NAME

ovn-controller - Open Virtual Network local controller

SYNOPSIS

ovn-controller [options] [ovs-database]

DESCRIPTION

ovn-controller is the local controller daemon for OVN, the Open Virtual Network It connects up to the OVN Southbound database (see ovn-sb(5)) over the OVSDB protocol, and down to the Open vSwitch database (see ovs-vswitchdconfdb(5)) over the OVSDB protocol and to ovs-vswitchd(8) via OpenFlow Each hypervisor and software gateway in an OVN deployment runs its own independent copy of ovn-controller; thus, ovn-controller’s downward connections are machine-local and do not run over a physical network

ACL LOGGING

ACL log messages are logged through ovn-controller’s logging mechanism ACL log entries have the module acl_log at log level info Configuring logging is described below in the Logging Options section

OPTIONS

Daemon Options

--pidfile[=pidfile]
Causes a file (by default, programpid) to be created indicating the PID of the running process If the pidfile argument is not specified, or if it does not begin with /, then it is created in
If --pidfile is not specified, no pidfile is created
--overwrite-pidfile
By default, when --pidfile is specified and the specified pidfile already exists and is locked by a running process, the daemon refuses to start Specify --overwrite-pidfile to cause it to instead overwrite the pidfile
When --pidfile is not specified, this option has no effect
--detach
Runs this program as a background process The process forks, and in the child it starts a new session, closes the standard file descriptors (which has the side effect of disabling logging to the console), and changes its current directory to the root (unless --no-chdir is specified) After the child completes its initialization, the parent exits
--monitor
Creates an additional process to monitor this program If it dies due to a signal that indicates a programming error ( SIGABRT, SIGALRM, SIGBUS, SIGFPE, SIGILL, SIGPIPE, SIGSEGV, SIGXCPU, or SIGXFSZ) then the monitor process starts a new copy of it If the daemon dies or exits for another reason, the monitor process exits
This option is normally used with --detach, but it also functions without it
--no-chdir
By default, when --detach is specified, the daemon changes its current working directory to the root directory after it detaches Otherwise, invoking the daemon from a carelessly chosen directory would prevent the administrator from unmounting the file system that holds that directory
Specifying --no-chdir suppresses this behavior, preventing the daemon from changing its current working directory This may be useful for collecting core files, since it is common behavior to write core dumps into the current working directory and the root directory is not a good directory to use
This option has no effect when --detach is not specified
--no-self-confinement
By default this daemon will try to self-confine itself to work with files under well-known directories determined at build time It is better to stick with this default behavior and not to use this flag unless some other Access Control is used to confine daemon Note that in contrast to other access control implementations that are typically enforced from kernel-space (eg DAC or MAC), self-confinement is imposed from the user-space daemon itself and hence should not be considered as a full confinement strategy, but instead should be viewed as an additional layer of security
--user=user:group
Causes this program to run as a different user specified in user:group, thus dropping most of the root privileges Short forms user and :group are also allowed, with current user or group assumed, respectively Only daemons started by the root user accepts this argument
On Linux, daemons will be granted CAP_IPC_LOCK and CAP_NET_BIND_SERVICES before dropping root privileges Daemons that interact with a datapath, such as ovs-vswitchd, will be granted three additional capabilities, namely CAP_NET_ADMIN, CAP_NET_BROADCAST and CAP_NET_RAW The capability change will apply even if the new user is root
On Windows, this option is not currently supported For security reasons, specifying this option will cause the daemon process not to start

Logging Options

-v[spec]
 
--verbose=[spec]
Sets logging levels Without any spec, sets the log level for every module and destination to dbg Otherwise, spec is a list of words separated by spaces or commas or colons, up to one from each category below:
A valid module name, as displayed by the vlog/list command on ovs-appctl(8), limits the log level change to the specified module
syslog, console, or file, to limit the log level change to only to the system log, to the console, or to a file, respectively (If --detach is specified, the daemon closes its standard file descriptors, so logging to the console will have no effect)
On Windows platform, syslog is accepted as a word and is only useful along with the --syslog-target option (the word has no effect otherwise)
off, emer, err, warn, info, or dbg, to control the log level Messages of the given severity or higher will be logged, and messages of lower severity will be filtered out off filters out all messages See ovs-appctl(8) for a definition of each log level
Case is not significant within spec
Regardless of the log levels set for file, logging to a file will not take place unless --log-file is also specified (see below)
For compatibility with older versions of OVS, any is accepted as a word but has no effect
-v
 
--verbose
Sets the maximum logging verbosity level, equivalent to --verbose=dbg
-vPATTERN:destination:pattern
 
--verbose=PATTERN:destination:pattern
Sets the log pattern for destination to pattern Refer to ovs-appctl(8) for a description of the valid syntax for pattern
-vFACILITY:facility
 
--verbose=FACILITY:facility
Sets the RFC5424 facility of the log message facility can be one of kern, user, mail, daemon, auth, syslog, lpr, news, uucp, clock, ftp, ntp, audit, alert, clock2, local0, local1, local2, local3, local4, local5, local6 or local7 If this option is not specified, daemon is used as the default for the local system syslog and local0 is used while sending a message to the target provided via the --syslog-target option
--log-file[=file]
Enables logging to a file If file is specified, then it is used as the exact name for the log file The default log file name used if file is omitted is /var/log/ovn/programlog
--syslog-target=host:port
Send syslog messages to UDP port on host, in addition to the system syslog The host must be a numerical IP address, not a hostname
--syslog-method=method
Specify method as how syslog messages should be sent to syslog daemon The following forms are supported:
libc, to use the libc syslog() function Downside of using this options is that libc adds fixed prefix to every message before it is actually sent to the syslog daemon over /dev/log UNIX domain socket
unix:file, to use a UNIX domain socket directly It is possible to specify arbitrary message format with this option However, rsyslogd 89 and older versions use hard coded parser function anyway that limits UNIX domain socket use If you want to use arbitrary message format with older rsyslogd versions, then use UDP socket to localhost IP address instead
udp:ip:port, to use a UDP socket With this method it is possible to use arbitrary message format also with older rsyslogd When sending syslog messages over UDP socket extra precaution needs to be taken into account, for example, syslog daemon needs to be configured to listen on the specified UDP port, accidental iptables rules could be interfering with local syslog traffic and there are some security considerations that apply to UDP sockets, but do not apply to UNIX domain sockets
null, to discard all messages logged to syslog
The default is taken from the OVS_SYSLOG_METHOD environment variable; if it is unset, the default is libc

PKI Options

PKI configuration is required in order to use SSL for the connections to the Northbound and Southbound databases
-p privkeypem
 
--private-key=privkeypem
Specifies a PEM file containing the private key used as identity for outgoing SSL connections
-c certpem
 
--certificate=certpem
Specifies a PEM file containing a certificate that certifies the private key specified on -p or --private-key to be trustworthy The certificate must be signed by the certificate authority (CA) that the peer in SSL connections will use to verify it
-C cacertpem
 
--ca-cert=cacertpem
Specifies a PEM file containing the CA certificate for verifying certificates presented to this program by SSL peers (This may be the same certificate that SSL peers use to verify the certificate specified on -c or --certificate, or it may be a different one, depending on the PKI design in use)
-C none
 
--ca-cert=none
Disables verification of certificates presented by SSL peers This introduces a security risk, because it means that certificates cannot be verified to be those of known trusted hosts
--bootstrap-ca-cert=cacertpem
When cacertpem exists, this option has the same effect as -C or --ca-cert If it does not exist, then the executable will attempt to obtain the CA certificate from the SSL peer on its first SSL connection and save it to the named PEM file If it is successful, it will immediately drop the connection and reconnect, and from then on all SSL connections must be authenticated by a certificate signed by the CA certificate thus obtained
This option exposes the SSL connection to a man-in-the-middle attack obtaining the initial CA certificate, but it may be useful for bootstrapping
This option is only useful if the SSL peer sends its CA certificate as part of the SSL certificate chain The SSL protocol does not require the server to send the CA certificate
This option is mutually exclusive with -C and --ca-cert
--peer-ca-cert=peer-cacertpem
Specifies a PEM file that contains one or more additional certificates to send to SSL peers peer-cacertpem should be the CA certificate used to sign the program’s own certificate, that is, the certificate specified on -c or --certificate If the program’s certificate is self-signed, then --certificate and --peer-ca-cert should specify the same file
This option is not useful in normal operation, because the SSL peer must already have the CA certificate for the peer to have any confidence in the program’s identity However, this offers a way for a new installation to bootstrap the CA certificate on its first SSL connection

Other Options

-h
 
--help
Prints a brief help message to the console
-V
 
--version
Prints version information to the console

CONFIGURATION

ovn-controller retrieves most of its configuration information from the local Open vSwitch’s ovsdb-server instance The default location is dbsock in the local Open vSwitch’s "run" directory It may be overridden by specifying the ovs-database argument as an OVSDB active or passive connection method, as described in ovsdb(7)
ovn-controller assumes it gets configuration information from the following keys in the Open_vSwitch table of the local OVS instance:
external_ids:system-id
The chassis name to use in the Chassis table Changing the system-id while ovn-controller is running is not directly supported Users have two options: either first gracefully stop ovn-controller or manually delete the stale Chassis and Chassis_Private records after changing the system-id Note that the chassis name can also be provided via the system-id-override file in the local OVN "etc" directory or via the -n command-line option The following precedence is used: first, the command-line option is read; if not present, the system-id-override file is read; if not present, then the name configured in the database is used
external_ids:hostname
The hostname to use in the Chassis table
external_ids:ovn-bridge
The integration bridge to which logical ports are attached The default is br-int If this bridge does not exist when ovn-controller starts, it will be created automatically with the default configuration suggested in ovn-architecture(7) When more than one controllers are running on the same host, external_ids:ovn-bridge-CHASSIS_NAME should be set for each of them, pointing to a unique bridge This is required to avoid controllers stepping on each others’ feet
external_ids:ovn-bridge-datapath-type
This configuration is optional If set, then the datapath type of the integration bridge will be set to the configured value If this option is not set, then ovn-controller will not modify the existing datapath-type of the integration bridge
external_ids:ovn-remote
The OVN database that this system should connect to for its configuration, in one of the same forms documented above for the ovs-database
external_ids:ovn-monitor-all
A boolean value that tells if ovn-controller should monitor all records of tables in ovs-database If set to false, it will conditionally monitor the records that is needed in the current chassis
It is more efficient to set it to true in use cases where the chassis would anyway need to monitor most of the records in OVN Southbound database, which would save the overhead of conditions processing, especially for server side Typically, set it to true for environments that all workloads need to be reachable from each other
Default value is false
external_ids:ovn-remote-probe-interval
The inactivity probe interval of the connection to the OVN database, in milliseconds If the value is zero, it disables the connection keepalive feature
If the value is nonzero, then it will be forced to a value of at least 1000 ms
external_ids:ovn-openflow-probe-interval
The inactivity probe interval of the OpenFlow connection to the OpenvSwitch integration bridge, in seconds If the value is zero, it disables the connection keepalive feature
If the value is nonzero, then it will be forced to a value of at least 5s
external_ids:ovn-encap-type
The encapsulation type that a chassis should use to connect to this node Multiple encapsulation types may be specified with a comma-separated list Each listed encapsulation type will be paired with ovn-encap-ip
Supported tunnel types for connecting hypervisors and gateways are geneve, vxlan, and stt
Due to the limited amount of metadata in vxlan, the capabilities and performance of connected gateways and hypervisors will be reduced versus other tunnel formats
external_ids:ovn-encap-ip
The IP address that a chassis should use to connect to this node using encapsulation types specified by external_ids:ovn-encap-type
external_ids:ovn-encap-df_default
indicates the DF flag handling of the encapulation Set to true to set the DF flag for new data paths or false to clear the DF flag
external_ids:ovn-bridge-mappings
A list of key-value pairs that map a physical network name to a local ovs bridge that provides connectivity to that network An example value mapping two physical network names to two ovs bridges would be: physnet1:br-eth0,physnet2:br-eth1
external_ids:ovn-encap-csum
ovn-encap-csum indicates that encapsulation checksums can be transmitted and received with reasonable performance It is a hint to senders transmitting data to this chassis that they should use checksums to protect OVN metadata Set to true to enable or false to disable Depending on the capabilities of the network interface card, enabling encapsulation checksum may incur performance loss In such cases, encapsulation checksums can be disabled
external_ids:ovn-encap-tos
ovn-encap-tos indicates the value to be applied to OVN tunnel interface’s option:tos as specified in the Open_vSwitch database Interface table Please refer to Open VSwitch Manual for details
external_ids:ovn-cms-options
A list of options that will be consumed by the CMS Plugin and which specific to this particular chassis An example would be: cms_option1,cms_option2:foo
external_ids:ovn-transport-zones
The transport zone(s) that this chassis belongs to Transport zones is a way to group different chassis so that tunnels are only formed between members of the same group(s) Multiple transport zones may be specified with a comma-separated list For example: tz1,tz2,tz3
If not set, the Chassis will be considered part of a default transport zone
external_ids:ovn-chassis-mac-mappings
A list of key-value pairs that map a chassis specific mac to a physical network name An example value mapping two chassis macs to two physical network names would be: physnet1:aa:bb:cc:dd:ee:ff,physnet2:a1:b2:c3:d4:e5:f6 These are the macs that ovn-controller will replace a router port mac with, if packet is going from a distributed router port on vlan type logical switch
external_ids:ovn-is-interconn
The boolean flag indicates if the chassis is used as an interconnection gateway
external_ids:ovn-match-northd-version
The boolean flag indicates if ovn-controller needs to check ovn-northd version If this flag is set to true and the ovn-northd’s version (reported in the Southbound database) doesn’t match with the ovn-controller’s internal version, then it will stop processing the southbound and local Open vSwitch database changes The default value is considered false if this option is not defined
external_ids:ovn-ofctrl-wait-before-clear
The time, in milliseconds, to wait before clearing flows in OVS after OpenFlow connection/reconnection during ovn-controller initialization The purpose of this wait is to give time for ovn-controller to compute the new flows before clearing existing ones, to avoid data plane down time during ovn-controller restart/upgrade at large scale environments where recomputing the flows takes more than a few seconds or even longer It is difficult for ovn-controller to determine when the new flows computing is completed, because of the dynamics in the cloud environments, which is why this configuration is provided for users to adjust based on the scale of the environment By default, it is 0, which means clearing existing flows without waiting Not setting the value, or setting it too small, may result in data plane down time during upgrade/restart, while setting it too big may result in unnecessary extra control plane latency of applying new changes of CMS during upgrade/restart In most cases, a slightly bigger value is not harmful, because the extra control plane latency happens only once during the OpenFlow connection To get a reasonable range of the value setting, it is recommended to run the below commands on a node in the target environment and then set this configuration to twice the value of Maximum shown in the output of the second command
ovn-appctl -t ovn-controller inc-engine/recompute
ovn-appctl -t ovn-controller stopwatch/show flow-generation
external_ids:ovn-enable-lflow-cache
The boolean flag indicates if ovn-controller should enable/disable the logical flow in-memory cache it uses when processing Southbound database logical flow changes By default caching is enabled
external_ids:ovn-limit-lflow-cache
When used, this configuration value determines the maximum number of logical flow cache entries ovn-controller may create when the logical flow cache is enabled By default the size of the cache is unlimited
external_ids:ovn-memlimit-lflow-cache-kb
When used, this configuration value determines the maximum size of the logical flow cache (in KB) ovn-controller may create when the logical flow cache is enabled By default the size of the cache is unlimited
external_ids:ovn-trim-limit-lflow-cache
When used, this configuration value sets the minimum number of entries in the logical flow cache starting with which automatic memory trimming is performed By default this is set to 10000 entries
external_ids:ovn-trim-wmark-perc-lflow-cache
When used, this configuration value sets the percentage from the high watermark number of entries in the logical flow cache under which automatic memory trimming is performed Eg, if the trim watermark percentage is set to 50%, automatic memory trimming happens only when the number of entries in the logical flow cache gets reduced to less than half of the last measured high watermark By default this is set to 50
external_ids:ovn-trim-timeout-ms
When used, this configuration value specifies the time, in milliseconds, since the last logical flow cache operation after which ovn-controller performs memory trimming regardless of how many entries there are in the cache By default this is set to 30000 (30 seconds)
external_ids:ovn-set-local-ip
The boolean flag indicates if ovn-controller when create tunnel ports should set local_ip parameter Can be heplful to pin source outer IP for the tunnel when multiple interfaces are used on the host for overlay traffic
Most of configuration options listed above can also be set for a particular chassis name (see external_ids:system-id for more information) This can be achieved by setting external_ids:option-[chassis] instead of external_ids:option For example, set external_ids:ovn-encap-ip-otherhv to use a particular IP address for the controller instance named otherhv Name specific configuration options always override any global options set in the database
Chassis-specific configuration options in the database plus the ability to configure the chassis name to use via the system-id-override file or command line allows to run multiple ovn-controller instances with unique chassis names on the same host using the same vswitchd instance This may be useful when running a hybrid setup with more than one CMS managing ports on the host, or to use different datapath types on the same host Note that this ability is highly experimental and has known limitations (for example, stateful ACLs are not supported) Use at your own risk
ovn-controller reads the following values from the Open_vSwitch database of the local OVS instance:
datapath-type from Bridge table
This value is read from local OVS integration bridge row of Bridge table and populated in other_config:datapath-type of the Chassis table in the OVN_Southbound database
iface-types from Open_vSwitch table
This value is populated in external_ids:iface-types of the Chassis table in the OVN_Southbound database
private_key, certificate, ca_cert, and bootstrap_ca_cert from SSL table
These values provide the SSL configuration used for connecting to the OVN southbound database server when an SSL connection type is configured via external_ids:ovn-remote Note that this SSL configuration can also be provided via command-line options, the configuration in the database takes precedence if both are present

OPEN VSWITCH DATABASE USAGE

ovn-controller uses a number of external_ids keys in the Open vSwitch database to keep track of ports and interfaces For proper operation, users should not change or clear these keys:
external_ids:ovn-chassis-id in the Port table
The presence of this key identifies a tunnel port within the integration bridge as one created by ovn-controller to reach a remote chassis Its value is the chassis ID of the remote chassis
external_ids:ct-zone-* in the Bridge table
Logical ports and gateway routers are assigned a connection tracking zone by ovn-controller for stateful services To keep state across restarts of ovn-controller, these keys are stored in the integration bridge’s Bridge table The name contains a prefix of ct-zone- followed by the name of the logical port or gateway router’s zone key The value for this key identifies the zone used for this port
external_ids:ovn-localnet-port in the Port table
The presence of this key identifies a patch port as one created by ovn-controller to connect the integration bridge and another bridge to implement a localnet logical port Its value is the name of the logical port with type set to localnet that the port implements See external_ids:ovn-bridge-mappings, above, for more information
Each localnet logical port is implemented as a pair of patch ports, one in the integration bridge, one in a different bridge, with the same external_ids:ovn-localnet-port value
external_ids:ovn-l2gateway-port in the Port table
The presence of this key identifies a patch port as one created by ovn-controller to connect the integration bridge and another bridge to implement a l2gateway logical port Its value is the name of the logical port with type set to l2gateway that the port implements See external_ids:ovn-bridge-mappings, above, for more information
Each l2gateway logical port is implemented as a pair of patch ports, one in the integration bridge, one in a different bridge, with the same external_ids:ovn-l2gateway-port value
external-ids:ovn-l3gateway-port in the Port table
This key identifies a patch port as one created by ovn-controller to implement a l3gateway logical port Its value is the name of the logical port with type set to l3gateway This patch port is similar to the OVN logical patch port, except that l3gateway port can only be bound to a particular chassis
external-ids:ovn-logical-patch-port in the Port table
This key identifies a patch port as one created by ovn-controller to implement an OVN logical patch port within the integration bridge Its value is the name of the OVN logical patch port that it implements
external-ids:ovn-startup-ts in the Bridge table
This key represents the timestamp (in milliseconds) at which ovn-controller process was started
external-ids:ovn-nb-cfg in the Bridge table
This key represents the last known OVN_SouthboundSB_Globalnb_cfg value for which all flows have been successfully installed in OVS
external-ids:ovn-nb-cfg-ts in the Bridge table
This key represents the timestamp (in milliseconds) of the last known OVN_SouthboundSB_Globalnb_cfg value for which all flows have been successfully installed in OVS
external_ids:ovn-installed and external_ids:ovn-installed-ts in the Interface table
This key is set after all openflow operations corresponding to the OVS interface have been processed by ovs-vswitchd At the same time a timestamp, in milliseconds since the epoch, is stored in external_ids:ovn-installed-ts

OVN SOUTHBOUND DATABASE USAGE

ovn-controller reads from much of the OVN_Southbound database to guide its operation ovn-controller also writes to the following tables:
Chassis
Upon startup, ovn-controller creates a row in this table to represent its own chassis Upon graceful termination, eg with ovs-appctl -t ovn-controller exit (but not SIGTERM), ovn-controller removes its row
Encap
Upon startup, ovn-controller creates a row or rows in this table that represent the tunnel encapsulations by which its chassis can be reached, and points its Chassis row to them Upon graceful termination, ovn-controller removes these rows
Port_Binding
At runtime, ovn-controller sets the chassis columns of ports that are resident on its chassis to point to its Chassis row, and, conversely, clears the chassis column of ports that point to its Chassis row but are no longer resident on its chassis The chassis column has a weak reference type, so when ovn-controller gracefully exits and removes its Chassis row, the database server automatically clears any remaining references to that row
MAC_Binding
At runtime, ovn-controller updates the MAC_Binding table as instructed by put_arp and put_nd logical actions These changes persist beyond the lifetime of ovn-controller

RUNTIME MANAGEMENT COMMANDS

ovs-appctl can send commands to a running ovn-controller process The currently supported commands are described below
exit
Causes ovn-controller to gracefully terminate
ct-zone-list
Lists each local logical port and its connection tracking zone
meter-table-list
Lists each meter table entry and its local meter id
group-table-list
Lists each group table entry and its local group id
inject-pkt microflow
Injects microflow into the connected Open vSwitch instance microflow must contain an ingress logical port (inport argument) that is present on the Open vSwitch instance
The microflow argument describes the packet whose forwarding is to be simulated, in the syntax of an OVN logical expression, as described in ovn-sb(5), to express constraints The parser understands prerequisites; for example, if the expression refers to ip4src, there is no need to explicitly state ip4 or ethtype == 0x800
connection-status
Show OVN SBDB connection status for the chassis
recompute
Trigger a full compute iteration in ovn-controller based on the contents of the Southbound database and local OVS database
This command is intended to use only in the event of a bug in the incremental processing engine in ovn-controller to avoid inconsistent states It should therefore be used with care as full recomputes are cpu intensive
sb-cluster-state-reset
Reset southbound database cluster status when databases are destroyed and rebuilt
If all databases in a clustered southbound database are removed from disk, then the stored index of all databases will be reset to zero This will cause ovn-controller to be unable to read or write to the southbound database, because it will always detect the data as stale In such a case, run this command so that ovn-controller will reset its local index so that it can interact with the southbound database again
debug/delay-nb-cfg-report seconds
This command is used to delay ovn-controller updating the nb_cfg back to OVN_Southbound database This is useful when ovn-nbctl --wait=hv is used to measure end-to-end latency in a large scale environment See ovn-nbctl(8) for more details
lflow-cache/flush
Flushes the ovn-controller logical flow cache
lflow-cache/show-stats
Displays logical flow cache statistics: enabled/disabled, per cache type entry counts
inc-engine/show-stats
Display ovn-controller engine counters For each engine node the following counters have been added:
recompute
compute
abort
inc-engine/show-stats engine_node_name counter_name
Display the ovn-controller engine counter(s) for the specified engine_node_name counter_name is optional and can be one of recompute, compute or abort
inc-engine/clear-stats
Reset ovn-controller engine counters

Recommended readings

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