Patroni configuration validation helpers.

This module contains facilities for validating configuration of Patroni processes.

var schema :

configuration schema of the daemon launched by patroni command.

class patroni.validator. AtMostOne ( * args : str ) View on GitHub

Bases: object

Mark that at most one option from a Case can be suplied.

Represents a list of possible configuration options in a given scope, where at most one can actually be provided.

Note

It should be used together with a Case object.

__init__ ( * args : str ) → None View on GitHub

Create a :class`AtMostOne` object.

Parameters :

*args – any arguments that the caller wants to be stored in this Or object.

Example : 
AtMostOne("nofailover", "failover_priority"): Case({
    "nofailover": bool,
    "failover_priority": IntValidator(min=0, raise_assert=True),
})

The :class`AtMostOne` object is used to define that at most one of nofailover and failover_priority can be provided.

class patroni.validator. BinDirectory ( contains : List [ str ] | None = None , contains_executable : List [ str ] | None = None ) View on GitHub

Bases: Directory

Check if a Postgres binary directory contains the expected files.

It is a subclass of Directory with an extended capability: translating BINARIES according to configured postgresql.bin_name , if any.

Variables :

BINARIES – list of executable files that should exist directly under a given Postgres binary directory.

BINARIES = ['pg_ctl', 'initdb', 'pg_controldata', 'pg_basebackup', 'postgres', 'pg_isready']
validate ( name : str ) → Iterator [ Result ] View on GitHub

Check if the expected executables can be found under name binary directory.

Parameters :

name – path to the base directory against which executables will be validated. Check against PATH if name is not provided.

Yields :

objects with the error message related to the failure, if any check fails.

class patroni.validator. Case ( schema : Dict [ str , Any ] ) View on GitHub

Bases: object

Map how a list of available configuration options should be validated.

Note

It should be used together with an Or object. The Or object will define the list of possible configuration options in a given context, and the Case object will dictate how to validate each of them, if they are set.

__init__ ( schema : Dict [ str , Any ] ) → None View on GitHub

Create a Case object.

Parameters :

schema – the schema for validating a set of attributes that may be available in the configuration. Each key is the configuration that is available in a given scope and that should be validated, and the related value is the validation function or expected type.

Example : 
Case({
    "host": validate_host_port,
    "url": str,
})

That will check that host configuration, if given, is valid based on validate_host_port() , and will also check that url configuration, if given, is a str instance.

class patroni.validator. Directory ( contains : List [ str ] | None = None , contains_executable : List [ str ] | None = None ) View on GitHub

Bases: object

Check if a directory contains the expected files.

The attributes of objects of this class are used by their validate() method.

Parameters :

  • contains – list of paths that should exist relative to a given directory.

  • contains_executable – list of executable files that should exist directly under a given directory.

__init__ ( contains : List [ str ] | None = None , contains_executable : List [ str ] | None = None ) → None View on GitHub

Create a Directory object.

Parameters :

  • contains – list of paths that should exist relative to a given directory.

  • contains_executable – list of executable files that should exist directly under a given directory.

_check_executables ( path : str | None = None ) → Iterator [ Result ] View on GitHub

Check that all executables from contains_executable list exist within the given directory or within PATH .

Parameters :

path – optional path to the base directory against which executables will be validated. If not provided, check within PATH .

Yields :

objects with the error message containing the name of the executable, if any check fails.

validate ( name : str ) → Iterator [ Result ] View on GitHub

Check if the expected paths and executables can be found under name directory.

Parameters :

name – path to the base directory against which paths and executables will be validated. Check against PATH if name is not provided.

Yields :

objects with the error message related to the failure, if any check fails.

class patroni.validator. EnumValidator ( allowed_values : Tuple [ str , ... ] , case_sensitive : bool = False , raise_assert : bool = False ) View on GitHub

Bases: object

Validate enum setting

Variables :

  • allowed_values – a set or CaseInsensitiveSet object with allowed enum values.

  • raise_assert – if an assert call should be performed regarding expected type and valid range.

__init__ ( allowed_values : Tuple [ str , ... ] , case_sensitive : bool = False , raise_assert : bool = False ) → None View on GitHub

Create an EnumValidator object with given allowed values.

Parameters :

  • allowed_values – a tuple with allowed enum values

  • case_sensitive – set to True to do case sensitive comparisons

  • raise_assert – if an assert call should be performed regarding expected values.

class patroni.validator. IntValidator ( min : int | None = None , max : int | None = None , base_unit : str | None = None , expected_type : Any | None = None , raise_assert : bool = False ) View on GitHub

Bases: object

Validate an integer setting.

Variables :

  • min – minimum allowed value for the setting, if any.

  • max – maximum allowed value for the setting, if any.

  • base_unit – the base unit to convert the value to before checking if it’s within min and max range.

  • expected_type – the expected Python type.

  • raise_assert – if an assert test should be performed regarding expected type and valid range.

__init__ ( min : int | None = None , max : int | None = None , base_unit : str | None = None , expected_type : Any | None = None , raise_assert : bool = False ) → None View on GitHub

Create an IntValidator object with the given rules.

Parameters :

  • min – minimum allowed value for the setting, if any.

  • max – maximum allowed value for the setting, if any.

  • base_unit – the base unit to convert the value to before checking if it’s within min and max range.

  • expected_type – the expected Python type.

  • raise_assert – if an assert test should be performed regarding expected type and valid range.

class patroni.validator. Optional ( name : str , default : Any | None = None ) View on GitHub

Bases: object

Mark a configuration option as optional.

Variables :

  • name – name of the configuration option.

  • default – value to set if the configuration option is not explicitly provided

__init__ ( name : str , default : Any | None = None ) → None View on GitHub

Create an Optional object.

Parameters :

  • name – name of the configuration option.

  • default – value to set if the configuration option is not explicitly provided

class patroni.validator. Or ( * args : Any ) View on GitHub

Bases: object

Represent the list of options that are available.

It can represent either a list of configuration options that are available in a given scope, or a list of validation functions and/or expected types for a given configuration option.

__init__ ( * args : Any ) → None View on GitHub

Create an Or object.

Parameters :

*args – any arguments that the caller wants to be stored in this Or object.

Example : 
Or("host", "hosts"): Case({
    "host": validate_host_port,
    "hosts": Or(comma_separated_host_port, [validate_host_port]),
})

The outer Or is used to define that host and hosts are possible options in this scope. The inner :class`Or` in the hosts key value is used to define that hosts option is valid if either of comma_separated_host_port() or validate_host_port() succeed to validate it.

class patroni.validator. Result ( status : bool , error : str | None = "didn't pass validation" , level : int = 0 , path : str = '' , data : Any = '' ) View on GitHub

Bases: object

Represent the result of a given validation that was performed.

Variables :

  • status – If the validation succeeded.

  • path – YAML tree path of the configuration option.

  • data – value of the configuration option.

  • level – error level, in case of error.

  • error – error message if the validation failed, otherwise None .

__init__ ( status : bool , error : str | None = "didn't pass validation" , level : int = 0 , path : str = '' , data : Any = '' ) → None View on GitHub

Create a Result object based on the given arguments.

Note

error attribute is only set if status is failed.

Parameters :

  • status – if the validation succeeded.

  • error – error message related to the validation that was performed, if the validation failed.

  • level – error level, in case of error.

  • path – YAML tree path of the configuration option.

  • data – value of the configuration option.

class patroni.validator. Schema ( validator : Dict [ Any , Any ] | List [ Any ] | Any ) View on GitHub

Bases: object

Define a configuration schema.

It contains all the configuration options that are available in each scope, including the validation(s) that should be performed against each one of them. The validations will be performed whenever the Schema object is called, or its validate() method is called.

Variables :

validator –

validator of the configuration schema. Can be any of these:

  • str : defines that a string value is required; or

  • type : any subclass of type , defines that a value of the given type is required; or

  • callable : any callable object, defines that validation will follow the code defined in the callable object. If the callable object contains an expected_type attribute, then it will check if the configuration value is of the expected type before calling the code of the callable object; or

  • list : list representing one or more values in the configuration; or

  • dict : dictionary representing the YAML configuration tree.

__init__ ( validator : Dict [ Any , Any ] | List [ Any ] | Any ) → None View on GitHub

Create a Schema object.

Note

This class is expected to be initially instantiated with a dict based validator argument. The idea is that dict represents the full YAML tree of configuration options. The validate() method will then walk recursively through the configuration tree, creating new instances of Schema with the new "base path", to validate the structure and the leaf values of the tree. The recursion stops on leaf nodes, when it performs checks of the actual setting values.

Parameters :

validator –

validator of the configuration schema. Can be any of these:

  • str : defines that a string value is required; or

  • type : any subclass of type , defines that a value of the given type is required; or

  • callable : Any callable object, defines that validation will follow the code defined in the callable object. If the callable object contains an expected_type attribute, then it will check if the configuration value is of the expected type before calling the code of the callable object; or

  • list : list representing it expects to contain one or more values in the configuration; or

  • dict : dictionary representing the YAML configuration tree.

The first 3 items in the above list are here referenced as "base validators", which cause the recursion to stop.

If validator is a dict , then you should follow these rules:

  • For the keys it can be either:

    • A str instance. It will be the name of the configuration option; or

    • An Optional instance. The name attribute of that object will be the name of the configuration option, and that class makes this configuration option as optional to the user, allowing it to not be specified in the YAML; or

    • An Or instance. The args attribute of that object will contain a tuple of

      configuration option names. At least one of them should be specified by the user in the YAML;

  • For the values it can be either:

    • A new dict instance. It will represent a new level in the YAML configuration tree; or

    • A Case instance. This is required if the key of this value is an Or instance, and the Case instance is used to map each of the args in Or to their corresponding base validator in Case ; or

    • An Or instance with one or more base validators; or

    • A list instance with a single item which is the base validator; or

    • A base validator.

Example : 
Schema({
    "application_name": str,
    "bind": {
        "host": validate_host,
        "port": int,
    },
    "aliases": [str],
    Optional("data_directory"): "/var/lib/myapp",
    Or("log_to_file", "log_to_db"): Case({
        "log_to_file": bool,
        "log_to_db": bool,
    }),
    "version": Or(int, float),
})

This sample schema defines that your YAML configuration follows these rules:

  • It must contain an application_name entry which value should be a str instance;

  • It must contain a bind.host entry which value should be valid as per function validate_host ;

  • It must contain a bind.port entry which value should be an int instance;

  • It must contain a aliases entry which value should be a list of str instances;

  • It may optionally contain a data_directory entry, with a value which should be a string;

  • It must contain at least one of log_to_file or log_to_db , with a value which should be a bool instance;

  • It must contain a version entry which value should be either an int or a float instance.

_data_key ( key : str | Optional | Or | AtMostOne ) → Iterator [ str ] View on GitHub

Map a key from the validator dictionary to the corresponding key(s) in the data dictionary.

Parameters :

key – key from the validator attribute.

Yields :

keys that should be used to access corresponding value in the data attribute.

iter ( ) → Iterator [ Result ] View on GitHub

Iterate over validator , if it is an iterable object, to validate the corresponding entries in data .

Only dict , list , Directory and Or objects are considered iterable objects.

Yields :

objects with the error message related to the failure, if any check fails.

iter_dict ( ) → Iterator [ Result ] View on GitHub

Iterate over a dict based validator to validate the corresponding entries in data .

Yields :

objects with the error message related to the failure, if any check fails.

iter_or ( ) → Iterator [ Result ] View on GitHub

Perform all validations defined in an Or object for a given configuration option.

This method can be only called against leaf nodes in the configuration tree. Or objects defined in the validator keys will be handled by iter_dict() method.

Yields :

objects with the error message related to the failure, if any check fails.

validate ( data : Dict [ Any , Any ] | Any ) → Iterator [ Result ] View on GitHub

Perform all validations from the schema against the given configuration.

It first checks that data argument type is compliant with the type of validator attribute.

Additionally:
  • If validator attribute is a callable object, calls it to validate data argument. Before doing so, if

    validator contains an expected_type attribute, check if data argument is compliant with that expected type.

  • If validator attribute is an iterable object ( dict , list , Directory or

    Or ), then it iterates over it to validate each of the corresponding entries in data argument.

Parameters :

data – configuration to be validated against validator .

Yields :

objects with the error message related to the failure, if any check fails.

patroni.validator. _get_type_name ( python_type : Any ) → str View on GitHub

Get a user-friendly name for a given Python type.

Parameters :

python_type – Python type which user friendly name should be taken.

Returns :

User friendly name of the given Python type.

patroni.validator. assert_ ( condition : bool , message : str = 'Wrong value' ) → None View on GitHub

Assert that a given condition is True .

If the assertion fails, then throw a message.

Parameters :

  • condition – result of a condition to be asserted.

  • message – message to be thrown if the condition is False .

patroni.validator. comma_separated_host_port ( string : str ) → bool View on GitHub

Validate a list of host and port items.

Call validate_host_port_list() with a list represented by the CSV string .

Parameters :

string – comma-separated list of host and port items.

Returns :

True if all items in the CSV string are valid.

patroni.validator. data_directory_empty ( data_dir : str ) → bool View on GitHub

Check if PostgreSQL data directory is empty.

Parameters :

data_dir – path to the PostgreSQL data directory to be checked.

Returns :

True if the data directory is empty.

patroni.validator. get_bin_name ( bin_name : str ) → str View on GitHub

Get the value of postgresql.bin_name[*bin_name*] configuration option.

Parameters :

bin_name – a key to be retrieved from postgresql.bin_name configuration.

Returns :

value of postgresql.bin_name[*bin_name*] , if present, otherwise bin_name .

patroni.validator. is_ipv4_address ( ip : str ) → bool View on GitHub

Check if ip is a valid IPv4 address.

Parameters :

ip – the IP to be checked.

Returns :

True if the IP is an IPv4 address.

Raises :

ConfigParseError : if ip is not a valid IPv4 address.

patroni.validator. is_ipv6_address ( ip : str ) → bool View on GitHub

Check if ip is a valid IPv6 address.

Parameters :

ip – the IP to be checked.

Returns :

True if the IP is an IPv6 address.

Raises :

ConfigParseError : if ip is not a valid IPv6 address.

patroni.validator. validate_binary_name ( bin_name : str ) → bool View on GitHub

Validate the value of postgresql.binary_name[*bin_name*] configuration option.

If postgresql.bin_dir is set and the value of the bin_name meets these conditions:

  • The path join of postgresql.bin_dir plus the bin_name value exists; and

  • The path join as above is executable

If postgresql.bin_dir is not set, then validate that the value of bin_name meets this condition:

  • Is found in the system PATH using which

Parameters :

bin_name – the value of the postgresql.bin_name[*bin_name*]

Returns :

True if the conditions are true

Raises :
ConfigParseError if:

  • bin_name is not set; or

  • the path join of the postgresql.bin_dir plus bin_name does not exist; or

  • the path join as above is not executable; or

  • the bin_name cannot be found in the system PATH

patroni.validator. validate_connect_address ( address : str ) → bool View on GitHub

Check if options related to connection address were properly configured.

Parameters :

address – address to be validated in the format host:ip .

Returns :

True if the address is valid.

Raises :
ConfigParseError :

  • If the address is not in the expected format; or

  • If the host is set to not allowed values ( 127.0.0.1 , 0.0.0.0 , * , ::1 , or localhost ).

patroni.validator. validate_data_dir ( data_dir : str ) → bool View on GitHub

Validate the value of postgresql.data_dir configuration option.

It requires that postgresql.data_dir is set and match one of following conditions:

  • Point to a path that does not exist yet; or

  • Point to an empty directory; or

  • Point to a non-empty directory that seems to contain a valid PostgreSQL data directory.

Parameters :

data_dir – the value of postgresql.data_dir configuration option.

Returns :

True if the PostgreSQL data directory is valid.

Raises :
ConfigParseError :

  • If no data_dir was given; or

  • If data_dir is a file and not a directory; or

  • If data_dir is a non-empty directory and:

    • PG_VERSION file is not available in the directory

    • pg_wal / pg_xlog is not available in the directory

    • PG_VERSION content does not match the major version reported by postgres --version

patroni.validator. validate_host_port ( host_port : str , listen : bool = False , multiple_hosts : bool = False ) → bool View on GitHub

Check if host(s) and port are valid and available for usage.

Parameters :

  • host_port –

    the host(s) and port to be validated. It can be in either of these formats:

    • host:ip , if multiple_hosts is False ; or

    • host_1,host_2,...,host_n:port , if multiple_hosts is True .

  • listen – if the address is expected to be available for binding. False means it expects to connect to that address, and True that it expects to bind to that address.

  • multiple_hosts – if host_port can contain multiple hosts.

Returns :

True if the host(s) and port are valid.

Raises :
ConfigParseError :

  • If the host_port is not in the expected format; or

  • If * was specified along with more hosts in host_port ; or

  • If we are expecting to bind to an address that is already in use; or

  • If we are not able to connect to an address that we are expecting to do so; or

  • If gaierror is thrown by socket module when attempting to connect to the given address(es).

patroni.validator. validate_host_port_list ( value : List [ str ] ) → bool View on GitHub

Validate a list of host(s) and port items.

Call validate_host_port() with each item in value .

Parameters :

value – list of host(s) and port items to be validated.

Returns :

True if all items are valid.

patroni.validator. validate_host_port_listen ( host_port : str ) → bool View on GitHub

Check if host and port are valid and available for binding.

Call validate_host_port() with listen set to True .

Parameters :

host_port – the host and port to be validated. Must be in the format host:ip .

Returns :

True if the host and port are valid and available for binding.

patroni.validator. validate_host_port_listen_multiple_hosts ( host_port : str ) → bool View on GitHub

Check if host(s) and port are valid and available for binding.

Call validate_host_port() with both listen and multiple_hosts set to True .

Parameters :

host_port –

the host(s) and port to be validated. It can be in either of these formats

  • host:ip ; or

  • host_1,host_2,...,host_n:port

Returns :

True if the host(s) and port are valid and available for binding.

patroni.validator. validate_watchdog_mode ( value : Any ) → None View on GitHub

Validate watchdog.mode configuration option.

Parameters :

value – value of watchdog.mode to be validated.