Category Archives: Windows

LDAP under WSL2

The Python Flask application I have been dabbling with for the past year or so uses LDAP to authenticate add and update actions. Moving my development host to Ubuntu on Windows Services for Linux on Windows 10 Home edition means I need a local LDAP server.

Slapd on Ubuntu

Now, since I have a Ubuntu ‘VM’ available that is running native and supports installation of standard Ubuntu packages, installing the slapd package would be a natural starting point. But

Setting up slapd (2.4.45+dfsg-1ubuntu1.4) ...
  Backing up /etc/ldap/slapd.d in /var/backups/slapd-... done.
  Moving old database directory to /var/backups:
  - directory unknown... done.
  Creating initial configuration... done.
  Creating LDAP directory... failed.
Loading the initial configuration from the ldif file () failed with
the following error while running slapadd:
    5d72add0 => mdb_next_id: get failed: MDB_BAD_TXN: Transaction must abort, has a child, or is invalid (-30782)
    5d72add0 => mdb_tool_entry_put: cursor_open failed: MDB_BAD_TXN: Transaction must abort, has a child, or is invalid (-30782)
    slapadd: could not add entry dn="dc=localdomain" (line=1): cursor_open failed: MDB_BAD_TXN: Transaction must abort, has a child, or is invalid (-30782)
    5d72add0 mdb_tool_entry_close: database dc=localdomain: txn_commit failed: MDB_BAD_TXN: Transaction must abort, has a child, or is invalid (-30782)
dpkg: error processing package slapd (--configure):
 installed slapd package post-installation script subprocess returned error exit status 1

This kind of service isn’t supported on WSL2.

Slapd on Docker

Slapd is a service well suited to running under a Docker container. But, Docker on Windows desktop is only supported for Windows 10 Pro. I’m on ome.

Slapd for Windows

A quick search for OpenLDAP on Windows turns up an installer from Note that there is a later 2.4.44 version available but this requires a registration key that is no longer available.

Anyhow, Ubuntu’s ldappasswd can be used to create a new rootpw to be added to OpenLDAP\etc\openldap\slapd.conf

$ slappasswd -h {SSHA}

The slapd service can then be started via the Start menu and an ldif in OpenLDAP\etc\ldif\base.ldif edited to include the necessary directory ous, users and groups needed for the Flask service, using the OpenLDAP CLI from the Start menu,

$ ldapadd.exe -v -x -D "cn=Manager,dc=my-domain,dc=com" -f ..\etc\ldif\base.ldif -W

With that the Flask application can make a connection to the LDAP server and authenticate users before allowing updates.


Windows Services for Linux – WSL2

With the ending of development of Antergos Linux announced I started looking around for a new distribution, although to be honest I had tired somewhat on Arch anyway so was eager to branch out a bit.

A friend suggested Manjaro as another Arch-based distro. It didn’t even manage to start the desktop environment for the installer.

I felt guilty at not stumping up any money for the download of elemental Linux but promised that I would donate some of my hard-earneds if it was still around after a week. It was so slow and the interface too much like Unity and really hard to use that it only lasted a day.

Reluctantly I decided to give xubuntu a spin despite my reservations about Ubuntu desktops. But before I could complete the install the PCs power supply failed.

With my son off back to University there’s a Windows 10 desktop idly sitting there only getting powered up to install the latest updates. After a work colleague’s enthusiasm for using Windows Services for Linux I thought I had the perfect opportunity to try it out; I was in the mood for getting back into some project work.

In a word: Loveit.

Sometimes there’s a feeling about something being right and WSL2 is pretty close to that mark. So much so that I doubt that I will make any serious efforts to get the old Linux desktop running again.

It’s not something I’d ever expected to be saying but desktop Linux does seem very tired and very far behind. If I can do my git and build operations from my ubuntu consoles I’ve got everything I need.

I even managed to get the 1903 Win10 update downloaded and installed from