Decode plot data from bytestring to utf-8 before storing in database

[backmari]

Short description of the changes:

When storing plot data from a request to Live Data Server, we need to decode the plot data from bytestring to UTF-8 first.

Long description of the changes:

After deploying the latest version of Live Data Server, new plots that are published to Live Data Server appear on monitor.sns.gov with '\n' instead of linebreaks:

This seems related to a Django 2.0 change in how bytestrings are handled: https://docs.djangoproject.com/en/5.0/releases/2.0/#removed-support-for-bytestrings-in-some-places

Check list for the pull request

• I have read the [CONTRIBUTING]
• I have read the [CODE_OF_CONDUCT]
• I have added tests for my changes
• I have updated the documentation accordingly

Check list for the reviewer

• I have read the [CONTRIBUTING]
• I have verified the proposed changes
• best software practices
  • all internal functions have an underbar, as is python standard
  • clearly named variables (better to be verbose in variable names)
  • code comments explaining the intent of code blocks
• All the tests are passing
• The documentation is up to date
• code comments added when explaining intent

Manual test for the reviewer

Define environment variables (set the hidden values to any strings you like):

export DATABASE_NAME=***
export DATABASE_USER=***
export DATABASE_PASS=***
export DATABASE_HOST=db  # name of the db docker service
export DATABASE_PORT=5432
export LIVE_PLOT_SECRET_KEY=***
export DJANGO_SUPERUSER_USERNAME=$DATABASE_USER
export DJANGO_SUPERUSER_PASSWORD=$DATABASE_PASS

Start the containers:

make local/docker/up

and when the containers are up run the unit test:

pytest tests

References

Defect 5534: Live Data Server plot html string encoding issue

[jmborr]

looks 👌