[platform] Add Support For Environment Variable File (#5010)

* [platform] Add Support For Environment Variable

This PR adds the ability to read environment file from /etc/sonic.
the file contains immutable SONiC config attributes such as platform,
hwsku, version, device_type. The aim is to minimize calls being made
into sonic-cfggen during boot time.

singed-off-by: Tamer Ahmed <tamer.ahmed@microsoft.com>

dockers/docker-orchagent/swssconfig.sh

@@ -39,7 +39,10 @@ rm -f /ready
 # Restore FDB and ARP table ASAP
 fast_reboot
 
-HWSKU=`sonic-cfggen -d -v "DEVICE_METADATA['localhost']['hwsku']"`
+# read SONiC immutable variables
+[ -f /etc/sonic/sonic-environment ] && . /etc/sonic/sonic-environment
+
+HWSKU=${HWSKU:-`sonic-cfggen -d -v "DEVICE_METADATA['localhost']['hwsku']"`}
 
 # Don't load json config if system warm start or
 # swss docker warm start is enabled, the data already exists in appDB.

files/build_templates/docker_image_ctl.j2

@@ -156,7 +156,7 @@ start() {
     BOOT_TYPE=`getBootType`
 
     # Obtain our platform as we will mount directories with these names in each docker
-    PLATFORM=`$SONIC_CFGGEN -H -v DEVICE_METADATA.localhost.platform`
+    PLATFORM=${PLATFORM:-`$SONIC_CFGGEN -H -v DEVICE_METADATA.localhost.platform`}
 
     # Parse the device specific asic conf file, if it exists
     ASIC_CONF=/usr/share/sonic/device/$PLATFORM/asic.conf
@@ -169,7 +169,7 @@ start() {
     HWSKU=""
     {%- else %}
     # Obtain our HWSKU as we will mount directories with these names in each docker
-    HWSKU=`$SONIC_CFGGEN -d -v 'DEVICE_METADATA["localhost"]["hwsku"]'`
+    HWSKU=${HWSKU:-`$SONIC_CFGGEN -d -v 'DEVICE_METADATA["localhost"]["hwsku"]'`}
     {%- endif %}
 
     DOCKERCHECK=`docker inspect --type container {{docker_container_name}}$DEV 2>/dev/null`
@@ -362,6 +362,9 @@ if [ "$DEV" ]; then
     SONIC_DB_CLI="sonic-db-cli"
 fi
 
+# read SONiC immutable variables
+[ -f /etc/sonic/sonic-environment ] && . /etc/sonic/sonic-environment
+
 case "$1" in
     start|wait|stop)
         $1

files/image_config/config-setup/config-setup

@@ -208,7 +208,7 @@ load_config()
 generate_config()
 {
     # Collect all information needed to generate configuration
-    PLATFORM=`sonic-cfggen -H -v DEVICE_METADATA.localhost.platform`
+    PLATFORM=${PLATFORM:-`sonic-cfggen -H -v DEVICE_METADATA.localhost.platform`}
     PRESET=(`head -n 1 /usr/share/sonic/device/$PLATFORM/default_sku`)
     HW_KEY=${PRESET[0]}
     DEFAULT_PRESET=${PRESET[1]}
@@ -403,8 +403,11 @@ boot_config()
     fi
 }
 
+# read SONiC immutable variables
+[ -f /etc/sonic/sonic-environment ] && . /etc/sonic/sonic-environment
+
 ### Execution starts here ###
-PLATFORM=`sonic-cfggen -H -v DEVICE_METADATA.localhost.platform`
+PLATFORM=${PLATFORM:-`sonic-cfggen -H -v DEVICE_METADATA.localhost.platform`}
 # Parse the device specific asic conf file, if it exists
 ASIC_CONF=/usr/share/sonic/device/$PLATFORM/asic.conf
 if [[ -f "$ASIC_CONF" ]]; then

files/image_config/platform/rc.local

@@ -11,9 +11,17 @@
 #
 # By default this script does nothing.
 
-SONIC_VERSION=$(sonic-cfggen -y /etc/sonic/sonic_version.yml -v build_version)
+SONIC_VERSION=$(cat /etc/sonic/sonic_version.yml | grep "build_version" | sed -e "s/build_version: //g;s/'//g")
 FIRST_BOOT_FILE="/host/image-${SONIC_VERSION}/platform/firsttime"
 
+# Move sonic-environment to /etc/sonic
+SONIC_CONFIG_DIR="/host/image-${SONIC_VERSION}/sonic-config"
+SONIC_ENV_FILE=${SONIC_CONFIG_DIR}/sonic-environment
+if [ -d ${SONIC_CONFIG_DIR} -a -f ${SONIC_ENV_FILE} ]; then
+    echo "moving file ${SONIC_ENV_FILE} to /etc/sonic" 1>&2
+    mv ${SONIC_ENV_FILE} /etc/sonic
+fi
+
 # In case the unit is migrating from another NOS, save the logs
 log_migration() {
     echo $1 >> /host/migration/migration.log

files/image_config/secureboot/allowlist_paths.conf

@@ -25,6 +25,7 @@ etc/sonic/config_db.json
 etc/sonic/minigraph.xml
 etc/sonic/old_config/.*
 etc/sonic/snmp.yml
+etc/sonic/sonic-environment
 etc/sonic/updategraph.conf
 etc/ssh/ssh_host_rsa_key.pub
 etc/ssh/ssh_host_rsa_key

files/image_config/topology/topology.sh

@@ -7,17 +7,20 @@
 
 start() {
     TOPOLOGY_SCRIPT="topology.sh"
-    PLATFORM=`sonic-cfggen -H -v DEVICE_METADATA.localhost.platform`
+    PLATFORM=${PLATFORM:-`sonic-cfggen -H -v DEVICE_METADATA.localhost.platform`}
-    HWSKU=`sonic-cfggen -d -v 'DEVICE_METADATA["localhost"]["hwsku"]'`
+    HWSKU=${HWSKU:-`sonic-cfggen -d -v 'DEVICE_METADATA["localhost"]["hwsku"]'`}
     /usr/share/sonic/device/$PLATFORM/$HWSKU/$TOPOLOGY_SCRIPT start
 }
 stop() {
     TOPOLOGY_SCRIPT="topology.sh"
-    PLATFORM=`sonic-cfggen -H -v DEVICE_METADATA.localhost.platform`
+    PLATFORM=${PLATFORM:-`sonic-cfggen -H -v DEVICE_METADATA.localhost.platform`}
-    HWSKU=`sonic-cfggen -d -v 'DEVICE_METADATA["localhost"]["hwsku"]'`
+    HWSKU=${HWSKU:-`sonic-cfggen -d -v 'DEVICE_METADATA["localhost"]["hwsku"]'`}
     usr/share/sonic/device/$PLATFORM/$HWSKU/$TOPOLOGY_SCRIPT stop 
 }
 
+# read SONiC immutable variables
+[ -f /etc/sonic/sonic-environment ] && . /etc/sonic/sonic-environment
+
 case "$1" in
     start|stop)
         $1

files/image_config/updategraph/updategraph

@@ -7,6 +7,9 @@ reload_minigraph()
     config save -y
 }
 
+# read SONiC immutable variables
+[ -f /etc/sonic/sonic-environment ] && . /etc/sonic/sonic-environment
+
 if [ ! -f /etc/sonic/updategraph.conf ]; then
     echo "No updategraph.conf found, generating a default one."
     echo "enabled=false" >/etc/sonic/updategraph.conf
@@ -46,7 +49,7 @@ if [ "$src" = "dhcp" ]; then
 
     if [ "`cat /tmp/dhcp_graph_url`" = "N/A" ]; then
         echo "No graph_url option in DHCP response. Skipping graph update and generating an empty configuration."
-        PLATFORM=`sonic-cfggen -H -v DEVICE_METADATA.localhost.platform`
+        PLATFORM=${PLATFORM:-`sonic-cfggen -H -v DEVICE_METADATA.localhost.platform`}
         if [ -f /etc/sonic/minigraph.xml ]; then
             sonic-cfggen -H -m /etc/sonic/minigraph.xml --preset empty > /tmp/device_meta.json
         else

platform/broadcom/sonic-platform-modules-dell/s6000/scripts/s6000_platform.sh

@@ -76,7 +76,7 @@ switch_board_qsfp_lpmode() {
 
 install_python_api_package() {
     device="/usr/share/sonic/device"
-    platform=$(/usr/local/bin/sonic-cfggen -H -v DEVICE_METADATA.localhost.platform)
+    platform=${PLATFORM:-`/usr/local/bin/sonic-cfggen -H -v DEVICE_METADATA.localhost.platform`}
 
     if [ -e $device/$platform/sonic_platform-1.0-py2-none-any.whl ]; then
         rv=$(pip install $device/$platform/sonic_platform-1.0-py2-none-any.whl)
@@ -90,6 +90,9 @@ remove_python_api_package() {
     fi
 }
 
+# read SONiC immutable variables
+[ -f /etc/sonic/sonic-environment ] && . /etc/sonic/sonic-environment
+
 if [[ "$1" == "init" ]]; then
         depmod -a
         modprobe nvram

src/sonic-daemon-base/sonic_daemon_base/daemon_base.py

@@ -18,6 +18,9 @@ REDIS_TIMEOUT_MSECS = 0
 # Platform root directory inside docker
 PLATFORM_ROOT_DOCKER = '/usr/share/sonic/platform'
 SONIC_CFGGEN_PATH = '/usr/local/bin/sonic-cfggen'
+SONIC_ENV_FILE = '/etc/sonic/sonic-environment'
+PLATFORM_ENVVAR = 'PLATFORM'
+HWSKU_ENVVAR = 'HWSKU'
 HWSKU_KEY = 'DEVICE_METADATA.localhost.hwsku'
 PLATFORM_KEY = 'DEVICE_METADATA.localhost.platform'
 
@@ -126,20 +129,31 @@ class DaemonBase(object):
     # Returns platform and hwsku
     def get_platform_and_hwsku(self):
         try:
+            platform = hwsku = None
+            if os.path.exists(SONIC_ENV_FILE):
+                with open(SONIC_ENV_FILE, "r") as env_file:
+                    for line in env_file:
+                        if PLATFORM_ENVVAR in line:
+                            platform = line.split('=')[1]
+                        if HWSKU_ENVVAR in line:
+                            hwsku = line.split('=')[1]
+
+            if not platform: 
                 proc = subprocess.Popen([SONIC_CFGGEN_PATH, '-H', '-v', PLATFORM_KEY],
                                         stdout=subprocess.PIPE,
-                                    shell=False,
+                                        stderr=subprocess.PIPE,
-                                    stderr=subprocess.STDOUT)
+                                        shell=False)
-            stdout = proc.communicate()[0]
+                stdout, stderr = proc.communicate()
-            proc.wait()
+                assert not stderr and not proc.returncode, "Failed to detect platform: %s, rc: %s" % (stderr, proc.returncode)
                 platform = stdout.rstrip('\n')
 
+            if not hwsku:
                 proc = subprocess.Popen([SONIC_CFGGEN_PATH, '-d', '-v', HWSKU_KEY],
                                         stdout=subprocess.PIPE,
-                                    shell=False,
+                                        stderr=subprocess.PIPE,
-                                    stderr=subprocess.STDOUT)
+                                        shell=False)
-            stdout = proc.communicate()[0]
+                stdout, stderr = proc.communicate()
-            proc.wait()
+                assert not stderr and not proc.returncode, "Failed to detect hwsku: %s, rc: %s" % (stderr, proc.returncode)
                 hwsku = stdout.rstrip('\n')
         except OSError, e:
             raise OSError("Failed to detect platform: %s" % (str(e)))