Code maintenance: OS package for file system

- OS custom internal package for file system interaction
- Remove fileManager external dependency
- Closer API to Go's native API on the OS
- Create directories at startup
- Better testability
- Move Unsetenv to os interface

internal/os/mock_os/os.go

@@ -0,0 +1,121 @@
+// Code generated by MockGen. DO NOT EDIT.
+// Source: github.com/qdm12/gluetun/internal/os (interfaces: OS)
+
+// Package mock_os is a generated GoMock package.
+package mock_os
+
+import (
+	gomock "github.com/golang/mock/gomock"
+	os "github.com/qdm12/gluetun/internal/os"
+	os0 "os"
+	reflect "reflect"
+)
+
+// MockOS is a mock of OS interface
+type MockOS struct {
+	ctrl     *gomock.Controller
+	recorder *MockOSMockRecorder
+}
+
+// MockOSMockRecorder is the mock recorder for MockOS
+type MockOSMockRecorder struct {
+	mock *MockOS
+}
+
+// NewMockOS creates a new mock instance
+func NewMockOS(ctrl *gomock.Controller) *MockOS {
+	mock := &MockOS{ctrl: ctrl}
+	mock.recorder = &MockOSMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use
+func (m *MockOS) EXPECT() *MockOSMockRecorder {
+	return m.recorder
+}
+
+// Chown mocks base method
+func (m *MockOS) Chown(arg0 string, arg1, arg2 int) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Chown", arg0, arg1, arg2)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// Chown indicates an expected call of Chown
+func (mr *MockOSMockRecorder) Chown(arg0, arg1, arg2 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Chown", reflect.TypeOf((*MockOS)(nil).Chown), arg0, arg1, arg2)
+}
+
+// MkdirAll mocks base method
+func (m *MockOS) MkdirAll(arg0 string, arg1 os.FileMode) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "MkdirAll", arg0, arg1)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// MkdirAll indicates an expected call of MkdirAll
+func (mr *MockOSMockRecorder) MkdirAll(arg0, arg1 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "MkdirAll", reflect.TypeOf((*MockOS)(nil).MkdirAll), arg0, arg1)
+}
+
+// OpenFile mocks base method
+func (m *MockOS) OpenFile(arg0 string, arg1 int, arg2 os.FileMode) (os.File, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "OpenFile", arg0, arg1, arg2)
+	ret0, _ := ret[0].(os.File)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// OpenFile indicates an expected call of OpenFile
+func (mr *MockOSMockRecorder) OpenFile(arg0, arg1, arg2 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "OpenFile", reflect.TypeOf((*MockOS)(nil).OpenFile), arg0, arg1, arg2)
+}
+
+// Remove mocks base method
+func (m *MockOS) Remove(arg0 string) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Remove", arg0)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// Remove indicates an expected call of Remove
+func (mr *MockOSMockRecorder) Remove(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Remove", reflect.TypeOf((*MockOS)(nil).Remove), arg0)
+}
+
+// Stat mocks base method
+func (m *MockOS) Stat(arg0 string) (os0.FileInfo, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Stat", arg0)
+	ret0, _ := ret[0].(os0.FileInfo)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// Stat indicates an expected call of Stat
+func (mr *MockOSMockRecorder) Stat(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Stat", reflect.TypeOf((*MockOS)(nil).Stat), arg0)
+}
+
+// Unsetenv mocks base method
+func (m *MockOS) Unsetenv(arg0 string) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Unsetenv", arg0)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// Unsetenv indicates an expected call of Unsetenv
+func (mr *MockOSMockRecorder) Unsetenv(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Unsetenv", reflect.TypeOf((*MockOS)(nil).Unsetenv), arg0)
+}