Port OSD on-node tasks to Celery worker system

Adds Celery versions of the osd_add, osd_replace, osd_refresh,
osd_remove, and osd_db_vg_add functions.

daemon-common/common.py

@@ -27,6 +27,7 @@ import signal
 from json import loads
 from re import match as re_match
 from re import split as re_split
+from re import sub as re_sub
 from distutils.util import strtobool
 from threading import Thread
 from shlex import split as shlex_split
@@ -869,3 +870,75 @@ def sortInterfaceNames(interface_names):
         return [atoi(c) for c in re_split(r"(\d+)", text)]
 
     return sorted(interface_names, key=natural_keys)
+
+
+#
+# Parse a "detect" device into a real block device name
+#
+def get_detect_device(detect_string):
+    """
+    Parses a "detect:" string into a normalized block device path using lsscsi.
+
+    A detect string is formatted "detect:<NAME>:<SIZE>:<ID>", where
+    NAME is some unique identifier in lsscsi, SIZE is a human-readable
+    size value to within +/- 3% of the real size of the device, and
+    ID is the Nth (0-indexed) matching entry of that NAME and SIZE.
+    """
+    _, name, size, idd = detect_string.split(":")
+    if _ != "detect":
+        return None
+
+    retcode, stdout, stderr = run_os_command("lsscsi -s")
+    if retcode:
+        print(f"Failed to run lsscsi: {stderr}")
+        return None
+
+    # Get valid lines
+    lsscsi_lines_raw = stdout.split("\n")
+    lsscsi_lines = list()
+    for line in lsscsi_lines_raw:
+        if not line:
+            continue
+        split_line = line.split()
+        if split_line[1] != "disk":
+            continue
+        lsscsi_lines.append(line)
+
+    # Handle size determination (+/- 3%)
+    lsscsi_sizes = set()
+    for line in lsscsi_lines:
+        lsscsi_sizes.add(split_line[-1])
+    for l_size in lsscsi_sizes:
+        b_size = float(re_sub(r"\D.", "", size))
+        t_size = float(re_sub(r"\D.", "", l_size))
+
+        plusthreepct = t_size * 1.03
+        minusthreepct = t_size * 0.97
+
+        if b_size > minusthreepct and b_size < plusthreepct:
+            size = l_size
+            break
+
+    blockdev = None
+    matches = list()
+    for idx, line in enumerate(lsscsi_lines):
+        # Skip non-disk entries
+        if line.split()[1] != "disk":
+            continue
+        # Skip if name is not contained in the line (case-insensitive)
+        if name.lower() not in line.lower():
+            continue
+        # Skip if the size does not match
+        if size != line.split()[-1]:
+            continue
+        # Get our blockdev and append to the list
+        matches.append(line.split()[-2])
+
+    blockdev = None
+    # Find the blockdev at index {idd}
+    for idx, _blockdev in enumerate(matches):
+        if int(idx) == int(idd):
+            blockdev = _blockdev
+            break
+
+    return blockdev