#!/usr/bin/python # -*- coding: utf-8 -*- # Copyright: (c) 2018, Andrew Klychkov (@Andersson007) # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt) from __future__ import absolute_import, division, print_function __metaclass__ = type DOCUMENTATION = r''' --- module: postgresql_set short_description: Change a PostgreSQL server configuration parameter description: - "IMPORTANT: If your PostgreSQL server version is 14 or later, use the M(community.postgresql.postgresql_alter_system) module instead as it will replace this module in future." - Allows to change a PostgreSQL server configuration parameter. - The module uses ALTER SYSTEM command and applies changes by reload server configuration. - ALTER SYSTEM is used for changing server configuration parameters across the entire database cluster. - It can be more convenient and safe than the traditional method of manually editing the postgresql.conf file. - ALTER SYSTEM writes the given parameter setting to the $PGDATA/postgresql.auto.conf file, which is read in addition to postgresql.conf. - The module allows to reset parameter to boot_val (cluster initial value) by I(reset=true) or remove parameter string from postgresql.auto.conf and reload I(value=default) (for settings with postmaster context restart is required). - After change you can see in the ansible output the previous and the new parameter value and other information using returned values and M(ansible.builtin.debug) module. options: name: description: - Name of PostgreSQL server parameter. Pay attention that parameters are case sensitive (see examples below). type: str required: true value: description: - Parameter value to set. - To remove parameter string from postgresql.auto.conf and reload the server configuration you must pass I(value=default). With I(value=default) the playbook always returns changed is true. type: str reset: description: - Restore parameter to initial state (boot_val). Mutually exclusive with I(value). type: bool default: false session_role: description: - Switch to session_role after connecting. The specified session_role must be a role that the current login_user is a member of. - Permissions checking for SQL commands is carried out as though the session_role were the one that had logged in originally. type: str login_db: description: - Name of database to connect. - The V(db) alias is deprecated and will be removed in version 5.0.0. type: str aliases: - db trust_input: description: - If C(false), check whether values of parameters are potentially dangerous. - It makes sense to use C(false) only when SQL injections are possible. type: bool default: true version_added: '0.2.0' notes: - Supported version of PostgreSQL is 9.4 and later. For PostgreSQL version 14 or later, the M(community.postgresql.postgresql_alter_system) module is recommended. - Pay attention, change setting with 'postmaster' context can return changed is true when actually nothing changes because the same value may be presented in several different form, for example, 1024MB, 1GB, etc. However in pg_settings system view it can be defined like 131072 number of 8kB pages. The final check of the parameter value cannot compare it because the server was not restarted and the value in pg_settings is not updated yet. - For some parameters restart of PostgreSQL server is required. See official documentation U(https://www.postgresql.org/docs/current/view-pg-settings.html). attributes: check_mode: support: full seealso: - module: community.postgresql.postgresql_alter_system - module: community.postgresql.postgresql_info - name: PostgreSQL server configuration description: General information about PostgreSQL server configuration. link: https://www.postgresql.org/docs/current/runtime-config.html - name: PostgreSQL view pg_settings reference description: Complete reference of the pg_settings view documentation. link: https://www.postgresql.org/docs/current/view-pg-settings.html - name: PostgreSQL ALTER SYSTEM command reference description: Complete reference of the ALTER SYSTEM command documentation. link: https://www.postgresql.org/docs/current/sql-altersystem.html author: - Andrew Klychkov (@Andersson007) - Daniele Giudice (@RealGreenDragon) extends_documentation_fragment: - community.postgresql.postgres ''' EXAMPLES = r''' - name: Restore wal_keep_segments parameter to initial state community.postgresql.postgresql_set: name: wal_keep_segments reset: true # Set work_mem parameter to 32MB and show what's been changed and restart is required or not # (output example: "msg": "work_mem 4MB >> 64MB restart_req: False") - name: Set work mem parameter community.postgresql.postgresql_set: name: work_mem value: 32mb register: set - name: Print the result if the setting changed ansible.builtin.debug: msg: "{{ set.name }} {{ set.prev_val_pretty }} >> {{ set.value_pretty }} restart_req: {{ set.restart_required }}" when: set.changed # Ensure that the restart of PostgreSQL server must be required for some parameters. # In this situation you see the same parameter in prev_val_pretty and value_pretty, but 'changed=True' # (If you passed the value that was different from the current server setting). - name: Set log_min_duration_statement parameter to 1 second community.postgresql.postgresql_set: name: log_min_duration_statement value: 1s - name: Set wal_log_hints parameter to default value (remove parameter from postgresql.auto.conf) community.postgresql.postgresql_set: name: wal_log_hints value: default - name: Set TimeZone parameter (careful, case sensitive) community.postgresql.postgresql_set: name: TimeZone value: 'Europe/Paris' ''' RETURN = r''' name: description: Name of PostgreSQL server parameter. returned: success type: str sample: 'shared_buffers' restart_required: description: Information about parameter current state. returned: success type: bool sample: true prev_val_pretty: description: Information about previous state of the parameter. returned: success type: str sample: '4MB' value_pretty: description: Information about current state of the parameter. returned: success type: str sample: '64MB' value: description: - Dictionary that contains the current parameter value (at the time of playbook finish). - Pay attention that for real change some parameters restart of PostgreSQL server is required. - Returns the current value in the check mode. returned: success type: dict sample: { "value": 67108864, "unit": "b" } context: description: - PostgreSQL setting context. returned: success type: str sample: user queries: description: - List of executed DML queries. returned: success type: list elements: str sample: ["ALTER SYSTEM SET shared_preload_libraries = ''"] version_added: '3.7.0' ''' from copy import deepcopy from ansible.module_utils._text import to_native from ansible.module_utils.basic import AnsibleModule from ansible_collections.community.postgresql.plugins.module_utils.database import \ check_input from ansible_collections.community.postgresql.plugins.module_utils.postgres import ( connect_to_db, ensure_required_libs, get_conn_params, get_server_version, pg_cursor_args, postgres_common_argument_spec, ) executed_queries = [] PG_REQ_VER = 90400 # To allow to set value like 1mb instead of 1MB, etc: LOWERCASE_SIZE_UNITS = ("mb", "gb", "tb") # GUC_LIST_QUOTE parameters list for each version where they changed (from PG_REQ_VER). # It is a tuple of tuples as we need to iterate it in order. PARAMETERS_GUC_LIST_QUOTE = ( (140000, ( 'local_preload_libraries', 'search_path', 'session_preload_libraries', 'shared_preload_libraries', 'temp_tablespaces', 'unix_socket_directories' )), (90400, ( 'local_preload_libraries', 'search_path', 'session_preload_libraries', 'shared_preload_libraries', 'temp_tablespaces' )), ) # =========================================== # PostgreSQL module specific support methods. # def param_is_guc_list_quote(server_version, name): for guc_list_quote_ver, guc_list_quote_params in PARAMETERS_GUC_LIST_QUOTE: if server_version >= guc_list_quote_ver: return name in guc_list_quote_params return False def param_guc_list_unquote(value): # Unquote GUC_LIST_QUOTE parameter (each element can be quoted or not) # Assume the parameter is GUC_LIST_QUOTE (check in param_is_guc_list_quote function) return ', '.join([v.strip('" ') for v in value.split(',')]) def param_get(cursor, module, name, is_guc_list_quote): query = ("SELECT name, setting, unit, context, boot_val " "FROM pg_settings WHERE name = %(name)s") try: cursor.execute(query, {'name': name}) info = cursor.fetchone() cursor.execute("SHOW %s" % name) val = cursor.fetchone() except Exception as e: module.fail_json(msg="Unable to get %s value due to : %s" % (name, to_native(e))) if not info: module.fail_json(msg="No such parameter: %s. " "Please check its spelling or presence in your PostgreSQL version " "(https://www.postgresql.org/docs/current/runtime-config.html)" % name) current_val = val[name] raw_val = info['setting'] unit = info['unit'] context = info['context'] boot_val = info['boot_val'] if current_val == 'True': current_val = 'on' elif current_val == 'False': current_val = 'off' if unit == 'kB': if int(raw_val) > 0: raw_val = int(raw_val) * 1024 if int(boot_val) > 0: boot_val = int(boot_val) * 1024 unit = 'b' elif unit == 'MB': if int(raw_val) > 0: raw_val = int(raw_val) * 1024 * 1024 if int(boot_val) > 0: boot_val = int(boot_val) * 1024 * 1024 unit = 'b' if is_guc_list_quote: current_val = param_guc_list_unquote(current_val) raw_val = param_guc_list_unquote(raw_val) return { 'current_val': current_val, 'raw_val': raw_val, 'unit': unit, 'boot_val': boot_val, 'context': context, } def pretty_to_bytes(pretty_val): # The function returns a value in bytes # if the value contains 'B', 'kB', 'MB', 'GB', 'TB'. # Otherwise it returns the passed argument. # It's sometimes possible to have an empty values if not pretty_val: return pretty_val # If the first char is not a digit, it does not make sense # to parse further, so just return a passed value if not pretty_val[0].isdigit(): return pretty_val # If the last char is not an alphabetical symbol, it means that # it does not contain any suffixes, so no sense to parse further if not pretty_val[-1].isalpha(): try: pretty_val = int(pretty_val) except ValueError: try: pretty_val = float(pretty_val) except ValueError: return pretty_val return pretty_val # Extract digits num_part = [] for c in pretty_val: # When we reach the first non-digit element, # e.g. in 1024kB, stop iterating if not c.isdigit(): break else: num_part.append(c) num_part = int(''.join(num_part)) val_in_bytes = None if len(pretty_val) >= 2: if 'kB' in pretty_val[-2:]: val_in_bytes = num_part * 1024 elif 'MB' in pretty_val[-2:]: val_in_bytes = num_part * 1024 * 1024 elif 'GB' in pretty_val[-2:]: val_in_bytes = num_part * 1024 * 1024 * 1024 elif 'TB' in pretty_val[-2:]: val_in_bytes = num_part * 1024 * 1024 * 1024 * 1024 # For cases like "1B" if not val_in_bytes and 'B' in pretty_val[-1]: val_in_bytes = num_part if val_in_bytes is not None: return val_in_bytes else: return pretty_val def param_set(cursor, module, name, value, server_version): if isinstance(value, str) and ',' in value and \ not name.endswith(('_command', '_prefix')) and \ not (server_version < 140000 and name == 'unix_socket_directories'): # Issue https://github.com/ansible-collections/community.postgresql/issues/78 # Change value from 'one, two, three' -> "'one','two','three'" # PR https://github.com/ansible-collections/community.postgresql/pull/400 # Parameter names ends with '_command' or '_prefix' can contains commas but are not lists # PR https://github.com/ansible-collections/community.postgresql/pull/521 # unix_socket_directories up to PostgreSQL 13 lacks GUC_LIST_INPUT and # GUC_LIST_QUOTE options so it is a single value parameter value = ','.join(["'" + elem.strip() + "'" for elem in value.split(',')]) query = "ALTER SYSTEM SET %s = %s" % (name, value) else: query = "ALTER SYSTEM SET %s = '%s'" % (name, value) fail_msg = "Unable to set %s value due to : %s" return exec_set_sql(cursor, module, query, name, fail_msg) def param_set_default(cursor, module, name): query = "ALTER SYSTEM SET %s = DEFAULT" % name fail_msg = "Unable to set default value for %s due to : %s" return exec_set_sql(cursor, module, query, name, fail_msg) def param_reset(cursor, module, name): query = "ALTER SYSTEM RESET %s" % name fail_msg = "Unable to reset %s due to : %s" return exec_set_sql(cursor, module, query, name, fail_msg) def exec_set_sql(cursor, module, query, setting_name, fail_msg): try: executed_queries.append(query) cursor.execute(query) except Exception as e: module.fail_json(msg=fail_msg % (setting_name, to_native(e))) return True # =========================================== # Module execution. # def main(): argument_spec = postgres_common_argument_spec() argument_spec.update( name=dict(type='str', required=True), login_db=dict(type='str', aliases=['db'], deprecated_aliases=[ { 'name': 'db', 'version': '5.0.0', 'collection_name': 'community.postgresql', }], ), value=dict(type='str'), reset=dict(type='bool', default=False), session_role=dict(type='str'), trust_input=dict(type='bool', default=True), ) module = AnsibleModule( argument_spec=argument_spec, supports_check_mode=True, ) name = module.params['name'] value = module.params['value'] reset = module.params['reset'] session_role = module.params['session_role'] trust_input = module.params['trust_input'] if not trust_input: # Check input for potentially dangerous elements: check_input(module, name, value, session_role) if value: # Convert a value like 1mb (Postgres does not support) to 1MB, etc: if len(value) > 2 and value[:-2].isdigit() and value[-2:] in LOWERCASE_SIZE_UNITS: value = value.upper() # Convert a value like 1b (Postgres does not support) to 1B: elif len(value) > 1 and ('b' in value[-1] and value[:-1].isdigit()): value = value.upper() if name == 'shared_preload_libraries' and value == '': msg = ("Due to a PostgreSQL bug in resetting shared_preload_libraries " "with ALTER SYSTEM SET, setting it as an empty string " "is not supported by the module to avoid crashes. " "Use the `value: default` or `reset: true` argument instead. " "If you think the bug has been fixed, please let us know.") module.fail_json(msg=msg) if value is not None and reset: module.fail_json(msg="%s: value and reset params are mutually exclusive" % name) if value is None and not reset: module.fail_json(msg="%s: at least one of value or reset param must be specified" % name) # Ensure psycopg libraries are available before connecting to DB: ensure_required_libs(module) conn_params = get_conn_params(module, module.params, warn_db_default=False) db_connection, dummy = connect_to_db(module, conn_params, autocommit=True) cursor = db_connection.cursor(**pg_cursor_args) kw = {} # Check server version (needs 9.4 or later): ver = get_server_version(db_connection) if ver < PG_REQ_VER: module.warn("PostgreSQL is %s version but %s or later is required" % (ver, PG_REQ_VER)) kw = dict( changed=False, restart_required=False, value_pretty="", prev_val_pretty="", value={"value": "", "unit": ""}, ) kw['name'] = name db_connection.close() module.exit_json(**kw) # Check parameter is GUC_LIST_QUOTE (done once as depend only on server version) is_guc_list_quote = param_is_guc_list_quote(ver, name) # Set default returned values: restart_required = False changed = False kw['name'] = name kw['restart_required'] = False # Get info about param state: res = param_get(cursor, module, name, is_guc_list_quote) current_val = res['current_val'] raw_val = res['raw_val'] unit = res['unit'] boot_val = res['boot_val'] context = res['context'] if value == 'True': value = 'on' elif value == 'False': value = 'off' kw['prev_val_pretty'] = current_val kw['value_pretty'] = deepcopy(kw['prev_val_pretty']) kw['context'] = context # Do job if context == "internal": module.fail_json(msg="%s: cannot be changed (internal context). See " "https://www.postgresql.org/docs/current/runtime-config-preset.html" % name) if context == "postmaster": restart_required = True # If check_mode, just compare and exit: if module.check_mode: if pretty_to_bytes(value) == pretty_to_bytes(current_val): kw['changed'] = False else: kw['value_pretty'] = value kw['changed'] = True # Anyway returns current raw value in the check_mode: kw['value'] = dict( value=raw_val, unit=unit, ) kw['restart_required'] = restart_required kw['queries'] = executed_queries module.exit_json(**kw) # Set param (value can be an empty string): if value is not None and value != current_val: if value == 'default': changed = param_set_default(cursor, module, name) else: changed = param_set(cursor, module, name, value, ver) kw['value_pretty'] = value # Reset param: elif reset: if raw_val == boot_val: # nothing to change, exit: kw['value'] = dict( value=raw_val, unit=unit, ) kw['queries'] = executed_queries module.exit_json(**kw) changed = param_reset(cursor, module, name) # When the setting can be changed w/o restart, apply it if not module.check_mode and changed and context != 'postmaster': cursor.execute("SELECT pg_reload_conf()") cursor.close() db_connection.close() # Reconnect and recheck current value: if context in ('sighup', 'superuser-backend', 'backend', 'superuser', 'user'): db_connection, dummy = connect_to_db(module, conn_params, autocommit=True) cursor = db_connection.cursor(**pg_cursor_args) res = param_get(cursor, module, name, is_guc_list_quote) # f_ means 'final' f_value = res['current_val'] f_raw_val = res['raw_val'] if raw_val == f_raw_val: changed = False else: changed = True kw['value_pretty'] = f_value kw['value'] = dict( value=f_raw_val, unit=unit, ) cursor.close() db_connection.close() kw['changed'] = changed kw['restart_required'] = restart_required kw['queries'] = executed_queries if restart_required and changed: module.warn("Restart of PostgreSQL is required for setting %s" % name) module.exit_json(**kw) if __name__ == '__main__': main()