Examples
Here are a few examples of calculation properties use cases:
Basic calculation propertyโ
In the following example, we will create a calculation property called MBMemory
of type number
, and then transform it into a GB unit:
"properties":{
"MBMemory":{
"type": "number"
},
},
"calculationProperties" : {
"GBMemory": {
"title": "GB Memory",
"type": "number",
"calculation": ".properties.MBMemory / 1024"
}
}
In this instance, if you have a MBMemory
string property with the value:
{
"MBMemory": 2048
}
Then the GBMemory
calculation property value will be:
{
"GBMemory": 2
}
This is an example of how calculation properties can be used to perform math equations over data ingested into Port.
Concatenate stringsโ
Assume you have two string
properties: one is called str1
with the value hello
, the other is called str2
with the value world
.
The following calculation will result in hello world
:
{
"title": "Concatenate strings example",
"type": "string",
"calculation": ".properties.str1 + .properties.str2"
}
If you want to provide your own string template to concatenate properties , wrap your template string with single quotes ('
), such as 'https://' + .properties.str1'
Calculate array lengthโ
Assume you have an array
property called myArr
with the value ["this", "is", "port"]
.
The following calculation will result in 3
:
{
"title": "Calculate array length",
"type": "number",
"calculation": ".properties.myArr | length"
}
Slice arrayโ
Assume you have an array
property called array1
with the value [1,2,3,4]
. You can use the following slicing calculation to get the result [2,3,4]
:
{
"title": "Slice array example",
"type": "string",
"calculation": ".properties.array1[1:4]"
}
Merge objectsโ
Assume you have two object
properties: one called deployed_config
with the value {cpu: 200}
, the other called service_config
with the value {memory: 400}
. You can merge these two object properties and receive a unified config by using the following calculation:
"calculationProperties" : {
"merge_config": {
"title": "Merge config",
"type": "object",
"calculation": ".properties.deployed_config * .properties.service_config",
}
}
The result will be {cpu: 200, memory: 400}
.
- Object merging performs a deep merge, resulting in nested keys from the original objects appearing in the resulting merged object.
- If the same
key
appears in one or more of the merged properties, the last property that appears will have itskeys
take precedence over thekeys
of properties that appeared earlier in the calculation.
For example, Let's assume we have 2 properties with type object
, and we want to perform a deep merge between them:
{
"obj1": {
"cpu": 200
},
"obj2": {
"cpu": 400
}
}
If the calculation is ".properties.obj1 * .properties.obj2"
, the result will be {cpu: 400}
,
If the calculation is ".properties.obj2 * .properties.obj1"
, the result will be {cpu: 200}
,
For merging YAML properties, the merging behavior will be the same, but if you specify type: "string
and format: "yaml"
, the result will be a YAML object.
If-else conditionsโ
Assume that your services use multiple packages, some written in Python and some written in Node.js.
By using an if-else JQ rule, you can specify a different URL for each package, based on its language:
"calculationProperties" : {
"package_manager_url": {
"title": "Package Link",
"type": "string",
"format": "url",
"calculation": "if .properties.language == \"Python\" then \"https://pypi.org/project/\" + .identifier else \"https://www.npmjs.com/package/\" + .identifier end",
}
}
For the following entity:
{
"identifier": "requests",
"properties": {
"language": "Python"
}
}
The result will be package_manager_url: "https://pypi.org/project/requests"
.
For the following entity:
{
"identifier": "axios",
"properties": {
"language": "Nodejs"
}
}
The result will be package_manager_url: "https://www.npmjs.com/package/axios"
.
Calculate K8S labelsโ
You can create a calculation property inside your Blueprint to display a specific tag. Looking at the Node Blueprint, you can find the following property:
"properties": {
...
"labels": {
"type": "object",
"title": "Labels",
"description": "Labels of the Node"
},
And the labels object looks like:
{
"kubernetes.io/metadata.name": "port-k8s-exporter",
"name": "port-k8s-exporter"
}
To display the value of name
, create a new calculation property within the same Blueprint. then use the following JQ calculation:
.properties.labels."name"
The result will be a property that displays port-k8s-exporter
.
Calculate Cloud resource tagsโ
Assuming you have a property tags
in your Blueprint, you can use JQ to display the value of a tag.
In Port's AWS exporter, you can find the following array:
"tags": [
{
"Value": "authentication-service",
"Key": "server-application"
},
{
"Value": "1a23-4bc5d-67efg-89k10",
"Key": "applyId"
},
{
"Value": "0.0.11",
"Key": "server-version"
}
]
To display a Value of applyId
, create a new calculation property within the Blueprint of the entity, and use the following JQ calculation:
.properties.tags.[] | select(.Key=="applyId") | .Value
The result will be a property that will display 1a23-4bc5d-67efg-89k10
.