Clean up conditionals

Makefile

@@ -2,18 +2,22 @@ XILINX_TARBALL	:= Xilinx_ISE_DS_Lin_14.7_1015_1.tar
 XILINX_LICENSE	:= Xilinx.lic
 XILINX_PKGDIR	:= fs/$(basename ${XILINX_TARBALL})
 
-BOOT_IMAGE	:= cryptech-builder:boot
 BOOT_CONTAINER	:= cryptech-builder-boot
+BOOT_IMAGE	:= cryptech-builder:boot
 BASE_IMAGE	:= cryptech-builder:base
 
+BASE_IMAGE_EXISTS	:= $(shell docker image ls -q ${BASE_IMAGE})
+BOOT_IMAGE_EXISTS	:= $(shell docker image ls -q ${BOOT_IMAGE})
+BOOT_CONTAINER_EXISTS	:= $(shell docker container ls -a --format='{{.Names}}'  --filter='name=^/${BOOT_CONTAINER}$$')
+
 ifneq (./,$(sort $(dir ${XILINX_TARBALL} ${XILINX_LICENSE})))
 $(error XILINX_TARBALL and XILINX_LICENSE must be in this directory for bind mount)
 endif
 
 all:
-ifeq (,$(shell docker image ls -q ${BASE_IMAGE}))
-	-docker container rm -f ${BOOT_CONTAINER}
-ifeq (,$(shell docker image ls -q ${BOOT_IMAGE}))
+ifeq (,${BASE_IMAGE_EXISTS})
+	docker container rm -f ${BOOT_CONTAINER} || true
+ifeq (,${BOOT_IMAGE_EXISTS})
 	rm -rf fs
 	mkdir fs
 	sudo /usr/sbin/debootstrap --foreign jessie fs
@@ -30,9 +34,7 @@ endif
 		${BOOT_IMAGE} \
 		/cryptech-builder/Builder
 	rm -rf fs
-ifneq (,$(wildcard /usr/bin/mogrify))
-	-mogrify -verbose -format png *.xwd && rm -f *.xwd
-endif
+	mogrify -verbose -format png *.xwd && rm -f *.xwd || true
 	docker commit ${BOOT_CONTAINER} ${BASE_IMAGE}
 	docker container rm -f ${BOOT_CONTAINER}
 endif
@@ -40,10 +42,10 @@ endif
 
 clean:
 	git clean -dfx -e ${XILINX_TARBALL} -e ${XILINX_LICENSE}
-	-docker container rm -f ${BOOT_CONTAINER}
+	docker container rm -f ${BOOT_CONTAINER} || true
 
 sandblast: clean
-	-docker image rm -f ${BOOT_IMAGE}
-	-docker image rm -f ${BASE_IMAGE}
+	docker image rm -f ${BOOT_IMAGE} || true
+	docker image rm -f ${BASE_IMAGE} || true
 
 .PHONY: all clean sandblast