Revert "[docker_image_ctl.j2] Share UTS namespace with host OS (#4169)"

This reverts commit 1ef7403.

files/build_templates/docker_image_ctl.j2

@@ -1,7 +1,7 @@
 #!/bin/bash
 
 # single instance containers are still supported (even though it might not look like it)
-# if no instance number is passed to this script, $DEV will simply be unset, resulting in docker
+# if no instance number is passed to this script, $DEV will simply be unset, resulting in docker 
 # commands being sent to the base container name. E.g. `docker start database$DEV` simply starts
 # the container `database` if no instance number is passed since `$DEV` is not defined
 
@@ -31,6 +31,32 @@ function getMountPoint()
     echo $1 | python -c "import sys, json, os; mnts = [x for x in json.load(sys.stdin)[0]['Mounts'] if x['Destination'] == '/usr/share/sonic/hwsku']; print '' if len(mnts) == 0 else os.path.basename(mnts[0]['Source'])" 2>/dev/null
 }
 
+function updateHostName()
+{
+    HOSTS=/etc/hosts
+    HOSTS_TMP=/etc/hosts.tmp
+
+    EXEC="docker exec -i {{docker_container_name}}$DEV bash -c"
+
+    NEW_HOSTNAME="$1"
+    HOSTNAME=`$EXEC "hostname"`
+    if ! [[ $HOSTNAME =~ ^[a-zA-Z0-9.\-]*$ ]]; then
+        HOSTNAME=`hostname`
+    fi
+
+    # copy HOSTS to HOSTS_TMP
+    $EXEC "cp $HOSTS $HOSTS_TMP"
+    # remove entry with hostname
+    $EXEC "sed -i \"/$HOSTNAME$/d\" $HOSTS_TMP"
+    # add entry with new hostname
+    $EXEC "echo -e \"127.0.0.1\t$NEW_HOSTNAME\" >> $HOSTS_TMP"
+
+    echo "Set hostname in {{docker_container_name}}$DEV container"
+    $EXEC "hostname '$NEW_HOSTNAME'"
+    $EXEC "cat $HOSTS_TMP > $HOSTS"
+    $EXEC "rm -f $HOSTS_TMP"
+}
+
 function getBootType()
 {
     # same code snippet in files/scripts/syncd.sh
@@ -135,7 +161,11 @@ start() {
     {%- else %}
     # Obtain our HWSKU as we will mount directories with these names in each docker
     HWSKU=`sonic-cfggen -d -v 'DEVICE_METADATA["localhost"]["hwsku"]'`
+    HOSTNAME=`sonic-cfggen -d -v 'DEVICE_METADATA["localhost"]["hostname"]'`
     {%- endif %}
+    if [ -z "$HOSTNAME" ] || ! [[ $HOSTNAME =~ ^[a-zA-Z0-9.\-]*$ ]]; then
+        HOSTNAME=`hostname`
+    fi
 
     DOCKERCHECK=`docker inspect --type container {{docker_container_name}}$DEV 2>/dev/null`
     if [ "$?" -eq "0" ]; then
@@ -153,6 +183,11 @@ start() {
             preStartAction
             docker start {{docker_container_name}}$DEV
             postStartAction
+            CURRENT_HOSTNAME="$(docker exec {{docker_container_name}}$DEV hostname)"
+            if [ x"$HOSTNAME" != x"$CURRENT_HOSTNAME" ]; then
+                updateHostName "$HOSTNAME"
+            fi
+            updateHostName "$HOSTNAME"
             exit $?
         fi
 
@@ -175,7 +210,7 @@ start() {
     if [ -z "$DEV" ]; then
         NET="host"
     else
-        {%- if docker_container_name == "database" %}
+        {%- if docker_container_name == "database" %} 
         NET="bridge"
         {%- else %}
         NET="container:database$DEV"
@@ -187,7 +222,6 @@ start() {
 {%- endif %}
     docker create {{docker_image_run_opt}} \
         --net=$NET \
-        --uts=host \{# W/A: this should be set per-docker, for those dockers which really need host's UTS namespace #}
 {%- if install_debug_image == "y" %}
         -v /src:/src:ro -v /debug:/debug:rw \
 {%- endif %}
@@ -224,6 +258,7 @@ start() {
     preStartAction
     docker start {{docker_container_name}}
     postStartAction
+    updateHostName "$HOSTNAME"
 }
 
 wait() {
@@ -245,8 +280,13 @@ case "$1" in
     start|wait|stop)
         $1
         ;;
+    updateHostName)
+        cmd=$1
+        shift 2
+        $cmd $@
+        ;;
     *)
-        echo "Usage: $0 {start namespace(optional)|wait namespace(optional)|stop namespace(optional)}"
+        echo "Usage: $0 {start namespace(optional)|wait namespace(optional)|stop namespace(optional)|updateHostName namespace(optional) new_hostname}"
         exit 1
         ;;
 esac

files/image_config/hostcfgd/hostcfgd

@@ -2,6 +2,7 @@
 # -*- coding: utf-8 -*-
 
 import os
+import re
 import sys
 import subprocess
 import syslog
@@ -23,6 +24,13 @@ TACPLUS_SERVER_TIMEOUT_DEFAULT = "5"
 TACPLUS_SERVER_AUTH_TYPE_DEFAULT = "pap"
 
 
+def is_valid_hostname(hostname):
+    if hostname[-1] == "." or len(hostname) > 253:
+        return False
+    allowed = re.compile("(?!-)[A-Z\d-]{1,63}(?<!-)$", re.IGNORECASE)
+    return all(allowed.match(x) for x in hostname.split("."))
+
+
 def is_true(val):
     if val == 'True' or val == 'true':
         return True
@@ -230,6 +238,7 @@ class HostConfigDaemon:
         tacacs_server = self.config_db.get_table('TACPLUS_SERVER')
         self.aaacfg = AaaCfg()
         self.aaacfg.load(aaa, tacacs_global, tacacs_server)
+        self.hostname_cache=""
         lpbk_table = self.config_db.get_table('LOOPBACK_INTERFACE')
         self.iptables = Iptables()
         self.iptables.load(lpbk_table)
@@ -251,6 +260,45 @@ class HostConfigDaemon:
             log_data['passkey'] = obfuscate(log_data['passkey'])
         syslog.syslog(syslog.LOG_INFO, 'value of {} changed to {}'.format(key, log_data))
 
+    def hostname_handler(self, key, data):
+        if key != "localhost":
+            return
+
+        hostname = data.get("hostname")
+
+        if not hostname:
+            syslog.syslog(syslog.LOG_WARNING, "hostname key is missing")
+            return
+        if not is_valid_hostname(hostname):
+            syslog.syslog(syslog.LOG_WARNING, "hostname {} is invalid".format(hostname))
+            return
+        if hostname == self.hostname_cache:
+            return
+
+        syslog.syslog(syslog.LOG_INFO, "Get all running containers")
+        cmd = 'docker ps --format "{{.Names}}"'
+        try:
+            containers = subprocess.check_output(cmd, shell=True).split("\n")[:-1]
+        except subprocess.CalledProcessError as err:
+            syslog.syslog(syslog.LOG_ERR, "{} - failed: return code - {}, output:\n{}"
+                          .format(err.cmd, err.returncode, err.output))
+
+        for name in containers:
+            script = '/usr/bin/{}.sh'.format(name)
+            exists = os.path.isfile(script)
+            if not exists:
+                syslog.syslog(syslog.LOG_ERR, "Can't find control script for {}".format(name))
+                continue
+
+            cmd = "{} updateHostName {}".format(script, hostname)
+            try:
+                subprocess.check_call(cmd, shell=True)
+            except subprocess.CalledProcessError as err:
+                syslog.syslog(syslog.LOG_ERR, "{} - failed: return code - {}, output:\n{}"
+                              .format(err.cmd, err.returncode, err.output))
+
+        self.hostname_cache = hostname
+
     def lpbk_handler(self, key, data):
         key = ConfigDBConnector.deserialize_key(key)
         #Check if delete operation by fetch existing keys
@@ -261,7 +309,7 @@ class HostConfigDaemon:
             add = False
 
         self.iptables.iptables_handler(key, data, add)
-
+        
     def feature_status_handler(self, key, data):
         status_data = self.config_db.get_table('FEATURE')
         for key in status_data.keys():
@@ -305,6 +353,7 @@ class HostConfigDaemon:
         self.config_db.subscribe('AAA', lambda table, key, data: self.aaa_handler(key, data))
         self.config_db.subscribe('TACPLUS_SERVER', lambda table, key, data: self.tacacs_server_handler(key, data))
         self.config_db.subscribe('TACPLUS', lambda table, key, data: self.tacacs_global_handler(key, data))
+        self.config_db.subscribe('DEVICE_METADATA', lambda table, key, data: self.hostname_handler(key, data))
         self.config_db.subscribe('LOOPBACK_INTERFACE', lambda table, key, data: self.lpbk_handler(key, data))
         self.config_db.subscribe('FEATURE', lambda table, key, data: self.feature_status_handler(key, data))
         self.config_db.listen()