xref: /freebsd/share/examples/flua/libjail.lua (revision d37eb51047221dc3322b34db1038ff3aa533883f)
1#!/usr/libexec/flua
2--[[
3/*-
4 * SPDX-License-Identifier: BSD-2-Clause
5 *
6 * Copyright (c) 2020, Ryan Moeller <freqlabs@FreeBSD.org>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29]]--
30
31jail = require("jail")
32ucl = require("ucl")
33
34name = "demo"
35
36local has_demo = false
37
38-- Make sure we don't have a demo jail to start with; "jid" and "name" are
39-- always present.
40for jparams in jail.list() do
41    if jparams["name"] == name then
42        has_demo = true
43        break
44    end
45end
46
47if not has_demo then
48    -- Create a persistent jail named "demo" with all other parameters default.
49    jid, err = jail.setparams(name, {persist = "true"}, jail.CREATE)
50    if not jid then
51        error(err)
52    end
53end
54
55-- Get a list of all known jail parameter names.
56allparams = jail.allparams()
57
58-- Get all the parameters of the jail we created.
59jid, res = jail.getparams(name, allparams)
60if not jid then
61    error(res)
62end
63
64-- Display the jail's parameters as a pretty-printed JSON object.
65print(ucl.to_json(res))
66
67-- Confirm that we still have it for now.
68has_demo = false
69for jparams in jail.list() do
70    if jparams["name"] == name then
71        has_demo = true
72        break
73    end
74end
75
76if not has_demo then
77    print("demo does not exist")
78end
79
80-- Update the "persist" parameter to "false" to remove the jail.
81jid, err = jail.setparams(name, {persist = "false"}, jail.UPDATE)
82if not jid then
83    error(err)
84end
85
86-- Verify that the jail is no longer on the system.
87local is_persistent = false
88has_demo = false
89for jparams in jail.list({"persist"}) do
90    if jparams["name"] == name then
91        has_demo = true
92        jid = jparams["jid"]
93        is_persistent = jparams["persist"] ~= "false"
94    end
95end
96
97-- In fact, it does remain until this process ends -- c'est la vie.
98if has_demo then
99    io.write("demo still exists, jid " .. jid .. ", ")
100    if is_persistent then
101        io.write("persistent\n")
102    else
103        io.write("not persistent\n")
104    end
105end
106