Built-in functions

CloudOps Orchestration Service (OOS) provides multiple built-in functions to help you process the parameters and outputs of templates.

Fn::Base64Encode: returns the Base64-encoded result of the source string.
Fn::Base64Decode: returns the Base64-decoded result of the source string.
Fn::MergeMapToList: returns a list in which multiple maps are merged.
Fn::MergeMap: returns a map in which multiple maps are merged.
Fn::Join: returns a string in which the elements in a list are joined by the specified delimiter.
Fn::Select: returns a data element from a data element container based on the specified index.
Fn::Split: splits a string into an array of substrings based on the specified delimiter and returns a list of the substrings.
Fn::Replace: returns a string in which the specified substring is replaced by another substring.
Fn::Min: returns the element with the smallest value in the specified list.
Fn::Max: returns the element with the largest value in the specified list.
Fn::First: returns the first element in the specified list.
Fn::Last: returns the last element in the specified list.
Fn::ListJoin: returns a list in which multiple elements are joined.
Fn::Equals: compares whether two values are equal.
Fn::If: returns one value if the specified condition evaluates to true or another value if the specified condition evaluates to false.
Fn::Not: returns true for a condition that evaluates to false, or returns false for a condition that evaluates to true.
Fn::AddHour: changes the time zone by offsetting N hours from the UTC time.
Fn::FormatUTCTime: changes the time granularity of the UTC time as required.
Fn::Eval: executes a single-line expression in a string and returns the execution result.
Fn::CalculateTimeByOpsWindow: returns a point in time in the specified time period based on the execution time of this function.
Fn::And: returns true if all the specified conditions evaluate to true, or returns false if any one of the conditions evaluates to false.
Fn:Or: returns true if any one of the specified conditions evaluates to true, or returns false if all the conditions evaluate to false.
Fn::Intersection: returns the intersection of multiple arrays.
Fn::Union: returns the union of multiple arrays.
Fn::Difference: returns a new array that contains the difference of the union and intersection of multiple arrays.
Fn::Jq: filters a JSON object and returns the required property values in the JSON object.
Fn::MapJoin: combines two lists into a map in which all values in the first list are used as the keys of key-value pairs and values in the second list are used as the values of key-value pairs.
Fn::IsIpInCIDR: evaluates whether the specified IP address falls within the specified CIDR block.
Fn::Sub: substitutes variables in an input string with the values that you specify.
Fn::DurationBetween: returns the duration between two points in time.
Fn::Escape: escapes a string.
Fn::ConvertMapToList: converts a JSON object into a table that stores data as key-value pairs.

Syntax

A built-in function consists of the name of the function and the parameters to be processed. When you call the declaration expression of a function, the function processes the parameters and returns a result. You can reference the returned result like other parameters.

Fn::Base64Encode

Returns the Base64-encoded result of the source string.

Syntax

{"Fn::Base64Encode": "StringToBeBase64"}

Parameters

StringToBeBase64: the string to be encoded in Base64.

Return value

The Base64-encoded result of the source string.

Sample request

{"Fn::Base64Encode": "hello"}

Sample return value

"aGVsbG8="

Fn::Base64Decode

Returns the Base64-decoded result of the source string.

Syntax

{"Fn::Base64Decode": "Base64ToBeString"}

Parameters

Base64ToBeString: the Base64-encoded string to be decoded.

Return value

The Base64-decoded result of the source string.

Sample request

{"Fn::Base64Decode": "aGVsbG8="}

Sample return value

"hello"

Fn::MergeMapToList

Returns a list in which multiple maps are merged.

Syntax

{"Fn::MergeMapToList": "aListConatinsDicts"}

Parameters

aListConatinsDicts: a list that contains multiple maps.

Return value

A list in which multiple maps are merged.

Sample request 1

{
  "Fn::MergeMapToList": [
    {
      "key_1": [
        "kye_1_item_1",
        "kye_1_item_2"
      ]
    },
    {
      "key_2": [
        "kye_2_item_1",
        "kye_2_item_2"
      ]
    },
    {
      "key_3": [
        "kye_3_item_1",
        "kye_3_item_2"
      ]
    }
  ]
}

Sample return value 1

[
  {
    "key_1": "kye_1_item_1",
    "key_2": "kye_2_item_1",
    "key_3": "kye_3_item_1"
  },
  {
    "key_1": "kye_1_item_2",
    "key_2": "kye_2_item_2",
    "key_3": "kye_3_item_2"
  }
]

Sample request 2

{
  "Fn::MergeMapToList": [
    {
      "key_1": [
        "kye_1_item_1",
        "kye_1_item_2"
      ]
    },
    {
      "key_2": [
        "kye_2_item_1",
        "kye_2_item_2",
        "key_2_item_3"
      ]
    },
    {
      "key_3": [
        "kye_3_item_1",
        "kye_3_item_2"
      ]
    }
  ]
}

Sample return value 2

[  
   {
      "key_1": "kye_1_item_1", 
      "key_2": "kye_2_item_1",
      "key_3": "kye_3_item_1"
    },
    {
      "key_1": "kye_1_item_2", 
      "key_2": "kye_2_item_2",
      "key_3": "kye_3_item_2"
    },
    {
      "key_1": "kye_1_item_2", 
      "key_2": "kye_2_item_3",
      "key_3": "kye_3_item_2"
    }
]

Fn::MergeMap

Returns a map in which multiple maps are merged.

Syntax

{  "Fn::MergeMap": "aListConatinsDicts"}

Parameters

aListConatinsDicts: a list that contains multiple maps.

Return value

A map in which multiple maps are merged.

Sample request

{
  "Fn::MergeMap": [
    {
      "key_1": "value_1"
    },
    {
      "key_2": "value_2"
    }
  ]
}

Sample return value

{"key_1": "value_1","key_2": "value_2"}

Fn::Join

Returns a string in which the elements in a list are joined by the specified delimiter.

Syntax

{"Fn::Join": ["Connector","aListContainsString"]}

Parameters

Connector: the string used to separate the elements in the returned string.

aListContainsString: a list that contains the elements to be joined.

Return value

A string in which the elements in the list are joined.

Sample request

{
  "Fn::Join": [
    ",",
    [
      "a",
      "b",
      "c"
    ]
  ]
}

Sample return value

"a,b,c"

Fn::Select

Returns a data element from a data element container based on the specified index.

Syntax

{"Fn::Select": ["Index","Container"]}

Parameters

Index: the String or Number index that is used to query a data element from the container.

Container: the list or map to be queried.

Return value

A data element queried from the container based on the specified index.

Sample request 1

{
  "Fn::Select": [
    "IpAddress",
    {
      "IpAddress": [
        "192.168.1.123",
        "192.168.1.234"
      ]
    }
  ]
}

Sample return value 1

["192.168.1.123","192.168.1.234"]

Sample request 2

{
  "Fn::Select": [
    "1",
    [
      "192.168.1.123",
      "192.168.1.234"
    ]
  ]
}

Sample return value 2

"192.168.1.234"

Fn::Split

Splits a string into an array of substrings based on the specified delimiter and returns a list of the substrings.

Syntax

{"Fn::Split": ["Separator","StringToSeprate"]}

Parameters

Separator: the string to be used as the delimiter.

StringToSeprate: the string to be split by the delimiter.

Return value

A list of substrings split by the delimiter.

Sample request

{
  "Fn:: Split": [",","a,b,c"]
}

Sample return value

[
  "a",
  "b",
  "c"
]

Fn::Replace

Returns a string in which the specified substring is replaced by another substring.

Syntax

{  "Fn::Replace": [{"$varName": "StringToReplaceWith"}, "StringToReplace"]}

Parameters

$varName: a placeholder that starts with the dollar sign ($) followed by the name of a common parameter. The name requirements for the parameter that follows the dollar sign ($) are the same as those for the template parameters.

StringToReplaceWith: the substring that is used to replace the placeholder.

StringToReplace: the substring, including the placeholder, to be replaced, such as $varName is foo.

Return value

If the StringToReplaceWith parameter is set to baz, the returned string is baz is foo.

Sample request

{  "Fn::Replace": [{"$varName": "baz"},    "$varName is foo"  ]}

Sample return value

"baz is foo"

Fn::Min

Returns the element with the smallest value in the specified list.

Syntax

{"Fn::Min": "aList"}

Parameters

aList: a list that contains elements. The type of the elements in the list can be String, Int, Datetime, or None. All elements in the same list must be of the same type.

Return value

The element with the smallest value in the list excluding the element whose value is None. If all the values of all elements in the list are None, None is returned.

Sample request

{
  "Fn::Min": ["123","234"]
}

Sample return value

"123"

Fn::Max

Returns the element with the largest value in the specified list.

Syntax

{"Fn::Max": "aList"}

Parameters

aList: a list that contains elements. The type of the elements in the list can be String, Int, Datetime, or None. All elements in the same list must be of the same type.

Return value

The element with the largest value in the list excluding the element whose value is None. If all the values of all elements in the list are None, None is returned.

Sample request

{
  "Fn::Max": ["123","234"]
}

Sample return value

"234"

Fn::First

Returns the first element in the specified list.

Syntax

{  "Fn::First": "aList"}

Parameters

aList: a list that contains elements. The types of elements in the list are not limited.

Return value

The first element returned for an iteration. For a loop task, the elements are sorted based on the task execution IDs generated for iterations.

Sample request

{
  "Fn::First": ["123","234"]
}

Sample return value

"123"

Fn::Last

Returns the last element in the specified list.

Syntax

{"Fn::Last": "aList"}

Parameters

aList: a list that contains elements. The types of elements in the list are not limited.

Return value

The last element returned for an iteration. For a loop task, the elements are sorted based on the task execution IDs generated for iterations.

Sample request

{
  "Fn::Last": ["123","234"]
}

Sample return value

"234"

Fn::ListJoin

Returns a list in which multiple elements are joined.

Syntax

{"Fn::ListJoin": "IterableContainer"}

Parameters

IterableContainer: a set of iterable elements. The types of the elements in the set are not limited.

Return value

A list in which the elements in the set are joined.

Sample request

{"Fn::ListJoin": ["a",2, 3]}

Sample return value

["a",2,3]

Fn::Equals

Compares whether two values are equal. If the two values are equal, true is returned. If the two values are not equal, false is returned.

Syntax

{  "Fn::Equals": ["parameter1", "parameter2"]}

Parameters

parameter1 and parameter2: the values to be compared. The types of the values are not limited.

Return value

If the two values are equal, true is returned. If the two values are not equal, false is returned.

Sample request

{  "Fn::Equals": ["Running","Stopped"]}

Sample return value

false

Fn::If

Returns one value if the specified condition evaluates to true or another value if the specified condition evaluates to false.

Syntax

{
  "Fn::If": [
    "condition",
    "value_if_true",
    "value_if_false"
  ]
}

Parameters

condition_name: the condition to be evaluated.

value_if_true: the value to be returned if the specified condition evaluates to true.

value_if_false: the value to be returned if the specified condition evaluates to false.

Return value

If the specified condition evaluates to true, the value specified by the value_if_true parameter is returned.

If the specified condition evaluates to false, the value specified by the value_if_false parameter is returned.

Sample request

{"Fn::If": [false,"Stopped","Running"]}

Sample return value

"Running"

Fn::Or

Returns true if any one of the specified conditions evaluates to true, or returns false if all the conditions evaluate to false.

Syntax

{"Fn::Or": ["condition1","condition2"]}

Parameters

condition1 and condition2: the conditions to be evaluated.

Return value

If both condition1 and condition2 evaluate to false, false is returned. Otherwise, true is returned.

Sample request

{"Fn::Or": [true,false]}

Sample return value

true

Fn::And

Returns true if any one of the specified conditions evaluates to true, or returns false if all the conditions evaluate to false.

Syntax

{"Fn::And": [ "condition1", "condition2"]}

Parameters

condition1 and condition2: the conditions to be evaluated.

Return value

If both condition1 and condition2 evaluate to true, true is returned. Otherwise, false is returned.

Sample request

{"Fn::And": [true,false]}

Sample return value

false

Fn::Not

Returns true for a condition that evaluates to false, or returns false for a condition that evaluates to true.

Syntax

{"Fn::Not": "condition"}

Parameters

condition: the condition to be evaluated.

Return value

If the condition evaluates to true, false is returned. If the condition evaluates to false, true is returned.

Sample request

{"Fn::Not": true}

Sample return value

false

Fn::AddHour

Changes the time zone by offsetting N hours from the UTC time.

Syntax

{"Fn::AddHour": ["utc_time", "hours_count"  ]}

Parameters

utc_time: the UTC time from which N hours is to be offset.

hours_count: the number of hours that you want to offset from the UTC time. The value must be an integer.

Return value

The new UTC time that is obtained after N hours is offset from the previous UTC time.

Sample request

{  "Fn::AddHour": ["2019-06-01T02:12:45Z", 6]}

Sample return value

"2019-06-01T08:12:45Z"

Fn::FormatUTCTime

Changes the time granularity of the UTC time as required.

Syntax

Fn::FormatUTCTime: ["utc_time", "to_be_utc_time_format"]

Parameters

utc_time: the UTC time for which you want to change the time granularity.

to_be_utc_time_format: the specified time granularity.

Return value

The UTC time in the specified time granularity.

Sample request

{  "Fn::FormatUTCTime": ["2019-06-01T02:12:45Z","%Y-%m-%dT%H:%MZ"]}

Sample return value

"2019-06-01T02:12Z"

Fn::Eval

Executes a single-line expression in a string and returns the execution result. You cannot use this function to execute expressions that contains line breaks. Syntax

{
  "Fn::Eval": [
    "expression"
  ]
}

Parameters

expression: the expression to be executed, such as an operation expression.

Return value

The execution result of the expression.

Sample request

{  "Fn::Eval": ["1+3*2+3%2+1"]}

Sample return value

Fn::CalculateTimeByOpsWindow

Returns a point in time in the specified time period based on the execution time of this function. The time period must be less than 24 hours. The Fn::CalculateTimeByOpsWindow function returns a point in time by following these rules: If the function is executed during the specified time period on the current day, it returns the point in time which is one minute later than the execution time of the specified function. If the function is executed earlier than the start time of the time period on the current day, it returns a random point in time during the time period on the current day. If the function is executed later than the end time of the time period on the current day, it returns a random point in time during the time period on the next day after the function is executed.

Syntax

Fn::CalculateTimeByOpsWindow: [ "startTime", "endTime" ]

Parameters

startTime: the start time of the time period, such as 01:00:00Z.

endTime: the end time of the time period, such as 03:00:00Z. The interval between the start time and end time must be less than 24 hours.

Return value

A string that indicates a point in time in the specified time period, in UTC.

Sample request

{  "Fn::CalculateTimeByOpsWindow": ["01:00:00Z", "03:00:00Z"]}

Sample return value

"2019-09-24T01:01:00Z"

Fn::Jq

Filters a JSON object and returns the required property values in the JSON object.

Syntax

{  "Fn::Jq": [ "type", "jqSelector", "jsonObject" ]}

Parameters

type: specifies whether to return the first property value or all property values in the specified JSON object. Valid values: First and All. If you set the type parameter to First, only the first property value is returned. If you set the type parameter to All, all property values are returned.

jqSelector: the jq expression used for filtering. For more information, visit https://yq.aliyun.com/articles/714479.

jsonObject: the JSON object to be filtered.

Return value

The result returned after the JSON object is filtered by using the jq expression.

Sample request 1

{
  "Fn::Jq": [
    "First",".PrivateIpAddress.IpAddress",
{
  "PrivateIpAddress": {
    "IpAddress": [
      "192.168.1.123", "192.168.1.234"
    ]
  },
  "VpcId": "vpc-xzxbamns",
  "VSwitchId": "vsw-zxcdsa"
}
}

Sample return value 1

"192.168.1.123"

Sample request 2

{
  "Fn::Jq": [
    "All",".PrivateIpAddress.IpAddress",
{
  "PrivateIpAddress": {
    "IpAddress": [
      "192.168.1.123", "192.168.1.234"
    ]
  },
  "VpcId": "vpc-xzxbamns",
  "VSwitchId": "vsw-zxcdsa"
}
}

Sample return value 2

["192.168.1.123", "192.168.1.234"]

Fn::Intersection

Returns the intersection of multiple arrays.

Syntax

{  "Fn::Intersection": [ list1, list2]}

Parameters

list1 and list2: the arrays of which you want to take the intersection.

Return value

An array whose elements are values shared by multiple arrays.

Sample request

{  "Fn::Intersection": [["i-1","i-2"],["i-1","i-3"]]}

Sample return value

["i-1"]

Fn::Union

Returns the union of multiple arrays.

Syntax

{  "Fn::Union": [ list1, list2]}

Parameters

list1 and list2: the arrays to be merged.

Return value

An array whose elements are the values in the union of multiple arrays.

Sample request

{
  "Fn::Union": [
    [
      "i-1",
      "i-2"
    ],
    [
      "i-1",
      "i-3"
    ]
  ]
}

Sample return value

["i-1","i-2","i-3"]

Fn::Difference

Returns a new array that contains the difference of the union and intersection of multiple arrays.

Syntax

{  "Fn::Difference": [ list1, list2]}

Parameters

list1 and list2: the arrays that contain different elements.

Return value

An array whose elements are the difference of the union and intersection of multiple arrays.

Sample request

{
  "Fn::Difference": [
    ["i-1","i-2"],
    ["i-1"]]
}

Sample return value

["i-2"]

Fn::MapJoin

Combines two lists into a map in which all values in the first list are used as the keys of key-value pairs and values in the second list are used as the values of key-value pairs.

Syntax

{'Fn::MapJoin': [List1, List2] }

Parameters

aListConatinsDicts: a list that contains multiple maps.

Return value

A map in which the keys of key-value pairs are the elements of the List1 list and the values of key-value pairs are the elements of the List2 list.

Sample request

{'Fn::MapJoin': [['i-1', 'i-2', 'i-3'], [1, 2, 3]] }

Sample return value

{'i-1': 1, 'i-2': 2, 'i-3': 3}

Fn::IsIpInCIDR

Evaluates whether the specified IP address falls within the specified CIDR block.

Syntax

{'Fn::IsIpInCIDR': [Ip, CIDR] }

Parameters

Ip: the IP address. CIDR: the CIDR block.

Return value

true or false

Sample request 1

{'Fn::IsIpInCIDR': ["10.0.1.159", "192.168.0.0/16"] }

Sample return value 1

false

Sample request 2

{'Fn::IsIpInCIDR': ["192.168.255.0", "192.168.0.0/16"] }

Sample return value 2

true

Fn::Sub

Substitutes variables in an input string with the values that you specify.

Syntax

{'Fn::Sub': [TargetString, JSON]}

Parameters

TargetString and JSON

Return value

String

Sample request

{
    "Fn::Sub": [
        "Var1: ${Var1}, Var2: ${Var2}",
        {
            "Var1": "Var1Value",
            "Var2": "Var2Value"
        }
    ]
}

Sample return value

"Var1: Var1Value, Var2: Var2Value"

Fn::DurationBetween

Returns the duration between two points in time.

Syntax

{'Fn::DurationBetween': [DateTime_1, DateTime_2]}

Parameters

DateTime_1 and DateTime_2

Return value

String

Sample request

{
    "Fn::DurationBetween": [
        "12:00:00",
        "13:00:00"
    ]
}

Sample return value

PT3600S

Fn::Escape

Escapes a string.

Syntax

{'Fn::Escape': [String, ShellType] }

Parameters

String and ShellType

Note

The ShellType parameter is set to PowerShell.

Return value

String

Sample request

{
    "Fn::Sub": [
        '{"ACS:File":{"Collection":"Enabled","Filters":"[{\\"Path\\": \\"/home/admin/test\\",\\"Pattern\\":[\\"*\\"],\\"Recursive\\":false}]"},"ACS:Application":{"Collection":"Enabled"}, "ACS:Network":{"Collection":"Enabled"}}',
        'PowerShell'
    ]
}

Sample return value

'{\\"ACS:File\\":{\\"Collection\\":\\"Enabled\\",\\"Filters\\":\\"[{\\\\\\"Path\\\\\\": \\\\\\"/home/admin/test\\\\\\",\\\\\\"Pattern\\\\\\":[\\\\\\"*\\\\\\"],\\\\\\"Recursive\\\\\\":false}]\\"},\\"ACS:Application\\":{\\"Collection\\":\\"Enabled\\"}, \\"ACS:Network\\":{\\"Collection\\":\\"Enabled\\"}}'

Fn::ConvertMapToList

Converts a JSON object into a table that stores data as key-value pairs.

Syntax

{'Fn::ConvertMapToList': [JSON/JSONString] }

Parameters

JSON

Return value

List

Sample request 1

{
    "Fn::ConvertMapToList": [
        {
            "key1": "value1",
            "key2": "value2"
        }
    ]
}

Sample return value 1

[
  {
    "Key": "key1",
    "Value": "value1"
  },
  {
    "Key": "key2",
    "Value": "value2"
  }
]

Sample request 2

{
    "Fn::ConvertMapToList": [
        "{\"key1\": \"value1\", \"key2\": \"value2\"}"
    ]
}

Sample return value 2

[
  {
    "Key": "key1",
    "Value": "value1"
  },
  {
    "Key": "key2",
    "Value": "value2"
  }
]