tereshkova"},
		},
	}

	respAdd, err := connection.Update(docAdd, true)
	checkErr(err)

	// Select the document.
	q := &solr.Query{
		Params: solr.URLParamMap{
			"q": []string{"id:123"},
		},
	}

	resSelect, err := connection.CustomSelect(q, "query")
	checkErr(err)

	// Delete the document and commit the operation.
	docDelete := map[string]interface{}{
		"delete": map[string]interface{}{
			"id": 123,
		},
	}

	resDel, err := connection.Update(docDelete, true)
	checkErr(err)

	message := fmt.Sprintf(\x60Adding one document - %s<br>
Selecting document (1 expected): %d<br>
Deleting document - %s<br>
  \x60, respAdd, resSelect.Results.NumFound, resDel)

	return message
}

Project templates

Platform.sh offers a project templates for Go applications using the structure described above. It can be used as a starting point or reference for building your own website or web application.

Generic Go application Beego Echo Gin Hugo