Merge lp:~kos.tsakalozos/charm-helpers/merge-addusers into lp:~bigdata-dev/charm-helpers/framework

[Konstantinos Tsakalozos]

Merge of host.py upstream with our bigdata-dev fork (host.py includes the adduser method).

[Kevin W Monroe (kwmonroe)]

LGTM, merged.

review: Approve

=== modified file 'charmhelpers/core/host.py'
--- charmhelpers/core/host.py	2015-05-13 20:47:37 +0000
+++ charmhelpers/core/host.py	2015-12-07 12:51:05 +0000
@@ -24,6 +24,7 @@
 import os
 import re
 import pwd
+import glob
 import grp
 import random
 import string
@@ -62,6 +63,56 @@
     return service_result
 
 
+def service_pause(service_name, init_dir="/etc/init", initd_dir="/etc/init.d"):
+    """Pause a system service.
+
+    Stop it, and prevent it from starting again at boot."""
+    stopped = True
+    if service_running(service_name):
+        stopped = service_stop(service_name)
+    upstart_file = os.path.join(init_dir, "{}.conf".format(service_name))
+    sysv_file = os.path.join(initd_dir, service_name)
+    if os.path.exists(upstart_file):
+        override_path = os.path.join(
+            init_dir, '{}.override'.format(service_name))
+        with open(override_path, 'w') as fh:
+            fh.write("manual\n")
+    elif os.path.exists(sysv_file):
+        subprocess.check_call(["update-rc.d", service_name, "disable"])
+    else:
+        # XXX: Support SystemD too
+        raise ValueError(
+            "Unable to detect {0} as either Upstart {1} or SysV {2}".format(
+                service_name, upstart_file, sysv_file))
+    return stopped
+
+
+def service_resume(service_name, init_dir="/etc/init",
+                   initd_dir="/etc/init.d"):
+    """Resume a system service.
+
+    Reenable starting again at boot. Start the service"""
+    upstart_file = os.path.join(init_dir, "{}.conf".format(service_name))
+    sysv_file = os.path.join(initd_dir, service_name)
+    if os.path.exists(upstart_file):
+        override_path = os.path.join(
+            init_dir, '{}.override'.format(service_name))
+        if os.path.exists(override_path):
+            os.unlink(override_path)
+    elif os.path.exists(sysv_file):
+        subprocess.check_call(["update-rc.d", service_name, "enable"])
+    else:
+        # XXX: Support SystemD too
+        raise ValueError(
+            "Unable to detect {0} as either Upstart {1} or SysV {2}".format(
+                service_name, upstart_file, sysv_file))
+
+    started = service_running(service_name)
+    if not started:
+        started = service_start(service_name)
+    return started
+
+
 def service(action, service_name):
     """Control a system service"""
     cmd = ['service', service_name, action]
@@ -95,8 +146,22 @@
         return True
 
 
-def adduser(username, password=None, shell='/bin/bash', system_user=False, group=None, groups=None):
-    """Add a user to the system"""
+def adduser(username, password=None, shell='/bin/bash', system_user=False,
+            primary_group=None, secondary_groups=None):
+    """
+    Add a user to the system.
+
+    Will log but otherwise succeed if the user already exists.
+
+    :param str username: Username to create
+    :param str password: Password for user; if ``None``, create a system user
+    :param str shell: The default shell for the user
+    :param bool system_user: Whether to create a login or system user
+    :param str primary_group: Primary group for user; defaults to their username
+    :param list secondary_groups: Optional list of additional groups
+
+    :returns: The password database entry struct, as returned by `pwd.getpwnam`
+    """
     try:
         user_info = pwd.getpwnam(username)
         log('user {0} already exists!'.format(username))
@@ -111,16 +176,32 @@
                 '--shell', shell,
                 '--password', password,
             ])
-        if group:
-            cmd.extend(['-g', group])
-        if groups:
-            cmd.extend(['-G', ','.join(groups)])
+        if not primary_group:
+            try:
+                grp.getgrnam(username)
+                primary_group = username  # avoid "group exists" error
+            except KeyError:
+                pass
+        if primary_group:
+            cmd.extend(['-g', primary_group])
+        if secondary_groups:
+            cmd.extend(['-G', ','.join(secondary_groups)])
         cmd.append(username)
         subprocess.check_call(cmd)
         user_info = pwd.getpwnam(username)
     return user_info
 
 
+def user_exists(username):
+    """Check if a user exists"""
+    try:
+        pwd.getpwnam(username)
+        user_exists = True
+    except KeyError:
+        user_exists = False
+    return user_exists
+
+
 def add_group(group_name, system_group=False):
     """Add a group to the system"""
     try:
@@ -262,6 +343,17 @@
     return system_mounts
 
 
+def fstab_mount(mountpoint):
+    """Mount filesystem using fstab"""
+    cmd_args = ['mount', mountpoint]
+    try:
+        subprocess.check_output(cmd_args)
+    except subprocess.CalledProcessError as e:
+        log('Error unmounting {}\n{}'.format(mountpoint, e.output))
+        return False
+    return True
+
+
 def file_hash(path, hash_type='md5'):
     """
     Generate a hash checksum of the contents of 'path' or None if not found.
@@ -278,6 +370,21 @@
         return None
 
 
+def path_hash(path):
+    """
+    Generate a hash checksum of all files matching 'path'. Standard wildcards
+    like '*' and '?' are supported, see documentation for the 'glob' module for
+    more information.
+
+    :return: dict: A { filename: hash } dictionary for all matched files.
+                   Empty if none found.
+    """
+    return {
+        filename: file_hash(filename)
+        for filename in glob.iglob(path)
+    }
+
+
 def check_hash(path, checksum, hash_type='md5'):
     """
     Validate a file using a cryptographic checksum.
@@ -367,6 +474,7 @@
         int_types = [nic_type]
     else:
         int_types = nic_type
+
     interfaces = []
     for int_type in int_types:
         cmd = ['ip', 'addr', 'show', 'label', int_type + '*']
@@ -439,7 +547,14 @@
         os.chdir(cur)
 
 
-def chownr(path, owner, group, follow_links=True):
+def chownr(path, owner, group, follow_links=True, chowntopdir=False):
+    """
+    Recursively change user and group ownership of files and directories
+    in given path. Doesn't chown path itself by default, only its children.
+
+    :param bool follow_links: Also Chown links if True
+    :param bool chowntopdir: Also chown path itself if True
+    """
     uid = pwd.getpwnam(owner).pw_uid
     gid = grp.getgrnam(group).gr_gid
     if follow_links:
@@ -447,6 +562,10 @@
     else:
         chown = os.lchown
 
+    if chowntopdir:
+        broken_symlink = os.path.lexists(path) and not os.path.exists(path)
+        if not broken_symlink:
+            chown(path, uid, gid)
     for root, dirs, files in os.walk(path):
         for name in dirs + files:
             full = os.path.join(root, name)
@@ -461,3 +580,18 @@
 
 def cpu_arch():
     return subprocess.check_output(['uname', '-p']).strip()
+
+def get_total_ram():
+    '''The total amount of system RAM in bytes.
+
+    This is what is reported by the OS, and may be overcommitted when
+    there are multiple containers hosted on the same machine.
+    '''
+    with open('/proc/meminfo', 'r') as f:
+        for line in f.readlines():
+            if line:
+                key, value, unit = line.split()
+                if key == 'MemTotal:':
+                    assert unit == 'kB', 'Unknown unit'
+                    return int(value) * 1024  # Classic, not KiB.
+        raise NotImplementedError()