netconsole remote kernel logger

To configure:

 * set system.netconsole.enabled to true
 * create system.netconsole.target dict
 * set a record with IP address and MAC and interface as subdict

It works with both static and DHCP interfaces, and applies online.
You could use bash-scripting in netconsole.conf.
You could override the MAC.

See tests/pillar/system.sls for further information.

Change-Id: I1cbde47575eb5d32a34cd6d79a063f42dbea7643

README.rst

@@ -1184,6 +1184,32 @@ config files for external use, eg. docker, etc.
                       username: test
                       password: test
 
+Netconsole Remote Kernel Logging
+--------------------------------
+
+Netconsole logger could be configured for configfs-enabled kernels
+(`CONFIG_NETCONSOLE_DYNAMIC` should be enabled). Configuration applies both in
+runtime (if network is already configured), and on-boot after interface
+initialization. Notes:
+
+ * receiver could be located only in same L3 domain
+   (or you need to configure gateway MAC manually)
+ * receiver's MAC is detected only on configuration time
+ * using broadcast MAC is not recommended
+
+.. code-block:: yaml
+
+    parameters:
+      linux:
+        system:
+          netconsole:
+            enabled: true
+            port: 514 (optional)
+            loglevel: debug (optional)
+            target:
+              192.168.0.1:
+                interface: bond0
+                mac: "ff:ff:ff:ff:ff:ff" (optional)
 
 Usage
 =====

linux/files/netconsole

@@ -0,0 +1,136 @@
+#!/bin/sh
+SYSFS_NETCONSOLE="/sys/kernel/config/netconsole"
+NETCONSOLE_CONF="/etc/default/netconsole.conf"
+NETCONSOLE_PORT="514"
+
+netconsole_remove() {
+	for sysfsnc in "${SYSFS_NETCONSOLE}/${interface:-}-"*
+	do
+		if [ -e "${sysfsnc}" ]
+		then
+			logger -t netconsole "remove ${sysfsnc}"
+			rmdir "${sysfsnc}"
+		fi
+	done
+}
+
+netconsole_remote_mac()
+{
+	neigh()
+	{
+		ip -4 -o neigh show to "${remote_ip}" dev "${interface}" | cut -d\  -f3
+	}
+	remote_mac="$(neigh)"
+	if [ -n "${remote_mac:-}" ] && [ "${remote_mac:-}" != "INCOMPLETE" ] 
+	then
+		if [ "${remote_mac:-}" != "FAILED" ] 
+		then
+			echo "${remote_mac:-}"
+			return 0
+		fi
+	else
+		if ping -n -q -c 1 -w 1 -I "${interface}" "${remote_ip}" >/dev/null && remote_mac="$(neigh)" && [ -n "${remote_mac:-}" ]
+		then
+			echo "${remote_mac:-}"
+			return 0
+		fi
+	fi
+	return 1
+}
+
+netconsole_add() {
+	netconsole() {
+		iface="${1:-}"
+		remote_ip="${2:-}"
+		remote_mac="${3:-}"
+
+		if [ "${iface:-}" = "${interface:-}" ] && [ -n "${remote_ip:-}" ]
+		then
+			logger -t netconsole "from ${new_ip_address:-}@${interface:-}"
+		else
+			return 1
+		fi
+		if [ -n "${remote_mac}" ] || remote_mac="$(netconsole_remote_mac)"
+		then
+			logger -t netconsole "to ${remote_ip} ${remote_mac}"
+		else
+			return 1
+		fi
+
+		sysfsnc="${SYSFS_NETCONSOLE}/${interface}-${remote_ip}"
+
+		if [ -e "${sysfsnc}" ] && [ -z "${old_ip_address:-}" ]
+		then
+		    old_ip_address="$(cat "${sysfsnc}/local_ip")"
+		fi
+
+		if [ "${old_ip_address:-}" != "${new_ip_address:-}" ] || ! [ -e "${sysfsnc}" ]
+		then
+			logger -t netconsole "setup netconsole"
+		else
+			return 1
+		fi
+
+		mkdir -p "${sysfsnc}"
+		if [ "$(cat "${sysfsnc}/enabled")" != "0" ]
+		then
+			echo "0" > "${sysfsnc}/enabled"
+		fi
+
+        if [ -n "${new_ip_address:-}" ]
+        then
+		    echo "${new_ip_address}" > "${sysfsnc}/local_ip"
+		fi
+		echo "${interface}" > "${sysfsnc}/dev_name"
+		echo "${remote_mac}" > "${sysfsnc}/remote_mac"
+		echo "${remote_ip}" > "${sysfsnc}/remote_ip"
+		echo "${PORT:-${NETCONSOLE_PORT}}" > "${sysfsnc}/remote_port"
+		echo "1" > "${sysfsnc}/enabled"
+		return 0
+	}
+
+	if [ -f "${NETCONSOLE_CONF}" ]
+	then
+		modprobe netconsole
+		mountpoint -q /sys/kernel/config || mount none -t configfs /sys/kernel/config
+
+		if [ -e "${SYSFS_NETCONSOLE}" ]
+		then
+			(
+				set -x
+				set +e
+				. "${NETCONSOLE_CONF}"
+			) ||:
+		fi
+	fi
+}
+
+netconsole_setup() {
+	case ${reason:-} in
+		BOUND|RENEW|REBIND|REBOOT)
+			netconsole_add
+			;;
+		EXPIRE|FAIL|RELEASE|STOP)
+			netconsole_remove
+			;;
+		PREINIT) : ;;
+		*)
+			if [ "${ADDRFAM:-}" = "inet" ] && [ "${METHOD:-}" = "static" ]
+			then
+				export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+				interface="${IFACE:-}"
+				new_ip_address="${IF_ADDRESS:-}"
+				case ${MODE:-} in
+					start)
+						netconsole_add
+						;;
+					stop)
+						netconsole_remove
+						;;
+					*) : ;;
+				esac
+			fi
+	esac
+}
+
+netconsole_setup

linux/files/netconsole.conf

@@ -0,0 +1,22 @@
+{%- from "linux/map.jinja" import system with context %}
+# default port is 514
+#PORT=6666
+{%- if system.netconsole is mapping and system.netconsole.port is defined %}
+PORT="{{ system.netconsole.port }}"
+{%- endif %}
+
+# unicast, could be multiline
+#netconsole ens3 192.168.1.32 fa:16:3e:8d:f6:d0
+{%- if system.netconsole is mapping and system.netconsole.target is mapping %}
+{%- for target, data in system.netconsole.target.iteritems() %}
+{%- if data is mapping %}
+netconsole "{{ data.get('interface', '${interface}') }}" "{{ target }}" "{{ data.get('mac', '') }}"
+{%- endif %}
+{%- endfor %}
+{%- endif %}
+
+# set up dmesg log level
+# dmesg -n info
+{%- if system.netconsole is mapping and system.netconsole.loglevel is defined %}
+dmesg -n "{{ system.netconsole.loglevel }}"
+{%- endif %}

linux/system/init.sls

@@ -80,3 +80,6 @@ include:
 {%- if system.sudo is defined %}
 - linux.system.sudo
 {%- endif %}
+{%- if system.netconsole is defined %}
+- linux.system.netconsole
+{%- endif %}

linux/system/netconsole.sls

@@ -0,0 +1,43 @@
+{% from "linux/map.jinja" import system with context %}
+{% if system.enabled and system.netconsole is mapping and system.netconsole.enabled %}
+
+/etc/dhcp/dhclient-exit-hooks.d/netconsole:
+  file.managed:
+    - source: salt://linux/files/netconsole
+    - makedirs: True
+
+/etc/network/if-up.d/netconsole:
+  file.managed:
+    - source: salt://linux/files/netconsole
+    - mode: 755
+
+/etc/network/if-down.d/netconsole:
+  file.managed:
+    - source: salt://linux/files/netconsole
+    - mode: 755
+
+/etc/default/netconsole.conf:
+  file.managed:
+    - source: salt://linux/files/netconsole.conf
+    - template: jinja
+
+{% if system.netconsole is mapping and system.netconsole.target is mapping %}
+{% for target, data in system.netconsole.target.iteritems() %}
+{% if data is mapping and data.interface is defined %}
+/etc/network/if-up.d/netconsole {{ target }} {{ data.interface }}:
+  cmd.run:
+    - name: /etc/network/if-up.d/netconsole
+    - env:
+      - IFACE: {{ data.interface }}
+      - METHOD: static
+      - ADDRFAM: inet
+      - MODE: start
+    - onchanges:
+      - file: /etc/default/netconsole.conf
+    - require:
+      - file: /etc/network/if-up.d/netconsole
+{% endif %}
+{% endfor %}
+{% endif %}
+
+{% endif %}

tests/integration/system/netconsole_spec.rb

@@ -0,0 +1,14 @@
+
+## NETCONSOLE
+#
+describe file('/etc/default/netconsole.conf') do
+    it('should exist')
+    its('content') { should match /^PORT="514"/}
+    its('content') { should match /^netconsole "bond0" "192.168.0.1" "ff:ff:ff:ff:ff:ff"/}
+    its('content') { should match /^dmesg -n "debug"/}
+end
+
+describe file('/etc/dhcp/dhclient-exit-hooks.d/netconsole') do
+    it('should exist')
+    its('content') { should match /netconsole_setup/}
+end

tests/pillar/system.sls

@@ -265,3 +265,13 @@ linux:
         - host1
         - host2
         - .local
+
+    # pillars for netconsole setup
+    netconsole:
+      enabled: true
+      port: 514
+      loglevel: debug
+      target:
+        192.168.0.1:
+          mac: "ff:ff:ff:ff:ff:ff"
+          interface: bond0