Create Cron Jobs for Backing Up Database Periodically

[rivernews]

Seems like the K8 cron job is not working, because doesn't receive admin email.

[rivernews]

For future reference:

If you want to migrate to an database that already has some data in it (it's like a restore):

• If you don't have a db backup .json yet, create one by dumping the previous database: ./manage.py dumpdata > backup.json.
• Flush Django database. python manage.py flush
• Load Django database from json.
  • (python manage.py migrate no need, only for brand new database)
  • Then echo "delete from auth_permission; delete from django_content_type;" | python manage.py dbshell
  • Then python manage.py loaddata the-dumped-db-backup.json

If you are migrating to a brand new database:

• Follow the steps above except no need to do flush.

Some useful K8 commands for debugging cron jobs

# Example: get the pods running the job `db-backup-cronjob-1566709740`
. ./my-kubectl.sh get pods --selector=job-name=db-backup-cronjob-1566709740 -n cicd-django

. ./my-kubectl.sh get jobs

# You can also grep to get cron job pods
. ./my-kubectl.sh get pods --all-namespaces | grep cron

# Or try combo to get the pod
job_name="$(. ./my-kubectl.sh get jobs | grep --max-count 1 cronjob | awk '{print $1;}')"
echo "job name is ${job_name}"
. ./my-kubectl.sh get pods --all-namespaces --selector=job-name=${job_name} 
# pods=$(. ./my-kubectl.sh get pods --selector=job-name=${job_name} --output=jsonpath={.items[].metadata.name})

# Get the log
 . ./my-kubectl.sh logs $pods

# Directly by the name
 . ./my-kubectl.sh get jobs
 . ./my-kubectl.sh logs jobs/<the job name you see>