tools: Start running pep8 against python tests

.travis.xml and containers/unit-tests/Dockerfile were adjusted to
install python3-pep8 package.

Closes #10657

.travis.yml

@@ -58,6 +58,7 @@ addons:
     - pcp
     - pkg-config
     - pyflakes
+    - python3-pep8
     - ssh
     - valgrind
     - xmlto

containers/unit-tests/Dockerfile

@@ -18,7 +18,7 @@ RUN dpkg --add-architecture ${arch} && echo ${arch} > /arch && apt-get update &&
     apt-get install -y --allow-downgrades libssh-dev:${arch}=0.6.3-4.3 libssh-4:${arch}=0.6.3-4.3 && \
     echo 'deb http://archive.ubuntu.com/ubuntu bionic universe' > /etc/apt/sources.list.d/stable.list && \
     apt-get update && \
-    apt-get install -y pyflakes pyflakes3 && \
+    apt-get install -y pyflakes pyflakes3 python3-pep8 && \
     apt-get clean
 
 # use latest npm/node

tools/test-static-code

@@ -2,7 +2,7 @@
 # run static code checks like pyflakes and pep8
 set -eu
 
-echo "1..6"
+echo "1..7"
 
 builddir=$(pwd)
 cd "${srcdir:-.}"
@@ -108,4 +108,25 @@ else
     echo "ok 6 json-verify # SKIP not a git tree"
 fi
 
+# pycodestyle/pep8 python syntax check
+if python3 -m pycodestyle /dev/null >/dev/null 2>&1; then
+    PYTHON_STYLE_CHECKER="pycodestyle"
+elif python3 -m pep8 /dev/null >/dev/null 2>&1; then
+    PYTHON_STYLE_CHECKER="pep8"
+fi
+
+if [ -z "${PYTHON_STYLE_CHECKER-}" ]; then
+    echo "ok 7 pycodestyle test # SKIP pycodestyle not installed"
+else
+    # FIXME: Fix code for the warnings and re-enable them
+    out=$(python3 -m "$PYTHON_STYLE_CHECKER" --ignore E501,E265,E261,W504,W605 test/verify/* --exclude=test/verify/nested-kvm) || true
+    if [ -n "$out" ]; then
+        echo "$out" >&2
+        echo "not ok 7 $PYTHON_STYLE_CHECKER test"
+        fail=1
+    else
+        echo "ok 7 $PYTHON_STYLE_CHECKER test"
+    fi
+fi
+
 exit $fail