JSONpath Support

Documentation for Kubernetes v1.5 is no longer actively maintained. The version you are currently viewing is a static snapshot. For up-to-date documentation, see the latest version.

JSONpath Support

JSONPath template is composed of JSONPath expressions enclosed by {}. And we add three functions in addition to the original JSONPath syntax:

The $ operator is optional since the expression always start from the root object by default.

We can use "" to quote text inside JSONPath expressions.

We can use range operator to iterate lists.

The result object is printed as its String() function.

Given the input:

{
  "kind": "List",
  "items":[
    {
      "kind":"None",
      "metadata":{"name":"127.0.0.1"},
      "status":{
        "capacity":{"cpu":"4"},
        "addresses":[{"type": "LegacyHostIP", "address":"127.0.0.1"}]
      }
    },
    {
      "kind":"None",
      "metadata":{"name":"127.0.0.2"},
      "status":{
        "capacity":{"cpu":"8"},
        "addresses":[
          {"type": "LegacyHostIP", "address":"127.0.0.2"},
          {"type": "another", "address":"127.0.0.3"}
        ]
      }
    }
  ],
  "users":[
    {
      "name": "myself",
      "user": {}
    },
    {
      "name": "e2e",
      "user": {"username": "admin", "password": "secret"}
    }
  ]
}

Function	Description	Example	Result
text	the plain text	kind is {.kind}	kind is List
@	the current object	{@}	the same as input
. or []	child operator	{.kind} or {[‘kind’]}	List
..	recursive descent	{..name}	127.0.0.1 127.0.0.2 myself e2e
*	wildcard. Get all objects	{.items[*].metadata.name}	[127.0.0.1 127.0.0.2]
[start:end :step]	subscript operator	{.users[0].name}	myself
[,]	union operator	{.items[*][‘metadata.name’, ‘status.capacity’]}	127.0.0.1 127.0.0.2 map[cpu:4] map[cpu:8]
?()	filter	{.users[?(@.name==”e2e”)].user.password}	secret
range, end	iterate list	{range .items[*]}[{.metadata.name}, {.status.capacity}] {end}	[127.0.0.1, map[cpu:4]] [127.0.0.2, map[cpu:8]]
””	quote interpreted string	{range .items[*]}{.metadata.name}{“\t”}{end}	127.0.0.1 127.0.0.2

Function

Description

Example

Result

text

the plain text

kind is {.kind}

kind is List

the current object

{@}

the same as input

. or []

child operator

{.kind} or {[‘kind’]}

List

recursive descent

{..name}

127.0.0.1 127.0.0.2 myself e2e

wildcard. Get all objects

{.items[*].metadata.name}

[127.0.0.1 127.0.0.2]

[start:end :step]

subscript operator

{.users[0].name}

myself

[,]

union operator

{.items[*][‘metadata.name’, ‘status.capacity’]}

127.0.0.1 127.0.0.2 map[cpu:4] map[cpu:8]

?()

filter

{.users[?(@.name==”e2e”)].user.password}

secret

range, end

iterate list

{range .items[*]}[{.metadata.name}, {.status.capacity}] {end}

[127.0.0.1, map[cpu:4]] [127.0.0.2, map[cpu:8]]

””

quote interpreted string

{range .items[*]}{.metadata.name}{“\t”}{end}

127.0.0.1 127.0.0.2

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Reference Documentation

Design docs, concept definitions, and references for APIs and CLIs.

Documentation for Kubernetes v1.5 is no longer actively maintained. The version you are currently viewing is a static snapshot. For up-to-date documentation, see the latest version.

JSONpath Support