This is the command ovsdb-server that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
PROGRAM:
NAME
ovsdb-server - Open vSwitch database server
SYNOPSIS
ovsdb-server [database]... [--remote=remote]... [--run=command]
Daemon options:
[--pidfile[=pidfile]] [--overwrite-pidfile] [--detach] [--no-chdir]
Service options:
[--service] [--service-monitor]
Logging options:
[-v[module[:destination[:level]]]]...
[--verbose[=module[:destination[:level]]]]...
[--log-file[=file]]
Public key infrastructure options:
[--private-key=privkey.pem]
[--certificate=cert.pem]
[--ca-cert=cacert.pem]
[--bootstrap-ca-cert=cacert.pem]
[--peer-ca-cert=peer-cacert.pem]
Runtime management options:
--unixctl=socket
Common options:
[-h | --help] [-V | --version]
DESCRIPTION
The ovsdb-server program provides RPC interfaces to one or more Open vSwitch databases
(OVSDBs). It supports JSON-RPC client connections over active or passive TCP/IP or Unix
domain sockets.
Each OVSDB file may be specified on the command line as database. If none is specified,
the default is /etc/openvswitch/conf.db. The database files must already have been
created and initialized using, for example, ovsdb-tool create.
OPTIONS
--remote=remote
Adds remote as a connection method used by ovsdb-server. remote must take one of
the following forms:
pssl:port[:ip]
Listen on the given SSL port for a connection. By default, connections are
not bound to a particular local IP address and it listens only on IPv4 (but
not IPv6) addresses, but specifying ip limits connections to those from the
given ip, either IPv4 or IPv6 address. If ip is an IPv6 address, then wrap
ip with square brackets, e.g.: pssl:6640:[::1]. The --private-key,
--certificate, and --ca-cert options are mandatory when this form is used.
ptcp:port[:ip]
Listen on the given TCP port for a connection. By default, connections are
not bound to a particular local IP address and it listens only on IPv4 (but
not IPv6) addresses, but ip may be specified to listen only for connections
to the given ip, either IPv4 or IPv6 address. If ip is an IPv6 address,
then wrap ip with square brackets, e.g.: ptcp:6640:[::1].
punix:file
On POSIX, listen on the Unix domain server socket named file for a
connection.
On Windows, listen on a kernel chosen TCP port on the localhost. The kernel
chosen TCP port value is written in file.
ssl:ip:port
The specified SSL port on the host at the given ip, which must be expressed
as an IP address (not a DNS name) in IPv4 or IPv6 address format. If ip is
an IPv6 address, then wrap ip with square brackets, e.g.: ssl:[::1]:6640.
The --private-key, --certificate, and --ca-cert options are mandatory when
this form is used.
tcp:ip:port
Connect to the given TCP port on ip, where ip can be IPv4 or IPv6 address.
If ip is an IPv6 address, then wrap ip with square brackets, e.g.:
tcp:[::1]:6640.
unix:file
On POSIX, connect to the Unix domain server socket named file.
On Windows, connect to a localhost TCP port whose value is written in file.
db:db,table,column
Reads additional connection methods from column in all of the rows in table
within db. As the contents of column changes, ovsdb-server also adds and
drops connection methods accordingly.
If column's type is string or set of strings, then the connection methods
are taken directly from the column. The connection methods in the column
must have one of the forms described above.
If column's type is UUID or set of UUIDs and references a table, then each
UUID is looked up in the referenced table to obtain a row. The following
columns in the row, if present and of the correct type, configure a
connection method. Any additional columns are ignored.
target (string)
Connection method, in one of the forms described above. This column
is mandatory: if it is missing or empty then no connection method can
be configured.
max_backoff (integer)
Maximum number of milliseconds to wait between connection attempts.
inactivity_probe (integer)
Maximum number of milliseconds of idle time on connection to client
before sending an inactivity probe message.
It is an error for column to have another type.
To connect or listen on multiple connection methods, use multiple --remote options.
--run=command]
Ordinarily ovsdb-server runs forever, or until it is told to exit (see RUNTIME
MANAGEMENT COMMANDS below). With this option, ovsdb-server instead starts a shell
subprocess running command. When the subprocess terminates, ovsdb-server also
exits gracefully. If the subprocess exits normally with exit code 0, then
ovsdb-server exits with exit code 0 also; otherwise, it exits with exit code 1.
This option can be useful where a database server is needed only to run a single
command, e.g.: ovsdb-server --remote=punix:socket --run='ovsdb-client dump
unix:socket Open_vSwitch'
This option is not supported on Windows platform.
Daemon Options
The following options are valid on POSIX based platforms.
--pidfile[=pidfile]
Causes a file (by default, ovsdb-server.pid) 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 /var/run/openvswitch.
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, ovsdb-server 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 ovsdb-server 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. ovsdb-server detaches only after it starts
listening on all configured remotes.
--monitor
Creates an additional process to monitor the ovsdb-server daemon. If the daemon
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, ovsdb-server changes its current working
directory to the root directory after it detaches. Otherwise, invoking
ovsdb-server 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 ovsdb-server 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.
--user Causes ovsdb-server 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 are 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 interact with datapath, such as ovs-vswitchd,
will be granted two additional capabilities, namely CAP_NET_ADMIN and CAP_NET_RAW.
The capability change will apply even if 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.
Service Options
The following options are valid only on Windows platform.
--service
Causes ovsdb-server to run as a service in the background. The service should
already have been created through external tools like SC.exe.
--service-monitor
Causes the ovsdb-server service to be automatically restarted by the Windows
services manager if the service dies or exits for unexpected reasons.
When --service is not specified, this option has no effect.
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, ovsdb-server 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/openvswitch/ovsdb-server.log.
--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 how syslog messages should be sent to syslog daemon. Following
forms are supported:
· libc, use libc syslog() function. This is the default behavior. 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, use UNIX domain socket directly. It is possible to specify
arbitrary message format with this option. However, rsyslogd 8.9 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, use 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.
Public Key Infrastructure Options
The options described below for configuring the SSL public key infrastructure accept a
special syntax for obtaining their configuration from the database. If any of these
options is given db:db,table,column as its argument, then the actual file name is read
from the specified column in table within the db database. The column must have type
string or set of strings. The first nonempty string in the table is taken as the file
name. (This means that ordinarily there should be at most one row in table.)
-p privkey.pem
--private-key=privkey.pem
Specifies a PEM file containing the private key used as ovsdb-server's identity for
outgoing SSL connections.
-c cert.pem
--certificate=cert.pem
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 cacert.pem
--ca-cert=cacert.pem
Specifies a PEM file containing the CA certificate that ovsdb-server should use to
verify certificates presented to it 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=cacert.pem
When cacert.pem exists, this option has the same effect as -C or --ca-cert. If it
does not exist, then ovsdb-server 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-cacert.pem
Specifies a PEM file that contains one or more additional certificates to send to
SSL peers. peer-cacert.pem should be the CA certificate used to sign
ovsdb-server's own certificate, that is, the certificate specified on -c or
--certificate. If ovsdb-server'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 ovsdb-server's
identity. However, this offers a way for a new installation to bootstrap the CA
certificate on its first SSL connection.
Other Options
--unixctl=socket
Sets the name of the control socket on which ovsdb-server listens for runtime
management commands (see RUNTIME MANAGEMENT COMMANDS, below). If socket does not
begin with /, it is interpreted as relative to /var/run/openvswitch. If --unixctl
is not used at all, the default socket is
/var/run/openvswitch/ovsdb-server.pid.ctl, where pid is ovsdb-server's process ID.
On Windows, uses a kernel chosen TCP port on the localhost to listen for runtime
management commands. The kernel chosen TCP port value is written in a file whose
absolute path is pointed by socket. If --unixctl is not used at all, the file is
created as ovsdb-server.ctl in the configured OVS_RUNDIR directory.
Specifying none for socket disables the control socket feature.
-h
--help Prints a brief help message to the console.
-V
--version
Prints version information to the console.
RUNTIME MANAGEMENT COMMANDS
ovs-appctl(8) can send commands to a running ovsdb-server process. The currently
supported commands are described below.
OVSDB-SERVER COMMANDS
These commands are specific to ovsdb-server.
exit Causes ovsdb-server to gracefully terminate.
ovsdb-server/compact [db]...
Compacts each database db in-place. If no db is specified, compacts every database
in-place. Databases are also automatically compacted occasionally.
ovsdb-server/reconnect
Makes ovsdb-server drop all of the JSON-RPC connections to database clients and
reconnect.
This command might be useful for debugging issues with database clients.
ovsdb-server/add-remote remote
Adds a remote, as if --remote=remote had been specified on the ovsdb-server command
line. (If remote is already a remote, this command succeeds without changing the
configuration.)
ovsdb-server/remove-remote remote
Removes the specified remote from the configuration, failing with an error if
remote is not configured as a remote. This command only works with remotes that
were named on --remote or ovsdb-server/add-remote, that is, it will not remove
remotes added indirectly because they were read from the database by configuring a
db:db,table,column remote. (You can remove a database source with
ovsdb-server/remove-remote db:db,table,column, but not individual remotes found
indirectly through the database.)
ovsdb-server/list-remotes
Outputs a list of the currently configured remotes named on --remote or
ovsdb-server/add-remote, that is, it does not list remotes added indirectly because
they were read from the database by configuring a db:db,table,column remote.
ovsdb-server/add-db database
Adds the database to the running ovsdb-server. The database file must already have
been created and initialized using, for example, ovsdb-tool create.
ovsdb-server/remove-db database
Removes database from the running ovsdb-server. database must be a database name
as listed by ovsdb-server/list-dbs.
If a remote has been configured that points to the specified database (e.g.
--remote=db:database,... on the command line), then it will be disabled until
another database with the same name is added again (with ovsdb-server/add-db).
Any public key infrastructure options specified through this database (e.g.
--private-key=db:database,... on the command line) will be disabled until another
database with the same name is added again (with ovsdb-server/add-db).
ovsdb-server/list-dbs
Outputs a list of the currently configured databases added either through the
command line or through the ovsdb-server/add-db command.
VLOG COMMANDS
These commands manage ovsdb-server's logging settings.
vlog/set [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.
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 ovsdb-server was invoked with the --log-file option.
For compatibility with older versions of OVS, any is accepted as a word but has no
effect.
vlog/set 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.
vlog/list
Lists the supported logging modules and their current levels.
vlog/list-pattern
Lists logging patterns used for each destination.
vlog/reopen
Causes ovsdb-server to close and reopen its log file. (This is useful after
rotating log files, to cause a new log file to be used.)
This has no effect unless ovsdb-server was invoked with the --log-file option.
vlog/disable-rate-limit [module]...
vlog/enable-rate-limit [module]...
By default, ovsdb-server limits the rate at which certain messages can be logged.
When a message would appear more frequently than the limit, it is suppressed. This
saves disk space, makes logs easier to read, and speeds up execution, but
occasionally troubleshooting requires more detail. Therefore,
vlog/disable-rate-limit allows rate limits to be disabled at the level of an
individual log module. Specify one or more module names, as displayed by the
vlog/list command. Specifying either no module names at all or the keyword any
disables rate limits for every log module.
The vlog/enable-rate-limit command, whose syntax is the same as
vlog/disable-rate-limit, can be used to re-enable a rate limit that was previously
disabled.
MEMORY COMMANDS
These commands report memory usage.
memory/show
Displays some basic statistics about ovsdb-server's memory usage. ovsdb-server
also logs this information soon after startup and periodically as its memory
consumption grows.
COVERAGE COMMANDS
These commands manage ovsdb-server's ``coverage counters,'' which count the number of
times particular events occur during a daemon's runtime. In addition to these commands,
ovsdb-server automatically logs coverage counter values, at INFO level, when it detects
that the daemon's main loop takes unusually long to run.
Coverage counters are useful mainly for performance analysis and debugging.
coverage/show
Displays the averaged per-second rates for the last few seconds, the last minute
and the last hour, and the total counts of all of the coverage counters.
SPECIFICATIONS
ovsdb-server implements the Open vSwitch Database (OVSDB) protocol specified in RFC 7047,
with the following clarifications:
3.1. JSON Usage
RFC 4627 says that names within a JSON object should be unique. The Open vSwitch
JSON parser discards all but the last value for a name that is specified more than
once.
The definition of <error> allows for implementation extensions. Currently
ovsdb-server uses the following additional "error" strings which might change in
later releases):
syntax error or unknown column
The request could not be parsed as an OVSDB request. An additional "syntax"
member, whose value is a string that contains JSON, may narrow down the
particular syntax that could not be parsed.
internal error
The request triggered a bug in ovsdb-server.
ovsdb error
A map or set contains a duplicate key.
3.2. Schema Format
RFC 7047 requires the "version" field in <database-schema>. Current versions of
ovsdb-server allow it to be omitted (future versions are likely to require it).
4. Wire Protocol
The original OVSDB specifications included the following reason, omitted from RFC
7047, to operate JSON-RPC directly over a stream instead of over HTTP:
· JSON-RPC is a peer-to-peer protocol, but HTTP is a client-server protocol,
which is a poor match. Thus, JSON-RPC over HTTP requires the client to
periodically poll the server to receive server requests.
· HTTP is more complicated than stream connections and doesn't provide any
corresponding advantage.
· The JSON-RPC specification for HTTP transport is incomplete.
4.1.5. Monitor
For backward compatibility, ovsdb-server currently permits a single <monitor-
request> to be used instead of an array; it is treated as a single-element array.
Future versions of ovsdb-server might remove this compatibility feature.
Because the <json-value> parameter is used to match subsequent update notifications
(see below) to the request, it must be unique among all active monitors.
ovsdb-server rejects attempt to create two monitors with the same identifier.
5.1. Notation
For <condition>, RFC 7047 only allows the use of !=, ==, includes, and excludes
operators with set types. Open vSwitch 2.4 and later extend <condition> to allow
the use of <, <=, >=, and > operators with columns with type ``set of 0 or 1
integer'' and ``set of 0 or 1 real''. These conditions evaluate to false when the
column is empty, and otherwise as described in RFC 7047 for integer and real types.
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