HOST(3)

💖 HOST(3) — the host module, bestie edition ✨

from the host manual, version 1.7 🎀

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🌸 NAME 🌸

nfstest.host — the Host module 💅

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🦋 DESCRIPTION 🦋

okay so. nfstest.host is basically your little toolbox for running commands — whether they're chillin' on the local host or vibing on a remote host. 🫶

And yes, she thought of everything: there's also a mechanism for running commands in the background, so you're not just sitting there staring at your terminal like 😭 waiting for something to finish. main character energy honestly.

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she also comes with methods for mounting and unmounting from an NFS server — so like, you can hop on and off a server whenever, no cap ✨

and for the drama girlies: there's a mechanism to simulate a network partition using iptables 🔥 literally building fake breakups between your hosts. iconic.

⚠️ but bestie listen — as of right now, there is no mechanism to restore the iptables rules to their original state. so once you partition that network, those rules are just… out there. living their life. 💀 no undo button, no take-backs, fr fr. be careful with that one. 🙈

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🌸 CLASSES 🌸

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💖 class Host(baseobj.BaseObj) 💖

Host object, and it's giving main character energy for all your NFS test host needs. 💅

Host() -> New Host object

Usage:

           from nfstest.host import Host

           # Create host object for local host
           x = Host()
           # Create host object for remote host
           y = Host(host='192.168.0.11')

           # Run command to the local host
           x.run_cmd("ls -l")

           # Send command to the remote host and run it as root
           y.run_cmd("ls -l", sudo=True)

           # Run command in the background
           x.run_cmd("tcpdump", sudo=True, wait=False)
           ....
           ....
           # Stop command running in the background
           x.stop_cmd()

           # Mount volume using default options
           x.mount()

           # Unmount volume
           x.umount()

           # Start packet trace
           x.trace_start()

           # Stop packet trace
           x.trace_stop()

           # Open packet trace
           x.trace_open()

           # Enable NFS kernel debug
           x.nfs_debug_enable(nfsdebug='all'):

           # Stop NFS kernel debug
           x.nfs_debug_reset()

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🫶 Methods defined here: 🫶

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• __del__(self) — Destructor. The goodbye kiss, the Irish exit, the bye bestie 💀
• __init__(self, **kwargs) — Constructor. Initialize object's private data. Here's every kwarg you can pass, no cap ✨
  • host: — Hostname or IP address [default: localhost]
  • user: — User to log in to host [default: '']
  • server: — NFS server name or IP address [default: None]
  • nfsversion: — NFS version [default: 4.1]
  • proto: — NFS protocol name [default: 'tcp']
  • port: — NFS server port [default: 2049]
  • sec: — Security flavor [default: 'sys']
  • nconnect: — Multiple TCP connections option [default: 1]
  • export: — Exported file system to mount [default: '/']
  • mtpoint: — Mount point [default: '/mnt/t']
  • datadir: — Data directory where files are created [default: '']
  • mtopts: — Mount options [default: 'hard,rsize=4096,wsize=4096']
  • interface: — Network device interface [default: 'eth0']
  • nomount: — Debug option so the server is not actually mounted [default: False]
  • tracename: — Base name for trace files to create [default: 'tracefile']
  • trcdelay: — Seconds to delay before stopping packet trace [default: 0.0]
  • tcpdump: — Tcpdump command [default: '/usr/sbin/tcpdump']
  • tbsize: — Capture buffer size in kB [default: 150000]
  • notrace: — Debug option so a trace is not actually started [default: False]
  • rpcdebug: — Set RPC kernel debug flags and save log messages [default: '']
  • nfsdebug: — Set NFS kernel debug flags and save log messages [default: '']
  • tracepoints: — List of trace points modules to enable [default: '']
  • nfsstats: — Get NFS stats [default: False]
  • dbgname: — Base name for log messages files to create [default: 'dbgfile']
  • trcpname: — Base name for trace point files to create [default: 'trcpfile']
  • nfsstatname: — Base name for NFS stats files to create [default: 'nfsstatfile']
  • messages: — Location of file for system messages [default: '/var/log/messages']
  • trcevents: — Tracing events directory [default: '/sys/kernel/debug/tracing/events']
  • trcpipe: — Trace pipe file [default: '/sys/kernel/debug/tracing/trace_pipe']
  • tmpdir: — Temporary directory where trace/debug files are created [default: '/tmp']
  • iptables: — Iptables command [default: '/usr/sbin/iptables']
  • kill: — kill command [default: '/usr/bin/kill']
  • nfsstat: — nfsstat command [default: '/usr/bin/nfsstat']
  • sudo: — Sudo command [default: '/usr/bin/sudo']
• abspath(self, filename, dir=None) — Return the absolute path for the given file name.
• cleanup(self) — Gracefully unmount volume and reset network.
• get_pids(self, pid) — Get all descendant PIDs for the given PID.
• get_route(self, ipaddr) — Get routing information for destination IP address. Returns a tuple: (gateway, device name, src IP address).
• mount(self, **kwargs) — Mount the file system on the given mount point. Like, actually attach that NFS thing 💅
  • server: — NFS server name or IP address [default: self.server]
  • nfsversion: — NFS version [default: self.nfsversion]
  • proto: — NFS protocol name [default: self.proto]
  • port: — NFS server port [default: self.port]
  • sec: — Security flavor [default: self.sec]
  • nconnect: — Multiple TCP connections option [default: self.nconnect]
  • export: — Exported file system to mount [default: self.export]
  • mtpoint: — Mount point [default: self.mtpoint]
  • datadir: — Data directory where files are created [default: self.datadir]
  • mtopts: — Mount options [default: self.mtopts]
  • Return the mount point. 🎯
• network_drop(self, ipaddr, port) — Simulate a network drop by dropping all tcp packets going to the given ipaddr and port using the iptables commands.
• network_reset(self) — Reset the network by flushing all the chains in the table using the iptables command.
• nfs_debug_enable(self, **kwargs) — Enable NFS debug messages. Let's snoop, but respectfully 👀
  • rpcdebug: — Set RPC kernel debug flags and save log messages [default: self.rpcdebug]
  • nfsdebug: — Set NFS kernel debug flags and save log messages [default: self.nfsdebug]
  • dbgfile: — Name of log messages file to create, default is a unique name created in the temporary directory using self.dbgname as the base name.
• nfs_debug_reset(self) — Reset NFS debug messages.
• nfsstat_get(self) — Get NFS stats.
• nfsstat_init(self) — Initialize NFS stats.
• nfsstr(self, version=None, prefix='NFSv') — Return the NFS string for the given NFS version.
  • version: — NFS version, default is the object attribute nfsversion
• nfsvers(self, version=None) — Return major and minor version for the given NFS version.
  • version: — NFS version, default is the object attribute nfsversion
• run_cmd(self, cmd, sudo=False, dlevel='DBG1', msg='', wait=True) — Run the command to the remote machine using ssh. There is no user authentication, so remote host must allow ssh connection without any passwords for the user. For a localhost the command is just executed and ssh is not used. 🖥️
  • The object for the process of the command is stored in object attribute self.process to be used by methods wait_cmd() and stop_cmd(). The standard output of the command is also stored in the object attribute self.pstdout while the standard error output of the command is stored in self.pstderr.
  • cmd: — Command to execute
  • sudo: — Run command using sudo if option is True
  • dlevel: — Debug level for displaying the command to the user
  • msg: — Prefix this message to the debug message to be displayed
  • wait: — Wait for command to complete before returning
  • Return the standard output of the command and the return code or exit status is stored in the object attribute self.returncode. 🔥
• stop_cmd(self, process=None, dlevel=None, msg='') — Terminate command started by run_cmd() by calling wait_cmd() with the 'terminate' option set to True. Bye bye, process 💀
  • process: — The object for the process of the command to terminate, or terminate all commands started by run_cmd() if this option is not given
  • dlevel: — Debug level for displaying the command to the user, default is the level given by run_cmd()
  • msg: — Prefix this message to the debug message to be displayed
  • Return the exit status of the last command.
• sudo_cmd(self, cmd) — Prefix the SUDO command if effective user is not root.
• trace_open(self, tracefile=None, **kwargs) — Open the trace file given or the trace file started by trace_start().
  • All extra options are passed directly to the packet trace object.
  • Return the packet trace object created, the packet trace object is also stored in the object attribute pktt.
• trace_points_enable(self) — Enable trace points.
• trace_points_reset(self) — Reset trace points.
• trace_start(self, tracefile=None, interface=None, capsize=None, clients=None) — Start trace on interface given. The interface arg is the interface, and here are the rest:
  • tracefile: — Name of trace file to create, default is a unique name created in the temporary directory using self.tracename as the base name.
  • capsize: — Use the -C option of tcpdump to split the trace files every 1000000*capsize bytes. See documentation for tcpdump for more information
  • clients: — List of Host() objects to monitor
  • Return the name of the trace file created.
• trace_stop(self) — Stop the trace started by trace_start().
• umount(self) — Unmount the file system.
• wait_cmd(self, process=None, terminate=False, dlevel=None, msg='') — Wait for command started by run_cmd() to finish. Patience, bestie 🧘
  • process: — The object for the process of the command to wait for, or wait for all commands started by run_cmd() if this option is not given
  • terminate: — If True, send a signal to terminate the command or commands and then wait for all commands to finish
  • dlevel: — Debug level for displaying the command to the user, default is the level given by run_cmd()
  • msg: — Prefix this message to the debug message to be displayed
  • Return the exit status of the last command.

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⭐ Static methods defined here: ⭐

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• get_ip_address(host='', ipv6=False) — Get IP address associated with the given host name. This could be run as an instance or class method.

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🔗 SEE ALSO 🔗

• baseobj(3)
• packet.pktt(3)

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🐛 BUGS 🐛

No known bugs. So clean, so slay. ✨

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👑 AUTHOR 👑

Jorge Mora (mora@netapp.com)

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This page is from NFStest 3.2, dated 21 March 2023 — and that's the whole Host(3) vibe, bestie. 💖