ovn-ic(8)

📦
version 26.09.0 · 16 versions
, in nixpkgs unstable, ubuntu stonking

💖 ovn-ic — Open Virtual Network interconnection controller 💖

okay bestie, welcome to the ovn-ic(8) page, part of the OVN Manual, and no cap this daemon is kind of a big deal. let's get into it 🫶

✨ NAME ✨

ovn-ic — Open Virtual Network interconnection controller. periodt. 👑

🌸 SYNOPSIS 🌸

ovn-ic [options]

like, that's it. that's the whole vibe. she takes options and she goes. 💅

🦋 DESCRIPTION 🦋

so ovn-ic, the OVN interconnection controller, is a centralized daemon — a real main character who doesn't need to be everywhere at once — and what she does is talk to the global interconnection databases IC_NB/IC_SB to configure and exchange data with the local NB/SB so that this OVN deployment can interconnect with other OVN deployments. it's giving diplomacy. it's giving group project where she's the only one actually communicating. 🌈

💜 OPTIONS 💜

  • --ovnnb-db=database — the OVSDB database holding the OVN Northbound Database. if the OVN_NB_DB environment variable is set, its value becomes the default. otherwise the default is unix:/ovnnb_db.sock. 🎀
  • --ovnsb-db=database — the OVSDB database holding the OVN Southbound Database. if the OVN_SB_DB environment variable is set, its value becomes the default. otherwise the default is unix:/ovnsb_db.sock. ✨
  • --ic-nb-db=database — the OVSDB database holding the OVN Interconnection Northbound Database. if the OVN_IC_NB_DB environment variable is set, its value becomes the default. otherwise the default is unix:/ovn_ic_nb_db.sock. 🦋
  • --ic-sb-db=database — the OVSDB database holding the OVN Interconnection Southbound Database. if the OVN_IC_SB_DB environment variable is set, its value becomes the default. otherwise the default is unix:/ovn_ic_sb_db.sock. 🌸

okay and database in all of the options above has to be an OVSDB active or passive connection method, exactly like it's described in ovsdb(7). iykyk. 💫

🌙 Daemon Options 🌙

  • --pidfile[=pidfile] — makes a file (by default, program.pid) appear, and that file is like "hi, here's the PID of the running process 🫶". if the pidfile argument isn't specified, or if it doesn't begin with /, then it is created in .

and if --pidfile is not specified at all? no pidfile is created. simple as that.

  • --overwrite-pidfile — so by default, when --pidfile is specified and that pidfile already exists and is locked by a running process, the daemon just refuses to start. specify --overwrite-pidfile and she'll overwrite the pidfile instead. dramatic girlboss move honestly. 💅

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 finishes its initialization, the parent exits. she's gone, she's independent, she said bye 👋
  • --monitor — creates an additional process to monitor this program. if it dies because of 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 too. 😭

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 (rude, honestly).

specifying --no-chdir suppresses this behavior, so the daemon doesn't change its current working directory. this may be useful for collecting core files, since it's 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 working with files under well-known directories determined at build time. bestie, it's better to stick with this default behavior and not use this flag unless some other Access Control is being used to confine the daemon. and note that in contrast to other access control implementations that are typically enforced from kernel-space (e.g. DAC or MAC), self-confinement is imposed from the user-space daemon itself and hence should not be considered as a full confinement strategy — instead, view it as an additional layer of security. layers, queen. 🧅
  • --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 the current user or group assumed, respectively. only daemons started by the root user accept 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.

📝 Logging Options 📝

  • -v[spec], --verbose=[spec] — sets logging levels. with no spec at all, it 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.) 💀
    • 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. max volume, no chill, we love her 🔊
  • -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's used as the exact name for the log file. the default log file name used if file is omitted is /var/log/ovn/program.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. no nicknames allowed 🙅
  • --syslog-method=method — specify method as how syslog messages should be sent to the syslog daemon. the following forms are supported:
    • libc, to use the libc syslog() function. downside of using this options is that libc adds a 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's possible to specify arbitrary message format with this option. however, rsyslogd 8.9 and older versions use a hard coded parser function anyway, which limits UNIX domain socket use. if you want to use arbitrary message format with older rsyslogd versions, then use a UDP socket to localhost IP address instead.
    • udp:ip:port, to use a UDP socket. with this method it's possible to use arbitrary message format also with older rsyslogd. when sending syslog messages over a UDP socket, extra precaution needs to be taken into account, for example, the 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. gone. deleted. 🗑️

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/TLS for the connections to the Northbound and Southbound databases. no certs, no entry. ✋

  • -p privkey.pem, --private-key=privkey.pem — specifies a PEM file containing the private key used as identity for outgoing SSL/TLS 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/TLS connections will use to verify it. 📜
  • -C cacert.pem, --ca-cert=cacert.pem — specifies a PEM file containing the CA certificate for verifying certificates presented to this program by SSL/TLS peers. (this may be the same certificate that SSL/TLS 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 — turns OFF verification of the certificates that SSL/TLS peers hand you. Bestie. This is a security risk, periodt — it literally means you can't confirm those certs belong to hosts you know and trust. 🚩

- *--ssl-server-name=servername* — sets the server name used for TLS Server Name Indication (SNI). By default the hostname from the connection string gets used for SNI, and this option lets you override that SNI hostname. Super handy when you're connecting through proxies or service meshes where the connection endpoint is not the same as the intended server name. 🦋

✨ Other Options ✨ (the lil extras)

  • --unixctl=socket — sets the name of the control socket that the program listens on for runtime management commands (scroll down to RUNTIME MANAGEMENT COMMANDS, bestie, it's right there 👀). If socket doesn't begin with /, it's interpreted as relative to . (yeah the page just... leaves that one hanging, gaps and all 💀). If you never pass --unixctl at all, the default socket is /program.pid.ctl, where pid is the program's process ID.

Hand it none for socket and you disable the control socket feature entirely. bye socket 👋

  • -h, --help — prints a brief help message to the console. little snack of information 🍓
  • -V, --version — prints version information to the console. flex the numbers 💅

🎛️ RUNTIME MANAGEMENT COMMANDS 🎛️

ovn-appctl can slide commands into a running ovn-ic process. Here's everything currently supported, no gatekeeping:

  • exit — causes ovn-ic to gracefully terminate. so polite of it 🫶
  • pause — pauses ovn-ic so it stops processing any database changes. This will also instruct ovn-ic to drop any lock on SB DB.
  • resume — resumes ovn-ic so it goes back to processing database contents. This will also instruct ovn-northd to aspire for the lock on SB DB.
  • is-paused — returns "true" if ovn-ic is currently paused, "false" otherwise. vibe check in string form ✨
  • status — prints this server's status. It'll be "active" if ovn-ic has acquired the OVSDB lock on SB DB, "standby" if it hasn't, or "paused" if this instance is paused. three moods, no fourth 🔥

👑 ACTIVE-STANDBY FOR HIGH AVAILABILITY 👑

You may run ovn-ic more than once in an OVN deployment — go off, run a whole squad. When it's connected to a standalone or clustered DB setup, OVN will automatically make sure that only one of them is active at a time. And if multiple instances of ovn-ic are running and the active one fails? One of the hot standby instances of ovn-ic will automatically take over. main character energy passing the crown, no drama, no drop 💖

okay bestie that's the whole page 🌈 every flag, every command, every lock, every string literal, all of it. this one was OVN 26.09.0, documented as ovn-ic(8), and it says ovn-ic right there in the corner too — go forth and fail over beautifully 🧚💜

📦 where this page comes from