diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..3629d9a
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,5 @@
+FROM python:3.8-slim
+RUN apt-get update \
+    && apt-get install -y git \
+    && apt-get autoclean \
+    && pip install pre-commit
diff --git a/README.md b/README.md
index bc78816..11ae720 100644
--- a/README.md
+++ b/README.md
@@ -101,3 +101,16 @@ Variables replaced in the service template:
 * `service_state` (= `$SERVICESTATE$`)
 * `long_date_time` (= `$LONGDATETIME$`)
 * `service_output` (= `$SERVICEOUTPUT$`)
+
+## How to contribute
+
+Contributions are welcomed! Feel free to update the code and create a pull-request.
+
+Be sure to lint the code before:
+```
+docker build -t pre-commit .
+docker run -it -v $(pwd):/mnt/ --rm pre-commit bash
+# cd /mnt/
+# pre-commit run --all-files
+# exit
+```
diff --git a/TODO.txt b/TODO.txt
index da36fd8..06b3974 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -1,2 +1 @@
-Add pre-commit Dockerfile and a doc to easily lint the code
 Add requirements.txt file