This documentation is for not yet released version of ytt. For the documentation of the latest release version, see the latest version.

Schema Validations Cheat Sheet

(For a more detailed guide, see Writing Schema Validations.)

Use Case Syntax

Use Case	Syntax
Required string usage: Using the empty/zero value reference: `min_len=`	`#@schema/validation min_len=1 username: ""`
Required integer usage: Using the empty/zero value reference: `min=`	`#@schema/validation min=1 replicas: 0`
Required array usage: Using the empty/zero value reference: `min_len=`	`#@schema/validation min_len=1 responseTypes: - ""`
Required map usage: mark as “nullable” and “not_null” reference: `@schema/nullable` and `not_null=`	`#@schema/nullable #@schema/validation not_null=True credential: name: "" cloud: ""`
Ensure string minimum length reference: `min_len=`	`#@schema/validation min_len=8 password: ""`
Ensure string exact length	`#@schema/validation min_len=8, max_len=8 password: ""`
Ensure a min value	`#@schema/validation min=3 replicas: 5`
Ensure a max value	`#@schema/validation max=5 replicas: 3`
Ensure a value between min and max	`#@schema/validation min=1, max=65535 port: 1024`
Enumeration usage: enumerations reference: `one_of=`	`#@schema/validation one_of=["aws", "azure", "vsphere"] provider: ""`
Exactly one is specified usage: mutually exclusive config reference: `one_not_null=`	`#@schema/validation one_not_null=["oidc", "ldap"] config: #@schema/nullable oidc: client_id: “” #@schema/nullable ldap: host: “”`
Conditionally run validations usage: conditional validations reference: `@schema/validation ... when=`	`#@data/values-schema --- service: type: LoadBalancer #@schema/validation min_len=1, when=lambda _, ctx: ctx.parent["type"] == "LoadBalancer" name: ""`
Custom description of valid value usage: writing custom rules reference: @ytt:assert	`#@ load("@ytt:assert", "assert") #@schema/validation ("a non-blank name", assert.min_len(1)) username: ""`
Disable validations flag	`$ ytt ... --dangerous-data-values-disable-validation`

Required string

usage: Using the empty/zero value
reference: min_len=

#@schema/validation min_len=1
username: ""

Required integer

usage: Using the empty/zero value
reference: min=

#@schema/validation min=1
replicas: 0

Required array

usage: Using the empty/zero value
reference: min_len=

#@schema/validation min_len=1 
responseTypes:
- ""

Required map

usage: mark as “nullable” and “not_null”
reference: @schema/nullable and not_null=

#@schema/nullable
#@schema/validation not_null=True
credential:
  name: ""
  cloud: ""

Ensure string minimum length

reference: min_len=

#@schema/validation min_len=8
password: ""

Ensure string exact length

#@schema/validation min_len=8, max_len=8
password: ""

Ensure a min value

#@schema/validation min=3
replicas: 5

Ensure a max value

#@schema/validation max=5
replicas: 3

Ensure a value between min and max

#@schema/validation min=1, max=65535
port: 1024

Enumeration

usage: enumerations
reference: one_of=

#@schema/validation one_of=["aws", "azure", "vsphere"]
provider: ""

Exactly one is specified

usage: mutually exclusive config
reference: one_not_null=

#@schema/validation one_not_null=["oidc", "ldap"]
config:
  #@schema/nullable
  oidc:
    client_id: “”
  #@schema/nullable
  ldap:
    host: “”

Conditionally run validations

usage: conditional validations
reference: @schema/validation ... when=

#@data/values-schema
---
service:
  type: LoadBalancer
  #@schema/validation min_len=1, when=lambda _, ctx: ctx.parent["type"] == "LoadBalancer"
  name: ""

Custom description of valid value

usage: writing custom rules
reference: @ytt:assert

#@ load("@ytt:assert", "assert")

#@schema/validation ("a non-blank name", assert.min_len(1))
username: ""

Disable validations flag

$ ytt ... --dangerous-data-values-disable-validation

(Help improve our docs: edit this page on GitHub)