runner.go

//go:generate go run github.com/maxbrunsfeld/counterfeiter/v6 . CommandRunner
package containertools

import (
	"fmt"
	"os/exec"
	"strings"

	"github.com/sirupsen/logrus"
)

// CommandRunner defines methods to shell out to common container tools
type CommandRunner interface {
	GetToolName() string
	Pull(image string) error
	Build(dockerfile, tag string) error
	Inspect(image string) ([]byte, error)
}

// ContainerCommandRunner is configured to select a container cli tool and
// execute commands with that tooling.
type ContainerCommandRunner struct {
	logger        *logrus.Entry
	containerTool ContainerTool
}

// NewCommandRunner takes the containerTool as an input string and returns a
// CommandRunner to run commands with that cli tool
func NewCommandRunner(containerTool ContainerTool, logger *logrus.Entry) *ContainerCommandRunner {
	r := &ContainerCommandRunner{
		logger:        logger,
		containerTool: containerTool,
	}
	return r
}

// GetToolName returns the container tool this command runner is using
func (r *ContainerCommandRunner) GetToolName() string {
	return r.containerTool.String()
}

// Pull takes a container image path hosted on a container registry and runs the
// pull command to download it onto the local environment
func (r *ContainerCommandRunner) Pull(image string) error {
	args := []string{"pull", image}

	command := exec.Command(r.containerTool.String(), args...)

	r.logger.Infof("running %s", command.String())

	out, err := command.CombinedOutput()
	if err != nil {
		r.logger.Errorf(string(out))
		return fmt.Errorf("error pulling image: %s. %v", string(out), err)
	}

	return nil
}

// Build takes a dockerfile and a tag and builds a container image
func (r *ContainerCommandRunner) Build(dockerfile, tag string) error {
	o := DefaultBuildOptions()
	if tag != "" {
		o.AddTag(tag)
	}
	o.SetDockerfile(dockerfile)
	o.SetContext(".")
	command, err := r.containerTool.CommandFactory().BuildCommand(o)
	if err != nil {
		return fmt.Errorf("unable to perform build: %v", err)
	}

	r.logger.Infof("running %s build", r.containerTool)
	r.logger.Infof("%s", command.Args)

	out, err := command.CombinedOutput()
	if err != nil {
		r.logger.Errorf(string(out))
		return fmt.Errorf("error building image: %s. %v", string(out), err)
	}

	return nil
}

// Unpack copies a directory from a local container image to a directory in the local filesystem.
func (r *ContainerCommandRunner) Unpack(image, src, dst string) error {
	args := []string{"create", image, ""}

	command := exec.Command(r.containerTool.String(), args...)

	r.logger.Infof("running %s create", r.containerTool)
	r.logger.Debugf("%s", command.Args)

	out, err := command.CombinedOutput()
	if err != nil {
		r.logger.Errorf(string(out))
		return fmt.Errorf("error creating container %s: %v", string(out), err)
	}

	id := strings.TrimSuffix(string(out), "\n")
	args = []string{"cp", id + ":" + src, dst}
	command = exec.Command(r.containerTool.String(), args...)

	r.logger.Infof("running %s cp", r.containerTool)
	r.logger.Debugf("%s", command.Args)

	out, err = command.CombinedOutput()
	if err != nil {
		r.logger.Errorf(string(out))
		return fmt.Errorf("error copying container directory %s: %v", string(out), err)
	}

	args = []string{"rm", id}
	command = exec.Command(r.containerTool.String(), args...)

	r.logger.Infof("running %s rm", r.containerTool)
	r.logger.Debugf("%s", command.Args)

	out, err = command.CombinedOutput()
	if err != nil {
		r.logger.Errorf(string(out))
		return fmt.Errorf("error removing container %s: %v", string(out), err)
	}

	return nil
}

// Inspect runs the 'inspect' command to get image metadata of a local container
// image and returns a byte array of the command's output
func (r *ContainerCommandRunner) Inspect(image string) ([]byte, error) {
	args := []string{"inspect", image}

	command := exec.Command(r.containerTool.String(), args...)

	r.logger.Infof("running %s inspect", r.containerTool)
	r.logger.Debugf("%s", command.Args)

	out, err := command.Output()
	if err != nil {
		r.logger.Errorf(string(out))
		return nil, err
	}

	return out, err
}