adding quiet option to assert (ansible#27124) (#52032)

* adding quiet option to assert (ansible#27124)

* adding doc for quiet to assert.py

* fixing PEP8 failure

* improving example

* improving docs

* adding changelog fragment

* adding . at end of descriptions

* removing trailing blank line

* adding integration test for assert

* fixing CI complaints

* disabling gather_facts in quiet.yml test

* rerunning to capture skip

* cleaning up python 2 vs 3

* following rebase

* fixing CI complaints

* fixing CI complaints

* fixing CI complaints

* fixing CI complaints

* fixing CI complaints

test/integration/targets/assert/runme.sh

@@ -0,0 +1,68 @@
+#!/usr/bin/env bash
+
+# This test compares "known good" output with various settings against output
+# with the current code. It's brittle by nature, but this is probably the
+# "best" approach possible.
+#
+# Notes:
+# * options passed to this script (such as -v) are ignored, as they would change
+#   the output and break the test
+# * the number of asterisks after a "banner" differs is forced to 79 by
+#   redirecting stdin from /dev/null
+
+set -eux
+
+run_test() {
+   # testname is playbook name
+   local testname=$1
+
+   # The shenanigans with redirection and 'tee' are to capture STDOUT and
+   # STDERR separately while still displaying both to the console
+   { ansible-playbook -i 'localhost,' -c local "${testname}.yml" \
+      > >(set +x; tee "${OUTFILE}.${testname}.stdout"); } \
+      2> >(set +x; tee "${OUTFILE}.${testname}.stderr" >&2) 0</dev/null
+
+   perl -pi -e 's/ *$//s' "${OUTFILE}.${testname}.stdout"
+   perl -pi -e 's/ *$//s' "${OUTFILE}.${testname}.stderr"
+
+   diff -u "${ORIGFILE}.${testname}.stdout" "${OUTFILE}.${testname}.stdout" || diff_failure
+   diff -u "${ORIGFILE}.${testname}.stderr" "${OUTFILE}.${testname}.stderr" || diff_failure
+}
+
+diff_failure() {
+   if [[ $INIT = 0 ]]; then
+      echo "FAILURE...diff mismatch!"
+      exit 1
+   fi
+}
+
+cleanup() {
+   if [[ $INIT = 0 ]]; then
+      rm -f "${OUTFILE}."*
+   fi
+}
+
+BASEFILE=assert_quiet.out
+
+ORIGFILE="${BASEFILE}"
+OUTFILE="${BASEFILE}.new"
+
+trap 'cleanup' EXIT
+
+# The --init flag will (re)generate the "good" output files used by the tests
+INIT=0
+if [[ ${1:-} == "--init" ]]; then
+   shift
+   OUTFILE=$ORIGFILE
+   INIT=1
+fi
+
+# Force the 'default' callback plugin
+export ANSIBLE_STDOUT_CALLBACK=default
+# Disable color in output for consistency
+export ANSIBLE_FORCE_COLOR=0
+export ANSIBLE_NOCOLOR=1
+# Disable retry files
+export ANSIBLE_RETRY_FILES_ENABLED=0
+
+run_test quiet