diff --git a/README.md b/README.md
index 5b032e3..1a56d3a 100644
--- a/README.md
+++ b/README.md
@@ -174,6 +174,7 @@ So, without further ado, here's the current list:
 - [Dockprom](apps/monitors/dockprom.md)
 - [PhpServerMonitor](apps/monitors/php-server-monitor.md)
 - [Statping](apps/monitors/statping.md)
+- [CheckMK](apps/monitors/checkmk.md)
 
 ### Other, not-fully tested
 - [Staytus](https://github.com/adamcooke/staytus) 🔗 - service status is updated manually!
diff --git a/apps/bookmarks/shaarli.md b/apps/bookmarks/shaarli.md
index c24c73c..e27cf74 100644
--- a/apps/bookmarks/shaarli.md
+++ b/apps/bookmarks/shaarli.md
@@ -7,6 +7,20 @@ Not too bad. Just stores & tags links, nothing more.
 ![Screenshot](shaarli.png)
 
 
+## Prerequisite
+Because of the permission issues with using directory mounts instead of named volumes, the two folders need to be created before running the container:
+```sh
+mkdir cache data
+```
+and their permissions must be changed to be writable by the shaarli user (Uid 100, Gid 101). The simplest and most convenient (but a bit less secure) is to change permissions to 777 (rwx for all):
+```sh
+chmod 777 cache/ data/
+```
+alternatively folders' owner can be changed to the UID 100:
+```sh
+sudo chown 100:101 cache/ data/
+```
+
 ## docker-compose.yml
 ```yml
 ---
diff --git a/apps/monitors/checkmk.md b/apps/monitors/checkmk.md
new file mode 100644
index 0000000..0f39e91
--- /dev/null
+++ b/apps/monitors/checkmk.md
@@ -0,0 +1,36 @@
+# CheckMK
+
+- Pretty complete solution for whole infrastructure monitoring
+- Based on Nagios 
+- Complex UI (not very intuitive)
+- Requires "some" learning & setup and doesn't do anything out of the box
+
+<br>
+
+- [Homepage](https://checkmk.com/)
+- [Github repo](https://github.com/tribe29/checkMK)
+- [DockerHub repo](https://hub.docker.com/r/checkmk/check-mk-raw)
+
+
+## docker-compose.yml
+```yml
+---
+version: '3.6'
+
+services:
+  checkmk:
+    image: checkmk/check-mk-raw
+    container_name: checkmk    
+    restart: unless-stopped
+    ulimits:
+      nofile: 1024
+    ports:
+      - "3123:5000"
+    volumes:
+      - /etc/localtime:/etc/localtime:ro
+      - ./monitoring:/omd/sites
+```
+
+- Open http://localhost:8080/cmk/check_mk/ 
+- Username is `cmkadmin`
+- Password is written in the logs when the container starts the first time, so just run `docker-compose logs` after starting the container