Merge pull request #2924 from TiejunChina/master-dev

Clarify to support Preempt-RT kernel

.mailmap

@@ -49,5 +49,6 @@ Sebastiaan van Stijn <sebastiaan.vanstijn@docker.com> <github@gone.nl>
 Simon Ferquel <simon.ferquel@docker.com> <simon.ferquel@hotmail.fr>
 Thomas Gazagnaire <thomas.gazagnaire@docker.com> <thomas@gazagnaire.com>
 Thomas Gazagnaire <thomas.gazagnaire@docker.com> <thomas@gazagnaire.org>
+Tiejun Chen <tiejun.china@gmail.com> <tiejunc@vmware.com>
 Vincent Demeester <Vincent.Demeester@docker.com> <vincent@sbr.pm>
 Vincent Demeester <Vincent.Demeester@docker.com> <vdemeester@docker.com>

AUTHORS

@@ -93,7 +93,7 @@ Thomas Gazagnaire <thomas.gazagnaire@docker.com>
 Thomas Leonard <thomas.leonard@docker.com>
 Thomas Shaw <tomwillfixit@users.noreply.github.com>
 Tiago Pires <tandrepires@gmail.com>
-Tiejun Chen <tiejunc@vmware.com>
+Tiejun Chen <tiejun.china@gmail.com>
 Tim Potter <tpot@hpe.com>
 Tobias Klauser <tklauser@distanz.ch>
 Tycho Andersen <tycho@docker.com>

docs/kernels.md

@@ -27,6 +27,11 @@ In addition to the official images, there are also some
 from some Linux distributions into LinuxKit kernel packages. These are
 mostly provided for testing purposes.
 
+Note now linuxkit also embraces Preempt-RT Linux kernel to support more
+use cases for the promising IoT scenarios. All -rt patches are grabbed from
+https://www.kernel.org/pub/linux/kernel/projects/rt/. But so far we just
+enable it over 4.14.x.
+
 
 ## Loading kernel modules
 

examples/rt-for-vmware.yml

@@ -0,0 +1,36 @@
+kernel:
+  image: linuxkit/kernel:4.14.18-rt
+  cmdline: "console=tty0"
+init:
+  - linuxkit/init:d899eee3560a40aa3b4bdd67b3bb82703714b2b9
+  - linuxkit/runc:7c39a68490a12cde830e1922f171c451fb08e731
+  - linuxkit/containerd:37e397ebfc6bd5d8e18695b121166ffd0cbfd9f0
+  - linuxkit/ca-certificates:v0.2
+onboot:
+  - name: sysctl
+    image: linuxkit/sysctl:v0.2
+services:
+  - name: getty
+    image: linuxkit/getty:v0.2
+    env:
+     - INSECURE=true
+  - name: rngd
+    image: linuxkit/rngd:v0.2
+  - name: dhcpcd
+    image: linuxkit/dhcpcd:v0.2
+  - name: open-vm-tools
+    image: linuxkit/open-vm-tools:v0.2
+  - name: nginx
+    image: nginx:1.13.8-alpine
+    capabilities:
+     - CAP_NET_BIND_SERVICE
+     - CAP_CHOWN
+     - CAP_SETUID
+     - CAP_SETGID
+     - CAP_DAC_OVERRIDE
+    binds:
+     - /etc/resolv.conf:/etc/resolv.conf
+trust:
+  org:
+    - linuxkit
+    - library

scripts/prefix-with-number.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+# This can help get patches prefixed by the term of number.
+#
+# Just please list all patches in the file "series" orderly, and then run this
+# script directly.
+#
+# $ cat series
+# $ xxxx.patch
+# $ yyyy.patch
+# $ zzzz.patch
+# $ ./prefix-with-number.sh
+# $ ls -l
+#   0001-xxxx.patch
+#   0002-yyyy.patch
+#   0003-zzzz.patch
+#
+i=0000
+for line in `sed -e "s/#.*//g" series`; do
+	i=$(expr $i + 1)
+	a=$((10000+$i))
+	mv $line ${a:1}-$line
+done;