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authorScott Moser <smoser@ubuntu.com>2018-04-20 12:22:23 -0600
committerChad Smith <chad.smith@canonical.com>2018-04-20 12:22:23 -0600
commit4952a8545b61ceb2fe26a933d2f64020d0281703 (patch)
tree6d765537ce93bf756eef3910e69edbe27ee63c26 /cloudinit/ssh_util.py
parent1081962eacf2814fea6f4fa3255c530de14e4a24 (diff)
downloadvyos-cloud-init-4952a8545b61ceb2fe26a933d2f64020d0281703.tar.gz
vyos-cloud-init-4952a8545b61ceb2fe26a933d2f64020d0281703.zip
set_passwords: Add newline to end of sshd config, only restart if updated.
This admittedly does a fairly extensive re-factor to simply add a newline to the end of sshd_config. It makes the ssh_config updating portion of set_passwords more testable and adds tests for that. The new function is in 'update_ssh_config_lines' which allows you to update a config with multiple changes even though only a single one is currently used. We also only restart the ssh daemon now if a change was made to the config file. Before it was always restarted if the user specified a value for ssh_pwauth other than 'unchanged'. Thanks to Lorens Kockum for initial diagnosis and patch. LP: #1677205
Diffstat (limited to 'cloudinit/ssh_util.py')
-rw-r--r--cloudinit/ssh_util.py70
1 files changed, 63 insertions, 7 deletions
diff --git a/cloudinit/ssh_util.py b/cloudinit/ssh_util.py
index 882517f5..73c31772 100644
--- a/cloudinit/ssh_util.py
+++ b/cloudinit/ssh_util.py
@@ -279,24 +279,28 @@ class SshdConfigLine(object):
def parse_ssh_config(fname):
+ if not os.path.isfile(fname):
+ return []
+ return parse_ssh_config_lines(util.load_file(fname).splitlines())
+
+
+def parse_ssh_config_lines(lines):
# See: man sshd_config
# The file contains keyword-argument pairs, one per line.
# Lines starting with '#' and empty lines are interpreted as comments.
# Note: key-words are case-insensitive and arguments are case-sensitive
- lines = []
- if not os.path.isfile(fname):
- return lines
- for line in util.load_file(fname).splitlines():
+ ret = []
+ for line in lines:
line = line.strip()
if not line or line.startswith("#"):
- lines.append(SshdConfigLine(line))
+ ret.append(SshdConfigLine(line))
continue
try:
key, val = line.split(None, 1)
except ValueError:
key, val = line.split('=', 1)
- lines.append(SshdConfigLine(line, key, val))
- return lines
+ ret.append(SshdConfigLine(line, key, val))
+ return ret
def parse_ssh_config_map(fname):
@@ -310,4 +314,56 @@ def parse_ssh_config_map(fname):
ret[line.key] = line.value
return ret
+
+def update_ssh_config(updates, fname=DEF_SSHD_CFG):
+ """Read fname, and update if changes are necessary.
+
+ @param updates: dictionary of desired values {Option: value}
+ @return: boolean indicating if an update was done."""
+ lines = parse_ssh_config(fname)
+ changed = update_ssh_config_lines(lines=lines, updates=updates)
+ if changed:
+ util.write_file(
+ fname, "\n".join([str(l) for l in lines]) + "\n", copy_mode=True)
+ return len(changed) != 0
+
+
+def update_ssh_config_lines(lines, updates):
+ """Update the ssh config lines per updates.
+
+ @param lines: array of SshdConfigLine. This array is updated in place.
+ @param updates: dictionary of desired values {Option: value}
+ @return: A list of keys in updates that were changed."""
+ found = set()
+ changed = []
+
+ # Keywords are case-insensitive and arguments are case-sensitive
+ casemap = dict([(k.lower(), k) for k in updates.keys()])
+
+ for (i, line) in enumerate(lines, start=1):
+ if not line.key:
+ continue
+ if line.key in casemap:
+ key = casemap[line.key]
+ value = updates[key]
+ found.add(key)
+ if line.value == value:
+ LOG.debug("line %d: option %s already set to %s",
+ i, key, value)
+ else:
+ changed.append(key)
+ LOG.debug("line %d: option %s updated %s -> %s", i,
+ key, line.value, value)
+ line.value = value
+
+ if len(found) != len(updates):
+ for key, value in updates.items():
+ if key in found:
+ continue
+ changed.append(key)
+ lines.append(SshdConfigLine('', key, value))
+ LOG.debug("line %d: option %s added with %s",
+ len(lines), key, value)
+ return changed
+
# vi: ts=4 expandtab