66 lines
2.1 KiB
Markdown
66 lines
2.1 KiB
Markdown
---
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title: "JSONPath template syntax"
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---
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JSONPath template is composed of JSONPath expressions enclosed by {}.
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And we add three functions in addition to the original JSONPath syntax:
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1. The `$` operator is optional since the expression always start from the root object by default.
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2. We can use `""` to quote text inside JSONPath expression.
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3. We can use `range` operator to iterate list.
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The result object is printed as its String() function.
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Given the input:
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{% highlight json %}
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{
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"kind": "List",
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"items":[
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{
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"kind":"None",
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"metadata":{"name":"127.0.0.1"},
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"status":{
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"capacity":{"cpu":"4"},
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"addresses":[{"type": "LegacyHostIP", "address":"127.0.0.1"}]
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}
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},
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{
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"kind":"None",
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"metadata":{"name":"127.0.0.2"},
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"status":{
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"capacity":{"cpu":"8"},
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"addresses":[
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{"type": "LegacyHostIP", "address":"127.0.0.2"},
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{"type": "another", "address":"127.0.0.3"}
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]
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}
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}
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],
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"users":[
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{
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"name": "myself",
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"user": {}
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},
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{
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"name": "e2e",
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"user": {"username": "admin", "password": "secret"}
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}
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]
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}
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{% endhighlight %}
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Function | Description | Example | Result
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---------|--------------------|--------------------|------------------
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text | the plain text | kind is {.kind} | kind is List
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"" | quote | {"{"} | {
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@ | the current object | {@} | the same as input
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. or [] | child operator | {.kind} or {['kind']}| List
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.. | recursive descent | {..name} | 127.0.0.1 127.0.0.2 myself e2e
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* | wildcard. Get all objects| {.items[*].metadata.name} | [127.0.0.1 127.0.0.2]
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[start:end :step] | subscript operator | {.users[0].name}| myself
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[,] | union operator | {.items[*]['metadata.name', 'status.capacity']} | 127.0.0.1 127.0.0.2 map[cpu:4] map[cpu:8]
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?() | filter | {.users[?(@.name=="e2e")].user.password} | secret
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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]] |