Add get_graph service to fetch minigraph automatically (#288)

- Add a functionality to get SNMP community from DHCP (option 224)
- Add a functionality to get minigraph from http service instead of using default minigraph
  - The url for graph service is passed through DHCP option 225
  - This feature is by default disabled. Modify rule/config to enable it on build time, or modify /etc/sonic/graph_service_url on run time.
- Fix a bug that getting hostname from DHCP is not working correctly

build_debian.sh

@@ -188,7 +188,8 @@ sudo LANG=C DEBIAN_FRONTEND=noninteractive chroot $FILESYSTEM_ROOT apt-get -y in
     usbutils                \
     pciutils                \
     iptables-persistent     \
-    logrotate
+    logrotate               \
+    curl
 
 ## Remove sshd host keys, and will regenerate on first sshd start
 sudo rm -f $FILESYSTEM_ROOT/etc/ssh/ssh_host_*_key*
@@ -241,6 +242,9 @@ EOF
 
 sudo cp files/dhcp/rfc3442-classless-routes $FILESYSTEM_ROOT/etc/dhcp/dhclient-exit-hooks.d
 sudo cp files/dhcp/sethostname $FILESYSTEM_ROOT/etc/dhcp/dhclient-exit-hooks.d/
+sudo cp files/dhcp/graphserviceurl $FILESYSTEM_ROOT/etc/dhcp/dhclient-exit-hooks.d/
+sudo cp files/dhcp/snmpcommunity $FILESYSTEM_ROOT/etc/dhcp/dhclient-exit-hooks.d/
+sudo cp files/dhcp/dhclient.conf $FILESYSTEM_ROOT/etc/dhcp/
 
 if [ -f sonic_debian_extension.sh ]; then
     ./sonic_debian_extension.sh $FILESYSTEM_ROOT

files/build_templates/sonic_debian_extension.j2

@@ -94,6 +94,21 @@ sudo LANG=C chroot $FILESYSTEM_ROOT systemctl enable interfaces-config.service
 sudo cp $IMAGE_CONFIGS/interfaces/interfaces-config.sh $FILESYSTEM_ROOT/usr/bin/
 sudo cp $IMAGE_CONFIGS/interfaces/*.j2 $FILESYSTEM_ROOT/etc/sonic/templates/
 
+# Copy initial interfaces configuration file, will be overwritten on first boot
+sudo cp $IMAGE_CONFIGS/interfaces/init_interfaces $FILESYSTEM_ROOT/etc/network
+
+# Copy updategraph script and service file
+sudo cp $IMAGE_CONFIGS/updategraph/updategraph.service  $FILESYSTEM_ROOT/etc/systemd/system/
+sudo LANG=C chroot $FILESYSTEM_ROOT systemctl enable updategraph.service
+sudo cp $IMAGE_CONFIGS/updategraph/updategraph $FILESYSTEM_ROOT/usr/bin/
+{% if enable_dhcp_graph_service == "y" %}
+sudo bash -c "echo enabled=true > $FILESYSTEM_ROOT/etc/sonic/updategraph.conf"
+sudo bash -c "echo src=dhcp >> $FILESYSTEM_ROOT/etc/sonic/updategraph.conf"
+sudo bash -c "echo dhcp_as_static=true >> $FILESYSTEM_ROOT/etc/sonic/updategraph.conf"
+{% else %}
+sudo bash -c "echo enabled=false > $FILESYSTEM_ROOT/etc/sonic/updategraph.conf"
+{% endif %}
+
 # Copy SNMP configuration files
 sudo cp $IMAGE_CONFIGS/snmp/snmp.yml $FILESYSTEM_ROOT/etc/sonic/
 

files/dhcp/dhclient.conf

@@ -0,0 +1,24 @@
+# Configuration file for /sbin/dhclient, which is included in Debian's
+#       dhcp3-client package.
+#
+# This is a sample configuration file for dhclient. See dhclient.conf's
+#       man page for more information about the syntax of this file
+#       and a more comprehensive list of the parameters understood by
+#       dhclient.
+#
+# Normally, if the DHCP server provides reasonable information and does
+#       not leave anything out (like the domain name, for example), then
+#       few changes must be made to this file, if any.
+#
+
+option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;
+option snmp-community code 224 = text;
+option minigraph-url code 225 = text;
+
+send host-name = gethostname();
+request subnet-mask, broadcast-address, time-offset, routers,
+        domain-name, domain-name-servers, domain-search, host-name,
+        dhcp6.name-servers, dhcp6.domain-search,
+        netbios-name-servers, netbios-scope, interface-mtu,
+        rfc3442-classless-static-routes, ntp-servers, snmp-community, minigraph-url;
+

files/dhcp/graphserviceurl

@@ -0,0 +1,9 @@
+case $reason in
+    BOUND|RENEW|REBIND|REBOOT)
+        if [ -n "$new_minigraph_url" ]; then
+            echo $new_minigraph_url > /tmp/dhcp_graph_url
+        else
+            echo "N/A" > /tmp/dhcp_graph_url
+        fi
+        ;;
+esac

files/dhcp/sethostname

@@ -1,20 +1,13 @@
-#!/bin/bash
-# This script is to update hostname of the system.
-
-if [ "$reason" != BOUND ] && [ "$reason" != RENEW ] \
-     && [ "$reason" != REBIND ] && [ "$reason" != REBOOT ]
-then
-    exit 0
-fi
-
+case $reason in
+    BOUND|RENEW|REBIND|REBOOT)
         current_host_name=`hostname -s`
-
-if [ "$current_host_name" != "$new_host_name" ]
+        if [ "$current_host_name" != "$new_host_name" ] && [ -n "$new_host_name" ]
         then
             echo $new_host_name > /etc/hostname
-    line_to_replace=`grep 127.0.0.1.*$current_host_name /etc/hosts`
-    new_line=`echo $line_to_replace | sed "s/$current_host_name/$new_host_name/"`
-    sed -i "s/$line_to_replace/$new_line/" /etc/hosts
-
             hostname -F /etc/hostname
+            sed -i "/\s$current_host_name$/d" /etc/hosts
+            echo "127.0.0.1 $new_host_name" >> /etc/hosts
         fi
+        ;;
+esac
+

files/dhcp/snmpcommunity

@@ -0,0 +1,11 @@
+case $reason in
+    BOUND|RENEW|REBIND|REBOOT)
+        if [ -n "${new_snmp_community}" ]; then
+            if [ -f /etc/sonic/snmp.yml ]; then
+                sed -i "s/^snmp_rocommunity:.*/snmp_rocommunity: $new_snmp_community/g" /etc/sonic/snmp.yml
+            else
+                echo "snmp_rocommunity: "$new_snmp_community > /etc/sonic/snmp.yml
+            fi
+        fi
+        ;;
+esac

files/image_config/interfaces/init_interfaces

@@ -0,0 +1,11 @@
+# Initial /etc/network/interface file for first boot 
+# Will be overwritten based on minigraph information by interfaces-config service
+
+# The loopback network interface
+auto lo
+iface lo inet loopback
+#
+# The management network interface
+auto eth0
+iface eth0 inet dhcp
+

files/image_config/interfaces/interfaces-config.service

@@ -1,6 +1,6 @@
 [Unit]
 Description=Update interfaces configuration
-Before=network.target
+Before=database.service
 
 [Service]
 Type=oneshot

files/image_config/interfaces/interfaces-config.sh

@@ -3,3 +3,6 @@
 sonic-cfggen -m /etc/sonic/minigraph.xml -t /etc/sonic/templates/interfaces.j2 >/etc/network/interfaces
 sonic-cfggen -m /etc/sonic/minigraph.xml -t /etc/sonic/templates/vlan_interfaces.j2 >/etc/network/interfaces.d/vlan_interfaces
 sonic-cfggen -m /etc/sonic/minigraph.xml -t /etc/sonic/templates/lag_interfaces.j2 >/etc/network/interfaces.d/lag_interfaces
+ifdown eth0 && ifup eth0
+ifdown lo && ifup lo
+

files/image_config/updategraph/updategraph

@@ -0,0 +1,50 @@
+#!/bin/bash
+
+if [ ! -f /etc/sonic/updategraph.conf ]; then
+    echo "No updategraph.conf found, generating a default one."
+    echo "enabled=false" >/etc/sonic/updategraph.conf
+fi
+
+. /etc/sonic/updategraph.conf
+
+if [ "$enabled" != "true" ]; then
+    echo "Disabled in updategraph.conf. Skipping graph update."
+    exit 0
+fi
+
+if [ "$src" = "dhcp" ]; then
+    while [ ! -f /tmp/dhcp_graph_url ]; do
+        echo "Waiting for DHCP response..."
+        sleep 1
+    done
+
+    if [ "`cat /tmp/dhcp_graph_url`" = "N/A" ]; then
+        echo "No graph_url option in DHCP response. Skipping graph update."
+        if [ "$dhcp_as_static" = "true" ]; then
+            sed -i "/enabled=/d" /etc/sonic/updategraph.conf
+            echo "enabled=false" >> /etc/sonic/updategraph.conf
+        fi
+        exit 0
+    fi
+
+    HOSTNAME=`hostname -s`
+    GRAPH_URL=`sonic-cfggen -t /tmp/dhcp_graph_url -a "{\"hostname\": \"$HOSTNAME\"}"`
+    if [ "$dhcp_as_static" = "true" ]; then
+        sed -i "/src=d/d" /etc/sonic/updategraph.conf
+        echo "src=$GRAPH_URL" >> /etc/sonic/updategraph.conf
+    fi
+else
+    GRAPH_URL=$src
+fi
+
+if [ -f /etc/sonic/minigraph.xml ]; then
+    echo "Renaming minigraph.xml to minigraph.old"
+    mv /etc/sonic/minigraph.xml /etc/sonic/minigraph.old
+fi
+
+echo "Getting minigraph from $GRAPH_URL"
+
+while true; do
+    curl -f $GRAPH_URL -o /etc/sonic/minigraph.xml --connect-timeout 15 && break
+    sleep 5
+done

files/image_config/updategraph/updategraph.service

@@ -0,0 +1,12 @@
+[Unit]
+Description=download minigraph from graph service
+Before=ntp-config.service
+Before=rsyslog-config.service
+Before=interfaces-config.service
+
+[Service]
+Type=oneshot
+ExecStart=/usr/bin/updategraph
+
+[Install]
+WantedBy=multi-user.target

rules/config

@@ -35,3 +35,10 @@ USERNAME = admin
 
 # PASSWORD - password for installer build
 PASSWORD = YourPaSsWoRd
+
+# ENABLE_DHCP_GRAPH_SERVICE - specify the source of minigraph to generate configuration file.
+# If set to y SONiC will get the minigraph from graph service. Graph service URL need to be 
+# passed through DHCP option 225.
+# If not set (default behavior) the default minigraph built into the image will be used.
+# ENABLE_DHCP_GRAPH_SERVICE = y
+

slave.mk

@@ -298,6 +298,8 @@ $(addprefix $(TARGET_PATH)/, $(SONIC_INSTALLERS)) : $(TARGET_PATH)/% : .platform
 	export sonicadmin_user="$(USERNAME)"
 	export sonic_hwsku="$(CONFIGURED_SKU)"
 	export sonic_asic_platform="$(CONFIGURED_PLATFORM)"
+	export enable_dhcp_graph_service="$(ENABLE_DHCP_GRAPH_SERVICE)"
+	
 	$(foreach docker, $($*_DOCKERS),\
 		export docker_image="$(docker)"
 		export docker_image_name="$(basename $(docker))"