Add logging project

Adds a logging daemon that collects logs in a ring buffer in a runc container.
The tools logwrite and logread can be used to read/write logs. The logging
daemon can be sent open file descriptors that will be read and included
in the logs.

Modifies init to start the daemon and use logwrite to capture logs from runc.

Signed-off-by: Magnus Skjegstad <magnus@skjegstad.com>

projects/logging/examples/logging.yml

@@ -0,0 +1,60 @@
+kernel:
+  image: "mobylinux/kernel:4.9.x"
+  cmdline: "console=ttyS0 console=tty0 page_poison=1"
+init:
+  - linuxkit/init:b5c88b78cd9cc73ed83b45f66bc9de618223768a # with runc, logwrite, startmemlogd
+  - mobylinux/runc:b0fb122e10dbb7e4e45115177a61a3f8d68c19a9
+  - mobylinux/containerd:18eaf72f3f4f9a9f29ca1951f66df701f873060b # unmodified containerd, from pre pr #1636
+  - mobylinux/ca-certificates:eabc5a6e59f05aa91529d80e9a595b85b046f935
+  - linuxkit/memlogd:9b5834189f598f43c507f6938077113906f51012
+onboot:
+  - name: sysctl
+    image: "mobylinux/sysctl:2cf2f9d5b4d314ba1bfc22b2fe931924af666d8c"
+    net: host
+    pid: host
+    ipc: host
+    capabilities:
+     - CAP_SYS_ADMIN
+    readonly: true
+  - name: binfmt
+    image: "linuxkit/binfmt:8881283ac627be1542811bd25c85e7782aebc692"
+    binds:
+     - /proc/sys/fs/binfmt_misc:/binfmt_misc
+    readonly: true
+  - name: dhcpcd
+    image: "linuxkit/dhcpcd:48e249ebef6a521eed886b3bce032db69fbb4afa"
+    binds:
+     - /var:/var
+     - /tmp/etc:/etc
+    capabilities:
+     - CAP_NET_ADMIN
+     - CAP_NET_BIND_SERVICE
+     - CAP_NET_RAW
+    net: host
+    command: ["/sbin/dhcpcd", "--nobackground", "-f", "/dhcpcd.conf", "-1"]
+services:
+  - name: rngd
+    image: "mobylinux/rngd:3dad6dd43270fa632ac031e99d1947f20b22eec9"
+    capabilities:
+     - CAP_SYS_ADMIN
+    oomScoreAdj: -800
+    readonly: true
+  - name: nginx
+    image: "nginx:alpine"
+    capabilities:
+     - CAP_NET_BIND_SERVICE
+     - CAP_CHOWN
+     - CAP_SETUID
+     - CAP_SETGID
+     - CAP_DAC_OVERRIDE
+    net: host
+files:
+  - path: etc/docker/daemon.json
+    contents: '{"debug": true}'
+trust:
+  image:
+    - mobylinux/kernel
+outputs:
+  - format: kernel+initrd
+  - format: iso-bios
+  - format: iso-efi