Adopt an instance service for providers

Instead of creating a unique service file for each provider, just use a
single instance service. We'll change the symlinks in packaging.

Makefile.am

@@ -16,6 +16,7 @@ EXTRA_DIST = \
 	LICENSE \
 	COPYING \
 	data/ucd.service.in \
+	data/ucd@.service.in \
 	docs/ucd.1.md \
 	docs/ucd-data-fetch.1.md \
 	docs/cloud-config.5.md
@@ -87,10 +88,7 @@ ucd_data_fetch_CFLAGS = $(AM_CFLAGS)
 SYSTEMD_DIR=$(prefix)/lib/systemd/system/
 systemdsystemunitdir = @SYSTEMD_SYSTEMUNITDIR@
 systemdsystemunit_DATA = data/ucd.service \
-	data/ucd-aws.service \
-	data/ucd-oci.service \
-	data/ucd-tencent.service \
-	data/ucd-aliyun.service
+			 data/ucd@.service
 
 systemdsystemunit-install-local:
 	mkdir -p $(DESTDIR)$(systemdsystemunitdir)/multi-user.target.wants/

configure.ac

@@ -8,10 +8,7 @@ AC_CONFIG_SRCDIR([src/main.c])
 AC_CONFIG_FILES([Makefile
 		tests/Makefile
 		data/ucd.service
-		data/ucd-aws.service
-		data/ucd-oci.service
-		data/ucd-tencent.service
-		data/ucd-aliyun.service])
+		data/ucd@.service])
 AC_CONFIG_HEADERS([config.h])
 
 LT_INIT

data/ucd-aws.service.in → data/ucd@.service.in

@@ -1,12 +1,12 @@
 [Unit]
-Description=micro-config-drive job for AWS
+Description=micro-config-drive job for %I
 After=network.target systemd-networkd.service
 Wants=local-fs.target sshd.service sshd-keygen.service
-ConditionPathExists=!/var/lib/cloud/aws-user-data
+ConditionPathExists=!/var/lib/cloud/%I-user-data
 
 [Service]
 Type=oneshot
-ExecStart=@prefix@/bin/ucd-data-fetch aws
+ExecStart=@prefix@/bin/ucd-data-fetch %I
 RemainAfterExit=yes
 TimeoutSec=0