Add Virtualenv struct

trellis/virtualenv.go

@@ -0,0 +1,82 @@
+package trellis
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	"trellis-cli/github"
+)
+
+const VirtualenvDir string = "virtualenv"
+const EnvName string = "VIRTUALENV"
+
+type Virtualenv struct {
+	Path    string
+	BinPath string
+}
+
+func NewVirtualenv(path string) *Virtualenv {
+	return &Virtualenv{
+		Path:    filepath.Join(path, VirtualenvDir),
+		BinPath: filepath.Join(path, VirtualenvDir, "bin"),
+	}
+}
+
+func (v *Virtualenv) Activate() {
+	os.Setenv(EnvName, v.Path)
+	os.Setenv("PATH", fmt.Sprintf("%s/bin:$PATH", v.Path))
+}
+
+func (v *Virtualenv) Active() bool {
+	return v.BinPath == os.Getenv(EnvName)
+}
+
+func (v *Virtualenv) Create() (err error) {
+	// TODO: error if not installed? or install
+	_, cmd := v.Installed()
+
+	cmd.Args = append(cmd.Args, v.Path)
+
+	err = cmd.Run()
+	if err != nil {
+		return err
+	}
+
+	v.Activate()
+	return nil
+}
+
+func (v *Virtualenv) Initialized() bool {
+	if _, err := os.Stat(filepath.Join(v.BinPath, "python")); os.IsNotExist(err) {
+		return false
+	}
+
+	if _, err := os.Stat(filepath.Join(v.BinPath, "pip")); os.IsNotExist(err) {
+		return false
+	}
+
+	return true
+}
+
+func (v *Virtualenv) Install(path string) string {
+	installPath := github.DownloadLatestRelease("pypa/virtualenv", os.TempDir(), path)
+	return installPath
+}
+
+func (v *Virtualenv) Installed() (ok bool, cmd *exec.Cmd) {
+	path, err := exec.LookPath("python3")
+	if err == nil {
+		return true, exec.Command(path, "-m", "venv")
+	}
+
+	path, err = exec.LookPath("virtualenv")
+	if err == nil {
+		return true, exec.Command(path)
+	}
+
+	// TODO: check for local virtualenv installed by trellis-cli
+
+	return false, nil
+}