FRR: T4020: Updated CLI options processing for FRR daemons

Instead of analyzing options for each daemon now we use a single
template for the whole configuration file. This makes logic a bit less
flexible, but much easier.
Removed unnecessary check for returned by the
`conf.get_config_dict(base)` config.

Also, added the ability to disable `strip()` of file content while
using `read_file()` what is necessary for proper comparing with
updated content.

3 files changed, 67 insertions, 95 deletions

diff --git a/data/templates/frr/daemons.frr.tmpl b/data/templates/frr/daemons.frr.tmpl
new file mode 100644
index 000000000..089cdae3b
--- /dev/null
+++ b/data/templates/frr/daemons.frr.tmpl
@@ -0,0 +1,50 @@
+zebra=yes
+bgpd=yes
+ospfd=yes
+ospf6d=yes
+ripd=yes
+ripngd=yes
+isisd=yes
+pimd=no
+ldpd=yes
+nhrpd=no
+eigrpd=no
+babeld=no
+sharpd=no
+pbrd=no
+bfdd=yes
+staticd=yes
+
+vtysh_enable=yes
+zebra_options="  -s 90000000 --daemon -A 127.0.0.1
+{%- if irdp is defined %} -M irdp{% endif -%}
+{%- if snmp is defined and snmp.zebra is defined %} -M snmp{% endif -%}
+"
+bgpd_options="   --daemon -A 127.0.0.1
+{%- if bmp is defined %} -M bmp{% endif -%}
+{%- if snmp is defined and snmp.bgpd is defined %} -M snmp{% endif -%}
+"
+ospfd_options="  --daemon -A 127.0.0.1
+{%- if snmp is defined and snmp.ospfd is defined %} -M snmp{% endif -%}
+"
+ospf6d_options=" --daemon -A ::1
+{%- if snmp is defined and snmp.ospf6d is defined %} -M snmp{% endif -%}
+"
+ripd_options="   --daemon -A 127.0.0.1
+{%- if snmp is defined and snmp.ripd is defined %} -M snmp{% endif -%}
+"
+ripngd_options=" --daemon -A ::1"
+isisd_options="  --daemon -A 127.0.0.1"
+pimd_options="  --daemon -A 127.0.0.1"
+ldpd_options="  --daemon -A 127.0.0.1"
+nhrpd_options="  --daemon -A 127.0.0.1"
+eigrpd_options="  --daemon -A 127.0.0.1"
+babeld_options="  --daemon -A 127.0.0.1"
+sharpd_options="  --daemon -A 127.0.0.1"
+pbrd_options="  --daemon -A 127.0.0.1"
+staticd_options="  --daemon -A 127.0.0.1"
+bfdd_options="  --daemon -A 127.0.0.1"
+
+watchfrr_enable=no
+valgrind_enable=no
+
diff --git a/python/vyos/util.py b/python/vyos/util.py
index d8e83ab8d..ce5dc51f5 100644
--- a/python/vyos/util.py
+++ b/python/vyos/util.py
@@ -182,16 +182,20 @@ def call(command, flag='', shell=None, input=None, timeout=None, env=None,
     return code
 
 
-def read_file(fname, defaultonfailure=None):
+def read_file(fname, defaultonfailure=None, strip_end=True):
     """
-    read the content of a file, stripping any end characters (space, newlines)
+    read the content of a file, optionally stripping any end characters (space, newlines)
     should defaultonfailure be not None, it is returned on failure to read
     """
     try:
         """ Read a file to string """
         with open(fname, 'r') as f:
-            data = f.read().strip()
-        return data
+            data = f.read()
+
+        if strip_end:
+            return data.strip()
+        else:
+            return data
     except Exception as e:
         if defaultonfailure is not None:
             return defaultonfailure
diff --git a/src/conf_mode/system_frr.py b/src/conf_mode/system_frr.py
index cc47aa5be..0d0b37e00 100755
--- a/src/conf_mode/system_frr.py
+++ b/src/conf_mode/system_frr.py
@@ -15,14 +15,13 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from pathlib import Path
-from re import compile as re_compile
-from re import M as re_M
 from sys import exit
 
 from vyos import ConfigError
 from vyos import airbag
 from vyos.config import Config
 from vyos.logger import syslog
+from vyos.template import render_to_string
 from vyos.util import read_file, write_file, run
 airbag.enable()
 
@@ -38,31 +37,13 @@ def get_config(config=None):
         conf = config
     else:
         conf = Config()
-    base = ['system', 'frr']
-    if not conf.exists(base):
-        return {}
 
-    frr_config = conf.get_config_dict(base)
+    base = ['system', 'frr']
+    frr_config = conf.get_config_dict(base, get_first_key=True)
 
     return frr_config
 
 
-def daemons_config_parse(daemons_config):
-    # create regex for parsing daemons options
-    regex_daemon_config = re_compile(
-        r'^(?P<daemon_name>\w+)_options="(?P<daemon_options>.*)"$', re_M)
-    # create empty dict for config
-    daemons_config_dict = {}
-    # fill dictionary with actual config
-    for daemon in regex_daemon_config.finditer(daemons_config):
-        daemon_name = daemon.group('daemon_name')
-        daemon_options = daemon.group('daemon_options')
-        daemons_config_dict[daemon_name] = daemon_options
-
-    # return daemons config
-    return (daemons_config_dict)
-
-
 def verify(frr_config):
     # Nothing to verify here
     pass
@@ -70,76 +51,13 @@ def verify(frr_config):
 
 def generate(frr_config):
     # read daemons config file
-    daemons_config = read_file(config_file)
-    daemons_config_current = daemons_config
-    daemons_config_dict = daemons_config_parse(daemons_config)
-
-    # configure SNMP integration
-    frr_snmp = frr_config.get('frr', {}).get('snmp', {})
-    # prepare regex for matching modules
-    regex_snmp = re_compile(r'^.* -M snmp.*$')
-    regex_bmp = re_compile(r'^.* -M bmp.*$')
-    regex_irdp = re_compile(r'^.* -M irdp.*$')
-    # check each daemon's config
-    for (daemon_name, daemon_options) in daemons_config_dict.items():
-        # check if SNMP integration is enabled in the config file
-        snmp_enabled = regex_snmp.match(daemon_options)
-        # check if BMP is enabled in the config file
-        bmp_enabled = regex_bmp.match(daemon_options)
-        # check if IRDP is enabled in the config file
-        irdp_enabled = regex_irdp.match(daemon_options)
-
-        # enable SNMP integration
-        if daemon_name in frr_snmp and not snmp_enabled:
-            daemon_options_new = f'{daemon_options} -M snmp'
-            daemons_config = daemons_config.replace(
-                f'{daemon_name}_options=\"{daemon_options}\"',
-                f'{daemon_name}_options=\"{daemon_options_new}\"')
-            daemon_options = daemon_options_new
-        # disable SNMP integration
-        if daemon_name not in frr_snmp and snmp_enabled:
-            daemon_options_new = daemon_options.replace(' -M snmp', '')
-            daemons_config = daemons_config.replace(
-                f'{daemon_name}_options=\"{daemon_options}\"',
-                f'{daemon_name}_options=\"{daemon_options_new}\"')
-            daemon_options = daemon_options_new
-
-        # enable BMP
-        if daemon_name == 'bgpd' and 'bmp' in frr_config.get(
-                'frr', {}) and not bmp_enabled:
-            daemon_options_new = f'{daemon_options} -M bmp'
-            daemons_config = daemons_config.replace(
-                f'{daemon_name}_options=\"{daemon_options}\"',
-                f'{daemon_name}_options=\"{daemon_options_new}\"')
-            daemon_options = daemon_options_new
-        # disable BMP
-        if daemon_name == 'bgpd' and 'bmp' not in frr_config.get(
-                'frr', {}) and bmp_enabled:
-            daemon_options_new = daemon_options.replace(' -M bmp', '')
-            daemons_config = daemons_config.replace(
-                f'{daemon_name}_options=\"{daemon_options}\"',
-                f'{daemon_name}_options=\"{daemon_options_new}\"')
-            daemon_options = daemon_options_new
-
-        # enable IRDP
-        if daemon_name == 'zebra' and 'irdp' in frr_config.get(
-                'frr', {}) and not irdp_enabled:
-            daemon_options_new = f'{daemon_options} -M irdp'
-            daemons_config = daemons_config.replace(
-                f'{daemon_name}_options=\"{daemon_options}\"',
-                f'{daemon_name}_options=\"{daemon_options_new}\"')
-            daemon_options = daemon_options_new
-        # disable IRDP
-        if daemon_name == 'zebra' and 'irdp' not in frr_config.get(
-                'frr', {}) and irdp_enabled:
-            daemon_options_new = daemon_options.replace(' -M irdp', '')
-            daemons_config = daemons_config.replace(
-                f'{daemon_name}_options=\"{daemon_options}\"',
-                f'{daemon_name}_options=\"{daemon_options_new}\"')
-
+    daemons_config_current = read_file(config_file, strip_end=False)
+    # generate new config file
+    daemons_config_new = render_to_string('frr/daemons.frr.tmpl', frr_config)
     # update configuration file if this is necessary
-    if daemons_config != daemons_config_current:
-        write_file(config_file, daemons_config)
+    if daemons_config_new != daemons_config_current:
+        syslog.warning('FRR daemons configuration file need to be changed')
+        write_file(config_file, daemons_config_new)
         frr_config['config_file_changed'] = True