Add logic to detect if the net/bsdec2-image-upload port needs

to be installed. [1]

For the cw-ec2-portinstall and ec2ami targets, touch the
.TARGET file after completion to prevent duplicate invocations.

Add cw-ec2-portinstall and ec2ami to CLEANFILES.

Submitted by:	cperciva[1]
MFC after:	3 days
Sponsored by:	The FreeBSD Foundation

release/Makefile.ec2

@@ -12,6 +12,15 @@ AMINAMESUFFIX!=	date +-%Y-%m-%d
 PUBLISH=	--public
 .endif
 
+CLEANFILES+=		ec2ami
+
+.if !exists(/usr/local/bin/bsdec2-image-upload)
+CW_EC2_PORTINSTALL=	cw-ec2-portinstall
+CLEANFILES+=		${CW_EC2_PORTINSTALL}
+.else
+CW_EC2_PORTINSTALL=
+.endif
+
 cw-ec2-portinstall:
 .if exists(${PORTSDIR}/net/bsdec2-image-upload/Makefile)
 	make -C ${PORTSDIR}/net/bsdec2-image-upload BATCH=1 all install clean
@@ -21,8 +30,10 @@ cw-ec2-portinstall:
 . endif
 	env ASSUME_ALWAYS_YES=yes pkg install -y net/bsdec2-image-upload
 .endif
+	@touch ${.TARGET}
 
-ec2ami: cw-ec2 cw-ec2-portinstall
+ec2ami: cw-ec2 ${CW_EC2_PORTINSTALL}
+	@false
 .if !defined(AWSKEYFILE) || !exists(${AWSKEYFILE})
 	@echo "--------------------------------------------------------------"
 	@echo ">>> AWSKEYFILE must point at AWS keys for EC2 AMI creation"
@@ -46,3 +57,4 @@ ec2ami: cw-ec2 cw-ec2-portinstall
 	    "${TYPE} ${REVISION}-${BRANCH}${AMINAMESUFFIX}"	\
 	    "${TYPE} ${REVISION}-${BRANCH}"			\
 	    ${AWSREGION} ${AWSBUCKET} ${AWSKEYFILE}
+	@touch ${.TARGET}