Mysqldump Action

Add the mysqldump and set-pxc-strict-mode actions to allow for dumping
databases in text form.

Change-Id: Ibb9c5e17d01c7bb1335d8a7c9087216af8d00b09

actions.yaml

@@ -34,3 +34,33 @@ bootstrap-pxc:
     https://www.percona.com/blog/2014/09/01/galera-replication-how-to-recover-a-pxc-cluster/
 notify-bootstrapped:
    descripttion: Notify the cluster of the new bootstrap uuid.
+set-pxc-strict-mode:
+  description: |
+    Set PXC strict mode.
+  params:
+    mode:
+      type: string
+      default: "ENFORCING"
+      description: |
+        PXC strict mode. Valid options are DISALBED, PERMISSIVE, ENFORCING or MASTER
+        See https://www.percona.com/doc/percona-xtradb-cluster/LATEST/features/pxc-strict-mode.html
+        for more detail.
+mysqldump:
+  description: |
+    MySQL dump of databases. Action will return mysqldump-file location of the
+    requested backup in the results. If the databases parameter is unset all
+    databases will be dumped. If the databases parameter is set only the
+    databases specified will be dumped. Note it may be necessary to use the
+    set-pxc-strict-mode action first to set either PERMISSIVE or MASTER to
+    allow locking of tables for mysqldump to complete successfully.
+    See https://www.percona.com/doc/percona-xtradb-cluster/LATEST/features/pxc-strict-mode.html
+    for more detail.
+  params:
+    basedir:
+      type: string
+      default: "/var/backups/mysql"
+      description: The base directory for backups
+    databases:
+      description: |
+        Comma delimited database names to dump. If left unset, all databases
+        will be dumped.

actions/actions.py

@@ -6,6 +6,9 @@ import subprocess
 import traceback
 from time import gmtime, strftime
 
+import MySQLdb
+
+
 _path = os.path.dirname(os.path.realpath(__file__))
 _hooks = os.path.abspath(os.path.join(_path, '../hooks'))
 _root = os.path.abspath(os.path.join(_path, '..'))
@@ -167,12 +170,67 @@ def notify_bootstrapped(args):
     percona_utils.notify_bootstrapped()
 
 
+def set_pxc_strict_mode(args):
+    """Set PXC Strict Mode.
+    """
+    mode = action_get("mode")
+    try:
+        percona_utils.set_pxc_strict_mode(mode)
+        action_set({"outcome": "Success"})
+    except (MySQLdb.OperationalError, ValueError) as e:
+        action_set({
+            "output": ", ".join(e.args),
+            "traceback": traceback.format_exc()})
+        action_fail("Setting PXC strict mode {} failed"
+                    .format(mode))
+
+
+def mysqldump(args):
+    """Execute a mysqldump backup.
+
+    Execute mysqldump of the database(s).  The mysqldump action will take
+    in the databases action parameter. If the databases parameter is unset all
+    databases will be dumped, otherwise only the named databases will be
+    dumped. The action will use the basedir action parameter to dump the
+    database into the base directory.
+
+    A successful mysqldump backup will set the action results key,
+    mysqldump-file, with the full path to the dump file.
+
+    :param args: sys.argv
+    :type args: sys.argv
+    :side effect: Calls instance.mysqldump
+    :returns: This function is called for its side effect
+    :rtype: None
+    :action param basedir: Base directory to dump the db(s)
+    :action param databases: Comma separated string of databases
+    :action return:
+    """
+    basedir = action_get("basedir")
+    databases = action_get("databases")
+
+    try:
+        filename = percona_utils.mysqldump(basedir, databases=databases)
+        action_set({
+            "mysqldump-file": filename,
+            "outcome": "Success"}
+        )
+    except subprocess.CalledProcessError as e:
+        action_set({
+            "output": e.output,
+            "return-code": e.returncode,
+            "traceback": traceback.format_exc()})
+        action_fail("mysqldump failed")
+
+
 # A dictionary of all the defined actions to callables (which take
 # parsed arguments).
 ACTIONS = {"pause": pause, "resume": resume, "backup": backup,
            "complete-cluster-series-upgrade": complete_cluster_series_upgrade,
            "bootstrap-pxc": bootstrap_pxc,
-           "notify-bootstrapped": notify_bootstrapped}
+           "notify-bootstrapped": notify_bootstrapped,
+           "set-pxc-strict-mode": set_pxc_strict_mode,
+           "mysqldump": mysqldump}
 
 
 def main(args):

actions/mysqldump

@@ -0,0 +1 @@
+actions.py

actions/set-pxc-strict-mode

@@ -0,0 +1 @@
+actions.py

hooks/percona_utils.py

@@ -1,5 +1,6 @@
 ''' General utilities for percona '''
 import collections
+import datetime
 import subprocess
 from subprocess import Popen, PIPE
 import socket
@@ -15,6 +16,7 @@ import time
 import yaml
 
 from charmhelpers.core.decorators import retry_on_exception
+from charmhelpers.core.templating import render
 from charmhelpers.core.host import (
     lsb_release,
     mkdir,
@@ -1605,3 +1607,85 @@ def maybe_notify_bootstrapped():
         cluster_state_uuid = get_wsrep_value('wsrep_cluster_state_uuid')
         if lead_cluster_state_uuid == cluster_state_uuid:
             notify_bootstrapped(cluster_uuid=cluster_state_uuid)
+
+
+def set_pxc_strict_mode(mode):
+    """Set PXC Strict Mode.
+
+    :param mode: Strict mode: DISALBED, PERMISSIVE, ENFORCING or MASTER
+    :type backup_dir: str
+    :raises: Raises ValueError if mode is not a valide parameter
+    :raises: Raises MySQLdb.OperationalError if SQL is not successful
+    :returns: None
+    :rtype: None
+    """
+    _VALID_PARAMS = ["DISABLED", "PERMISSIVE", "ENFORCING", "MASTER"]
+    mode = mode.upper()
+    if mode not in _VALID_PARAMS:
+        raise ValueError(
+            "'{}' is not a valid parameter for pxc_strict_mode. "
+            "Valid options are {}.".format(mode, ", ".join(_VALID_PARAMS)))
+    m_helper = get_db_helper()
+    m_helper.connect(password=m_helper.get_mysql_root_password())
+    m_helper.execute("SET GLOBAL pxc_strict_mode='{}'".format(mode))
+
+
+def write_root_my_cnf():
+    """Write root my.cnf
+
+    :side effect: calls render()
+    :returns: None
+    :rtype: None
+    """
+    my_cnf_template = "root-my.cnf"
+    root_my_cnf = "/root/.my.cnf"
+    context = {"mysql_passwd": leader_get("mysql.passwd")}
+    render(my_cnf_template, root_my_cnf, context, perms=0o600)
+
+
+def mysqldump(backup_dir, databases=None):
+    """Execute a MySQL dump
+
+    :param backup_dir: Path to the backup directory
+    :type backup_dir: str
+    :param databases: Comma delimited database names
+    :type database: str
+    :side effect: Calls subprocess.check_call
+    :raises subprocess.CalledProcessError: If the mysqldump fails
+    :returns: Path to the mysqldump file
+    :rtype: str
+    """
+    # In order to enable passwordless use of mysqldump
+    # write out my.cnf for user root
+    write_root_my_cnf()
+    # Enable use of my.cnf by setting HOME env variable
+    os.environ["HOME"] = "/root"
+    _user = "root"
+    _delimiter = ","
+    if not os.path.exists(backup_dir):
+        mkdir(
+            backup_dir, owner="mysql", group="mysql", perms=0o750)
+
+    bucmd = ["/usr/bin/mysqldump", "-u", _user,
+             "--column-statistics=0",
+             "--default-character-set=utf8",
+             "--triggers", "--routines", "--events",
+             "--ignore-table=mysql.event"]
+    if databases is not None:
+        _filename = os.path.join(
+            backup_dir,
+            "mysqldump-{}-{}".format(
+                "-".join(databases.split(_delimiter)),
+                datetime.datetime.now().strftime("%Y%m%d%H%M")))
+        bucmd.extend(["--result-file", _filename, "--databases"])
+        bucmd.extend(databases.split(_delimiter))
+    else:
+        _filename = os.path.join(
+            backup_dir,
+            "mysqldump-all-databases-{}".format(
+                datetime.datetime.now().strftime("%Y%m%d%H%M")))
+        bucmd.extend(["--result-file", _filename, "--all-databases"])
+    subprocess.check_call(bucmd)
+    gzcmd = ["gzip", _filename]
+    subprocess.check_call(gzcmd)
+    return "{}.gz".format(_filename)

templates/root-my.cnf

@@ -0,0 +1,4 @@
+[client]
+# The following password will be sent to all standard MySQL clients
+password="{{ mysql_passwd }}"
+