# Running Healthchecks - A Cron Job Monitoring Service - In Docker

## What is Healthchecks?

> Healthchecks is a cron job monitoring service. It listens for HTTP requests and email messages ("pings") from your cron jobs and scheduled tasks ("checks"). When a ping does not arrive on time, Healthchecks sends out alerts.

> Healthchecks comes with a web dashboard, API, 25+ integrations for delivering notifications, monthly email reports, WebAuthn 2FA support, team management features: projects, team members, read-only access. -https://github.com/healthchecks/healthchecks

## Installing Docker

1. Log into the Linux based device
2. Run the following commands in the terminal
   # install prerequisites
   sudo apt install apt-transport-https ca-certificates curl software-properties-common gnupg-agent -y
   # add docker gpg key
   curl -fsSL https://download.docker.com/linux/$(awk -F'=' '/^ID=/{ print $NF }' /etc/os-release)/gpg | sudo apt-key add -
   # add docker software repository
   sudo add-apt-repository "deb [arch=$(dpkg --print-architecture)] https://download.docker.com/linux/$(awk -F'=' '/^ID=/{ print $NF }' /etc/os-release) $(lsb_release -cs) stable"
   # install docker
   sudo apt install docker-ce docker-compose containerd.io -y
   # enable and start docker service
   sudo systemctl enable docker && sudo systemctl start docker
   # add the current user to the docker group
   sudo usermod -aG docker $USER
   # reauthenticate for the new group membership to take effect
   su - $USER

## Running the Healthchecks Container

1. Now that Docker is installed, run the following commands to setup the Healthchecks Docker container and run it
   # create working directories
   mkdir ~/docker/postresql -p && mkdir ~/docker/healthchecks -p
   # create containers network
   docker network create containers
   # download the base configuration
   wget -O ~/docker/healthchecks/.env https://raw.githubusercontent.com/healthchecks/healthchecks/master/docker/.env.example
   # generate a 32 character random string
   head /dev/urandom | LC_ALL=C tr -dc 'A-Za-z0-9' | head -c 32
   # copy the output string to the clipboard
   # edit the .env file
   nano ~/docker/healthchecks/.env
2. Scroll through the .env file, updating at least the key/value pairs listed below

   ALLOWED_HOSTS=*
   ---
   DB=postgres
   DB_HOST=postgres
   DB_NAME=healthchecks
   DB_PASSWORD=He@lt4Ch3ck$!
   DB_USER=healthchecks_rw
   ---
   DEFAULT_FROM_EMAIL=healthchecks@i12bretro.local
   ---
   EMAIL_HOST=smtp.i12bretro.local
   EMAIL_HOST_PASSWORD=
   EMAIL_HOST_USER=
   EMAIL_PORT=25
   EMAIL_USE_TLS=False
   EMAIL_USE_VERIFICATION=False
   ---
   SECRET_KEY=<% random string from clipboard %>

3. Press CTRL+W and search for localhost
4. Update all references to localhost with the DNS or IP address of the docker host (ie SITE_ROOT=http://localhost:8000 -> http://ubuntuserver.local:8000)
5. Press CTRL+O, Enter, CTRL+X to write the changes to .env
6. Continue with the following commands in terminal
   # set owner of working directories
   sudo chown "$USER":"$USER" ~/docker -R
   # run the postgresql docker container
   docker run -d --name postgres -e POSTGRES_USER=healthchecks_rw -e POSTGRES_PASSWORD='He@lt4Ch3ck$!' -e POSTGRES_DB=healthchecks -v /home/$USER/docker/postresql:/var/lib/postgresql/data --network containers --restart=unless-stopped postgres
   # run the healthchecks container
   docker run -d --name healthchecks --env-file ~/docker/healthchecks/.env -p 8000:8000 --network containers --restart=unless-stopped healthchecks/healthchecks
   # connect to healthchecks container shell
   docker exec -ti healthchecks /bin/bash
   # create an admin user
   /opt/healthchecks/manage.py createsuperuser
   # enter an email address
   # enter and confirm a password
   # exit the container shell
   exit
7. Open a web browser and navigate to http://DNSorIP:8000
8. Login with the admin account created earlier
9. Welcome to HealthChecks

Documentation: https://hub.docker.com/r/healthchecks/healthchecks