pyrox.dev
1import ./make-test-python.nix (
2 { pkgs, ... }:
3 let
4 # build a getent that itself doesn't see anything in /etc/hosts and
5 # /etc/nsswitch.conf, by using libredirect to steer its own requests to
6 # /dev/null.
7 # This means is /has/ to go via nscd to actually resolve any of the
8 # additionally configured hosts.
9 getent' = pkgs.writeScript "getent-without-etc-hosts" ''
10 export NIX_REDIRECTS=/etc/hosts=/dev/null:/etc/nsswitch.conf=/dev/null
11 export LD_PRELOAD=${pkgs.libredirect}/lib/libredirect.so
12 exec getent $@
13 '';
14 in
15 {
16 name = "nscd";
17
18 nodes.machine =
19 { pkgs, ... }:
20 {
21 imports = [ common/user-account.nix ];
22 networking.extraHosts = ''
23 2001:db8::1 somehost.test
24 192.0.2.1 somehost.test
25 '';
26
27 systemd.services.sockdump = {
28 wantedBy = [ "multi-user.target" ];
29 path = [
30 # necessary for bcc to unpack kernel headers and invoke modprobe
31 pkgs.gnutar
32 pkgs.xz.bin
33 pkgs.kmod
34 ];
35 environment.PYTHONUNBUFFERED = "1";
36
37 serviceConfig = {
38 ExecStart = "${pkgs.sockdump}/bin/sockdump /var/run/nscd/socket";
39 Restart = "on-failure";
40 RestartSec = "1";
41 Type = "simple";
42 };
43 };
44
45 specialisation = {
46 withGlibcNscd.configuration =
47 { ... }:
48 {
49 services.nscd.enableNsncd = false;
50 };
51 withUnscd.configuration =
52 { ... }:
53 {
54 services.nscd.enableNsncd = false;
55 services.nscd.package = pkgs.unscd;
56 };
57 };
58 };
59
60 testScript =
61 { nodes, ... }:
62 let
63 specialisations = "${nodes.machine.system.build.toplevel}/specialisation";
64 in
65 ''
66 # Regression test for https://github.com/NixOS/nixpkgs/issues/50273
67 def test_dynamic_user():
68 with subtest("DynamicUser actually allocates a user"):
69 assert "iamatest" in machine.succeed(
70 "systemd-run --pty --property=Type=oneshot --property=DynamicUser=yes --property=User=iamatest whoami"
71 )
72
73 # Test resolution of somehost.test with getent', to make sure we go via
74 # nscd protocol
75 def test_host_lookups():
76 with subtest("host lookups via nscd protocol"):
77 # ahosts
78 output = machine.succeed("${getent'} ahosts somehost.test")
79 assert "192.0.2.1" in output
80 assert "2001:db8::1" in output
81
82 # ahostsv4
83 output = machine.succeed("${getent'} ahostsv4 somehost.test")
84 assert "192.0.2.1" in output
85 assert "2001:db8::1" not in output
86
87 # ahostsv6
88 output = machine.succeed("${getent'} ahostsv6 somehost.test")
89 assert "192.0.2.1" not in output
90 assert "2001:db8::1" in output
91
92 # reverse lookups (hosts)
93 assert "somehost.test" in machine.succeed("${getent'} hosts 2001:db8::1")
94 assert "somehost.test" in machine.succeed("${getent'} hosts 192.0.2.1")
95
96
97 # Test host resolution via nss modules works
98 # We rely on nss-myhostname in this case, which resolves *.localhost and
99 # _gateway.
100 # We don't need to use getent' here, as non-glibc nss modules can only be
101 # discovered via nscd.
102 def test_nss_myhostname():
103 with subtest("nss-myhostname provides hostnames (ahosts)"):
104 # ahosts
105 output = machine.succeed("getent ahosts foobar.localhost")
106 assert "::1" in output
107 assert "127.0.0.1" in output
108
109 # ahostsv4
110 output = machine.succeed("getent ahostsv4 foobar.localhost")
111 assert "::1" not in output
112 assert "127.0.0.1" in output
113
114 # ahostsv6
115 output = machine.succeed("getent ahostsv6 foobar.localhost")
116 assert "::1" in output
117 assert "127.0.0.1" not in output
118
119 start_all()
120 machine.wait_for_unit("default.target")
121
122 # give sockdump some time to finish attaching.
123 machine.sleep(5)
124
125 # Test all tests with glibc-nscd.
126 test_dynamic_user()
127 test_host_lookups()
128 test_nss_myhostname()
129
130 with subtest("glibc-nscd"):
131 machine.succeed('${specialisations}/withGlibcNscd/bin/switch-to-configuration test')
132 machine.wait_for_unit("default.target")
133
134 test_dynamic_user()
135 test_host_lookups()
136 test_nss_myhostname()
137
138 with subtest("unscd"):
139 machine.succeed('${specialisations}/withUnscd/bin/switch-to-configuration test')
140 machine.wait_for_unit("default.target")
141
142 # known to fail, unscd doesn't load external NSS modules
143 # test_dynamic_user()
144
145 test_host_lookups()
146
147 # known to fail, unscd doesn't load external NSS modules
148 # test_nss_myhostname()
149 '';
150 }
151)