system: move out of internal

Signed-off-by: Ophestra <cat@gensokyo.uk>

1 files changed, 86 insertions, 0 deletions

diff --git a/system/mkdir.go b/system/mkdir.go
new file mode 100644
index 00000000..524289e5
--- /dev/null
+++ b/system/mkdir.go
@@ -0,0 +1,86 @@
+package system
+
+import (
+	"errors"
+	"fmt"
+	"os"
+)
+
+// Ensure the existence and mode of a directory.
+func (sys *I) Ensure(name string, perm os.FileMode) *I {
+	sys.lock.Lock()
+	defer sys.lock.Unlock()
+
+	sys.ops = append(sys.ops, &Mkdir{User, name, perm, false})
+
+	return sys
+}
+
+// Ephemeral ensures the temporary existence and mode of a directory through the life of et.
+func (sys *I) Ephemeral(et Enablement, name string, perm os.FileMode) *I {
+	sys.lock.Lock()
+	defer sys.lock.Unlock()
+
+	sys.ops = append(sys.ops, &Mkdir{et, name, perm, true})
+
+	return sys
+}
+
+type Mkdir struct {
+	et        Enablement
+	path      string
+	perm      os.FileMode
+	ephemeral bool
+}
+
+func (m *Mkdir) Type() Enablement {
+	return m.et
+}
+
+func (m *Mkdir) apply(sys *I) error {
+	sys.println("ensuring directory", m)
+
+	// create directory
+	err := os.Mkdir(m.path, m.perm)
+	if !errors.Is(err, os.ErrExist) {
+		return sys.wrapErrSuffix(err,
+			fmt.Sprintf("cannot create directory %q:", m.path))
+	}
+
+	// directory exists, ensure mode
+	return sys.wrapErrSuffix(os.Chmod(m.path, m.perm),
+		fmt.Sprintf("cannot change mode of %q to %s:", m.path, m.perm))
+}
+
+func (m *Mkdir) revert(sys *I, ec *Criteria) error {
+	if !m.ephemeral {
+		// skip non-ephemeral dir and do not log anything
+		return nil
+	}
+
+	if ec.hasType(m) {
+		sys.println("destroying ephemeral directory", m)
+		return sys.wrapErrSuffix(os.Remove(m.path),
+			fmt.Sprintf("cannot remove ephemeral directory %q:", m.path))
+	} else {
+		sys.println("skipping ephemeral directory", m)
+		return nil
+	}
+}
+
+func (m *Mkdir) Is(o Op) bool {
+	m0, ok := o.(*Mkdir)
+	return ok && m0 != nil && *m == *m0
+}
+
+func (m *Mkdir) Path() string {
+	return m.path
+}
+
+func (m *Mkdir) String() string {
+	t := "Ensure"
+	if m.ephemeral {
+		t = TypeString(m.Type())
+	}
+	return fmt.Sprintf("mode: %s type: %s path: %q", m.perm.String(), t, m.path)
+}