decK

1.10.x

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Set Up Object Defaults

Use object defaults to enforce a set of standard values and avoid repetition in your configuration.

You can set configuration defaults for the following core Kong Gateway objects:

Service
Route
Upstream
Target

decK supports setting object defaults both in self-managed Kong Gateway and with Kong Konnect.

Important: This feature has the following limitations:

Plugin object defaults are not supported.

If an existing property’s default value changes in a future Kong Gateway release, decK has no way of knowing that this change has occurred, as its defaults configuration would overwrite the value in your environment.

Object defaults behavior

Defaults get applied to both new and existing objects. If an object has an explicit setting for a property, the object-level setting takes precedence over the default.

Kong Gateway sets some default values for most objects. You can see what the defaults are for each object in the Admin API reference, or use the /schemas endpoint to retrieve the latest object schemas for your instance of the Kong Gateway.

Configuring your own defaults is a good way to keep updated on potential breaking changes between versions. If you upgrade Kong Gateway to a version which introduces a new property with a default value, a deck diff will catch the difference.

If defaults are not set in the declarative configuration file, any newly configured objects pick up Kong Gateway’s defaults and diverge from the source configuration file. This situation creates a false positive: decK sees a diff where one doesn’t exist. Refer to “Create a file and test without defaults” for an example.

Configure object defaults

The following guide creates a sample kong.yaml file with a service and route, shows you what responses look like without defaults set, and then walks you through setting defaults.

If you are already familiar with the problem or have a configuration file you want to use, skip to setting defaults.

Create a file and test without defaults

Create a kong.yaml configuration file.

Add the following sample service and route to the file:

 _format_version: "3.0"
 services:
   - host: mockbin.org
     name: example_service
     routes:
       - name: mockpath
         paths:
         - /mock

Compare this file with the object configuration in Kong Gateway:
Command

Response
deck diff
creating service example_service creating route mockpath Summary: Created: 2 Updated: 0 Deleted: 0
If you’re using a completely empty instance, you should only see the service and route creation messages with no extra JSON data.
Sync your changes with Kong Gateway:
```
 deck sync
```

Now, run another diff and note the difference in the response:

      Command
    

      Response
    
deck diff
updating service example_service  {
   "connect_timeout": 60000,
   "host": "mockbin.org",
   "id": "1c088e59-b5fb-4c14-8d3a-401c02fc50b7",
   "name": "example_service",
   "port": 80,
   "protocol": "http",
   "read_timeout": 60000,
-  "retries": 5,
   "write_timeout": 60000
 }
   
updating route mockpath  {
-  "https_redirect_status_code": 426,
   "id": "1f900445-1957-4c79-aa16-1c86ea41df7f",
   "name": "mockpath",
-  "path_handling": "v0",
   "paths": [
     "/mock"
   ],
   "preserve_host": false,
   "protocols": [
     "http",
     "https"
   ],
   "regex_priority": 0,
-  "request_buffering": true,
-  "response_buffering": true,
   "service": {
     "id": "1c088e59-b5fb-4c14-8d3a-401c02fc50b7"
   },
   "strip_path": false
 }
   
Summary:
  Created: 0
  Updated: 2
  Deleted: 0

Even though you’ve made no changes, the response shows a list of new property configurations. The list of new configurations appears because Kong Gateway applied defaults and decK is unaware of them, so decK treats them like changes to the configuration.

Set defaults

In your kong.yaml configuration file, add an _info section with defaults:

 _format_version: "3.0"
 _info:
   defaults:
 services:
   - host: mockbin.org
     name: example_service
     routes:
       - name: mockpath
         paths:
           - /mock

For production use in larger systems, we recommend that you break out your defaults into a separate defaults.yaml file or use tags to apply the defaults wherever they are needed.

Define the properties you want to set for core Kong Gateway objects.

You can define defaults for service, route, upstream, and target objects.

For example:

 _format_version: "3.0"
 _info:
   defaults:
     route:
       https_redirect_status_code: 426
       path_handling: v1
       preserve_host: false
       protocols:
       - http
       - https
       regex_priority: 0
       request_buffering: true
       response_buffering: true
       strip_path: true
     service:
       port: 80
       protocol: http
       connect_timeout: 60000
       write_timeout: 60000
       read_timeout: 60000
       retries: 5
 services:
   - host: mockbin.org
     name: example_service
     routes:
       - name: mockpath
         paths:
           - /mock

Save the file and run a diff:
Command

Response
deck diff
Summary: Created: 0 Updated: 0 Deleted: 0
Notice that the diff doesn’t show extra changes anymore.

Defaults reference

The following properties are the defaults applied by Kong Gateway (as of v2.5.x), and setting them in your declarative configuration file is required to avoid differences between the configuration file and the Kong Gateway.

Note: The following are only properties that have defaults, and are not all of the available properties for each object.

Route

Service

Upstream

Target

Set the following properties to the values you want to use across all Routes:

_info:
  defaults:
    route:
      https_redirect_status_code: 426
      path_handling: v0
      preserve_host: false
      protocols:
      - http
      - https
      regex_priority: 0
      request_buffering: true
      response_buffering: true
      strip_path: true

For all available properties, see the Route object documentation.

Set the following properties to the values you want to use across all Services:

_info:
  defaults:
    service:
      port: 80
      protocol: http
      connect_timeout: 60000
      write_timeout: 60000
      read_timeout: 60000
      retries: 5

For all available properties, see the Service object documentation.

Set the following properties to the values you want to use across all Upstreams:

_info:
  defaults:
    upstream:
      slots: 10000
      algorithm: round-robin
      hash_fallback: none
      hash_on: none
      hash_on_cookie_path: /
      healthchecks:
        active:
          concurrency: 10
          healthy:
            http_statuses:
            - 200
            - 302
            interval: 0
            successes: 0
          http_path: /
          https_verify_certificate: true
          timeout: 1
          type: http
          unhealthy:
            http_failures: 0
            http_statuses:
            - 429
            - 404
            - 500
            - 501
            - 502
            - 503
            - 504
            - 505
            interval: 0
            tcp_failures: 0
            timeouts: 0
        passive:
          healthy:
            http_statuses:
            - 200
            - 201
            - 202
            - 203
            - 204
            - 205
            - 206
            - 207
            - 208
            - 226
            - 300
            - 301
            - 302
            - 303
            - 304
            - 305
            - 306
            - 307
            - 308
            successes: 0
          type: http
          unhealthy:
            http_failures: 0
            http_statuses:
              - 429
              - 500
              - 503
            tcp_failures: 0
            timeouts: 0
        threshold: 0

For all available properties, see the Upstream object documentation.

Set the following property to the value you want to use across all Targets:

_info:
  defaults:
    target:
      weight: 100

For all available properties, see the Target object documentation.

Find default values for your Gateway version

For the most accurate default values for your version of Kong Gateway, see the Admin API reference, or use the /schemas endpoint. For example, you can check the schema for targets and look for any value that has defined defaults:

      cURL
    
      HTTPie
    
curl -i -X GET http://localhost:8001/schemas/targets
http :8001/schemas/targets