launchpad-reviewers team mailing list archive

[Colin Watson <cjwatson@xxxxxxxxxxxxx>]

Colin Watson has proposed merging ~cjwatson/lp-signing:charm-handle-missing-system-packages into lp-signing:master.

Commit message:
charm: Only link packages from system-packages.txt if it exists

Requested reviews:
  Launchpad code reviewers (launchpad-reviewers)

For more details, see:
https://code.launchpad.net/~cjwatson/lp-signing/+git/lp-signing/+merge/388193

Otherwise it's difficult to upgrade an existing environment, as the charm wouldn't tolerate the old code asset but the new code asset needs the new charm.
-- 
Your team Launchpad code reviewers is requested to review the proposed merge of ~cjwatson/lp-signing:charm-handle-missing-system-packages into lp-signing:master.

diff --git a/charm/lp-signing/reactive/lp-signing.py b/charm/lp-signing/reactive/lp-signing.py
index a563e26..23a594d 100644
--- a/charm/lp-signing/reactive/lp-signing.py
+++ b/charm/lp-signing/reactive/lp-signing.py
@@ -72,13 +72,15 @@ def configure(pgsql):
     if pgsql.master is None:
         return
 
-    site_packages = subprocess.check_output(
-        [os.path.join(base.code_dir(), 'env', 'bin', 'python'), '-c',
-         'from distutils.sysconfig import get_python_lib; '
-         'print(get_python_lib())'], universal_newlines=True).rstrip('\n')
-    subprocess.check_call(
-        [os.path.join(base.code_dir(), 'link-system-packages.py'),
-         site_packages, os.path.join(base.code_dir(), 'system-packages.txt')])
+    system_packages = os.path.join(base.code_dir(), 'system-packages.txt')
+    if os.path.exists(system_packages):
+        site_packages = subprocess.check_output(
+            [os.path.join(base.code_dir(), 'env', 'bin', 'python'), '-c',
+             'from distutils.sysconfig import get_python_lib; '
+             'print(get_python_lib())'], universal_newlines=True).rstrip('\n')
+        subprocess.check_call(
+            [os.path.join(base.code_dir(), 'link-system-packages.py'),
+             site_packages, system_packages])
 
     config = hookenv.config()
     config_path = base.service_config_path()