Add sample on how to run a cron task in a docker container

Dockerfile

@@ -0,0 +1,12 @@
+# Dockerfile to create image with cron services
+FROM ubuntu:latest
+
+# Install Cron
+RUN apt-get update \
+    && apt-get -y install cron \
+    && rm -rf /var/lib/apt/lists/*
+
+RUN useradd test
+
+# Run the command on container startup
+CMD crontab -u test /home/test/cron/crontab-file && cron -f

crontab-file

@@ -0,0 +1 @@
+* * * * * bash /test/cron/task.sh

docker-compose.yml

@@ -0,0 +1,8 @@
+version: '3'
+services:
+  cron:
+    build: .
+    volumes:
+      - ./output:/output
+      - ./:/home/test/cron
+    

output/out.txt

@@ -0,0 +1,19 @@
+Hello World at Thu Nov 30 21:45:01 UTC 2023
+Hello World at Thu Nov 30 21:46:01 UTC 2023
+Hello World at Thu Nov 30 21:47:01 UTC 2023
+Hello World at Thu Nov 30 21:48:01 UTC 2023
+Hello World at Thu Nov 30 21:52:01 UTC 2023
+Hello World at Thu Nov 30 21:53:01 UTC 2023
+Hello World at Thu Nov 30 21:54:01 UTC 2023
+Hello World at Thu Nov 30 21:55:01 UTC 2023
+Hello World at Thu Nov 30 21:56:01 UTC 2023
+Hello World at Thu Nov 30 21:57:01 UTC 2023
+Hello World at Thu Nov 30 22:02:01 UTC 2023
+Hello World at Thu Nov 30 22:03:01 UTC 2023
+Hello World at Thu Nov 30 22:04:01 UTC 2023
+Hello World at Thu Nov 30 22:05:01 UTC 2023
+Hello World at Thu Nov 30 22:06:01 UTC 2023
+Hello World at Thu Nov 30 22:07:01 UTC 2023
+Hello World at at at at at Thu Nov 30 22:08:01 UTC 2023
+Hello World at at at at at Thu Nov 30 22:09:01 UTC 2023: /root
+Hello World at at at at at Thu Nov 30 22:10:01 UTC 2023: /root

task.sh

@@ -0,0 +1 @@
+echo "Hello World at at at at at $(date): $(pwd)" >> /output/out.txt