task.go

package cali

import (
	"fmt"
	"os/user"
	"path/filepath"
	"strings"

	log "github.com/sirupsen/logrus"
)

// TaskFunc is a function executed by a Task when the command the Task belongs to is run
type TaskFunc func(t *Task, args []string)

// defaultTaskFunc is the TaskFunc which is executed unless a custom TaskFunc is
// attached to the Task
var defaultTaskFunc TaskFunc = func(t *Task, args []string) {
	if err := t.SetDefaults(args); err != nil {
		log.Fatalf("Error setting container defaults: %s", err)
	}
	if _, err := t.StartContainer(true, ""); err != nil {
		log.Fatalf("Error executing task: %s", err)
	}
}

// Task is the action performed when it's parent command is run
type Task struct {
	f, init TaskFunc
	*DockerClient
}

// SetFunc sets the TaskFunc which is run when the parent command is run
// if this is left unset, the defaultTaskFunc will be executed instead
func (t *Task) SetFunc(f TaskFunc) {
	t.f = f
}

// SetInitFunc sets the TaskFunc which is executed before the main TaskFunc. It's
// pupose is to do any setup of the DockerClient which depends on command line args
// for example
func (t *Task) SetInitFunc(f TaskFunc) {
	t.init = f
}

// SetDefaults sets the default host config for a task container
// Mounts the PWD to /tmp/workspace (Unless task WorkingDir config is set)
// Mounts your ~/.aws directory to /root - change this if your image runs as a non-root user
// Sets /tmp/workspace as the workdir
// Configures git
func (t *Task) SetDefaults(args []string) error {
	if len(t.Conf.WorkingDir) == 0 {
		t.SetWorkDir(workdir)
	}

	err := t.BindFromGit(gitCfg, func() error {
		pwd, err := t.Bind("./", workdir)
		if err != nil {
			return err
		}
		t.AddBinds([]string{pwd})
		return nil
	})
	if err != nil {
		return err
	}
	t.SetCmd(args)
	return nil
}

// Bind is a utility function which will return the correctly formatted string when given a source
// and destination directory
//
// The ~ symbol and relative paths will be correctly expanded depending on the host OS
func (t *Task) Bind(src, dst string) (string, error) {
	var expanded string

	if strings.HasPrefix(src, "~") {
		usr, err := user.Current()

		if err != nil {
			return expanded, fmt.Errorf("Error expanding bind path: %s", err)
		}
		expanded = filepath.Join(usr.HomeDir, src[2:])
	} else {
		expanded = src
	}
	expanded, err := filepath.Abs(expanded)

	if err != nil {
		return expanded, fmt.Errorf("Error expanding bind path: %s", err)
	}
	return fmt.Sprintf("%s:%s", expanded, dst), nil
}