demo README

demo/README.md

@@ -1,7 +1,34 @@
 # Demo and development
 
 To check out how canaille looks like, or to start contributions, just run it with `./run.sh`!
-You need to have either `OpenLDAP`, or `docker` plus `docker-compose` installed on your system.
+
+# Prerequisites
+
+You need to have `OpenLDAP` somewhere in your system.
+
+You can either:
+- install it with your distro packages *(for instance `sudo apt install slapd ldap-utils` with Ubuntu)*.
+  it is not required to launch the system ldap service.
+- have `docker` plus `docker-compose` installed on your system, the `./run.sh` script will download and
+  run a OpenLDAP image.
+
+canaille depends on [python-ldap](https://github.com/python-ldap/python-ldap), and this package needs
+some headers to be installed on your system to be built. For instance on Ubuntu you can install this:
+`sudo apt install libsasl2-dev python-dev libldap2-dev libssl-dev`. More info
+[on this SO ticket](https://stackoverflow.com/questions/4768446/i-cant-install-python-ldap).
+
+## Apparmor
+
+On Ubuntu systems, apparmor prevents *slapd* from accessing files that are not in the standard
+OpenLDAP installation. This may result in canaille being impossible to launch. To fix this you
+can pass slapd in complain mode:
+
+```bash
+sudo apt install --yes apparmor-utils
+sudo aa-complain /usr/sbin/slapd
+```
+
+# Run the demo
 
 Then you have access to: