K8s health utilities for cic containers

apps/util/liveness/liveness/linux.py

@@ -0,0 +1,54 @@
+# standard imports
+import importlib
+import sys
+import os
+import logging
+
+logg = logging.getLogger().getChild(__name__)
+
+pid = os.getpid()
+
+default_namespace = os.environ.get('LIVENESS_UNIT_NAME')
+if default_namespace == None:
+    import socket
+    default_namespace = socket.gethostname()
+
+
+def load(check_strs, namespace=default_namespace, rundir='/run', *args, **kwargs):
+
+    if namespace == None:
+        import socket
+        namespace = socket.gethostname()
+
+    logg.info('pid ' + str(pid))
+
+    checks = []
+    for m in check_strs:
+        logg.debug('added liveness check: {}'.format(str(m)))
+        module = importlib.import_module(m)
+        checks.append(module)
+
+    for check in checks:
+        r = check.health(args, kwargs)
+        if r == False:
+            raise RuntimeError('liveness check {} failed'.format(str(check)))
+        logg.info('liveness check passed: {}'.format(str(check)))
+
+    app_rundir = os.path.join(rundir, namespace)
+    os.makedirs(app_rundir, exist_ok=True) # should not already exist
+    f = open(os.path.join(app_rundir, 'pid'), 'w')
+    f.write(str(pid))
+    f.close()
+
+
+def set(error=0, namespace=default_namespace, rundir='/run'):
+    app_rundir = os.path.join(rundir, namespace)
+    f = open(os.path.join(app_rundir, 'error'), 'w')
+    f.write(str(error))
+    f.close()
+
+
+def reset(namespace=default_namespace, rundir='/run'):
+    app_rundir = os.path.join(rundir, namespace)
+    os.unlink(os.path.join(app_rundir, 'pid'))
+    os.unlink(os.path.join(app_rundir, 'error'))