Scheduling
Categories:
Create crontab scheduling on the docker
Create custom crontab file
Create the custom crontab file in the project that names my_docker_crontab
# my_docker_crontab
# m h dom mon dow command
# use the bin/bash as the default environment
* * * * * echo "Hello, world!111" >> /var/log/cron.log 2>&1
* * * * * echo "Hello, world!222" >> /dev/null 2>&1
# If your docker doesn't use the bin/bash as the default environment
* * * * * /bin/bash -l -c 'cd /my/laravel/app/ && php artisan schedule:run >> /dev/null 2>&1'
Install cron application on docker container
FROM ubuntu:latest
RUN apt-get update && apt-get -y install cron
Add custom crontab file
We will copy the custom crontab file my_docker_crontab to docker images. and specify crontab to run this tasks scheduling.
# Add docker custom crontab
ADD my_docker_crontab /etc/cron.d/my_docker_crontab
# Update the crontab file permission
RUN chmod 0644 /etc/cron.d/my_docker_crontab
# Specify crontab file for running
RUN crontab /etc/cron.d/my_docker_crontab
Executing crontab
Finally, we will execute command cron -f to execute our cron tasks every minutes.
# execute crontab
CMD ["cron", "-f"]
Here is the full version of the crontab laravel.cron.Dockerfile
# cronjob.Dockerfile
FROM ubuntu:latest
RUN apt-get update && apt-get -y install cron
# Add docker custom crontab
ADD my_docker_crontab /etc/cron.d/my_docker_crontab
# Update the crontab file permission
RUN chmod 0644 /etc/cron.d/my_docker_crontab
# Specify crontab file for running
RUN crontab /etc/cron.d/my_docker_crontab
# execute crontab
CMD ["cron", "-f"]
Run docker-compose
We will set the setting in docker-compose.yml to run our Dockerfile. And execute docker-compose up -d to running this cronjob container in background
# docker-compose.yml
version: '3'
services:
cronjob:
container_name: cronjob
build: cronjob.Dockerfile
image: cronjob:v1.0
volumes:
- /home/KJ/app:/my/app/
restart: always
docker-compose up -d cronjob
Troubleshooting
/bin/sh: 1: not found
To make sure that the command is run in the /bin/bash environment, you can modify your cron job to explicitly load the Bash environment before running the command.
# my_docker_crontab
# m h dom mon dow command
* * * * * /bin/bash -l -c 'php /path/to/your/script.php'
This will tell cron to run the command in a login shell (-l option), which will load the Bash environment, including any environment variables and aliases that you may have defined.
The -c option is used to specify the command to run. In this case, we’re running the php command with the path to your script as an argument.