NPM module - izara-shared

Overview

Shared libraries used across multiple izara projects

Repository

https://bitbucket.org/stb_working/izara-shared/src/master/

CoreSharedLib

constants

• {string} systemTextGraphTag ("systemText")
• {string} systemTextServiceNameGraphTag ("systemTextServiceName")

LambdaSharedLib

Helper functions for interacting with Lambda resources.

LambdaSharedLib.lambdaFunctionName

/**
 * Executes a Get query to DynamoDB
 * @param {string} serviceName
 * @param {string} functionName
 *
 * @returns {string} deployed Lambda service name
 */

• concatenate with env stage setting

DynamodbSharedLib

Helper functions for interacting with DynamoDB resources.

Idempotence

• DynamodbSharedLib functions that have invoke queries with conditional expression can pass in a setting that says whether to throw on conditionalExpression failure
• if for idempotent conditionalExpression error not want to throw, we want to keep processing as if the query passed like normal
• default is to not throw, because in most cases we will be protecting for idempotent processing
• if conditionalExpression is critical, eg not for idemptent test, then we throw, calling code can set whether to throw noRetryError or normal error that will trigger retries, calling code passes in a setting to do this, default is noRetryError

Notes

• could add another setting that waits and retries on certain errors, within the one function call, could also set delay and how many retries
• might not be needed as DynamoDocument library already has built in retry logic, errors might be an edge case that can be handled through normal throw/retry/dlq flow

dynamodbSharedLib.getItem

/**
 * Executes a GetItem query to DynamoDB
 * @param {string} tableName
 * @param {object} keyValues
 * @param {[object]} queryElements // eg returned only some attributes (ProjectionExpression)
 * @param {[object]} settings
 * @param {boolean} settings.errorOnNoRecordFound
 * @param {boolean} settings.retryOnErrorNoRecordFound
 * @returns {object} single record return value from the query, or Null if none found
 */

• return the .Item property
• if record not found Null will be returned unless errorOnNoRecordFound set to true which will throw error

errorOnNoRecordFound

• if set truthy create an error that includes tableName and keyValues
• noRetryError error is thrown unless retryOnErrorNoRecordFound is set truthy, then a normal error is thrown which will trigger retry code

other errors

• other unhandled DynamoDB errors might include Dynamo throttling/failure
• for these we throw a normal error so the request gets retried before passing to DLQ

dynamodbSharedLib.query

/**
 * Executes a Query on DynamoDB
 * @param {string} tableName
 * @param {object} partitionKeyValue
 * @param {[object]} queryElements
 * @param {[object]} queryElements.sortKeyConditions
 * @param {[object]} queryElements.ExclusiveStartKey
 * @param {[object]} settings
 * @param {numeric} settings.numPagesToRequest // not sure will use? Script will automatically request multiple pages of results
 *
 * @returns {object[], object} array of records from .Items in query result, and queryInfo object with properties such as LastEvaluatedKey
 */

errors

• unhandled DynamoDB errors might include Dynamo throttling/failure
• for these we throw a normal error so the request gets retried before passing to DLQ

dynamodbSharedLib.putItem

/**
 * Executes a PutItem query on DynamoDB
 * @param {string} tableName
 * @param {object} keyValues
 * @param {object} attributes
 * @param {[object]} queryElements 
 * @param {[object]} queryElements.conditionalExpressions
 * @param {[object]} settings
 * @param {numeric} settings.errorOnConditionalExpNotPass // if set then an error will be thrown, otherwise function returns with no error
 * @param {numeric} settings.retryOnErrorConditionalExpNotPass
 *
 * @returns {} .. maybe nothing
 */

errorOnConditionalExpNotPass

• if set truthy create an error that includes tableName and keyValues, maybe conditionalExpressions or DynamoDB error if it describes not passing condition/s
• noRetryError error is thrown unless retryOnErrorConditionalExpNotPass is set truthy, then a normal error is thrown which will trigger retry code

other errors

• other unhandled DynamoDB errors might include Dynamo throttling/failure
• for these we throw a normal error so the request gets retried before passing to DLQ

dynamodbSharedLib.updateItem

/**
 * Executes an UpdateItem query on DynamoDB
 * @param {string} tableName
 * @param {object} keyValues
 * @param {object} attributes
 * @param {[object]} queryElements 
 * @param {[object]} queryElements.conditionalExpressions
 * @param {[object]} settings
 * @param {numeric} settings.errorOnConditionalExpNotPass // if set then an error will be thrown, otherwise function returns with no error
 * @param {numeric} settings.retryOnErrorConditionalExpNotPass
 *
 * @returns {} .. maybe nothing
 */

errorOnConditionalExpNotPass

• if set truthy create an error that includes tableName and keyValues, maybe conditionalExpressions or DynamoDB error if it describes not passing condition/s
• noRetryError error is thrown unless retryOnErrorConditionalExpNotPass is set truthy, then a normal error is thrown which will trigger retry code

other errors

• other unhandled DynamoDB errors might include Dynamo throttling/failure
• for these we throw a normal error so the request gets retried before passing to DLQ

dynamodbSharedLib.deleteItem

/**
 * Executes a DeleteItem query on DynamoDB
 * @param {string} tableName
 * @param {object} keyValues
 * @param {[object]} queryElements 
 * @param {[object]} queryElements.conditionalExpressions
 * @param {[object]} settings
 * @param {numeric} settings.errorOnConditionalExpNotPass // if set then an error will be thrown, otherwise function returns with no error
 * @param {numeric} settings.retryOnErrorConditionalExpNotPass
 *
 * @returns {} .. maybe nothing
 */

errorOnConditionalExpNotPass

• if set truthy create an error that includes tableName and keyValues, maybe conditionalExpressions or DynamoDB error if it describes not passing condition/s
• noRetryError error is thrown unless retryOnErrorConditionalExpNotPass is set truthy, then a normal error is thrown which will trigger retry code

other errors

• other unhandled DynamoDB errors might include Dynamo throttling/failure
• for these we throw a normal error so the request gets retried before passing to DLQ

dynamodbSharedLib.createStringSet

/**
 * Creates a string set element for use with documentClient
 * @param {string[]} stringSet
 *
 * @returns {string} String formatted as a string set for Dynamo
 */

ConfigSharedLib

Helper functions for Config tables.

configSharedLib.getConfigValue

/**
 * @param {string} configTag
 * @param {string} configKey
 *
 * @returns {Object} returns the configValue for a single config record, or null if none found
 */

GraphSharedLib

Helper functions for interacting with Neptune graph databases from any service.

constants

• {string} userNodeLabel ("User")
• {string} userIdPropertyName ("userId")
• {string} createdByRelationshipType ("createdBy")
• {string} hasRelationshipTypePrefix ("has")
• {string} currentRelationshipTypePrefix ("current")
• {string} versionedDataFromPropertyName ("from")
• {string} versionedDataToPropertyName ("to")
• {string} originTimestamp ("originTimestamp")

graphSharedLib.createVersionedDataHasRelationshipType

/**
 * @param {string} versionedDataLabel
 *
 * @returns {string} versionedDataHasRelationshipType
 */

1. Concatenate this.currentRelationshipTypePrefix + versionedDataLabel

graphSharedLib.createVersionedDataCurrentRelationshipType

/**
 * @param {string} versionedDataLabel
 *
 * @returns {string} versionedDataHasRelationshipType
 */

1. Concatenate this.currentRelationshipTypePrefix + versionedDataLabel

graphSharedLib.getChildNodes

/**
 * @param {string[]} parentNodeIdentifierLabels                 - array of labels
 * @param {object} parentNodeUniqueIdProperties       - node properties
 * @param {string[]} relationshipTypes                - array of parent>child relationship types to find
 * @param {string[]} [versionedDataLabels=[]]         - array of versionDataTags to find results for each child node found
 *
 * @returns {object[]}  - array of child nodes properties and relationship properties
 */

1. invoke sync 2021-02-16 - Graph Handler - Functions#Node/GetChildNodes

MsgCfgSharedLib

Helper functions for interacting with Message Configs

MsgCfgLib.createMsgConfigId

/**
 * 
 * @param {string} serviceName
 * @param {string} topicName
 *
 * @returns {string} msgCfgId
 */

• concatenate {serviceName} + "_" + {topicName}

MsgCfgLib.explodeMsgConfigId

/**
 * 
 * @param {string} msgCfgId
 *
 * @returns {string[]} serviceName, topicName
 */

AwsSharedLib

Generic functions for AWS

AwsSharedLib.getResourceNameFromArn

/**
 * 
 * @param {string} arn
 * @param {string} serviceName
 *
 * @returns {string} resourceName
 */

• invoke AwsSharedLib.explodeArn to get fullResourceName
• remove serviceName and env.iz_stage to from fullResourceName to return basic resourceName

AwsSharedLib.explodeArn

/**
 * 
 * @param {string} arn
 *
 * @returns {object} arnElements
 */

• explodes the arn and returns the different elements
• currently only need arnElements.fullResourceName

Working documents

Working_documents - NPM module - izara-shared