CI pipeline for mysql unit tests

Summary

The pipeline should also run the tests with a MySQL as backend server. This MR implements this.

See also #33 (closed).

Focus

• Does the MySQL pipeline fail at the expected point?
• Is outsourcing pipeline code to a Makefile a reasonable step to prevent redundancy in the scripts?

Test Environment

Just watch the pipeline run.

Check List for the Author

Please, prepare your MR for a review. Be sure to write a summary and a focus and create gitlab comments for the reviewer. They should guide the reviewer through the changes, explain your changes and also point out open questions. For further good practices have a look at our review guidelines

• All automated tests pass
• Reference related Issues
• Up-to-date CHANGELOG.md
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there specifications? Are they satisfied?

For further good practices have a look at our review guidelines.

utils/load_settings.sh

@@ -34,7 +34,12 @@ if [ -z "$MAINPATH" ]; then
 fi
 
 # Make a backup of the important environment variables.
-my_env=$(export -p | grep -E '(MYSQL|DATABASE)' || true)
+# Take care: Assignments may be more than one line!
+_expr="(MYSQL|DATABASE)"
+my_env=$(export -p | awk '/^declare -x '"$_expr"'/                   {PRINT=1} \
+                          /^declare -x/ && !/^declare -x '"$_expr"'/ {PRINT=0} \
+                          PRINT                                      {print}' \
+             || true)
 
 source "$MAINPATH/config.defaults"