[libvirt] [PATCH 1/3] tests: add targets for building libvirt inside docker containers

[Daniel P. Berrangé]

The Travis CI system uses docker containers for its build environment.
These are pre-built and hosted under quay.io/libvirt so that developers
can use them for reproducing problems locally.

Getting the right docker command syntax to use them, however, is not
entirely easy. This patch addresses that usability issue by introducing
some make targets

   make cibuild-fedora-28

will run a build of the local git repo using the buildenv-fedora-28
docker container, running the default make target in the container.

   make cibuild-fedora-28

will run "make check" while for more advanced debugging developers
can get a direct shell and run any make command manually

   make cishell-fedora-28

In all cases the GIT source tree is cloned locally into a 'citree/src'
sub-directory which is then exposed to the container at '/build'. It is
setup to facilitate VPATH build so the initial working directory
is '/build/vpath'.

The make rules are kept in a standalone file that is included into the
main Makefile.am, so that it is possible to run them without having to
invoke autotools first.

Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
---
 .gitignore            |   1 +
 Makefile.am           |   2 +
 tests/Makefile.ci.inc | 123 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 126 insertions(+)
 create mode 100644 tests/Makefile.ci.inc

diff --git a/.gitignore b/.gitignore
index df0ac8e3d4..a7499bbbb6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -46,6 +46,7 @@
 /autom4te.cache
 /build-aux/*
 /build/
+/citree/
 /confdefs.h
 /config.cache
 /config.guess
diff --git a/Makefile.am b/Makefile.am
index 709064c6a6..0c8ab13ebc 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -123,3 +123,5 @@ gen-AUTHORS:
 	  mv -f $(distdir)/AUTHORS-tmp $(distdir)/AUTHORS && \
 	  rm -f all.list maint.list contrib.list; \
 	fi
+
+include tests/Makefile.ci.inc
diff --git a/tests/Makefile.ci.inc b/tests/Makefile.ci.inc
new file mode 100644
index 0000000000..9deee91fd0
--- /dev/null
+++ b/tests/Makefile.ci.inc
@@ -0,0 +1,123 @@
+# -*- makefile -*-
+
+HERE = $(shell pwd)
+TOP = $(shell git rev-parse --show-toplevel)
+
+# Default to using all possible CPUs
+SMP = $(getconf _NPROCESSORS_ONLN)
+
+# Any extra arguments to pass to make
+MAKE_ARGS =
+
+# Avoid pulling submodules over the network by locally
+# cloning them
+SUBMODULES = .gnulib src/keycodemapdb
+
+IMAGE_PREFIX = quay.io/libvirt/buildenv
+IMAGE_TAG = :master
+
+# We delete the virtual root after completion, set
+# to 0 if you need to keep it around for debugging
+CLEAN = 1
+
+# We'll always freshly clone the virtual root each
+# time in case it was not cleaned up before. Set
+# to 0 if you want to try restarting a previously
+# preserved env
+RECLONE = 1
+
+SCRIPT =
+
+# We need the container process to run with current host IDs
+# so that it can access the passed in build directory
+UID = $(shell id -u)
+GID = $(shell id -g)
+
+# Docker doesn't require the IDs you run as to exist in
+# the container's /etc/passwd & /etc/group files, but
+# if they do not, then libvirt's  'make check' will fail
+# many tests
+PWDB_MOUNTS = \
+	--volume $(HERE)/citree/group:/etc/group:ro,z \
+	--volume $(HERE)/citree/passwd:/etc/passwd:ro,z
+
+# Docker containers can have very large ulimits
+# for nofiles - as much as 1048576. This makes
+# libvirt very slow at exec'ing programs.
+ULIMIT_FILES = 1024
+
+DOCKER_ARGS = \
+	--rm \
+	--interactive \
+	--tty \
+	--user $(UID):$(GID) \
+	$(PWDB_MOUNTS) \
+	--volume $(HERE)/citree/src:/build:z \
+	--workdir /build/vpath \
+        --ulimit nofile=$(ULIMIT_FILES):$(ULIMIT_FILES) \
+	$(NULL)
+
+preparetree:
+	@if test "$(RECLONE)" = "1" ; then \
+                rm -rf citree ; \
+	fi
+	@if ! test -d citree ; then \
+		mkdir -p citree/src; \
+		cp /etc/passwd citree; \
+		cp /etc/group citree; \
+		echo "Cloning $(TOP) to $(HERE)/citree/root"; \
+                git clone -q --local $(TOP) $(HERE)/citree/src; \
+                for mod in $(SUBMODULES) ; \
+                do \
+			echo "Cloning $(TOP)/$$mod to $(HERE)/citree/$$mod"; \
+                        git clone -q --local $(TOP)/$$mod $(HERE)/citree/src/$$mod ; \
+                done ; \
+                mkdir -p citree/src/vpath ; \
+	else \
+		test "$(CLEAN)" = "1" && rm -rf citree || : ; \
+        fi
+
+# $LIBVIRT_CONFIGURE_OPTS is a env that can optionally be
+# set in the container, populated at build time from the
+# Dockerfile. A typical use case would be to pass --host/--target
+# args to trigger cross-compilation
+cibuild-%: preparetree
+	docker run $(DOCKER_ARGS) $(IMAGE_PREFIX)-$*$(IMAGE_TAG) \
+		/bin/bash -c '\
+		echo "../autogen.sh $${LIBVIRT_CONFIGURE_OPTS}" && \
+                ../autogen.sh $${LIBVIRT_CONFIGURE_OPTS} && make -j $(SMP) $(MAKE_ARGS)'
+	@test "$(CLEAN)" = "1" && rm -rf citree || :
+
+cicheck-%:
+	$(MAKE) cibuild-$* MAKE_ARGS="check gl_public_submodule_commit="
+
+cishell-%: preparetree
+	docker run $(DOCKER_ARGS) $(IMAGE_PREFIX)-$*$(IMAGE_TAG) /bin/bash
+	@test "$(CLEAN)" = "1" && rm -rf citree || :
+
+cihelp:
+	@echo "Build libvirt inside docker containers used for CI"
+	@echo
+	@echo "Available targets:"
+	@echo
+	@echo "    cibuild-\$$IMAGE  - run a default 'make'"
+	@echo "    cicheck-\$$IMAGE  - run a 'make check'"
+	@echo "    cishell-\$$IMAGE  - run an interactive shell"
+	@echo
+	@echo "Available container images:"
+	@echo
+	@echo "    centos-7"
+	@echo "    debian-8"
+	@echo "    debian-9"
+	@echo "    debian-sid"
+	@echo "    fedora-28"
+	@echo "    fedora-29"
+	@echo "    fedora-rawhide"
+	@echo "    ubuntu-16"
+	@echo "    ubuntu-18"
+	@echo
+	@echo "Available make variables:"
+	@echo
+	@echo "    CLEAN=0   - do not delete '$(HERE)/citree' after completion"
+	@echo "    RECLONE=0 - re-use existing '$(HERE)/citree' content"
+	@echo
-- 
2.20.1