systemd.bbclass: helper class for recipes with systemd units

This class adds postinst/prerm scripts to start/stop/enable/disable the services
as relevant, and some magic to ensure the service files are installed.

Based on (but not the same as) the systemd.bbclass in meta-systemd, so thanks to
the following for their work there:

Enrico Scholz <enrico.scholz@sigma-chemnitz.de>
Khem Raj <raj.khem@gmail.com>
Martin Jansa <Martin.Jansa@gmail.com>
Andreas Müller <schnitzeltony@googlemail.com>
Koen Kooi <koen@dominion.thruhere.net>

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 158 insertions, 0 deletions

diff --git a/meta/classes/systemd.bbclass b/meta/classes/systemd.bbclass
new file mode 100644
index 0000000000..e0ea65c87e
--- /dev/null
+++ b/meta/classes/systemd.bbclass
@@ -0,0 +1,158 @@
+# The list of packages that should have systemd packaging scripts added.  For
+# each entry, optionally have a SYSTEMD_SERVICE_[package] that lists the service
+# files in this package.  If this variable isn't set, [package].service is used.
+SYSTEMD_PACKAGES ?= "${PN}"
+
+# Whether to enable or disable the services on installation.
+SYSTEMD_AUTO_ENABLE ??= "enable"
+
+# This class will be included in any recipe that supports systemd init scripts,
+# even if the systemd DISTRO_FEATURE isn't enabled.  As such don't make any
+# changes directly but check the DISTRO_FEATURES first.
+python __anonymous() {
+    if oe.utils.contains ('DISTRO_FEATURES', 'systemd', True, False, d):
+        d.appendVar("DEPENDS", " systemd-systemctl-native")
+        # Set a variable so that update-rcd.bbclass knows we're active and can
+        # disable itself.
+        d.setVar("SYSTEMD_BBCLASS_ENABLED", "1")
+}
+
+systemd_postinst() {
+OPTS=""
+
+if [ -n "$D" ]; then
+    OPTS="--root=$D"
+fi
+
+systemctl $OPTS ${SYSTEMD_AUTO_ENABLE} ${SYSTEMD_SERVICE}
+
+if [ -z "$D" -a "${SYSTEMD_AUTO_ENABLE}" = "enable" ]; then
+    systemctl start ${SYSTEMD_SERVICE}
+fi
+}
+
+systemd_prerm() {
+if [ -z "$D" ]; then
+    systemctl stop ${SYSTEMD_SERVICE}
+fi
+
+systemctl disable ${SYSTEMD_SERVICE}
+}
+
+def systemd_populate_packages(d):
+    def get_package_var(d, var, pkg):
+        val = (d.getVar('%s_%s' % (var, pkg), True) or "").strip()
+        if val == "":
+            val = (d.getVar(var, True) or "").strip()
+        return val
+
+
+    # Add a runtime dependency on systemd to pkg
+    def systemd_add_rdepends(pkg):
+        rdepends = d.getVar('RDEPENDS_' + pkg, True) or ""
+        if not 'systemd' in rdepends.split():
+            rdepends = '%s %s' % (rdepends, 'systemd')
+        d.setVar('RDEPENDS_' + pkg, rdepends)
+
+
+    def systemd_generate_package_scripts(pkg):
+        bb.debug(1, 'adding systemd calls to postinst/postrm for %s' % pkg)
+
+        # Add pkg to the overrides so that it finds the SYSTEMD_SERVICE_pkg
+        # variable.
+        localdata = d.createCopy()
+        localdata.prependVar("OVERRIDES", pkg + ":")
+        bb.data.update_data(localdata)
+
+        postinst = d.getVar('pkg_postinst_%s' % pkg, True)
+        if not postinst:
+            postinst = '#!/bin/sh\n'
+        postinst += localdata.getVar('systemd_postinst', True)
+        d.setVar('pkg_postinst_%s' % pkg, postinst)
+
+        prerm = d.getVar('pkg_prerm_%s' % pkg, True)
+        if not prerm:
+            prerm = '#!/bin/sh\n'
+        prerm += localdata.getVar('systemd_prerm', True)
+        d.setVar('pkg_prerm_%s' % pkg, prerm)
+
+
+    # Add files to FILES_*-systemd if existent and not already done
+    def systemd_append_file(pkg_systemd, file_append):
+        appended = False
+        if os.path.exists(oe.path.join(d.getVar("D", True), file_append)):
+            var_name = "FILES_" + pkg_systemd
+            files = d.getVar(var_name, False) or ""
+            if file_append not in files.split():
+                d.appendVar(var_name, " " + file_append)
+                appended = True
+        return appended
+
+    # Add systemd files to FILES_*-systemd, parse for Also= and follow recursive
+    def systemd_add_files_and_parse(pkg_systemd, path, service, keys):
+        # avoid infinite recursion
+        if systemd_append_file(pkg_systemd, oe.path.join(path, service)):
+            fullpath = oe.path.join(d.getVar("D", True), path, service)
+            if service.find('.service') != -1:
+                # for *.service add *@.service
+                service_base = service.replace('.service', '')
+                systemd_add_files_and_parse(pkg_systemd, path, service_base + '@.service', keys)
+            if service.find('.socket') != -1:
+                # for *.socket add *.service and *@.service
+                service_base = service.replace('.socket', '')
+                systemd_add_files_and_parse(pkg_systemd, path, service_base + '.service', keys)
+                systemd_add_files_and_parse(pkg_systemd, path, service_base + '@.service', keys)
+            for key in keys.split():
+                # recurse all dependencies found in keys ('Also';'Conflicts';..) and add to files
+                cmd = "grep %s %s | sed 's,%s=,,g' | tr ',' '\\n'" % (key, fullpath, key)
+                pipe = os.popen(cmd, 'r')
+                line = pipe.readline()
+                while line:
+                    line = line.replace('\n', '')
+                    systemd_add_files_and_parse(pkg_systemd, path, line, keys)
+                    line = pipe.readline()
+                pipe.close()
+
+    # Check service-files and call systemd_add_files_and_parse for each entry
+    def systemd_check_services():
+        base_libdir = d.getVar('base_libdir', True)
+        searchpaths = [oe.path.join(d.getVar("sysconfdir", True), "systemd", "system"),]
+        searchpaths.append(oe.path.join(d.getVar("base_libdir", True), "systemd", "system"))
+        searchpaths.append(oe.path.join(d.getVar("libdir", True), "systemd", "system"))
+        searchpaths.append(oe.path.join(d.getVar("libdir", True), "systemd", "user"))
+        systemd_packages = d.getVar('SYSTEMD_PACKAGES', True)
+        has_exactly_one_service = len(systemd_packages.split()) == 1
+        if has_exactly_one_service:
+            has_exactly_one_service = len(get_package_var(d, 'SYSTEMD_SERVICE', systemd_packages).split()) == 1
+
+        keys = 'Also' # Conflicts??
+        if has_exactly_one_service:
+            # single service gets also the /dev/null dummies
+            keys = 'Also Conflicts'
+        # scan for all in SYSTEMD_SERVICE[]
+        for pkg_systemd in systemd_packages.split():
+            for service in get_package_var(d, 'SYSTEMD_SERVICE', pkg_systemd).split():
+                path_found = ''
+                for path in searchpaths:
+                    if os.path.exists(oe.path.join(d.getVar("D", True), path, service)):
+                        path_found = path
+                        break
+                if path_found != '':
+                    systemd_add_files_and_parse(pkg_systemd, path_found, service, keys)
+                else:
+                    raise bb.build.FuncFailed, "\n\nSYSTEMD_SERVICE_%s value %s does not exist" % \
+                        (pkg_systemd, service)
+
+    # Run all modifications once when creating package
+    if os.path.exists(d.getVar("D", True)):
+        for pkg in d.getVar('SYSTEMD_PACKAGES', True).split():
+            if d.getVar('SYSTEMD_SERVICE_' + pkg, True):
+                systemd_generate_package_scripts(pkg)
+                systemd_add_rdepends(pkg)
+        systemd_check_services()
+
+
+python populate_packages_prepend () {
+    if oe.utils.contains ('DISTRO_FEATURES', 'systemd', True, False, d):
+        systemd_populate_packages (d)
+}