[AIRFLOW-5744] Environment variables not correctly set in SparkSubmitHook

[jmccartin]

This pull request fixes a case where the environment variables supported by the Spark submit operator were not being applied at runtime when running in YARN mode. This is useful when creating dynamic clusters on a cloud environment, where the master address isn't known apriori. For more information, please see the associated Jira.

Also fixed a typo in a comment in the same file.

Closes AIRFLOW-5744

Jira

• My PR addresses the following Airflow Jira issues and references them in the PR title. For example, "[AIRFLOW-XXX] My Airflow PR"
  • https://issues.apache.org/jira/browse/AIRFLOW-5744
  • In case you are fixing a typo in the documentation you can prepend your commit with [AIRFLOW-XXX], code changes always need a Jira issue.
  • In case you are proposing a fundamental code change, you need to create an Airflow Improvement Proposal (AIP).
  • In case you are adding a dependency, check if the license complies with the ASF 3rd Party License Policy.

Description

• Here are some details about my PR, including screenshots of any UI changes:

Tests

• My PR adds the following unit tests OR does not need testing for this extremely good reason:

Commits

• My commits all reference Jira issues in their subject lines, and I have squashed multiple commits if they address the same issue. In addition, my commits follow the guidelines from "How to write a good git commit message":
  1. Subject is separated from body by a blank line
  2. Subject is limited to 50 characters (not including Jira issue reference)
  3. Subject does not end with a period
  4. Subject uses the imperative mood ("add", not "adding")
  5. Body wraps at 72 characters
  6. Body explains "what" and "why", not "how"

Documentation

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  • All the public functions and the classes in the PR contain docstrings that explain what it does
  • If you implement backwards incompatible changes, please leave a note in the Updating.md so we can assign it to a appropriate release

[codecov-io]

Codecov Report

Merging #6796 into master will decrease coverage by 0.36%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #6796      +/-   ##
==========================================
- Coverage   84.55%   84.19%   -0.37%     
==========================================
  Files         672      672              
  Lines       38183    38184       +1     
==========================================
- Hits        32285    32148     -137     
- Misses       5898     6036     +138

Impacted Files	Coverage Δ
airflow/contrib/hooks/spark_submit_hook.py	82.5% <100%> (+0.07%)	⬆️
airflow/operators/postgres_operator.py	0% <0%> (-100%)	⬇️
airflow/kubernetes/volume_mount.py	44.44% <0%> (-55.56%)	⬇️
airflow/kubernetes/volume.py	52.94% <0%> (-47.06%)	⬇️
airflow/kubernetes/pod_launcher.py	45.25% <0%> (-46.72%)	⬇️
airflow/kubernetes/refresh_config.py	50.98% <0%> (-23.53%)	⬇️
...rflow/contrib/operators/kubernetes_pod_operator.py	78.2% <0%> (-20.52%)	⬇️
airflow/utils/sqlalchemy.py	94.91% <0%> (-1.7%)	⬇️
airflow/hooks/dbapi_hook.py	89.83% <0%> (-1.7%)	⬇️
airflow/hooks/postgres_hook.py	92.95% <0%> (-1.41%)	⬇️
... and 1 more

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[dimberman]

LGTM