[pkgcfg] Remove config if package is removed (#324)

## Summary

Removes config and broken symlinks when a package is removed. We could also clean up configs as part of `ensurePackagesAreInstalled` (which makes it more reliable) but this requires a bit of refactoring I didn't want to do as part of this PR.

Small unrelated change: made `installMode` type an int using iota (which is a bit more inline with golang quasi-enum pattern)

## How was it tested?

Manual testing:

* Added nginx and mariadb. 
* Inspected conf directory
* Removed one by one
* Inspected conf directory at each step.

Author: mikeland73

devbox.go

@@ -147,6 +147,12 @@ func (d *Devbox) Remove(pkgs ...string) error {
 		return err
 	}
 
+	if featureflag.Get(featureflag.PKGConfig).Enabled() {
+		if err := pkgcfg.Remove(d.configDir, uninstalledPackages); err != nil {
+			return err
+		}
+	}
+
 	if err := d.ensurePackagesAreInstalled(uninstall); err != nil {
 		return err
 	}
@@ -452,6 +458,12 @@ func (d *Devbox) ensurePackagesAreInstalled(mode installMode) error {
 	}
 	fmt.Println("done.")
 
+	if featureflag.Get(featureflag.PKGConfig).Enabled() {
+		if err := pkgcfg.RemoveInvalidSymlinks(d.configDir); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 

pkgcfg/pkgcfg.go

@@ -101,7 +101,7 @@ func createEnvFile(pkg, rootDir string) error {
 		}
 		env += fmt.Sprintf("export %s=%s\n", k, escaped)
 	}
-	filePath := filepath.Join(rootDir, ".devbox/conf/", pkg, "/env")
+	filePath := filepath.Join(rootDir, confPath, pkg, "/env")
 	if err = createDir(filepath.Dir(filePath)); err != nil {
 		return err
 	}
@@ -192,7 +192,8 @@ func displaySourceEnvMessage(pkg, rootDir string, w io.Writer) error {
 	if len(env) > 0 {
 		_, err = fmt.Fprintf(
 			w,
-			"\nTo ensure environment is set, run `source .devbox/conf/%s/env`\n\n",
+			"\nTo ensure environment is set, run `source %s/%s/env`\n\n",
+			confPath,
 			pkg,
 		)
 	}

pkgcfg/rm.go

@@ -0,0 +1,31 @@
+package pkgcfg
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/pkg/errors"
+)
+
+func Remove(rootDir string, pkgs []string) error {
+	for _, pkg := range pkgs {
+		if err := os.RemoveAll(filepath.Join(rootDir, confPath, pkg)); err != nil {
+			return errors.WithStack(err)
+		}
+	}
+	return nil
+}
+
+func RemoveInvalidSymlinks(rootDir string) error {
+	dirEntry, err := os.ReadDir(filepath.Join(rootDir, confPath, "bin"))
+	if err != nil {
+		return errors.WithStack(err)
+	}
+	for _, entry := range dirEntry {
+		_, err := os.Stat(filepath.Join(rootDir, confPath, "bin", entry.Name()))
+		if errors.Is(err, os.ErrNotExist) {
+			os.Remove(filepath.Join(rootDir, confPath, "bin", entry.Name()))
+		}
+	}
+	return nil
+}