Postgres¶

Since testcontainers-go v0.20.0

Introduction¶

The Testcontainers module for Postgres.

Adding this module to your project dependencies¶

Please run the following command to add the Postgres module to your Go dependencies:

go get github.com/testcontainers/testcontainers-go/modules/postgres

Usage example¶

Creating a Postgres container

container, err := RunContainer(ctx,
    testcontainers.WithImage(tt.image),
    WithDatabase(dbname),
    WithUsername(user),
    WithPassword(password),
    testcontainers.WithWaitStrategy(tt.wait),
)
if err != nil {
    t.Fatal(err)
}

Module reference¶

The Postgres module exposes one entrypoint function to create the Postgres container, and this function receives two parameters:

func RunContainer(ctx context.Context, opts ...testcontainers.ContainerCustomizer) (*PostgresContainer, error)

context.Context, the Go context.
testcontainers.ContainerCustomizer, a variadic argument for passing options.

Container Options¶

When starting the Postgres container, you can pass options in a variadic way to configure it.

Tip

You can find all the available configuration and environment variables for the Postgres Docker image on Docker Hub.

Image¶

If you need to set a different Postgres Docker image, you can use testcontainers.WithImage with a valid Docker image for Postgres. E.g. testcontainers.WithImage("docker.io/postgres:9.6").

Initial Database¶

If you need to set a different database, and its credentials, you can use the WithInitialDatabase.

Set Initial database

container, err := RunContainer(
    ctx,
    WithDatabase(dbname),
    WithUsername(user),
    WithPassword(password),
    testcontainers.WithWaitStrategy(wait.ForSQL(nat.Port(port), "postgres", dbURL)),
)
require.NoError(t, err)
require.NotNil(t, container)

Init Scripts¶

If you would like to do additional initialization in the Postgres container, add one or more *.sql, *.sql.gz, or *.sh scripts to the container request. Those files will be copied after the container is created but before it's started under /docker-entrypoint-initdb.d. According to Postgres Docker image, it will run any *.sql files, run any executable *.sh scripts, and source any non-executable *.sh scripts found in that directory to do further initialization before starting the service.

Include init scripts

container, err := RunContainer(ctx,
    testcontainers.WithImage("docker.io/postgres:15.2-alpine"),
    WithInitScripts(filepath.Join("testdata", "init-user-db.sh")),
    WithDatabase(dbname),
    WithUsername(user),
    WithPassword(password),
    testcontainers.WithWaitStrategy(wait.ForLog("database system is ready to accept connections").WithOccurrence(2).WithStartupTimeout(5*time.Second)),
)
if err != nil {
    t.Fatal(err)
}

Init script content

#!/bin/bash
set -e

psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" --dbname "$POSTGRES_DB" <<-EOSQL
    CREATE USER docker;
    CREATE DATABASE docker;
    GRANT ALL PRIVILEGES ON DATABASE docker TO docker;
    CREATE TABLE IF NOT EXISTS testdb (id int, name varchar(255));
    INSERT INTO testdb (id, name) VALUES (1, 'test')
EOSQL

Database configuration¶

In the case you have a custom config file for Postgres, it's possible to copy that file into the container before it's started.

Tip

For information on what is available to configure, see the PostgreSQL docs for the specific version of PostgreSQL that you are running.

Include custom configuration file

container, err := RunContainer(ctx,
    WithConfigFile(filepath.Join("testdata", "my-postgres.conf")),
    WithDatabase(dbname),
    WithUsername(user),
    WithPassword(password),
    testcontainers.WithWaitStrategy(wait.ForLog("database system is ready to accept connections").WithOccurrence(2).WithStartupTimeout(5*time.Second)),
)
if err != nil {
    t.Fatal(err)
}

Wait Strategies¶

Given you could need to wait for different conditions, in particular using a wait.ForSQL strategy, the Postgres container exposes a testcontainers.WithWaitStrategy option to set a custom wait strategy.

Set Wait Strategy

container, err := RunContainer(
    ctx,
    WithDatabase(dbname),
    WithUsername(user),
    WithPassword(password),
    testcontainers.WithWaitStrategy(wait.ForSQL(nat.Port(port), "postgres", dbURL).WithStartupTimeout(time.Second*5).WithQuery("SELECT 10")),
)
require.NoError(t, err)
require.NotNil(t, container)

Container Methods¶

ConnectionString¶

This method returns the connection string to connect to the Postgres container, using the default 5432 port. It's possible to pass extra parameters to the connection string, e.g. sslmode=disable or application_name=myapp, in a variadic way.

Get connection string

// explicitly set sslmode=disable because the container is not configured to use TLS
connStr, err := container.ConnectionString(ctx, "sslmode=disable", "application_name=test")
assert.NoError(t, err)

Postgres variants¶

It's possible to use the Postgres container with Timescale or Postgis, to name a few. You simply need to update the image name and the wait strategy.

Image for Timescale

image: "docker.io/timescale/timescaledb:2.1.0-pg11",
wait:  wait.ForLog("database system is ready to accept connections").WithOccurrence(2).WithStartupTimeout(5 * time.Second),

Image for Postgis

image: "docker.io/postgis/postgis:12-3.0",
wait:  wait.ForLog("database system is ready to accept connections").WithOccurrence(2).WithStartupTimeout(30 * time.Second),