Ensure poetry path to binaries in local files #2540

Following our transition to Poetry, some local files generated
by Rockstor can still include now-legacy path to Rockstor binaries.
This commit ensures these local files include the new paths to the
binaries in the Poetry venv or correct when necessary at Rockstor's
start time.

Explicitly set file mask to defined setting or copied from target
file.

Check for status of associated systemd service (if defined) and
restart if currently active.

src/rockstor/scripts/initrock.py

@@ -21,16 +21,17 @@
 import os
 import re
 import shutil
+import stat
 import sys
 from tempfile import mkstemp
 
 from django.conf import settings
 
 from system import services
-from system.osi import run_command, md5sum
+from system.osi import run_command, md5sum, replace_pattern_inline
 from system.ssh import remove_sftp_server_subsystem, init_sftp_config
 from system.constants import SYSTEMCTL
-from collections import OrderedDict
+from collections import OrderedDict, namedtuple
 
 
 logger = logging.getLogger(__name__)
@@ -105,6 +106,30 @@
     "rockstor-ipv6check.service",  # Legacy service from pre v4.1.0-0 development.
 ]
 
+# Local files that need checking
+# path: path to file.
+# mask: use constants from the stat module to apply desired permissions to file.
+#       use None to use the current mask of the target file defined at <path>.
+# services: Python List of service(s) to restart, if any, after modifying the file.
+LocalFile = namedtuple("LocalFile", "path mask services")
+LOCAL_FILES = {
+    "samba_config": LocalFile(
+        path="/etc/samba/smb.conf",
+        mask=None,
+        services=["nmb", "smb"]
+    ),
+    "rockstor_crontab": LocalFile(
+        path="/etc/cron.d/rockstortab",
+        mask=stat.S_IRUSR | stat.S_IWUSR,
+        services=None
+    ),
+    "replication_crontab": LocalFile(
+        path="/etc/cron.d/replicationtab",
+        mask=stat.S_IRUSR | stat.S_IWUSR,
+        services=None
+    ),
+}
+
 
 def inet_addrs(interface=None):
     cmd = [IP, "addr", "show"]
@@ -379,6 +404,48 @@ def install_or_update_systemd_service(
     return False
 
 
+def establish_poetry_paths():
+    """Ensure path to Rockstor's binaries point to Poetry venv
+
+    Before our move to Poetry, our binaries lived in /opt/rockstor/bin.
+    After our move to Poetry, these now reside in /opt/rockstor/.venv/bin.
+    While the generation of new local files using these paths account for these
+    new paths, pre-existing files still use the non-existent old paths.
+    This function checks for these local files and changes them accordingly. If one
+    or more systemd service is associated to these files, it restarts it/them if the
+    given service(s) is/are currently active.
+    The local files in questions are defined in the LOCAL_FILES constant.
+    """
+    logger.info("### BEGIN Establishing poetry path to binaries in local files...")
+    pattern = "/opt/rockstor/bin/"
+    replacement = "/opt/rockstor/.venv/bin/"
+    for local_file in LOCAL_FILES:
+        if os.path.isfile(LOCAL_FILES[local_file].path):
+            fh, npath = mkstemp()
+            altered = replace_pattern_inline(
+                LOCAL_FILES[local_file].path, npath, pattern, replacement
+            )
+            if altered:
+                if LOCAL_FILES[local_file].mask is not None:
+                    logger.debug("Set {} to mask {}".format(local_file, oct(LOCAL_FILES[local_file].mask)))
+                    os.chmod(npath, LOCAL_FILES[local_file].mask)
+                else:
+                    shutil.copystat(LOCAL_FILES[local_file].path, npath)
+                shutil.move(npath, LOCAL_FILES[local_file].path)
+                logger.info("The path to binaries in {} ({}) has been updated.".format(local_file, LOCAL_FILES[local_file].path))
+                if LOCAL_FILES[local_file].services is not None:
+                    for service in LOCAL_FILES[local_file].services:
+                        if services.is_systemd_service_active(service):
+                            logger.info("The {} service is currently active... restart it".format(service))
+                            run_command([SYSTEMCTL, "restart", service], log=True)
+            else:
+                os.remove(npath)
+                logger.info("{} already looks good.".format(local_file))
+        else:
+            logger.info("The {} ({}) could not be found".format(local_file, LOCAL_FILES[local_file].path))
+    logger.info("### DONE establishing poetry path to binaries in local files.")
+
+
 def main():
     loglevel = logging.INFO
     if len(sys.argv) > 1 and sys.argv[1] == "-x":
@@ -559,6 +626,8 @@ def main():
 
     establish_systemd_services()
 
+    establish_poetry_paths()
+
 
 if __name__ == "__main__":
     main()

src/rockstor/system/osi.py

@@ -182,6 +182,30 @@ def append_to_line(original_file, new_file, regexes, new_content, sep, remove=Fa
                 tfo.write(line)
 
 
+def replace_pattern_inline(source_file, target_file, pattern, replacement):
+    """Replace a regex pattern with a string inline
+
+    Similar to `sed`, this function will search for the presence of the regex
+    pattern (re module) in a given line, and replace it with the `replacement`
+    string.
+
+    @param source_file: path to source file
+    @param target_file: path to target file
+    @param pattern: regex pattern
+    @param replacement: string
+    @return: boolean; True if pattern was found and replaced
+    """
+    altered = False
+    with open(source_file) as sfo, open(target_file, "w") as tfo:
+        for line in sfo.readlines():
+            if re.search(pattern, line) is not None:
+                tfo.write(re.sub(pattern, replacement, line))
+                altered = True
+            else:
+                tfo.write(line)
+    return altered
+
+
 def run_command(
     cmd,
     shell=False,

src/rockstor/system/services.py

@@ -54,6 +54,7 @@ def init_service_op(service_name, command, throw=True):
     #  to be used in for example model properties etc, where we need only a boolean.
     supported_services = (
         "nfs-server",
+        "nmb",
         "smb",
         "sshd",
         "ypbind",