systemd: support disabling cloud-init via file or kernel cmdline

This adds a systemd generator for a 'cloud-init.target'.  That target will
be WantedBy multi-user.target in the default case.  If there is a file
/etc/cloud/cloud-init.disabled or the kernel command line contains
'cloud-init=disabled' then cloud-init will not affect boot at all.

There are some packages/debian changes to affect this:
 * postinst, preinst: these are necessary to remove some
   old target files for multi-user.target (LP: #1552999)
 * changes to include these files in the debian source package.
 * rules.in: supports DEB_BUILD_OPTIONS=nocheck to not run check

setup.py: mostly changes to support installing the generator
          but also pep8 fixes along the way

systemd/*: make each of the services 'WantedBy=cloud-init.target'
           rather than being wanted by multi-user.target

4 files changed, 46 insertions, 5 deletions

diff --git a/packages/bddeb b/packages/bddeb
index c4efe264..c141b1ab 100755
--- a/packages/bddeb
+++ b/packages/bddeb
@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 
+import glob
 import os
 import shutil
 import sys
@@ -105,11 +106,11 @@ def write_debian_folder(root, version, revno, pkgmap,
                              util.abs_join(deb_dir, 'rules'),
                              params={'python': python, 'pyver': pyver})
 
-    # Just copy the following directly
-    for base_fn in ['dirs', 'copyright', 'compat']:
-        shutil.copy(util.abs_join(find_root(),
-                                  'packages', 'debian', base_fn),
-                    util.abs_join(deb_dir, base_fn))
+    # Just copy any other files directly (including .in)
+    pdeb_d = util.abs_join(find_root(), 'packages', 'debian')
+    for f in [os.path.join(pdeb_d, f) for f in os.listdir(pdeb_d)]:
+        if os.path.isfile(f):
+            shutil.copy(f, util.abs_join(deb_dir, os.path.basename(f)))
 
 
 def main():
diff --git a/packages/debian/cloud-init.postinst b/packages/debian/cloud-init.postinst
new file mode 100644
index 00000000..cdd0466d
--- /dev/null
+++ b/packages/debian/cloud-init.postinst
@@ -0,0 +1,16 @@
+#!/bin/sh
+cleanup_lp1552999() {
+    local oldver="$1" last_bad_ver="0.7.7~bzr1178"
+    dpkg --compare-versions "$oldver" le "$last_bad_ver" || return 0
+    local edir="/etc/systemd/system/multi-user.target.wants"
+    rm -f "$edir/cloud-config.service" "$edir/cloud-final.service" \
+        "$edir/cloud-init-local.service" "$edir/cloud-init.service"
+}
+
+
+#DEBHELPER#
+
+if [ "$1" = "configure" ]; then
+   oldver="$2"
+   cleanup_lp1552999 "$oldver"
+fi
diff --git a/packages/debian/cloud-init.preinst b/packages/debian/cloud-init.preinst
new file mode 100644
index 00000000..3c2af06d
--- /dev/null
+++ b/packages/debian/cloud-init.preinst
@@ -0,0 +1,20 @@
+#!/bin/sh
+# vi: ts=4 expandtab
+
+cleanup_lp1552999() {
+    local oldver="$1" last_bad_ver="0.7.7~bzr1178"
+    dpkg --compare-versions "$oldver" le "$last_bad_ver" || return 0
+    local hdir="/var/lib/systemd/deb-systemd-helper-enabled"
+    hdir="$hdir/multi-user.target.wants" 
+    local edir="/etc/systemd/system/multi-user.target.wants"
+    rm -f "$hdir/cloud-config.service" "$hdir/cloud-final.service" \
+        "$hdir/cloud-init-local.service" "$hdir/cloud-init.service"
+}
+
+
+if [ "$1" = "upgrade" ]; then
+   oldver="$2"
+   cleanup_lp1552999 "$oldver"
+fi
+
+#DEBHELPER#
diff --git a/packages/debian/rules.in b/packages/debian/rules.in
index 66e80946..5420949c 100755
--- a/packages/debian/rules.in
+++ b/packages/debian/rules.in
@@ -13,7 +13,11 @@ override_dh_install:
 	cp tools/21-cloudinit.conf debian/cloud-init/etc/rsyslog.d/21-cloudinit.conf
 
 override_dh_auto_test:
+ifeq (,$(findstring nocheck,$(DEB_BUILD_OPTIONS)))
 	http_proxy= make check
+else
+	@echo check disabled by DEB_BUILD_OPTIONS=$(DEB_BUILD_OPTIONS)
+endif
 
 override_dh_systemd_start:
 	dh_systemd_start --no-restart-on-upgrade --no-start