From 21a0fc30e81ae824ddca607f4fd46e85047c0a7d Mon Sep 17 00:00:00 2001
From: Marc CARRE <carre.marc@gmail.com>
Date: Mon, 13 Mar 2017 14:49:40 +0000
Subject: [PATCH] Run weaver without exec.

This:

1. prevents from generating defunct (a.k.a. zombie) processes, and therefore fixes #2836; but also
2. reintroduces #2684/#2688 as shells do not forward signals and we are still running more than one process.

A proper fix would leverage something like tini.
See also:

- github.com/krallin/tini
- github.com/krallin/tini/issues/8
- github.com/docker-library/official-images#init

Sample output:

- during initialisation:

```
$ ps auxf
[...]
root      1380  0.4  1.9 879660 74660 ?        Ssl  Mar13   6:02 /usr/bin/docker daemon -H fd:// -H unix:///
root      1664  0.0  0.4 502116 18528 ?        Ssl  Mar13   0:06  \_ docker-containerd -l /var/run/docker/li
root     15482  0.0  0.0 200496  3364 ?        Sl   15:04   0:00      \_ docker-containerd-shim 3d1f5eb6e090
root     15496  0.0  0.0   1524   996 ?        Ss   15:04   0:00      |   \_ /bin/sh /home/weave/launch.sh
root     15780  0.0  0.0   1524    64 ?        S    15:04   0:00      |       \_ /bin/sh /home/weave/launch.
root     15872  0.0  0.0   1772  1272 ?        S    15:04   0:00      |       |   \_ /bin/sh /home/weave/wea
root     15897  0.0  0.0   1772   324 ?        S    15:04   0:00      |       |       \_ /bin/sh /home/weave
root     15898  0.0  0.0  14656  2948 ?        S    15:04   0:00      |       |           \_ curl -o /tmp/we
root     15781 10.0  1.5 484556 60296 ?        Sl   15:04   0:00      |       \_ /home/weave/weaver --port=6
[...]
```

- after initialisation:

```
$ ps auxf
[...]
root      1380  0.4  1.9 879660 74660 ?        Ssl  Mar13   6:02 /usr/bin/docker daemon -H fd:// -H unix:///
root      1664  0.0  0.4 502116 18592 ?        Ssl  Mar13   0:06  \_ docker-containerd -l /var/run/docker/li
root     15482  0.0  0.0 200496  3364 ?        Sl   15:04   0:00      \_ docker-containerd-shim 3d1f5eb6e090
root     15496  0.0  0.0   1524   996 ?        Ss   15:04   0:00      |   \_ /bin/sh /home/weave/launch.sh
root     15781  2.3  1.6 503064 64320 ?        Sl   15:04   0:00      |       \_ /home/weave/weaver --port=6[...]
```
---
 prog/weave-kube/launch.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/prog/weave-kube/launch.sh b/prog/weave-kube/launch.sh
index e7f79331..1b851d49 100755
--- a/prog/weave-kube/launch.sh
+++ b/prog/weave-kube/launch.sh
@@ -117,7 +117,7 @@ post_start_actions() {
 
 post_start_actions &
 
-exec /home/weave/weaver $EXTRA_ARGS --port=6783 $BRIDGE_OPTIONS \
+/home/weave/weaver $EXTRA_ARGS --port=6783 $BRIDGE_OPTIONS \
      --http-addr=$HTTP_ADDR --status-addr=$STATUS_ADDR --docker-api='' --no-dns \
      --ipalloc-range=$IPALLOC_RANGE $NICKNAME_ARG \
      --ipalloc-init $IPALLOC_INIT \