common: add docker helper functions and tests

common/dockertest_helper.go

@@ -0,0 +1,61 @@
+package common
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+
+	"github.com/ory/dockertest/v3"
+)
+
+// DockerPool is a docker pool resource
+var dockerpool *dockertest.Pool
+
+// GetDockerPool initializes a docker pool
+func GetDockerPool() (*dockertest.Pool, error) {
+	var err error
+	if dockerpool == nil {
+		dockerpool, err = dockertest.NewPool("")
+		if err != nil {
+			err = fmt.Errorf("cannot attach to docker: %v", err)
+			return nil, err
+		}
+	}
+	err = dockerpool.Client.Ping()
+	if err != nil {
+		err = fmt.Errorf("could not connect to Docker: %s", err)
+		return nil, err
+	}
+	return dockerpool, nil
+}
+
+// GetContainerHostAndPort returns the mapped host and port of a docker container for a given portID
+func GetContainerHostAndPort(container *dockertest.Resource, portID string) (server string, port int) {
+	dockerURL := os.Getenv("DOCKER_HOST")
+	containerAddress := container.GetHostPort(portID)
+	s, p, _ := GetHostPort(containerAddress)
+	if dockerURL == "" {
+		server = s
+	} else {
+		// replace server with docker host
+		server, _, _ = GetHostPort(dockerURL)
+	}
+	port = p
+	return
+}
+
+// DestroyDockerContainer destroys a docker container
+func DestroyDockerContainer(container *dockertest.Resource) {
+	if err := dockerpool.Purge(container); err != nil {
+		fmt.Printf("Could not purge resource: %s\n", err)
+	}
+}
+
+// ExecDockerCmd  executes an OS cmd within container and print output
+func ExecDockerCmd(container *dockertest.Resource, cmd []string) (out string, code int, err error) {
+	var cmdout bytes.Buffer
+	cmdout.Reset()
+	code, err = container.Exec(cmd, dockertest.ExecOptions{StdOut: &cmdout})
+	out = cmdout.String()
+	return
+}

common/dockertest_helper_test.go

@@ -0,0 +1,54 @@
+package common
+
+import (
+	"os"
+	"testing"
+
+	"github.com/ory/dockertest/v3"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetDockerHelper(t *testing.T) {
+	var pool *dockertest.Pool
+	var err error
+	var container *dockertest.Resource
+	var server string
+	var port int
+	t.Run("Test GetDockerPool", func(t *testing.T) {
+		pool, err = GetDockerPool()
+		assert.NoErrorf(t, err, "GetDockerPool() should not return error")
+		require.NotNil(t, pool, "GetDockerPool() should not return nil")
+	})
+	t.Run("Test GetDockerContainer", func(t *testing.T) {
+		container, err = pool.Run("nginx", "latest", []string{})
+		assert.NoErrorf(t, err, "Container should start without error")
+		require.NotNil(t, container, "Container should not be nil")
+	})
+	t.Run("Test GetContainerHostAndPort", func(t *testing.T) {
+		server, port = GetContainerHostAndPort(container, "80/tcp")
+		t.Logf("server: %s, port: %d", server, port)
+		assert.Greaterf(t, port, 30000, "GetContainerHostAndPort() should return a port >30000")
+		assert.True(t, server == "localhost" || server == "docker", "GetContainerHostAndPort() should return localhost or docker as server")
+	})
+	t.Run("Test GetContainerHostAndPort other docker", func(t *testing.T) {
+		_ = os.Setenv("DOCKER_HOST", "tcp://web:2375")
+		server, port = GetContainerHostAndPort(container, "80/tcp")
+		t.Logf("server: %s, port: %d", server, port)
+		assert.Greaterf(t, port, 30000, "GetContainerHostAndPort() should return a port >30000")
+		assert.True(t, server == "web", "GetContainerHostAndPort() should return localhost or docker as server")
+	})
+	t.Run("Test Exec on Container", func(t *testing.T) {
+		var cmdout string
+		cmd := []string{"ls", "-ld", "/etc/nginx"}
+		cmdout, _, err = ExecDockerCmd(container, cmd)
+		t.Logf("cmdout: %s", cmdout)
+		assert.NoErrorf(t, err, "ExecDockerCmd() should not return error")
+		assert.Contains(t, cmdout, "/etc/nginx", "ExecDockerCmd() should return /etc/nginx")
+	})
+	t.Run("Test DestroyDockerContainer", func(t *testing.T) {
+		DestroyDockerContainer(container)
+		_, ok := pool.ContainerByName(container.Container.Name)
+		assert.False(t, ok, "Container should not be found in pool after DestroyDockerContainer()")
+	})
+}