From 8cc82ba98b7ce8bdf97ae14f92e4f89d3bf39e39 Mon Sep 17 00:00:00 2001
From: Justin Cormack <justin.cormack@docker.com>
Date: Wed, 10 Feb 2016 15:47:37 -0800
Subject: [PATCH] Add some wrappers to support at least the default uid mapping

The busybox adduser and addgroup commands are ignored by docker,
as it avoids symlinks, but they are not compatible so this is
kind of a good idea.

See https://github.com/docker/docker/blob/master/pkg/idtools/usergroupadd_linux.go

However, these do not yet deal with creating mapping ranges in /etc/subuid and
/etc/subgid, so initially we provide a set that match the default docker name
so at least docker daemon --userns-remap=default should work.

Signed-off-by: Justin Cormack <justin.cormack@docker.com>
---
 alpine/Dockerfile                 |  3 +++
 alpine/packages/userns/etc/subgid |  1 +
 alpine/packages/userns/etc/subuid |  1 +
 alpine/packages/userns/groupadd   |  3 +++
 alpine/packages/userns/useradd    | 13 +++++++++++++
 5 files changed, 21 insertions(+)
 create mode 100644 alpine/packages/userns/etc/subgid
 create mode 100644 alpine/packages/userns/etc/subuid
 create mode 100755 alpine/packages/userns/groupadd
 create mode 100755 alpine/packages/userns/useradd

diff --git a/alpine/Dockerfile b/alpine/Dockerfile
index d0981a8c2..285dc7ab8 100644
--- a/alpine/Dockerfile
+++ b/alpine/Dockerfile
@@ -48,6 +48,9 @@ COPY packages/hvtools/etc /etc/
 COPY packages/hvtools/hv_get_dhcp_info /sbin/
 COPY packages/hvtools/hv_get_dns_info /sbin/
 COPY packages/hvtools/hv_set_ifconfig /sbin/
+COPY packages/userns/etc /etc/
+COPY packages/userns/groupadd /usr/sbin
+COPY packages/userns/useradd /usr/sbin
 
 RUN \
   rc-update add swap boot && \
diff --git a/alpine/packages/userns/etc/subgid b/alpine/packages/userns/etc/subgid
new file mode 100644
index 000000000..b8b245e67
--- /dev/null
+++ b/alpine/packages/userns/etc/subgid
@@ -0,0 +1 @@
+dockremap:100000:65536
diff --git a/alpine/packages/userns/etc/subuid b/alpine/packages/userns/etc/subuid
new file mode 100644
index 000000000..b8b245e67
--- /dev/null
+++ b/alpine/packages/userns/etc/subuid
@@ -0,0 +1 @@
+dockremap:100000:65536
diff --git a/alpine/packages/userns/groupadd b/alpine/packages/userns/groupadd
new file mode 100755
index 000000000..3e12d0ef5
--- /dev/null
+++ b/alpine/packages/userns/groupadd
@@ -0,0 +1,3 @@
+#!/bin/sh
+
+exec /usr/sbin/addgroup $@
diff --git a/alpine/packages/userns/useradd b/alpine/packages/userns/useradd
new file mode 100755
index 000000000..fff2a130c
--- /dev/null
+++ b/alpine/packages/userns/useradd
@@ -0,0 +1,13 @@
+#!/bin/sh
+
+for a in $*
+do
+        [ "$a" = "-N" ] && a=""
+        [ "$a" = "-M" ] && a="-H"
+        [ "$a" = "-g" ] && a="-G"
+        args="$args $a"
+done
+
+echo $args
+
+exec /usr/sbin/adduser -D ${args}