python: Run flake8 at build time.

If flake8 is installed, run it at build time.  Similar to most Makefile
targets, run it once and then only run again if the files change.

flake8 is set to ignore all error and warning types that currently occur.
Future patches will remove items from the ignore list as they are
resolved.

Signed-off-by: Russell Bryant <russell@ovn.org>
Acked-by: Ben Pfaff <blp@ovn.org>

INSTALL.md

@@ -129,6 +129,8 @@ installing the following to obtain better warnings:
 
   - clang, version 3.4 or later
 
+  - flake8 (for Python code)
+
 Also, you may find the ovs-dev script found in utilities/ovs-dev.py useful.
 
 Installation Requirements

Makefile.am

@@ -141,6 +141,7 @@ SUFFIXES =
 check_DATA =
 check_SCRIPTS =
 pkgconfig_DATA =
+FLAKE8_PYFILES =
 
 scriptsdir = $(pkgdatadir)/scripts
 completiondir = $(sysconfdir)/bash_completion.d
@@ -339,6 +340,12 @@ manpage-check: $(man_MANS) $(dist_man_MANS) $(noinst_man_MANS)
 CLEANFILES += manpage-check
 endif
 
+if HAVE_FLAKE8
+ALL_LOCAL += flake8-check
+flake8-check: $(FLAKE8_PYFILES)
+	$(AM_V_GEN) if flake8 $^ --ignore=E111,E112,E113,E123,E126,E127,E128,E129,E131,E201,E203,E222,E225,E226,E231,E241,E251,E261,E262,E265,E271,E302,E303,E501,E502,E703,E711,E713,E721,F401,F811,F821,F841,W601 ${FLAKE8_FLAGS}; then touch $@; else exit 1; fi
+endif
+
 include $(srcdir)/manpages.mk
 $(srcdir)/manpages.mk: $(MAN_ROOTS) build-aux/sodepends.pl
 	@$(PERL) $(srcdir)/build-aux/sodepends.pl -I. -I$(srcdir) $(MAN_ROOTS) >$(@F).tmp

configure.ac

@@ -95,6 +95,7 @@ OVS_CHECK_OPENSSL
 OVS_CHECK_LIBCAPNG
 OVS_CHECK_LOGDIR
 OVS_CHECK_PYTHON
+OVS_CHECK_FLAKE8
 OVS_CHECK_DOT
 OVS_CHECK_IF_PACKET
 OVS_CHECK_IF_DL

debian/automake.mk

@@ -75,6 +75,9 @@ EXTRA_DIST += \
 	debian/ifupdown.sh \
 	debian/source/format
 
+FLAKE8_PYFILES += \
+	debian/ovs-monitor-ipsec
+
 check-debian-changelog-version:
 	@DEB_VERSION=`echo '$(VERSION)' | sed 's/pre/~pre/'`;		     \
 	if $(FGREP) '($(DEB_VERSION)' $(srcdir)/debian/changelog >/dev/null; \

m4/openvswitch.m4

@@ -352,6 +352,18 @@ else:
    fi
    AM_CONDITIONAL([HAVE_PYTHON], [test "$HAVE_PYTHON" = yes])])
 
+dnl Checks for dot.
+AC_DEFUN([OVS_CHECK_FLAKE8],
+  [AC_CACHE_CHECK(
+    [for flake8],
+    [ovs_cv_flake8],
+    [if flake8 --version >/dev/null 2>&1; then
+       ovs_cv_flake8=yes
+     else
+       ovs_cv_flake8=no
+     fi])
+   AM_CONDITIONAL([HAVE_FLAKE8], [test "$ovs_cv_flake8" = yes])])
+
 dnl Checks for dot.
 AC_DEFUN([OVS_CHECK_DOT],
   [AC_CACHE_CHECK(

ofproto/automake.mk

@@ -82,3 +82,5 @@ ofproto/ipfix-entities.def: ofproto/ipfix.xml ofproto/ipfix-gen-entities
 
 # IPFIX enterprise entity definition macros.
 EXTRA_DIST += ofproto/ipfix-enterprise-entities.def
+
+FLAKE8_PYFILES += ofproto/ipfix-gen-entities

python/automake.mk

@@ -50,6 +50,13 @@ PYFILES = $(ovs_pyfiles) python/ovs/dirs.py $(ovstest_pyfiles)
 EXTRA_DIST += $(PYFILES)
 PYCOV_CLEAN_FILES += $(PYFILES:.py=.py,cover)
 
+FLAKE8_PYFILES += \
+	$(filter-out python/ovs/dirs.py,$(PYFILES)) \
+	python/setup.py \
+	python/build/__init__.py \
+	python/build/nroff.py \
+	python/ovs/dirs.py.template
+
 if HAVE_PYTHON
 nobase_pkgdata_DATA = $(ovs_pyfiles) $(ovstest_pyfiles)
 ovs-install-data-local:

tests/automake.mk

@@ -354,6 +354,8 @@ CHECK_PYFILES = \
 EXTRA_DIST += $(CHECK_PYFILES)
 PYCOV_CLEAN_FILES += $(CHECK_PYFILES:.py=.py,cover) .coverage
 
+FLAKE8_PYFILES += $(CHECK_PYFILES)
+
 if HAVE_OPENSSL
 TESTPKI_FILES = \
 	tests/testpki-cacert.pem \

utilities/automake.mk

@@ -153,4 +153,6 @@ bin_PROGRAMS += utilities/ovs-benchmark
 utilities_ovs_benchmark_SOURCES = utilities/ovs-benchmark.c
 utilities_ovs_benchmark_LDADD = lib/libopenvswitch.la
 
+FLAKE8_PYFILES += utilities/ovs-pcap.in
+
 include utilities/bugtool/automake.mk

vtep/automake.mk

@@ -43,6 +43,8 @@ scripts_SCRIPTS += \
 docs += vtep/README.ovs-vtep.md
 EXTRA_DIST += vtep/ovs-vtep
 
+FLAKE8_PYFILES += vtep/ovs-vtep
+
 # VTEP schema and IDL
 EXTRA_DIST += vtep/vtep.ovsschema
 pkgdata_DATA += vtep/vtep.ovsschema

xenserver/automake.mk

@@ -26,6 +26,9 @@ EXTRA_DIST += \
 	xenserver/usr_share_openvswitch_scripts_ovs-xapi-sync \
 	xenserver/usr_share_openvswitch_scripts_sysconfig.template
 
+FLAKE8_PYFILES += \
+	xenserver/usr_share_openvswitch_scripts_ovs-xapi-sync
+
 $(srcdir)/xenserver/openvswitch-xen.spec: xenserver/openvswitch-xen.spec.in $(top_builddir)/config.status
 	$(AM_V_GEN)($(ro_shell) && sed -e 's,[@]VERSION[@],$(VERSION),g') \
 		< $(srcdir)/xenserver/$(@F).in > $(@F).tmp || exit 1; \