patroni.dcs.kubernetes module

class patroni.dcs.kubernetes.CoreV1ApiProxy(use_endpoints: Optional[bool] = False, bypass_api_service: Optional[bool] = False)

Bases: object

Proxy class to work with k8s_client.CoreV1Api() object

configure_retriable_http_codes(retriable_http_codes: List[int]) → None

configure_timeouts(loop_wait: int, retry_timeout: Union[int, float], ttl: int) → None

refresh_api_servers_cache() → None

property use_endpoints: bool

class patroni.dcs.kubernetes.K8sClient

Bases: object

class ApiClient(bypass_api_service: Optional[bool] = False)

Bases: object

property api_servers_cache: List[str]

call_api(method: str, path: str, headers: Optional[Dict[str, str]] = None, body: Optional[Any] = None, _retry: Optional[Retry] = None, _preload_content: bool = True, _request_timeout: Optional[float] = None, **kwargs: Any) → Union[HTTPResponse, K8sObject]

refresh_api_servers_cache() → None

request(retry: Optional[Retry], method: str, path: str, timeout: Optional[Union[int, float, Tuple[Union[int, float], Union[int, float]], Timeout]] = None, **kwargs: Any) → HTTPResponse

set_api_servers_cache_ttl(ttl: int) → None

set_base_uri(value: str) → None

set_read_timeout(timeout: Union[int, float]) → None

class CoreV1Api(api_client: Optional[ApiClient] = None)

Bases: object

class rest

Bases: object

exception ApiException(status: Optional[int] = None, reason: Optional[str] = None, http_resp: Optional[HTTPResponse] = None)

Bases: Exception

class patroni.dcs.kubernetes.K8sConfig

Bases: object

exception ConfigException

Bases: Exception

property headers: Dict[str, str]

load_incluster_config(ca_certs: str = '/var/run/secrets/kubernetes.io/serviceaccount/ca.crt', token_refresh_interval: timedelta = datetime.timedelta(seconds=60)) → None

load_kube_config(context: Optional[str] = None) → None

property server: str

exception patroni.dcs.kubernetes.K8sConnectionFailed

Bases: K8sException

exception patroni.dcs.kubernetes.K8sException

Bases: Exception

class patroni.dcs.kubernetes.K8sObject(kwargs: Dict[str, Any])

Bases: object

get(name: str, default: Optional[Any] = None) → Optional[Any]

to_dict() → Dict[str, Any]

class patroni.dcs.kubernetes.Kubernetes(config: Dict[str, Any])

Bases: AbstractDCS

attempt_to_acquire_leader() → bool

Attempt to acquire leader lock.

Note

This method should create /leader key with the value _name.

The key must be created atomically. In case the key already exists it should not be overwritten and False must be returned.

If key creation fails due to DCS not being accessible or because it is not able to process requests (hopefully temporary), the DCSError exception should be raised.

Returns:

True if key has been created successfully.

cancel_initialization() → bool

Removes the initialize key for a cluster.

Returns:

True if successfully committed to DCS.

client_path(path: str) → str

Construct the absolute key name from appropriate parts for the DCS type.

Parameters:

path – The key name within the current Patroni cluster.

Returns:

absolute key name for the current Patroni cluster.

static compare_ports(p1: K8sObject, p2: K8sObject) → bool

delete_cluster(*args: Any, **kwargs: Any) → Any

Delete cluster from DCS.

Returns:

True if successfully committed to DCS.

delete_leader(last_lsn: Optional[int] = None) → bool

Update optime/leader and voluntarily remove leader key from DCS.

This method should remove leader key if current instance is the leader.

Parameters:

last_lsn – latest checkpoint location in bytes.

Returns:

boolean result of called abstract _delete_leader().

delete_sync_state(version: Optional[str] = None) → bool

Patch annotations of $SCOPE-sync Endpoint or ConfigMap with empty values.

Effectively it removes “leader” and “sync_standby” annotations from the object. :param version: last known resource_version for conditional update of the object :returns: True if “delete” was successful

get_citus_coordinator() → Optional[Cluster]

Load the Patroni cluster for the Citus Coordinator.

Note

This method is only executed on the worker nodes (group!=0) to find the coordinator.

Returns:

Select Cluster instance associated with the Citus Coordinator group ID.

initialize(create_new: bool = True, sysid: str = '') → bool

Race for cluster initialization.

This method should atomically create initialize key and return True, otherwise it should return False.

Parameters:

• create_new – False if the key should already exist (in the case we are setting the system_id).

• sysid – PostgreSQL cluster system identifier, if specified, is written to the key.

Returns:

True if key has been created successfully.

property leader_path: str

Get the client path for leader.

manual_failover(leader: Optional[str], candidate: Optional[str], scheduled_at: Optional[datetime] = None, version: Optional[str] = None) → bool

Prepare dictionary with given values and set /failover key in DCS.

Parameters:

• leader – value to set for leader.

• candidate – value to set for member.

• scheduled_at – value converted to ISO date format for scheduled_at.

• version – for conditional update of the key/object.

Returns:

True if successfully committed to DCS.

static member(pod: K8sObject) → Member

patch_or_create(*args: Any, **kwargs: Any) → Any

patch_or_create_config(annotations: Dict[str, Any], resource_version: Optional[str] = None, patch: bool = False, retry: bool = True) → bool

reload_config(config: Union[Config, Dict[str, Any]]) → None

Handles dynamic config changes.

Either cause by changes in the local configuration file + SIGHUP or by changes of dynamic configuration

retry(method: Callable[[...], Any], *args: Any, **kwargs: Any) → Any

set_config_value(value: str, version: Optional[str] = None) → bool

Create or update /config key in DCS.

Parameters:

• value – new value to set in the config key.

• version – for conditional update of the key/object.

Returns:

True if successfully committed to DCS.

set_failover_value(value: str, version: Optional[str] = None) → bool

Unused

set_history_value(value: str) → bool

Set value for history in DCS.

Parameters:

value – new value of history key/object.

Returns:

True if successfully committed to DCS.

set_retry_timeout(retry_timeout: int) → None

Set the new value for retry_timeout.

set_sync_state_value(value: str, version: Optional[str] = None) → bool

Unused

set_ttl(ttl: int) → Optional[bool]

Set the new ttl value for DCS keys.

static subsets_changed(last_observed_subsets: List[K8sObject], ip: str, ports: List[K8sObject]) → bool

>>> ip = '1.2.3.4'
>>> a = [k8s_client.V1EndpointAddress(ip=ip)]
>>> s = [k8s_client.V1EndpointSubset(addresses=a)]
>>> Kubernetes.subsets_changed(s, '1.2.3.5', [])
True
>>> s = [k8s_client.V1EndpointSubset(addresses=a, ports=[k8s_client.V1EndpointPort(protocol='TCP', port=1)])]
>>> Kubernetes.subsets_changed(s, '1.2.3.4', [k8s_client.V1EndpointPort(port=5432)])
True
>>> p1 = k8s_client.V1EndpointPort(name='port1', port=1)
>>> p2 = k8s_client.V1EndpointPort(name='port2', port=2)
>>> p3 = k8s_client.V1EndpointPort(name='port3', port=3)
>>> s = [k8s_client.V1EndpointSubset(addresses=a, ports=[p1, p2])]
>>> Kubernetes.subsets_changed(s, ip, [p2, p3])
True
>>> s2 = [k8s_client.V1EndpointSubset(addresses=a, ports=[p2, p1])]
>>> Kubernetes.subsets_changed(s, ip, [p2, p1])
False

take_leader() → bool

Establish a new leader in DCS.

Note

This method should create leader key with value of _name and ttl of ttl.

Since it could be called only on initial cluster bootstrap it could create this key regardless, overwriting the key if necessary.

Returns:

True if successfully committed to DCS.

touch_member(*args: Any, **kwargs: Any) → Any

Update member key in DCS.

Note

This method should create or update key with the name with /members/ + _name and the value of data in a given DCS.

Parameters:

data – information about an instance (including connection strings).

Returns:

True if successfully committed to DCS.

property ttl: int

Get current ttl value.

update_leader(leader: Leader, last_lsn: Optional[int], slots: Optional[Dict[str, int]] = None, failsafe: Optional[Dict[str, str]] = None) → bool

Update leader key (or session) ttl and optime/leader.

Parameters:

• leader – Leader object with information about the leader.

• last_lsn – absolute WAL LSN in bytes.

• slots – dictionary with permanent slots confirmed_flush_lsn.

• failsafe – if defined dictionary passed to write_failsafe().

Returns:

True if leader key (or session) has been updated successfully.

watch(leader_version: Optional[str], timeout: float) → bool

Sleep if the current node is a leader, otherwise, watch for changes of leader key with a given timeout.

Parameters:

• leader_version – version of a leader key.

• timeout – timeout in seconds.

Returns:

if True this will reschedule the next run of the HA cycle.

write_leader_optime(last_lsn: int) → None

Write value for WAL LSN to optime annotation of the leader object.

Parameters:

last_lsn – absolute WAL LSN in bytes.

write_sync_state(leader: Optional[str], sync_standby: Optional[Collection[str]], version: Optional[str] = None) → Optional[SyncState]

Prepare and write annotations to $SCOPE-sync Endpoint or ConfigMap.

Parameters:

• leader – name of the leader node that manages /sync key

• sync_standby – collection of currently known synchronous standby node names

• version – last known resource_version for conditional update of the object

Returns:

the new SyncState object or None

exception patroni.dcs.kubernetes.KubernetesError(value: Any)

Bases: DCSError

exception patroni.dcs.kubernetes.KubernetesRetriableException(orig: ApiException)

Bases: ApiException

property sleeptime: Optional[int]

class patroni.dcs.kubernetes.ObjectCache(dcs: Kubernetes, func: Callable[[...], Any], retry: Retry, condition: Condition, name: Optional[str] = None)

Bases: Thread

copy() → Dict[str, K8sObject]

delete(name: str, resource_version: str) → Tuple[bool, Optional[K8sObject]]

get(name: str) → Optional[K8sObject]

is_ready() → bool

Must be called only when holding the lock on _condition

kill_stream() → None

run() → None

Method representing the thread’s activity.

You may override this method in a subclass. The standard run() method invokes the callable object passed to the object’s constructor as the target argument, if any, with sequential and keyword arguments taken from the args and kwargs arguments, respectively.

set(name: str, value: K8sObject) → Tuple[bool, Optional[K8sObject]]

patroni.dcs.kubernetes.catch_kubernetes_errors(func: Callable[[...], Any]) → Callable[[...], Any]

patroni.dcs.kubernetes.to_camel_case(value: str) → str