mpm: filesystem_status: tolerate absence of mender

If the mender utility is not installed or exits with a failure, return
NULL for the artifact rather than raising an exception (and disrupting
device initialization).

2 files changed, 10 insertions, 6 deletions

diff --git a/mpm/python/usrp_mpm/periph_manager/base.py b/mpm/python/usrp_mpm/periph_manager/base.py
index 324e47dc9..a6bffafed 100644
--- a/mpm/python/usrp_mpm/periph_manager/base.py
+++ b/mpm/python/usrp_mpm/periph_manager/base.py
@@ -168,7 +168,9 @@ class PeriphManagerBase(object):
             version_string = ""
         mboard_info["mpm_sw_version"] = version_string
 
-        mboard_info["fs_version"] = get_fs_version()
+        fs_version = get_fs_version()
+        if fs_version is not None:
+            mboard_info["fs_version"] = fs_version
         # Mender artifacts are generally not present on a machine hosting
         # a simulated device--let it slide if not found on sim devices
         try:
diff --git a/mpm/python/usrp_mpm/sys_utils/filesystem_status.py b/mpm/python/usrp_mpm/sys_utils/filesystem_status.py
index 865741316..b9617cf0a 100644
--- a/mpm/python/usrp_mpm/sys_utils/filesystem_status.py
+++ b/mpm/python/usrp_mpm/sys_utils/filesystem_status.py
@@ -38,16 +38,18 @@ def get_mender_artifact(filesystem_root='/', parse_manually=False):
         # parse mender artifact manually
         file = pathlib.Path(filesystem_root, 'etc/mender/artifact_info')
         if not file.exists():
-            return 'FILE NOT FOUND'
+            return None
         return parse_artifact(file.read_text())
-    else:
+    try:
         output = subprocess.check_output(['/usr/bin/mender', '-show-artifact']).decode('utf-8')
         return output.splitlines()[0]
+    except:
+        return None
 
 def get_fs_version(filesystem_root='/'):
     file = pathlib.Path(filesystem_root, 'etc/version')
     if not file.exists():
-        return 'FILE NOT FOUND'
+        return None
     return file.read_text().splitlines()[0]
 
 def get_opkg_status_date(date_only=False, filesystem_root='/'):
@@ -57,11 +59,11 @@ def get_opkg_status_date(date_only=False, filesystem_root='/'):
         tformat = "%Y-%m-%d %H:%M:%S"
     file = pathlib.Path(filesystem_root, 'var/lib/opkg/status')
     if not file.exists():
-        return 'FILE NOT FOUND'
+        return None
     return time.strftime(tformat, time.gmtime(file.stat().st_mtime))
 
 def get_opkg_status_md5sum(filesystem_root='/'):
     file = pathlib.Path(filesystem_root, 'var/lib/opkg/status')
     if not file.exists():
-        return 'FILE NOT FOUND'
+        return None
     return hashlib.md5sum(file.read_text()).hexdigest()