Implement node logging into Zookeeper

Adds the ability to send node daemon logs to Zookeeper to facilitate a
command like "pvc node log", similar to "pvc vm log". Each node stores
its logs in a separate tree under "/logs" which can then be combined or
queried. By default, set by config, only 2000 lines are kept.

daemon-common/log.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 
-# log.py - Output (stdout + logfile) functions
+# log.py - PVC daemon logger functions
 # Part of the Parallel Virtual Cluster (PVC) system
 #
 #    Copyright (C) 2018-2021 Joshua M. Boniface <joshua@boniface.me>
@@ -19,7 +19,12 @@
 #
 ###############################################################################
 
-import datetime
+from collections import deque
+from threading import Thread
+from queue import Queue
+from datetime import datetime
+
+from daemon_lib.zkhandler import ZKHandler
 
 
 class Logger(object):
@@ -77,6 +82,10 @@ class Logger(object):
         self.last_colour = ''
         self.last_prompt = ''
 
+        if self.config['zookeeper_logging']:
+            self.zookeeper_logger = ZookeeperLogger(config)
+            self.zookeeper_logger.start()
+
     # Provide a hup function to close and reopen the writer
     def hup(self):
         self.writer.close()
@@ -87,7 +96,7 @@ class Logger(object):
 
         # Get the date
         if self.config['log_dates']:
-            date = '{} - '.format(datetime.datetime.now().strftime('%Y/%m/%d %H:%M:%S.%f'))
+            date = '{} - '.format(datetime.now().strftime('%Y/%m/%d %H:%M:%S.%f'))
         else:
             date = ''
 
@@ -123,6 +132,53 @@ class Logger(object):
         if self.config['file_logging']:
             self.writer.write(message + '\n')
 
+        # Log to Zookeeper
+        if self.config['zookeeper_logging']:
+            self.zookeeper_logger.queue.put(message)
+
         # Set last message variables
         self.last_colour = colour
         self.last_prompt = prompt
+
+
+class ZookeeperLogger(Thread):
+    """
+    Defines a threaded writer for Zookeeper locks. Threading prevents the blocking of other
+    daemon events while the records are written. They will be eventually-consistent
+    """
+    def __init__(self, config):
+        self.config = config
+        self.node = self.config['node']
+        self.max_lines = self.config['node_log_lines']
+        self.queue = Queue()
+        self.zkhandler = None
+        self.start_zkhandler()
+        self.zkhandler.write([(('logs', self.node), '')])
+        Thread.__init__(self, args=(), kwargs=None)
+
+    def start_zkhandler(self):
+        # We must open our own dedicated Zookeeper instance because we can't guarantee one already exists when this starts
+        if self.zkhandler is not None:
+            try:
+                self.zkhandler.disconnect()
+            except Exception:
+                pass
+        self.zkhandler = ZKHandler(self.config, logger=None)
+        self.zkhandler.connect(persistent=True)
+
+    def run(self):
+        while True:
+            message = self.queue.get()
+            self.write_log(message)
+
+    def write_log(self, message):
+        # Log to Zookeeper
+        with self.zkhandler.writelock(('logs.messages', self.node)):
+            logs = deque(self.zkhandler.read(('logs.messages', self.node)).split('\n'), self.max_lines)
+            if not self.config['log_dates']:
+                # We want to log dates here, even if the log_dates config is not set
+                date = '{} - '.format(datetime.now().strftime('%Y/%m/%d %H:%M:%S.%f'))
+            else:
+                date = ''
+            logs.append(f'{date}{message}')
+            self.zkhandler.write([(('logs.messages', self.node), '\n'.join(logs))])

daemon-common/migrations/versions/4.json

@@ -0,0 +1 @@
+{"version": "4", "root": "", "base": {"root": "", "schema": "/schema", "schema.version": "/schema/version", "config": "/config", "config.maintenance": "/config/maintenance", "config.primary_node": "/config/primary_node", "config.primary_node.sync_lock": "/config/primary_node/sync_lock", "config.upstream_ip": "/config/upstream_ip", "config.migration_target_selector": "/config/migration_target_selector", "cmd": "/cmd", "cmd.node": "/cmd/nodes", "cmd.domain": "/cmd/domains", "cmd.ceph": "/cmd/ceph", "logs": "/logs", "node": "/nodes", "domain": "/domains", "network": "/networks", "storage": "/ceph", "storage.util": "/ceph/util", "osd": "/ceph/osds", "pool": "/ceph/pools", "volume": "/ceph/volumes", "snapshot": "/ceph/snapshots"}, "logs": {"node": "", "messages": "/messages"}, "node": {"name": "", "keepalive": "/keepalive", "mode": "/daemonmode", "data.active_schema": "/activeschema", "data.latest_schema": "/latestschema", "data.static": "/staticdata", "data.pvc_version": "/pvcversion", "running_domains": "/runningdomains", "count.provisioned_domains": "/domainscount", "count.networks": "/networkscount", "state.daemon": "/daemonstate", "state.router": "/routerstate", "state.domain": "/domainstate", "cpu.load": "/cpuload", "vcpu.allocated": "/vcpualloc", "memory.total": "/memtotal", "memory.used": "/memused", "memory.free": "/memfree", "memory.allocated": "/memalloc", "memory.provisioned": "/memprov", "ipmi.hostname": "/ipmihostname", "ipmi.username": "/ipmiusername", "ipmi.password": "/ipmipassword", "sriov": "/sriov", "sriov.pf": "/sriov/pf", "sriov.vf": "/sriov/vf"}, "sriov_pf": {"phy": "", "mtu": "/mtu", "vfcount": "/vfcount"}, "sriov_vf": {"phy": "", "pf": "/pf", "mtu": "/mtu", "mac": "/mac", "phy_mac": "/phy_mac", "config": "/config", "config.vlan_id": "/config/vlan_id", "config.vlan_qos": "/config/vlan_qos", "config.tx_rate_min": "/config/tx_rate_min", "config.tx_rate_max": "/config/tx_rate_max", "config.spoof_check": "/config/spoof_check", "config.link_state": "/config/link_state", "config.trust": "/config/trust", "config.query_rss": "/config/query_rss", "pci": "/pci", "pci.domain": "/pci/domain", "pci.bus": "/pci/bus", "pci.slot": "/pci/slot", "pci.function": "/pci/function", "used": "/used", "used_by": "/used_by"}, "domain": {"name": "", "xml": "/xml", "state": "/state", "profile": "/profile", "stats": "/stats", "node": "/node", "last_node": "/lastnode", "failed_reason": "/failedreason", "storage.volumes": "/rbdlist", "console.log": "/consolelog", "console.vnc": "/vnc", "meta.autostart": "/node_autostart", "meta.migrate_method": "/migration_method", "meta.node_selector": "/node_selector", "meta.node_limit": "/node_limit", "meta.tags": "/tags", "migrate.sync_lock": "/migrate_sync_lock"}, "tag": {"name": "", "type": "/type", "protected": "/protected"}, "network": {"vni": "", "type": "/nettype", "rule": "/firewall_rules", "rule.in": "/firewall_rules/in", "rule.out": "/firewall_rules/out", "nameservers": "/name_servers", "domain": "/domain", "reservation": "/dhcp4_reservations", "lease": "/dhcp4_leases", "ip4.gateway": "/ip4_gateway", "ip4.network": "/ip4_network", "ip4.dhcp": "/dhcp4_flag", "ip4.dhcp_start": "/dhcp4_start", "ip4.dhcp_end": "/dhcp4_end", "ip6.gateway": "/ip6_gateway", "ip6.network": "/ip6_network", "ip6.dhcp": "/dhcp6_flag"}, "reservation": {"mac": "", "ip": "/ipaddr", "hostname": "/hostname"}, "lease": {"mac": "", "ip": "/ipaddr", "hostname": "/hostname", "expiry": "/expiry", "client_id": "/clientid"}, "rule": {"description": "", "rule": "/rule", "order": "/order"}, "osd": {"id": "", "node": "/node", "device": "/device", "stats": "/stats"}, "pool": {"name": "", "pgs": "/pgs", "stats": "/stats"}, "volume": {"name": "", "stats": "/stats"}, "snapshot": {"name": "", "stats": "/stats"}}

daemon-common/zkhandler.py

@@ -466,7 +466,7 @@ class ZKHandler(object):
 #
 class ZKSchema(object):
     # Current version
-    _version = 3
+    _version = 4
 
     # Root for doing nested keys
     _schema_root = ''
@@ -490,6 +490,7 @@ class ZKSchema(object):
             'cmd.node': f'{_schema_root}/cmd/nodes',
             'cmd.domain': f'{_schema_root}/cmd/domains',
             'cmd.ceph': f'{_schema_root}/cmd/ceph',
+            'logs': '/logs',
             'node': f'{_schema_root}/nodes',
             'domain': f'{_schema_root}/domains',
             'network': f'{_schema_root}/networks',
@@ -500,6 +501,11 @@ class ZKSchema(object):
             'volume': f'{_schema_root}/ceph/volumes',
             'snapshot': f'{_schema_root}/ceph/snapshots',
         },
+        # The schema of an individual logs entry (/logs/{node_name})
+        'logs': {
+            'node': '',  # The root key
+            'messages': '/messages',
+        },
         # The schema of an individual node entry (/nodes/{node_name})
         'node': {
             'name': '',  # The root key
@@ -771,7 +777,7 @@ class ZKSchema(object):
                         logger.out(f'Key not found: {self.path(kpath)}', state='w')
                     result = False
 
-        for elem in ['node', 'domain', 'network', 'osd', 'pool']:
+        for elem in ['logs', 'node', 'domain', 'network', 'osd', 'pool']:
             # First read all the subelements of the key class
             for child in zkhandler.zk_conn.get_children(self.path(f'base.{elem}')):
                 # For each key in the schema for that particular elem
@@ -850,7 +856,7 @@ class ZKSchema(object):
                         data = ''
                     zkhandler.zk_conn.create(self.path(kpath), data.encode(zkhandler.encoding))
 
-        for elem in ['node', 'domain', 'network', 'osd', 'pool']:
+        for elem in ['logs', 'node', 'domain', 'network', 'osd', 'pool']:
             # First read all the subelements of the key class
             for child in zkhandler.zk_conn.get_children(self.path(f'base.{elem}')):
                 # For each key in the schema for that particular elem

node-daemon/pvcnoded.sample.yaml

@@ -140,6 +140,8 @@ pvc:
         file_logging: True
         # stdout_logging: Enable or disable logging to stdout (i.e. journald)
         stdout_logging: True
+        # zookeeper_logging: Enable ot disable logging to Zookeeper (for `pvc node log` functionality)
+        zookeeper_logging: True
         # log_colours: Enable or disable ANSI colours in log output
         log_colours: True
         # log_dates: Enable or disable date strings in log output
@@ -152,10 +154,12 @@ pvc:
         log_keepalive_storage_details: True
         # console_log_lines: Number of console log lines to store in Zookeeper per VM
         console_log_lines: 1000
+        # node_log_lines: Number of node log lines to store in Zookeeper per node
+        node_log_lines: 2000
       # networking: PVC networking configuration
       # OPTIONAL if enable_networking: False
       networking:
-        # bridge_device: Underlying device to use for bridged vLAN networks; usually the device underlying <cluster>
+        # bridge_device: Underlying device to use for bridged vLAN networks; usually the device of <cluster>
         bridge_device: ens4
         # sriov_enable: Enable or disable (default if absent) SR-IOV network support
         sriov_enable: False

node-daemon/pvcnoded/Daemon.py

@@ -158,12 +158,14 @@ def readConfig(pvcnoded_config_file, myhostname):
             'console_log_directory': o_config['pvc']['system']['configuration']['directories']['console_log_directory'],
             'file_logging': o_config['pvc']['system']['configuration']['logging']['file_logging'],
             'stdout_logging': o_config['pvc']['system']['configuration']['logging']['stdout_logging'],
+            'zookeeper_logging': o_config['pvc']['system']['configuration']['logging'].get('zookeeper_logging', False),
             'log_colours': o_config['pvc']['system']['configuration']['logging']['log_colours'],
             'log_dates': o_config['pvc']['system']['configuration']['logging']['log_dates'],
             'log_keepalives': o_config['pvc']['system']['configuration']['logging']['log_keepalives'],
             'log_keepalive_cluster_details': o_config['pvc']['system']['configuration']['logging']['log_keepalive_cluster_details'],
             'log_keepalive_storage_details': o_config['pvc']['system']['configuration']['logging']['log_keepalive_storage_details'],
             'console_log_lines': o_config['pvc']['system']['configuration']['logging']['console_log_lines'],
+            'node_log_lines': o_config['pvc']['system']['configuration']['logging'].get('node_log_lines', 0),
             'vm_shutdown_timeout': int(o_config['pvc']['system']['intervals']['vm_shutdown_timeout']),
             'keepalive_interval': int(o_config['pvc']['system']['intervals']['keepalive_interval']),
             'fence_intervals': int(o_config['pvc']['system']['intervals']['fence_intervals']),