Spanner

Creating a Spanner container

package spanner

import (
    "context"
    "fmt"

    "github.com/testcontainers/testcontainers-go/wait"

    "github.com/testcontainers/testcontainers-go"
)

// spannerContainer represents the spanner container type used in the module
type spannerContainer struct {
    testcontainers.Container
    GRPCEndpoint string
}

// startContainer creates an instance of the spanner container type
func startContainer(ctx context.Context) (*spannerContainer, error) {
    req := testcontainers.ContainerRequest{
        Image:        "gcr.io/cloud-spanner-emulator/emulator:1.4.0",
        ExposedPorts: []string{"9010/tcp"},
        WaitingFor:   wait.ForLog("Cloud Spanner emulator running"),
    }
    container, err := testcontainers.GenericContainer(ctx, testcontainers.GenericContainerRequest{
        ContainerRequest: req,
        Started:          true,
    })
    if err != nil {
        return nil, err
    }

    mappedPort, err := container.MappedPort(ctx, "9010")
    if err != nil {
        return nil, err
    }

    hostIP, err := container.Host(ctx)
    if err != nil {
        return nil, err
    }

    grpcEndpoint := fmt.Sprintf("%s:%s", hostIP, mappedPort.Port())

    return &spannerContainer{Container: container, GRPCEndpoint: grpcEndpoint}, nil
}

Test for a Spanner container

package spanner

import (
    "cloud.google.com/go/spanner"
    database "cloud.google.com/go/spanner/admin/database/apiv1"
    instance "cloud.google.com/go/spanner/admin/instance/apiv1"
    "context"
    "fmt"
    "google.golang.org/api/option"
    "google.golang.org/api/option/internaloption"
    databasepb "google.golang.org/genproto/googleapis/spanner/admin/database/v1"
    instancepb "google.golang.org/genproto/googleapis/spanner/admin/instance/v1"
    "google.golang.org/grpc"
    "google.golang.org/grpc/credentials/insecure"
    "testing"
)

const (
    projectId    = "test-project"
    instanceId   = "test-instance"
    databaseName = "test-db"
)

func TestSpanner(t *testing.T) {
    ctx := context.Background()

    container, err := startContainer(ctx)
    if err != nil {
        t.Fatal(err)
    }

    // Clean up the container after the test is complete
    t.Cleanup(func() {
        if err := container.Terminate(ctx); err != nil {
            t.Fatalf("failed to terminate container: %s", err)
        }
    })

    options := []option.ClientOption{
        option.WithEndpoint(container.GRPCEndpoint),
        option.WithGRPCDialOption(grpc.WithTransportCredentials(insecure.NewCredentials())),
        option.WithoutAuthentication(),
        internaloption.SkipDialSettingsValidation(),
    }

    instanceAdmin, err := instance.NewInstanceAdminClient(ctx, options...)
    if err != nil {
        t.Fatal(err)
    }
    defer instanceAdmin.Close()

    instanceOp, err := instanceAdmin.CreateInstance(ctx, &instancepb.CreateInstanceRequest{
        Parent:     fmt.Sprintf("projects/%s", projectId),
        InstanceId: instanceId,
        Instance: &instancepb.Instance{
            DisplayName: instanceId,
        },
    })
    if err != nil {
        t.Fatal(err)
    }
    _, err = instanceOp.Wait(ctx)
    if err != nil {
        t.Fatal(err)
    }

    c, err := database.NewDatabaseAdminClient(ctx, options...)
    if err != nil {
        t.Fatal(err)
    }
    defer c.Close()

    databaseOp, err := c.CreateDatabase(ctx, &databasepb.CreateDatabaseRequest{
        Parent:          fmt.Sprintf("projects/%s/instances/%s", projectId, instanceId),
        CreateStatement: fmt.Sprintf("CREATE DATABASE `%s`", databaseName),
        ExtraStatements: []string{
            "CREATE TABLE Languages (Language STRING(MAX), Mascot STRING(MAX)) PRIMARY KEY (Language)",
        },
    })
    if err != nil {
        t.Fatal(err)
    }
    _, err = databaseOp.Wait(ctx)
    if err != nil {
        t.Fatal(err)
    }

    db := fmt.Sprintf("projects/%s/instances/%s/databases/%s", projectId, instanceId, databaseName)
    client, err := spanner.NewClient(ctx, db, options...)
    if err != nil {
        t.Fatal(err)
    }
    defer client.Close()

    _, err = client.Apply(ctx, []*spanner.Mutation{
        spanner.Insert("Languages",
            []string{"language", "mascot"},
            []interface{}{"Go", "Gopher"})})
    if err != nil {
        t.Fatal(err)
    }
    row, err := client.Single().ReadRow(ctx, "Languages",
        spanner.Key{"Go"}, []string{"mascot"})
    if err != nil {
        t.Fatal(err)
    }

    var mascot string
    err = row.ColumnByName("Mascot", &mascot)
    if err != nil {
        t.Fatal(err)
    }
    // perform assertions
    if mascot != "Gopher" {
        t.Fatalf("Expected value %s. Got %s.", "Gopher", mascot)
    }
}