List of Functions

Oracle Cloud Stack offers several intrinsic functions that you can use when creating a template. These functions are executed at runtime by Oracle Cloud Stack when a stack is being created.

Function	Description and Syntax	Examples
`And`	Return `true` if the sequence of expressions all evaluate to `true`; otherwise return `false`. `Fn::And: [exp1, exp2, expN]`	`"Fn::And": [{"Fn::Equals": [{"Fn::GetParam": stage}, "dev"]}, {"Fn::Equals": [{"Fn::GetParam": container}, ""]}]`
`Base64`	Convert the given string to base64 encoding. `Fn::Base64: string`	`publicKeyText: { "Fn::Base64": {"Fn::GetParam": "key"} }`
`Contains`	Return `true` if the first string is found in the second string, or if the specified value is found in a sequence of values; otherwise return `false`. `Fn::Contains: [valueToSearchFor, stringOrSequence]`	`"Fn::Contains": ["us", {"Fn::GetParam": region}]`
`Empty`	Return `true` if the provided string is empty; otherwise return `false`. `Fn::Empty: string`	`"Fn::Empty": {"Fn::GetParam": region}`
`Equals`	Compare a sequence containing two expressions and return `true` if the expressions evaluate to the same value; otherwise return `false`. `Fn::Equals: [exp1, exp2]`	`"Fn::Equals": [{"Fn::GetParam": appType}, "Java"]`
`FindInMap`	Retrieve the value for the specified key from a map that’s defined in this template. `Fn::FindInMap: [mapName, submapName, keyName]`	`usableStorage: "Fn::FindInMap": ["dbMap", "size", {"Fn::GetParam": projectType}]`
`GetAtt`	Retrieve the value of the runtime attribute from a specific resource. The attribute name supports a dot notation to access nested attributes within a JSON payload. `Fn::GetAtt: [resourceName, attributeName]`	`dbServiceName: { "Fn::GetAtt": [HRDatabase, serviceName] }` `shape: { "Fn::GetAtt": [HRWeb, options.clusters.shape] }`
`GetParam`	Retrieve the value of a template parameter. `Fn::GetParam: parameterName`	`network: { "Fn::GetParam": networkName }` `description: { "Fn::GetParam": serviceName }` `container: { "Fn::GetParam": backupStorage.cloudStorageContainer }`
`GetRandom`	Generate a string of random characters. `Fn::GetRandom: [size, characterSet]` Use `characterSet` to limit the characters that are allowed in the generated string: `ALPHANUMERIC` - The characters `A-Z,a-z,0-9` `ALPHABET` - The characters `A-Z,a-z` `NUMERIC` - The characters `0–9` A custom sequence of characters. For example: `[$,!,#,&]`	`password: { "Fn::GetRandom": [10, "ALPHANUMERIC"] }` `dbServiceName: { "Fn::Join": ["", ["DB",{"Fn::GetRandom" : [8, "ALPHABET"] }]] }`
`GetResource`	Retrieve a resource’s definition. `Fn::GetResource: resourceName`	`configs: - name: DB1-dbScripts config: { "Fn::GetResource": dbScripts }`
`GetTimestamp`	Return the current time in the specified format. `Fn::GetTimestamp: format` See SimpleDateFormat for the available date and time options in the `format` string.	`serviceName: { "Fn::GetTimestamp": "'DB'yyMMdd" }` For example: `DB180521` `description: { "Fn::GetTimestamp": "'Created on' EEE, MMM dd" }` For example: `Created on Wed, May 21`
`GreaterThan`	Compare a sequence containing two expressions and return `true` if the first expression evaluates to a value that is greater than the value of the second expression; otherwise return `false`. `Fn::GreaterThan: [exp1, exp2]`	`"Fn::GreaterThan": [{"Fn::GetParam": clusterSize}, 1]`
`If`	Evaluate a global condition defined in this template. If the specified condition evaluates to `true`, return the second item in the sequence; otherwise return the third item in the sequence. `Fn::If: [conditionName, trueValue, falseValue]`	`shape: { "Fn::If": ["prodEnv","oc4","oc3"] }`
`Join`	Combine a sequence of values into a single string, and using the specified delimiter character between the values. The function takes a sequence (delimiter, values) as its argument, and the values themselves are a sequence. To simply join the values without a delimiter specify an empty string for the first argument. `Fn::Join: [delimiterChar, [value1, value2, valueN]]`	`serviceName: { "Fn::Join": ["_", [HRApp, "Fn::GetParam": userName]] }` If the `userName` parameter’s value is `bill5`, the `serviceName` parameter would be `HRApp_bill5`.
`LessThan`	Compare a sequence containing two expressions and return `true` if the first expression evaluates to a value that is less than the value of the second expression; otherwise return `false`. `Fn::LessThan: [exp1, exp2]`	`"Fn::LessThan": [{"Fn::GetParam": clusterSize}, 2]`
`Match`	Return `true` if a string matches a regular expression; otherwise return `false`. `Fn::Match: [regularExpression, string]`	This expression returns `true` if the `region` parameter begins with the text `us`: `"Fn::Match": ["^us", {"Fn::GetParam": region}]` This expression returns `true` if the `schemaName` parameter contains only letters and the numbers 0-3: `"Fn::Match": ["^(?=.?[A-Z])(?=.?[a-z])(?=.*[0-3])[a-zA-Z]([a-zA-Z0-3_#])+$", {"Fn::GetParam": schemaName}]`
`Not`	Negate the boolean value of an expression. If the expression evaluates to `true`, return `false`. `Fn::Not: booleanExpression`	`"Fn::Not": {"Fn::Equals": [{"Fn::GetParam":"userName"}, ""]}}`
`Or`	Return `true` if at least one expression in the sequence evaluates to `true`; otherwise return `false`. `Fn::Or: [exp1, exp2, expN]`	`"Fn::Or": [{"Fn::Equals": [{"Fn::GetParam": shape}, "oc3"]}, {"Fn::Equals": [{"Fn::GetParam": shape}, "oc4"]}]`
`Replace`	Dynamically find and replace one or more values in a string (`body`). The replacements (`substitutions`) object can contain one or more name/value attributes and their values can be static or dynamic. `Fn::Replace: {"body" : string, "substitutions" : {find:replace, find:replace, ...}`	`appURL: { "Fn::Replace": {"body" : "host:port/myapp", "substitutions" : {"host" : "Fn:GetParam": publicIP, "port" : "7002"}} }` If the `publicIP` parameter’s value is `192.0.2.10`, the `appURL` parameter would be `192.0.2.10:7002/myapp`.
`Select`	Select an object from a list of indexed objects, by passing in the index of the desired object. `Fn::Select: [indexToFetch, objectList]`	`serverHost: { "Fn::Select": [0, "Fn::Split": [":", "host123:9001"]] }` The `serverHost` parameter is assigned the value `host123`.
`Size`	Return the number of characters in the specified string, or the number of elements in the specified sequence. `Fn::Size: stringOrSequence`	`"Fn::Size": {"Fn::GetParam": dbName}` If the `dbName` parameter is the string “mydb”, the value returned is 4. If the parameter is a sequence `["db1","db2"]`, the value returned is 2.
`Split`	Split a single string into a sequence of strings by using the specified delimiter character. The function takes a sequence (delimiter, string) as its argument, and returns a sequence. You can also use the `Select` function on the result of `Split` to retrieve a specific item in the sequence. `Fn::Split: [delimiterChar, string]`	`databases: { "Fn::Split": ["_", "mydb1_mydb2"] }` The `databases` parameter is assigned the sequence `[mydb1, mydb2]`.