nixosTest: Document stdout waiting behavior

This commit is contained in:
Robert Hensing 2021-11-05 01:41:32 +01:00
parent bce05e3b6a
commit 698fb089d8
4 changed files with 39 additions and 1 deletions

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@ -159,6 +159,10 @@ The following methods are available on machine objects:
`execute`
: Execute a shell command, returning a list `(status, stdout)`.
If the command detaches, it must close stdout, as `execute` will wait
for this to consume all output reliably. This can be achieved by
redirecting stdout to stderr `>&2`, to `/dev/console`, `/dev/null` or
a file.
Takes an optional parameter `check_return` that defaults to `True`.
Setting this parameter to `False` will not check for the return code
and return -1 instead. This can be used for commands that shut down
@ -179,6 +183,8 @@ The following methods are available on machine objects:
- Dereferencing unset variables fail the command.
- It will wait for stdout to be closed. See `execute`.
`fail`
: Like `succeed`, but raising an exception if the command returns a zero

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@ -266,7 +266,12 @@ start_all()
<listitem>
<para>
Execute a shell command, returning a list
<literal>(status, stdout)</literal>. Takes an optional
<literal>(status, stdout)</literal>. If the command detaches,
it must close stdout, as <literal>execute</literal> will wait
for this to consume all output reliably. This can be achieved
by redirecting stdout to stderr <literal>&gt;&amp;2</literal>,
to <literal>/dev/console</literal>,
<literal>/dev/null</literal> or a file. Takes an optional
parameter <literal>check_return</literal> that defaults to
<literal>True</literal>. Setting this parameter to
<literal>False</literal> will not check for the return code
@ -306,6 +311,12 @@ start_all()
Dereferencing unset variables fail the command.
</para>
</listitem>
<listitem>
<para>
It will wait for stdout to be closed. See
<literal>execute</literal>.
</para>
</listitem>
</itemizedlist>
</listitem>
</varlistentry>

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@ -423,6 +423,23 @@
<section xml:id="sec-release-21.11-incompatibilities">
<title>Backward Incompatibilities</title>
<itemizedlist>
<listitem>
<para>
The NixOS VM test framework,
<literal>pkgs.nixosTest</literal>/<literal>make-test-python.nix</literal>,
now requires non-terminating commands such as
<literal>succeed(&quot;foo &amp;&quot;)</literal> to close
stdout. This can be done with a redirect such as
<literal>succeed(&quot;foo &gt;&amp;2 &amp;&quot;)</literal>.
This breaking change was necessitated by a race condition
causing tests to fail or hang. It applies to all methods that
invoke commands on the nodes, including
<literal>execute</literal>, <literal>succeed</literal>,
<literal>fail</literal>,
<literal>wait_until_succeeds</literal>,
<literal>wait_until_fails</literal>.
</para>
</listitem>
<listitem>
<para>
The <literal>services.wakeonlan</literal> option was removed,

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@ -128,6 +128,10 @@ In addition to numerous new and upgraded packages, this release has the followin
## Backward Incompatibilities {#sec-release-21.11-incompatibilities}
- The NixOS VM test framework, `pkgs.nixosTest`/`make-test-python.nix`, now requires non-terminating commands such as `succeed("foo &")` to close stdout.
This can be done with a redirect such as `succeed("foo >&2 &")`. This breaking change was necessitated by a race condition causing tests to fail or hang.
It applies to all methods that invoke commands on the nodes, including `execute`, `succeed`, `fail`, `wait_until_succeeds`, `wait_until_fails`.
- The `services.wakeonlan` option was removed, and replaced with `networking.interfaces.<name>.wakeOnLan`.
- The `security.wrappers` option now requires to always specify an owner, group and whether the setuid/setgid bit should be set.