Merge pull request #97 from mdelapenya/25-docker-compose

(#25) Create very basic implementation of Local Docker Compose

README.md

@@ -158,3 +158,71 @@ if err != nil {
 	// do something with err
 }
 ```
+
+## Using Docker Compose
+
+Similar to generic containers support, it's also possible to run a bespoke set of services specified in a docker-compose.yml file.
+
+This is intended to be useful on projects where Docker Compose is already used in dev or other environments to define services that an application may be dependent upon.
+
+You can override Testcontainers' default behaviour and make it use a docker-compose binary installed on the local machine. This will generally yield an experience that is closer to running docker-compose locally, with the caveat that Docker Compose needs to be present on dev and CI machines.
+
+### Examples
+
+```go
+composeFilePaths := "testresources/docker-compose.yml"
+identifier := strings.ToLower(uuid.New().String())
+
+compose := tc.NewLocalDockerCompose(composeFilePaths, identifier)
+execError := compose.
+	WithCommand([]string{"up", "-d"}).
+	WithEnv(map[string]string {
+		"key1": "value1",
+		"key2": "value2",
+	}).
+	Invoke()
+err := execError.Error
+if err != nil {
+	return fmt.Errorf("Could not run compose file: %v - %v", composeFilePaths, err)
+}
+return nil
+```
+
+Note that the environment variables in the `env` map will be applied, if possible, to the existing variables declared in the docker compose file.
+
+In the following example, we demonstrate how to stop a Docker compose using the convenient `Down` method.
+
+```go
+composeFilePaths := "testresources/docker-compose.yml"
+
+compose := tc.NewLocalDockerCompose(composeFilePaths, identifierFromExistingRunningCompose)
+execError := compose.Down()
+err := execError.Error
+if err != nil {
+	return fmt.Errorf("Could not run compose file: %v - %v", composeFilePaths, err)
+}
+return nil
+```
+
+## Troubleshooting Travis
+
+If you want to reproduce a Travis build locally, please follow this instructions to spin up a Travis build agent locally:
+```shell
+export BUILDID="build-testcontainers"
+export INSTANCE="travisci/ci-sardonyx:packer-1564753982-0c06deb6"
+docker run --name $BUILDID -w /root/go/src/github.com/testcontainers/testcontainers-go -v /Users/mdelapenya/sourcecode/src/github.com/mdelapenya/testcontainers-go:/root/go/src/github.com/testcontainers/testcontainers-go -v /var/run/docker.sock:/var/run/docker.sock -dit $INSTANCE /sbin/init
+```
+
+Once the container has been created, enter it (`docker exec -ti $BUILDID bash`) and reproduce Travis steps:
+
+```shell
+eval "$(gimme 1.11.4)"
+export GO111MODULE=on
+export GOPATH="/root/go"
+export PATH="$GOPATH/bin:$PATH"
+go get gotest.tools/gotestsum
+go mod tidy
+go fmt ./...
+go vet ./...
+gotestsum --format short-verbose ./...
+```

compose.go

@@ -0,0 +1,264 @@
+package testcontainers
+
+import (
+	"bytes"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"sync"
+
+	"gopkg.in/yaml.v2"
+)
+
+const (
+	envProjectName = "COMPOSE_PROJECT_NAME"
+	envComposeFile = "COMPOSE_FILE"
+)
+
+// DockerCompose defines the contract for running Docker Compose
+type DockerCompose interface {
+	Down() ExecError
+	Invoke() ExecError
+	WithCommand([]string) DockerCompose
+	WithEnv(map[string]string) DockerCompose
+}
+
+// LocalDockerCompose represents a Docker Compose execution using local binary
+// docker-compose or docker-compose.exe, depending on the underlying platform
+type LocalDockerCompose struct {
+	Executable          string
+	ComposeFilePaths    []string
+	absComposeFilePaths []string
+	Identifier          string
+	Cmd                 []string
+	Env                 map[string]string
+	Services            map[string]interface{}
+}
+
+// NewLocalDockerCompose returns an instance of the local Docker Compose, using an
+// array of Docker Compose file paths and an identifier for the Compose execution.
+//
+// It will iterate through the array adding '-f compose-file-path' flags to the local
+// Docker Compose execution. The identifier represents the name of the execution,
+// which will define the name of the underlying Docker network and the name of the
+// running Compose services.
+func NewLocalDockerCompose(filePaths []string, identifier string) *LocalDockerCompose {
+	dc := &LocalDockerCompose{}
+
+	dc.Executable = "docker-compose"
+	if runtime.GOOS == "windows" {
+		dc.Executable = "docker-compose.exe"
+	}
+
+	dc.ComposeFilePaths = filePaths
+
+	dc.absComposeFilePaths = make([]string, len(filePaths))
+	for i, cfp := range dc.ComposeFilePaths {
+		abs, _ := filepath.Abs(cfp)
+		dc.absComposeFilePaths[i] = abs
+	}
+
+	dc.validate()
+
+	dc.Identifier = strings.ToLower(identifier)
+
+	return dc
+}
+
+// Down executes docker-compose down
+func (dc *LocalDockerCompose) Down() ExecError {
+	return executeCompose(dc, []string{"down"})
+}
+
+func (dc *LocalDockerCompose) getDockerComposeEnvironment() map[string]string {
+	environment := map[string]string{}
+
+	composeFileEnvVariableValue := ""
+	for _, abs := range dc.absComposeFilePaths {
+		composeFileEnvVariableValue += abs + string(os.PathListSeparator)
+	}
+
+	environment[envProjectName] = dc.Identifier
+	environment[envComposeFile] = composeFileEnvVariableValue
+
+	return environment
+}
+
+// Invoke invokes the docker compose
+func (dc *LocalDockerCompose) Invoke() ExecError {
+	return executeCompose(dc, dc.Cmd)
+}
+
+// WithCommand assigns the command
+func (dc *LocalDockerCompose) WithCommand(cmd []string) DockerCompose {
+	dc.Cmd = cmd
+	return dc
+}
+
+// WithEnv assigns the environment
+func (dc *LocalDockerCompose) WithEnv(env map[string]string) DockerCompose {
+	dc.Env = env
+	return dc
+}
+
+// validate checks if the files to be run in the compose are valid YAML files, setting up
+// references to all services in them
+func (dc *LocalDockerCompose) validate() error {
+	type compose struct {
+		Services map[string]interface{}
+	}
+
+	for _, abs := range dc.absComposeFilePaths {
+		c := compose{}
+
+		yamlFile, err := ioutil.ReadFile(abs)
+		if err != nil {
+			return err
+		}
+		err = yaml.Unmarshal(yamlFile, &c)
+		if err != nil {
+			return err
+		}
+
+		dc.Services = c.Services
+	}
+
+	return nil
+}
+
+// ExecError is super struct that holds any information about an execution error, so the client code
+// can handle the result
+type ExecError struct {
+	Command []string
+	Error   error
+	Stdout  error
+	Stderr  error
+}
+
+// execute executes a program with arguments and environment variables inside a specific directory
+func execute(
+	dirContext string, environment map[string]string, binary string, args []string) ExecError {
+
+	var errStdout, errStderr error
+
+	cmd := exec.Command(binary, args...)
+	cmd.Dir = dirContext
+	cmd.Env = os.Environ()
+
+	for key, value := range environment {
+		cmd.Env = append(cmd.Env, key+"="+value)
+	}
+
+	stdoutIn, _ := cmd.StdoutPipe()
+	stderrIn, _ := cmd.StderrPipe()
+
+	stdout := newCapturingPassThroughWriter(os.Stdout)
+	stderr := newCapturingPassThroughWriter(os.Stderr)
+
+	err := cmd.Start()
+	if err != nil {
+		execCmd := []string{"Starting command", dirContext, binary}
+		execCmd = append(execCmd, args...)
+
+		return ExecError{
+			// add information about the CMD and arguments used
+			Command: execCmd,
+			Error:   err,
+			Stderr:  errStderr,
+			Stdout:  errStdout,
+		}
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+
+	go func() {
+		_, errStdout = io.Copy(stdout, stdoutIn)
+		wg.Done()
+	}()
+
+	_, errStderr = io.Copy(stderr, stderrIn)
+	wg.Wait()
+
+	err = cmd.Wait()
+
+	execCmd := []string{"Reading std", dirContext, binary}
+	execCmd = append(execCmd, args...)
+
+	return ExecError{
+		Command: execCmd,
+		Error:   err,
+		Stderr:  errStderr,
+		Stdout:  errStdout,
+	}
+}
+
+func executeCompose(dc *LocalDockerCompose, args []string) ExecError {
+	if which(dc.Executable) != nil {
+		panic("Local Docker Compose not found. Is " + dc.Executable + " on the PATH?")
+	}
+
+	environment := dc.getDockerComposeEnvironment()
+	for k, v := range dc.Env {
+		environment[k] = v
+	}
+
+	cmds := []string{}
+	pwd := "."
+	if len(dc.absComposeFilePaths) > 0 {
+		pwd, _ = filepath.Split(dc.absComposeFilePaths[0])
+
+		for _, abs := range dc.absComposeFilePaths {
+			cmds = append(cmds, "-f", abs)
+		}
+	} else {
+		cmds = append(cmds, "-f", "docker-compose.yml")
+	}
+	cmds = append(cmds, args...)
+
+	execErr := execute(pwd, environment, dc.Executable, cmds)
+	err := execErr.Error
+	if err != nil {
+		args := strings.Join(dc.Cmd, " ")
+		panic(
+			"Local Docker compose exited abnormally whilst running " +
+				dc.Executable + ": [" + args + "]. " + err.Error())
+	}
+
+	return execErr
+}
+
+// capturingPassThroughWriter is a writer that remembers
+// data written to it and passes it to w
+type capturingPassThroughWriter struct {
+	buf bytes.Buffer
+	w   io.Writer
+}
+
+// newCapturingPassThroughWriter creates new capturingPassThroughWriter
+func newCapturingPassThroughWriter(w io.Writer) *capturingPassThroughWriter {
+	return &capturingPassThroughWriter{
+		w: w,
+	}
+}
+
+func (w *capturingPassThroughWriter) Write(d []byte) (int, error) {
+	w.buf.Write(d)
+	return w.w.Write(d)
+}
+
+// Bytes returns bytes written to the writer
+func (w *capturingPassThroughWriter) Bytes() []byte {
+	return w.buf.Bytes()
+}
+
+// Which checks if a binary is present in PATH
+func which(binary string) error {
+	_, err := exec.LookPath(binary)
+
+	return err
+}