Move subp into its own module. (#416)

This was painful, but it finishes a TODO from cloudinit/subp.py.

It moves the following from util to subp:
  ProcessExecutionError
  subp
  which
  target_path

I moved subp_blob_in_tempfile into cc_chef, which is its only caller.
That saved us from having to deal with it using write_file
and temp_utils from subp (which does not import any cloudinit things now).

It is arguable that 'target_path' could be moved to a 'path_utils' or
something, but in order to use it from subp and also from utils,
we had to get it out of utils.

1 files changed, 8 insertions, 7 deletions

diff --git a/cloudinit/config/cc_mounts.py b/cloudinit/config/cc_mounts.py
index 85a89cd1..e57d1b1f 100644
--- a/cloudinit/config/cc_mounts.py
+++ b/cloudinit/config/cc_mounts.py
@@ -69,6 +69,7 @@ import os.path
 import re
 
 from cloudinit import type_utils
+from cloudinit import subp
 from cloudinit import util
 
 # Shortname matches 'sda', 'sda1', 'xvda', 'hda', 'sdb', xvdb, vda, vdd1, sr0
@@ -252,8 +253,8 @@ def create_swapfile(fname: str, size: str) -> None:
                    'count=%s' % size]
 
         try:
-            util.subp(cmd, capture=True)
-        except util.ProcessExecutionError as e:
+            subp.subp(cmd, capture=True)
+        except subp.ProcessExecutionError as e:
             LOG.warning(errmsg, fname, size, method, e)
             util.del_file(fname)
 
@@ -267,15 +268,15 @@ def create_swapfile(fname: str, size: str) -> None:
     else:
         try:
             create_swap(fname, size, "fallocate")
-        except util.ProcessExecutionError as e:
+        except subp.ProcessExecutionError as e:
             LOG.warning(errmsg, fname, size, "dd", e)
             LOG.warning("Will attempt with dd.")
             create_swap(fname, size, "dd")
 
     util.chmod(fname, 0o600)
     try:
-        util.subp(['mkswap', fname])
-    except util.ProcessExecutionError:
+        subp.subp(['mkswap', fname])
+    except subp.ProcessExecutionError:
         util.del_file(fname)
         raise
 
@@ -538,9 +539,9 @@ def handle(_name, cfg, cloud, log, _args):
     for cmd in activate_cmds:
         fmt = "Activate mounts: %s:" + ' '.join(cmd)
         try:
-            util.subp(cmd)
+            subp.subp(cmd)
             log.debug(fmt, "PASS")
-        except util.ProcessExecutionError:
+        except subp.ProcessExecutionError:
             log.warning(fmt, "FAIL")
             util.logexc(log, fmt, "FAIL")