xref: /freebsd/libexec/flua/libjail/jail.3lua (revision 96190b4fef3b4a0cc3ca0606b0c4e3e69a5e6717)
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27.Dd October 24, 2020
28.Dt JAIL 3lua
29.Os
30.Sh NAME
31.Nm attach ,
32.Nm getid ,
33.Nm getname ,
34.Nm list ,
35.Nm allparams ,
36.Nm getparams ,
37.Nm remove ,
38.Nm setparams ,
39.Nm CREATE ,
40.Nm UPDATE ,
41.Nm ATTACH ,
42.Nm DYING
43.Nd Lua binding to
44.Xr jail 3
45.Sh SYNOPSIS
46.Bd -literal
47local jail = require('jail')
48.Ed
49.Pp
50.Bl -tag -width XXXX -compact
51.It Dv ok, err = jail.attach(jid|name)
52.It Dv jid, err = jail.getid(name)
53.It Dv name, err = jail.getname(jid)
54.It Dv params, err = jail.allparams()
55.It Dv iter, jail_obj = jail.list([params])
56.It Dv jid, res = jail.getparams(jid|name, params [, flags ] )
57.It Dv ok, err = jail.remove(jid|name)
58.It Dv jid, err = jail.setparams(jid|name, params, flags )
59.It Dv jail.CREATE
60.It Dv jail.UPDATE
61.It Dv jail.ATTACH
62.It Dv jail.DYING
63.El
64.Sh DESCRIPTION
65The
66.Nm jail
67module is a binding to the
68.Xr jail 3
69library.
70It provides a string-oriented interface for the
71.Xr jail_get 2
72and
73.Xr jail_set 2
74system calls.
75.Bl -tag -width XXXX
76.It Dv ok, err = jail.attach(jid|name)
77Attach to the given jail, identified by an integer
78.Fa jid
79or the
80.Fa name .
81.It Dv jid, err = jail.getid(name)
82Get the jail identifier
83.Pq jid
84as an integer.
85.Fa name
86is the name of a jail or a jid in the form of a string.
87.It Dv name, err = jail.getname(jid)
88Get the name of a jail as a string for the given
89.Fa jid
90.Pq an integer .
91.It Dv iter, jail_obj = jail.list([params])
92Returns an iterator over running jails on the system.
93.Dv params
94is a list of parameters to fetch for each jail as we iterate.
95.Dv jid
96and
97.Dv name
98will always be returned, and may be omitted from
99.Dv params .
100Additionally,
101.Dv params
102may be omitted or an empty table, but not nil.
103.Pp
104See
105.Sx EXAMPLES .
106.It Dv params, err = jail.allparams()
107Get a list of all supported parameter names
108.Pq as strings .
109See
110.Xr jail 8
111for descriptions of the core jail parameters.
112.It Dv jid, res = jail.getparams(jid|name, params [, flags ] )
113Get a table of the requested parameters for the given jail.
114.Nm jid|name
115can either be the jid as an integer or the jid or name as a string.
116.Nm params
117is a list of parameter names.
118.Nm flags
119is an optional integer representing the flag bits to apply for the operation.
120See the list of flags below.
121Only the
122.Dv DYING
123flag is valid to set.
124.It Dv ok, err = jail.remove(jid|name)
125Remove the given jail, identified by an integer
126.Fa jid
127or the
128.Fa name .
129.It Dv jid, err = jail.setparams(jid|name, params [, flags ] )
130Set parameters for a given jail.
131This is used to create, update, attach to, or destroy a jail.
132.Nm jid|name
133can either be the jid as an integer or the jid or name as a string.
134.Nm params
135is a table of parameters to apply to the jail, where each key in the table
136is a parameter name as a string and each value is a string that will be
137converted to the internal value type by
138.Xr jailparam_import 3 .
139.Nm flags
140is an optional integer representing the flag bits to apply for the operation.
141See the list of flags below.
142.El
143.Pp
144The
145.Nm flags
146arguments are an integer bitwise-or combination of one or more of the following
147flags:
148.Bl -tag -width XXXX
149.It Dv jail.CREATE
150Used with
151.Fn setparams
152to create a new jail.
153The jail must not already exist, unless combined with
154.Dv UPDATE .
155.It Dv jail.UPDATE
156Used with
157.Fn setparams
158to modify an existing jail.
159The jail must already exist, unless combined with
160.Dv CREATE .
161.It Dv jail.ATTACH
162Used with
163.Fn setparams
164in combination with
165.Dv CREATE
166or
167.Dv UPDATE
168to attach the current process to a jail.
169.It Dv jail.DYING
170Allow operating on a jail that is in the process of being removed.
171.El
172.Sh RETURN VALUES
173The
174.Fn getid
175and
176.Fn setparams
177functions return a jail identifier integer on success, or
178.Dv nil
179and an error message string if an error occurred.
180.Pp
181The
182.Fn getname
183function returns a jail name string on success, or
184.Dv nil
185and an error message string if an error occurred.
186.Pp
187The
188.Fn allparams
189function returns a list of parameter name strings on success, or
190.Dv nil
191and an error message string if an error occurred.
192.Pp
193The
194.Fn getparams
195function returns a jail identifier integer and a table of jail parameters
196with parameter name strings as keys and strings for values on success, or
197.Dv nil
198and an error message string if an error occurred.
199.Pp
200The
201.Fn list
202function returns an iterator over the list of running jails.
203.Pp
204The
205.Fn attach
206and
207.Fn remove
208functions return true on success, or
209.Dv nil
210and an error message string if an error occurred.
211.Sh EXAMPLES
212Set the hostname of jail
213.Dq foo
214to
215.Dq foo.bar :
216.Bd -literal -offset indent
217local jail = require('jail')
218
219jid, err = jail.setparams("foo", {["host.hostname"]="foo.bar"},
220    jail.UPDATE)
221if not jid then
222    error(err)
223end
224.Ed
225.Pp
226Retrieve the hostname of jail
227.Dq foo :
228.Bd -literal -offset indent
229local jail = require('jail')
230
231jid, res = jail.getparams("foo", {"host.hostname"})
232if not jid then
233    error(res)
234end
235print(res["host.hostname"])
236.Ed
237.Pp
238Iterate over jails on the system:
239.Bd -literal -offset indent
240local jail = require('jail')
241
242-- Recommended: just loop over it
243for jparams in jail.list() do
244    print(jparams["jid"] .. " = " .. jparams["name"])
245end
246
247-- Request path and hostname, too
248for jparams in jail.list({"path", "host.hostname"}) do
249    print(jparams["host.hostname"] .. " mounted at " .. jparams["path"])
250end
251
252-- Raw iteration protocol
253local iter, jail_obj = jail.list()
254
255-- Request the first params
256local jparams = jail_obj:next()
257while jparams do
258    print(jparams["jid"] .. " = " .. jparams["name"])
259    -- Subsequent calls may return nil
260    jparams = jail_obj:next()
261end
262.Ed
263.Sh SEE ALSO
264.Xr jail 2 ,
265.Xr jail 3 ,
266.Xr jail 8
267.Sh HISTORY
268The
269.Nm jail
270Lua module for flua first appeared in
271.Fx 13.0 .
272.Sh AUTHORS
273.An Ryan Moeller ,
274with inspiration from
275.Nx
276gpio(3lua), by
277.An Mark Balmer .
278