From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <zsh-workers-return-34506-mason-zsh=primenet.com.au@zsh.org>
Received: (qmail 24106 invoked by alias); 11 Feb 2015 10:11:41 -0000
Mailing-List: contact zsh-workers-help@zsh.org; run by ezmlm
Precedence: bulk
X-No-Archive: yes
List-Id: Zsh Workers List <zsh-workers.zsh.org>
List-Post: <mailto:zsh-workers@zsh.org>
List-Help: <mailto:zsh-workers-help@zsh.org>
X-Seq: 34506
Received: (qmail 29550 invoked from network); 11 Feb 2015 10:11:38 -0000
X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on f.primenet.com.au
X-Spam-Level: 
X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_HI,
	SPF_HELO_PASS autolearn=ham version=3.3.2
X-AuditID: cbfec7f4-b7f126d000001e9a-b0-54db2a44437f
Date: Wed, 11 Feb 2015 10:11:30 +0000
From: Peter Stephenson <p.stephenson@samsung.com>
To: "zsh-workers@zsh.org" <zsh-workers@zsh.org>
Cc: Soares Chen <soares.chen@gmail.com>
Subject: Re: Zsh scripts leave defunct processes when running under docker exec
Message-id: <20150211101130.2ac4d9b5@pwslap01u.europe.root.pri>
In-reply-to:
 <CAH+w=7YBD6ocsd6+PL-AgpkDt4-O2AHPQa06U2=b7s2LfeORQw@mail.gmail.com>
References:
 <CACUDQOE1y34_b_OF8g4kf7JJisyBc0T5Chr_E8xkZiyO_kTRGQ@mail.gmail.com>
 <CAH+w=7YBD6ocsd6+PL-AgpkDt4-O2AHPQa06U2=b7s2LfeORQw@mail.gmail.com>
Organization: Samsung Cambridge Solution Centre
X-Mailer: Claws Mail 3.7.9 (GTK+ 2.22.0; i386-redhat-linux-gnu)
MIME-version: 1.0
Content-type: text/plain; charset=US-ASCII
Content-transfer-encoding: 7bit
X-Brightmail-Tracker:
 H4sIAAAAAAAAA+NgFtrLLMWRmVeSWpSXmKPExsVy+t/xy7ouWrdDDB63alhcuLiUzeJg80Mm
	ByaPnbPusnusOviBKYApissmJTUnsyy1SN8ugStj4uO/bAW3OSpap6xgb2D8xdbFyMkhIWAi
	0b3oNzuELSZx4d56oDgXh5DAUkaJrbseMUM4PUwSkzZPYYdwtjFKrJ+2jQWkhUVAVeLaqfdg
	NpuAocTUTbMZQWwRAX2Ji39ugdnMAuoSe6Y/YwaxhQX8JV4dncwEYvMK2EvMONcKtppTIFji
	x7PtTBALZjJKTHg5E6yZH2jQ1b+fmCDus5eYeeUMI0SzoMSPyfdYIBZoSWze1sQKYctLbF7z
	FmyZENDiG3d3s09gFJ6FpGUWkpZZSFoWMDKvYhRNLU0uKE5KzzXUK07MLS7NS9dLzs/dxAgJ
	8i87GBcfszrEKMDBqMTDGzDhZogQa2JZcWXuIUYJDmYlEd4IsdshQrwpiZVVqUX58UWlOanF
	hxiZODilGhhtfzBm3kzI6j/UU3R2Gatu9bV9L9jPJtW//No5a67YLt1zj59m17+f7iRvpZ6w
	30DjVdbdsAkvGzee6l00c/1kZ/kEwUnS21VPJj6fIJH7bdeHDIMsr62qN+67mpgK73p9w3dy
	vnnWrLB+V8U1Af5zbsl8vnEjS2/JB5nAc4GMD3fMPq5knpOhxFKckWioxVxUnAgAcDfFGVAC	AAA=

On Tue, 10 Feb 2015 22:53:13 -0800
Bart Schaefer <schaefer@brasslantern.com> wrote:
> I'm not exactly a docker expert, but my understanding is that docker
> incorporates (is built on?) the relatively recent Linux feature of "PID
> namespaces".  Under a PID namespace, the first process started is assigned
> PID 1and is expected to behave like the "init" process in a traditional
> Unix/Linux system, and be the ultimate manager of all the other processes
> spawned within the namespace.
> 
> Zsh is not designed to assume that role.  In particular, when processing a
> script, it will optimize process handling and perform an implicit "exec" of
> the final command in the script, so that it need not hang around waiting
> for that process to exit, assuming that it's own parent will reap it.  In a
> "docker exec" there is no parent to do so.

Yeah, another special case we don't have either the bandwidth or the
expertise to support...

If that *is* it, is it just a case of special-casing PID 1 not to do
"fake" execs?  That's not so hard and shouldn't be problematic in other
cases.

pws