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, 3 insertions, 2 deletions

diff --git a/cloudinit/config/cc_rsyslog.py b/cloudinit/config/cc_rsyslog.py
index 5df0137d..1354885a 100644
--- a/cloudinit/config/cc_rsyslog.py
+++ b/cloudinit/config/cc_rsyslog.py
@@ -182,6 +182,7 @@ import os
 import re
 
 from cloudinit import log as logging
+from cloudinit import subp
 from cloudinit import util
 
 DEF_FILENAME = "20-cloud-config.conf"
@@ -215,7 +216,7 @@ def reload_syslog(command=DEF_RELOAD, systemd=False):
             cmd = ['service', service, 'restart']
     else:
         cmd = command
-    util.subp(cmd, capture=True)
+    subp.subp(cmd, capture=True)
 
 
 def load_config(cfg):
@@ -429,7 +430,7 @@ def handle(name, cfg, cloud, log, _args):
         restarted = reload_syslog(
             command=mycfg[KEYNAME_RELOAD],
             systemd=cloud.distro.uses_systemd()),
-    except util.ProcessExecutionError as e:
+    except subp.ProcessExecutionError as e:
         restarted = False
         log.warning("Failed to reload syslog", e)