Update syncfile examples and el7 support

confluent_osdeploy/el7/profiles/default/scripts/syncfileclient

@@ -198,11 +198,26 @@ class CredMerger:
                         continue
                     shadout.write(name + ':!::\n')
 
+def appendonce(basepath, filename):
+    with open(filename, 'rb') as filehdl:
+        thedata = filehdl.read()
+    targname = filename.replace(basepath, '')
+    try:
+        with open(targname, 'rb') as filehdl:
+            targdata = filehdl.read()
+    except IOError:
+        targdata = b''
+    if thedata in targdata:
+        return
+    with open(targname, 'ab') as targhdl:
+        targhdl.write(thedata)
+
 def synchronize():
     tmpdir = tempfile.mkdtemp()
+    appendoncedir = tempfile.mkdtemp()
     try:
         ac = apiclient.HTTPSClient()
-        data = json.dumps({'merge': tmpdir})
+        data = json.dumps({'merge': tmpdir, 'appendonce': appendoncedir})
         status, rsp = ac.grab_url_with_status('/confluent-api/self/remotesyncfiles', data)
         if status == 202:
             lastrsp = ''
@@ -230,6 +245,9 @@ def synchronize():
                 cm.read_source(pendhosts)
                 cm.read_target('/etc/hosts')
                 cm.write_out('/etc/hosts')
+            for dirn in os.walk(appendoncedir):
+                for filen in dirn[2]:
+                    appendonce(appendoncedir, os.path.join(dirn[0], filen))
             if lastrsp:
                 lastrsp = json.loads(lastrsp)
                 opts = lastrsp.get('options', {})

confluent_osdeploy/el7/profiles/default/syncfiles

@@ -5,7 +5,15 @@
 # If wanting to simply use the same path for source and destinaiton, the -> may be skipped:
 # /etc/hosts
 
-# Entries under MERGE will attempt to be intelligently merged. This supports /etc/group and /etc/passwd
+# More function is available, for example to limit the entry to run only on n1 through n8, and to set
+# owner, group, and permissions in octal notation:
+# /example/source -> n1-n8:/etc/target (owner=root,group=root,permissions=600)
+
+# Entries under APPENDONCE: will be added to specified target, only if the target does not already
+# contain the data in the source already in its entirety. This allows append in a fashion that
+# is friendly to being run repeatedly
+
+# Entries under MERGE: will attempt to be intelligently merged. This supports /etc/group and /etc/passwd
 # Any supporting entries in /etc/shadow or /etc/gshadow are added automatically, with password disabled
 # It also will not inject 'system' ids (under 1,000 usually) as those tend to be local and rpm managed.
 MERGE:

confluent_osdeploy/el8-diskless/profiles/default/syncfiles

@@ -5,7 +5,15 @@
 # If wanting to simply use the same path for source and destinaiton, the -> may be skipped:
 # /etc/hosts
 
-# Entries under MERGE will attempt to be intelligently merged. This supports /etc/group and /etc/passwd
+# More function is available, for example to limit the entry to run only on n1 through n8, and to set
+# owner, group, and permissions in octal notation:
+# /example/source -> n1-n8:/etc/target (owner=root,group=root,permissions=600)
+
+# Entries under APPENDONCE: will be added to specified target, only if the target does not already
+# contain the data in the source already in its entirety. This allows append in a fashion that
+# is friendly to being run repeatedly
+
+# Entries under MERGE: will attempt to be intelligently merged. This supports /etc/group and /etc/passwd
 # Any supporting entries in /etc/shadow or /etc/gshadow are added automatically, with password disabled
 # It also will not inject 'system' ids (under 1,000 usually) as those tend to be local and rpm managed.
 MERGE:

confluent_osdeploy/el8/profiles/default/syncfiles

@@ -5,7 +5,15 @@
 # If wanting to simply use the same path for source and destinaiton, the -> may be skipped:
 # /etc/hosts
 
-# Entries under MERGE will attempt to be intelligently merged. This supports /etc/group and /etc/passwd
+# More function is available, for example to limit the entry to run only on n1 through n8, and to set
+# owner, group, and permissions in octal notation:
+# /example/source -> n1-n8:/etc/target (owner=root,group=root,permissions=600)
+
+# Entries under APPENDONCE: will be added to specified target, only if the target does not already
+# contain the data in the source already in its entirety. This allows append in a fashion that
+# is friendly to being run repeatedly
+
+# Entries under MERGE: will attempt to be intelligently merged. This supports /etc/group and /etc/passwd
 # Any supporting entries in /etc/shadow or /etc/gshadow are added automatically, with password disabled
 # It also will not inject 'system' ids (under 1,000 usually) as those tend to be local and rpm managed.
 MERGE: