Add support for (make check CHECK_BASE_IMAGES='fedora centos')

This is intended for use in Travis (or perhaps also locally).  The
default behavior remains the same, uses the fedora image.

(Note that the (yum install) does not fail when one of the packages
is missing.  This is not a dealbreaker, but it will make diagnosing
future bugs more difficult.)

Uses CentOS 7 because CentOS 8 is missing some necessary -devel packages.

Signed-off-by: Miloslav Trmač <mitr@redhat.com>

Dockerfile

@@ -1,6 +1,7 @@
 FROM fedora
 
-RUN dnf -y update && dnf install -y make git golang golang-github-cpuguy83-md2man \
+RUN if (. /etc/os-release ; [ "$ID" != centos ]); then dnf=dnf; md2man=golang-github-cpuguy83-md2man; else dnf=yum; md2man=golang-github-cpuguy83-go-md2man; $dnf install -y epel-release; fi \
+	&& $dnf -y update && $dnf install -y make git golang $md2man \
 	# storage deps
 	btrfs-progs-devel \
 	device-mapper-devel \
@@ -11,9 +12,9 @@ RUN dnf -y update && dnf install -y make git golang golang-github-cpuguy83-md2ma
 	httpd-tools \
 	# OpenShift deps
 	which tar wget hostname util-linux bsdtar socat ethtool device-mapper iptables tree findutils nmap-ncat e2fsprogs xfsprogs lsof docker iproute \
-        bats jq podman runc \
+        bats jq podman runc openssl \
 	golint \
-	&& dnf clean all
+	&& $dnf clean all
 
 # Install two versions of the registry. The first is an older version that
 # only supports schema1 manifests. The second is a newer version that supports

Makefile

@@ -48,7 +48,16 @@ ifeq ($(shell $(GO) env GOOS), linux)
 endif
 
 GIT_BRANCH := $(shell git rev-parse --abbrev-ref HEAD 2>/dev/null)
-IMAGE := skopeo-dev$(if $(GIT_BRANCH),:$(GIT_BRANCH))
+# Default base container image on which to run tests
+DEFAULT_BASE := fedora
+# Base image for most commands, overridable by command-line arguments
+BASE_IMAGE := fedora
+# Base images (one or more) used for (make check), overridable by command-line arguments
+CHECK_BASE_IMAGES := $(BASE_IMAGE)
+# Name for our containers: skopeo-dev[-base-image][:branch]
+define image_name
+skopeo-dev$(if $(filter-out $(DEFAULT_BASE),$1),-$1)$(if $(GIT_BRANCH),:$(GIT_BRANCH))
+endef
 # set env like gobuildtag?
 CONTAINER_CMD := ${CONTAINER_RUNTIME} run --rm -i -e TESTFLAGS="$(TESTFLAGS)" #$(CONTAINER_ENVS)
 # if this session isn't interactive, then we don't want to allocate a
@@ -58,7 +67,6 @@ INTERACTIVE := $(shell [ -t 0 ] && echo 1 || echo 0)
 ifeq ($(INTERACTIVE), 1)
 	CONTAINER_CMD += -t
 endif
-CONTAINER_RUN := $(CONTAINER_CMD) "$(IMAGE)"
 
 GIT_COMMIT := $(shell git rev-parse HEAD 2> /dev/null || true)
 
@@ -114,8 +122,12 @@ nixpkgs:
 bin/skopeo:
 	$(GPGME_ENV) $(GO) build $(MOD_VENDOR) ${GO_DYN_FLAGS} ${LDFLAGS} -gcflags "$(GOGCFLAGS)" -tags "$(BUILDTAGS)" -o $@ ./cmd/skopeo
 
-build-container:
-	${CONTAINER_RUNTIME} build ${BUILD_ARGS} -t "$(IMAGE)" .
+build-container: build-container-$(BASE_IMAGE)
+build-container-%:
+	base=$*; if [ "$$base" = centos ]; then base=centos:7; fi; \
+		dockerfile=$$(mktemp -p .); sed "s/^FROM fedora/FROM $$base/" Dockerfile > "$$dockerfile"; \
+	${CONTAINER_RUNTIME} build ${BUILD_ARGS} -f $$dockerfile -t "$(call image_name,$*)" . ; exit=$$?; \
+	rm "$$dockerfile"; exit $$exit
 
 $(MANPAGES): %: %.md
 	@sed -e 's/\((skopeo.*\.md)\)//' -e 's/\[\(skopeo.*\)\]/\1/' $<  | $(GOMD2MAN) -in /dev/stdin -out $@
@@ -149,32 +161,37 @@ install-completions:
 	install -m 755 -d ${BASHINSTALLDIR}
 	install -m 644 completions/bash/skopeo ${BASHINSTALLDIR}/skopeo
 
-shell: build-container
-	$(CONTAINER_RUN) bash
+shell: shell-$(BASE_IMAGE)
+shell-%: build-container-%
+	$(CONTAINER_CMD) "$(call image_name,$*)" bash
 
-check: validate test-unit test-integration test-system
+check: $(foreach image,$(CHECK_BASE_IMAGES),validate-$(image) test-unit-$(image) test-integration-$(image) test-system-$(image))
 
+test-integration: test-integration-$(BASE_IMAGE)
 # The tests can run out of entropy and block in containers, so replace /dev/random.
-test-integration: build-container
-	$(CONTAINER_RUN) bash -c 'rm -f /dev/random; ln -sf /dev/urandom /dev/random; SKOPEO_CONTAINER_TESTS=1 BUILDTAGS="$(BUILDTAGS)" hack/make.sh test-integration'
+test-integration-%: build-container-%
+	$(CONTAINER_CMD) "$(call image_name,$*)" bash -c 'rm -f /dev/random; ln -sf /dev/urandom /dev/random; SKOPEO_CONTAINER_TESTS=1 BUILDTAGS="$(BUILDTAGS)" hack/make.sh test-integration'
 
+test-system: test-system-$(BASE_IMAGE)
 # complicated set of options needed to run podman-in-podman
-test-system: build-container
+test-system-%: build-container-%
 	DTEMP=$(shell mktemp -d --tmpdir=/var/tmp podman-tmp.XXXXXX); \
 	$(CONTAINER_CMD) --privileged \
 	    -v $$DTEMP:/var/lib/containers:Z -v /run/systemd/journal/socket:/run/systemd/journal/socket \
-            "$(IMAGE)" \
+            "$(call image_name,$*)" \
             bash -c 'BUILDTAGS="$(BUILDTAGS)" hack/make.sh test-system'; \
 	rc=$$?; \
 	$(RM) -rf $$DTEMP; \
 	exit $$rc
 
-test-unit: build-container
-	# Just call (make test unit-local) here instead of worrying about environment differences
-	$(CONTAINER_RUN) make test-unit-local BUILDTAGS='$(BUILDTAGS)'
+test-unit: test-unit-$(BASE_IMAGE)
+# Just call (make test unit-local) here instead of worrying about environment differences
+test-unit-%: build-container-%
+	$(CONTAINER_CMD) "$(call image_name,$*)" make test-unit-local BUILDTAGS='$(BUILDTAGS)'
 
-validate: build-container
-	$(CONTAINER_RUN) hack/make.sh validate-git-marks validate-gofmt validate-lint validate-vet
+validate: validate-$(BASE_IMAGE)
+validate-%: build-container-%
+	$(CONTAINER_CMD) "$(call image_name,$*)" hack/make.sh validate-git-marks validate-gofmt validate-lint validate-vet
 
 # This target is only intended for development, e.g. executing it from an IDE. Use (make test) for CI or pre-release testing.
 test-all-local: validate-local test-unit-local