Response Transformer Advanced: Transform the JSON body with a Lua function - Plugin

Transform the JSON body with a Lua functionv1.0+

Configure the plugin to use a Lua function to transform the response body.

Set up the plugin

Add this section to your kong.yaml configuration file:

kong.yaml

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_format_version: "3.0"
plugins:
  - name: response-transformer-advanced
    config:
      transform:
        functions:
        - |
          -- this function transforms
          -- { "foo": "something", "something": "else" }
          -- into
          -- { "foobar": "hello world", "something": "else" }
          return function (data)
          if type(data) ~= "table" then
            return data
          end
             -- remove foo key
          data["foo"] = nil
             -- add a new key
          data["foobar"] = "hello world"
             return data
          end

Make the following request:

curl -i -X POST http://localhost:8001/plugins/ \
    --header "Accept: application/json" \
    --header "Content-Type: application/json" \
    --data '
    {
      "name": "response-transformer-advanced",
      "config": {
        "transform": {
          "functions": [
            "-- this function transforms\n-- { \"foo\": \"something\", \"something\": \"else\" }\n-- into\n-- { \"foobar\": \"hello world\", \"something\": \"else\" }\nreturn function (data)\nif type(data) ~= \"table\" then\n  return data\nend\n\n-- remove foo key\ndata[\"foo\"] = nil\n\n-- add a new key\ndata[\"foobar\"] = \"hello world\"\n\nreturn data\nend\n"
          ]
        }
      },
      "tags": []
    }
    '

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Make the following request:

curl -X POST https://{region}.api.konghq.com/v2/control-planes/{controlPlaneId}/core-entities/plugins/ \
    --header "accept: application/json" \
    --header "Content-Type: application/json" \
    --header "Authorization: Bearer $KONNECT_TOKEN" \
    --data '
    {
      "name": "response-transformer-advanced",
      "config": {
        "transform": {
          "functions": [
            "-- this function transforms\n-- { \"foo\": \"something\", \"something\": \"else\" }\n-- into\n-- { \"foobar\": \"hello world\", \"something\": \"else\" }\nreturn function (data)\nif type(data) ~= \"table\" then\n  return data\nend\n\n-- remove foo key\ndata[\"foo\"] = nil\n\n-- add a new key\ndata[\"foobar\"] = \"hello world\"\n\nreturn data\nend\n"
          ]
        }
      },
      "tags": []
    }
    '

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Make sure to replace the following placeholders with your own values:

region: Geographic region where your Kong Konnect is hosted and operates.
controlPlaneId: The id of the control plane.
KONNECT_TOKEN: Your Personal Access Token (PAT) associated with your Konnect account.

See the Konnect API reference to learn about region-specific URLs and personal access tokens.

echo "
apiVersion: configuration.konghq.com/v1
kind: KongClusterPlugin
metadata:
  name: response-transformer-advanced
  namespace: kong
  annotations:
    kubernetes.io/ingress.class: kong
    konghq.com/tags: ''
  labels:
    global: 'true'
config:
  transform:
    functions:
    - |
      -- this function transforms
      -- { 'foo': 'something', 'something': 'else' }
      -- into
      -- { 'foobar': 'hello world', 'something': 'else' }
      return function (data)
      if type(data) ~= 'table' then
        return data
      end

      -- remove foo key
      data['foo'] = nil

      -- add a new key
      data['foobar'] = 'hello world'

      return data
      end
plugin: response-transformer-advanced
" | kubectl apply -f -

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Prerequisite: Configure your Personal Access Token

terraform {
  required_providers {
    konnect = {
      source  = "kong/konnect"
    }
  }
}

provider "konnect" {
  personal_access_token = "$KONNECT_TOKEN"
  server_url            = "https://us.api.konghq.com/"
}

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Add the following to your Terraform configuration to create a Konnect Gateway Plugin:

resource "konnect_gateway_plugin_response_transformer_advanced" "my_response_transformer_advanced" {
  enabled = true

  config = {

    transform = {
      functions = [<<EOF
-- this function transforms
-- { "foo": "something", "something": "else" }
-- into
-- { "foobar": "hello world", "something": "else" }
return function (data)
if type(data) ~= "table" then
  return data
end

-- remove foo key
data["foo"] = nil

-- add a new key
data["foobar"] = "hello world"

return data
end
EOF]
    }
  }
  tags = []

  control_plane_id = konnect_gateway_control_plane.my_konnect_cp.id
}

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Add this section to your kong.yaml configuration file:

kong.yaml

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_format_version: "3.0"
plugins:
  - name: response-transformer-advanced
    service: serviceName|Id
    config:
      transform:
        functions:
        - |
          -- this function transforms
          -- { "foo": "something", "something": "else" }
          -- into
          -- { "foobar": "hello world", "something": "else" }
          return function (data)
          if type(data) ~= "table" then
            return data
          end
             -- remove foo key
          data["foo"] = nil
             -- add a new key
          data["foobar"] = "hello world"
             return data
          end

Make sure to replace the following placeholders with your own values:

serviceName|Id: The id or name of the service the plugin configuration will target.

Make the following request:

curl -i -X POST http://localhost:8001/services/{serviceName|Id}/plugins/ \
    --header "Accept: application/json" \
    --header "Content-Type: application/json" \
    --data '
    {
      "name": "response-transformer-advanced",
      "config": {
        "transform": {
          "functions": [
            "-- this function transforms\n-- { \"foo\": \"something\", \"something\": \"else\" }\n-- into\n-- { \"foobar\": \"hello world\", \"something\": \"else\" }\nreturn function (data)\nif type(data) ~= \"table\" then\n  return data\nend\n\n-- remove foo key\ndata[\"foo\"] = nil\n\n-- add a new key\ndata[\"foobar\"] = \"hello world\"\n\nreturn data\nend\n"
          ]
        }
      },
      "tags": []
    }
    '

Copied!

Make sure to replace the following placeholders with your own values:

serviceName|Id: The id or name of the service the plugin configuration will target.

Make the following request:

curl -X POST https://{region}.api.konghq.com/v2/control-planes/{controlPlaneId}/core-entities/services/{serviceId}/plugins/ \
    --header "accept: application/json" \
    --header "Content-Type: application/json" \
    --header "Authorization: Bearer $KONNECT_TOKEN" \
    --data '
    {
      "name": "response-transformer-advanced",
      "config": {
        "transform": {
          "functions": [
            "-- this function transforms\n-- { \"foo\": \"something\", \"something\": \"else\" }\n-- into\n-- { \"foobar\": \"hello world\", \"something\": \"else\" }\nreturn function (data)\nif type(data) ~= \"table\" then\n  return data\nend\n\n-- remove foo key\ndata[\"foo\"] = nil\n\n-- add a new key\ndata[\"foobar\"] = \"hello world\"\n\nreturn data\nend\n"
          ]
        }
      },
      "tags": []
    }
    '

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Make sure to replace the following placeholders with your own values:

region: Geographic region where your Kong Konnect is hosted and operates.
controlPlaneId: The id of the control plane.
KONNECT_TOKEN: Your Personal Access Token (PAT) associated with your Konnect account.
serviceId: The id of the service the plugin configuration will target.

See the Konnect API reference to learn about region-specific URLs and personal access tokens.

echo "
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: response-transformer-advanced
  namespace: kong
  annotations:
    kubernetes.io/ingress.class: kong
    konghq.com/tags: ''
config:
  transform:
    functions:
    - |
      -- this function transforms
      -- { 'foo': 'something', 'something': 'else' }
      -- into
      -- { 'foobar': 'hello world', 'something': 'else' }
      return function (data)
      if type(data) ~= 'table' then
        return data
      end

      -- remove foo key
      data['foo'] = nil

      -- add a new key
      data['foobar'] = 'hello world'

      return data
      end
plugin: response-transformer-advanced
" | kubectl apply -f -

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Next, apply the KongPlugin resource by annotating the service resource:

kubectl annotate -n kong service SERVICE_NAME konghq.com/plugins=response-transformer-advanced

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Prerequisite: Configure your Personal Access Token

terraform {
  required_providers {
    konnect = {
      source  = "kong/konnect"
    }
  }
}

provider "konnect" {
  personal_access_token = "$KONNECT_TOKEN"
  server_url            = "https://us.api.konghq.com/"
}

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Add the following to your Terraform configuration to create a Konnect Gateway Plugin:

resource "konnect_gateway_plugin_response_transformer_advanced" "my_response_transformer_advanced" {
  enabled = true

  config = {

    transform = {
      functions = [<<EOF
-- this function transforms
-- { "foo": "something", "something": "else" }
-- into
-- { "foobar": "hello world", "something": "else" }
return function (data)
if type(data) ~= "table" then
  return data
end

-- remove foo key
data["foo"] = nil

-- add a new key
data["foobar"] = "hello world"

return data
end
EOF]
    }
  }
  tags = []

  control_plane_id = konnect_gateway_control_plane.my_konnect_cp.id
  service = {
    id = konnect_gateway_service.my_service.id
  }
}

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Add this section to your kong.yaml configuration file:

kong.yaml

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_format_version: "3.0"
plugins:
  - name: response-transformer-advanced
    route: routeName|Id
    config:
      transform:
        functions:
        - |
          -- this function transforms
          -- { "foo": "something", "something": "else" }
          -- into
          -- { "foobar": "hello world", "something": "else" }
          return function (data)
          if type(data) ~= "table" then
            return data
          end
             -- remove foo key
          data["foo"] = nil
             -- add a new key
          data["foobar"] = "hello world"
             return data
          end

Make sure to replace the following placeholders with your own values:

routeName|Id: The id or name of the route the plugin configuration will target.

Make the following request:

curl -i -X POST http://localhost:8001/routes/{routeName|Id}/plugins/ \
    --header "Accept: application/json" \
    --header "Content-Type: application/json" \
    --data '
    {
      "name": "response-transformer-advanced",
      "config": {
        "transform": {
          "functions": [
            "-- this function transforms\n-- { \"foo\": \"something\", \"something\": \"else\" }\n-- into\n-- { \"foobar\": \"hello world\", \"something\": \"else\" }\nreturn function (data)\nif type(data) ~= \"table\" then\n  return data\nend\n\n-- remove foo key\ndata[\"foo\"] = nil\n\n-- add a new key\ndata[\"foobar\"] = \"hello world\"\n\nreturn data\nend\n"
          ]
        }
      },
      "tags": []
    }
    '

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Make sure to replace the following placeholders with your own values:

routeName|Id: The id or name of the route the plugin configuration will target.

Make the following request:

curl -X POST https://{region}.api.konghq.com/v2/control-planes/{controlPlaneId}/core-entities/routes/{routeId}/plugins/ \
    --header "accept: application/json" \
    --header "Content-Type: application/json" \
    --header "Authorization: Bearer $KONNECT_TOKEN" \
    --data '
    {
      "name": "response-transformer-advanced",
      "config": {
        "transform": {
          "functions": [
            "-- this function transforms\n-- { \"foo\": \"something\", \"something\": \"else\" }\n-- into\n-- { \"foobar\": \"hello world\", \"something\": \"else\" }\nreturn function (data)\nif type(data) ~= \"table\" then\n  return data\nend\n\n-- remove foo key\ndata[\"foo\"] = nil\n\n-- add a new key\ndata[\"foobar\"] = \"hello world\"\n\nreturn data\nend\n"
          ]
        }
      },
      "tags": []
    }
    '

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Make sure to replace the following placeholders with your own values:

region: Geographic region where your Kong Konnect is hosted and operates.
controlPlaneId: The id of the control plane.
KONNECT_TOKEN: Your Personal Access Token (PAT) associated with your Konnect account.
routeId: The id of the route the plugin configuration will target.

See the Konnect API reference to learn about region-specific URLs and personal access tokens.

echo "
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: response-transformer-advanced
  namespace: kong
  annotations:
    kubernetes.io/ingress.class: kong
    konghq.com/tags: ''
config:
  transform:
    functions:
    - |
      -- this function transforms
      -- { 'foo': 'something', 'something': 'else' }
      -- into
      -- { 'foobar': 'hello world', 'something': 'else' }
      return function (data)
      if type(data) ~= 'table' then
        return data
      end

      -- remove foo key
      data['foo'] = nil

      -- add a new key
      data['foobar'] = 'hello world'

      return data
      end
plugin: response-transformer-advanced
" | kubectl apply -f -

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Next, apply the KongPlugin resource by annotating the httproute or ingress resource:

kubectl annotate -n kong httproute  konghq.com/plugins=response-transformer-advanced

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kubectl annotate -n kong ingress  konghq.com/plugins=response-transformer-advanced

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Prerequisite: Configure your Personal Access Token

terraform {
  required_providers {
    konnect = {
      source  = "kong/konnect"
    }
  }
}

provider "konnect" {
  personal_access_token = "$KONNECT_TOKEN"
  server_url            = "https://us.api.konghq.com/"
}

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Add the following to your Terraform configuration to create a Konnect Gateway Plugin:

resource "konnect_gateway_plugin_response_transformer_advanced" "my_response_transformer_advanced" {
  enabled = true

  config = {

    transform = {
      functions = [<<EOF
-- this function transforms
-- { "foo": "something", "something": "else" }
-- into
-- { "foobar": "hello world", "something": "else" }
return function (data)
if type(data) ~= "table" then
  return data
end

-- remove foo key
data["foo"] = nil

-- add a new key
data["foobar"] = "hello world"

return data
end
EOF]
    }
  }
  tags = []

  control_plane_id = konnect_gateway_control_plane.my_konnect_cp.id
  route = {
    id = konnect_gateway_route.my_route.id
  }
}

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Add this section to your kong.yaml configuration file:

kong.yaml

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_format_version: "3.0"
plugins:
  - name: response-transformer-advanced
    consumer: consumerName|Id
    config:
      transform:
        functions:
        - |
          -- this function transforms
          -- { "foo": "something", "something": "else" }
          -- into
          -- { "foobar": "hello world", "something": "else" }
          return function (data)
          if type(data) ~= "table" then
            return data
          end
             -- remove foo key
          data["foo"] = nil
             -- add a new key
          data["foobar"] = "hello world"
             return data
          end

Make sure to replace the following placeholders with your own values:

consumerName|Id: The id or name of the consumer the plugin configuration will target.

Make the following request:

curl -i -X POST http://localhost:8001/consumers/{consumerName|Id}/plugins/ \
    --header "Accept: application/json" \
    --header "Content-Type: application/json" \
    --data '
    {
      "name": "response-transformer-advanced",
      "config": {
        "transform": {
          "functions": [
            "-- this function transforms\n-- { \"foo\": \"something\", \"something\": \"else\" }\n-- into\n-- { \"foobar\": \"hello world\", \"something\": \"else\" }\nreturn function (data)\nif type(data) ~= \"table\" then\n  return data\nend\n\n-- remove foo key\ndata[\"foo\"] = nil\n\n-- add a new key\ndata[\"foobar\"] = \"hello world\"\n\nreturn data\nend\n"
          ]
        }
      },
      "tags": []
    }
    '

Copied!

Make sure to replace the following placeholders with your own values:

consumerName|Id: The id or name of the consumer the plugin configuration will target.

Make the following request:

curl -X POST https://{region}.api.konghq.com/v2/control-planes/{controlPlaneId}/core-entities/consumers/{consumerId}/plugins/ \
    --header "accept: application/json" \
    --header "Content-Type: application/json" \
    --header "Authorization: Bearer $KONNECT_TOKEN" \
    --data '
    {
      "name": "response-transformer-advanced",
      "config": {
        "transform": {
          "functions": [
            "-- this function transforms\n-- { \"foo\": \"something\", \"something\": \"else\" }\n-- into\n-- { \"foobar\": \"hello world\", \"something\": \"else\" }\nreturn function (data)\nif type(data) ~= \"table\" then\n  return data\nend\n\n-- remove foo key\ndata[\"foo\"] = nil\n\n-- add a new key\ndata[\"foobar\"] = \"hello world\"\n\nreturn data\nend\n"
          ]
        }
      },
      "tags": []
    }
    '

Copied!

Make sure to replace the following placeholders with your own values:

region: Geographic region where your Kong Konnect is hosted and operates.
controlPlaneId: The id of the control plane.
KONNECT_TOKEN: Your Personal Access Token (PAT) associated with your Konnect account.
consumerId: The id of the consumer the plugin configuration will target.

See the Konnect API reference to learn about region-specific URLs and personal access tokens.

echo "
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: response-transformer-advanced
  namespace: kong
  annotations:
    kubernetes.io/ingress.class: kong
    konghq.com/tags: ''
config:
  transform:
    functions:
    - |
      -- this function transforms
      -- { 'foo': 'something', 'something': 'else' }
      -- into
      -- { 'foobar': 'hello world', 'something': 'else' }
      return function (data)
      if type(data) ~= 'table' then
        return data
      end

      -- remove foo key
      data['foo'] = nil

      -- add a new key
      data['foobar'] = 'hello world'

      return data
      end
plugin: response-transformer-advanced
" | kubectl apply -f -

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Next, apply the KongPlugin resource by annotating the KongConsumer resource:

kubectl annotate -n kong  CONSUMER_NAME konghq.com/plugins=response-transformer-advanced

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Prerequisite: Configure your Personal Access Token

terraform {
  required_providers {
    konnect = {
      source  = "kong/konnect"
    }
  }
}

provider "konnect" {
  personal_access_token = "$KONNECT_TOKEN"
  server_url            = "https://us.api.konghq.com/"
}

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Add the following to your Terraform configuration to create a Konnect Gateway Plugin:

resource "konnect_gateway_plugin_response_transformer_advanced" "my_response_transformer_advanced" {
  enabled = true

  config = {

    transform = {
      functions = [<<EOF
-- this function transforms
-- { "foo": "something", "something": "else" }
-- into
-- { "foobar": "hello world", "something": "else" }
return function (data)
if type(data) ~= "table" then
  return data
end

-- remove foo key
data["foo"] = nil

-- add a new key
data["foobar"] = "hello world"

return data
end
EOF]
    }
  }
  tags = []

  control_plane_id = konnect_gateway_control_plane.my_konnect_cp.id
  consumer = {
    id = konnect_gateway_consumer.my_consumer.id
  }
}

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Add this section to your kong.yaml configuration file:

kong.yaml

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_format_version: "3.0"
plugins:
  - name: response-transformer-advanced
    consumer_group: consumerGroupName|Id
    config:
      transform:
        functions:
        - |
          -- this function transforms
          -- { "foo": "something", "something": "else" }
          -- into
          -- { "foobar": "hello world", "something": "else" }
          return function (data)
          if type(data) ~= "table" then
            return data
          end
             -- remove foo key
          data["foo"] = nil
             -- add a new key
          data["foobar"] = "hello world"
             return data
          end

Make sure to replace the following placeholders with your own values:

consumerGroupName|Id: The id or name of the consumer group the plugin configuration will target.

Make the following request:

curl -i -X POST http://localhost:8001/consumer_groups/{consumerGroupName|Id}/plugins/ \
    --header "Accept: application/json" \
    --header "Content-Type: application/json" \
    --data '
    {
      "name": "response-transformer-advanced",
      "config": {
        "transform": {
          "functions": [
            "-- this function transforms\n-- { \"foo\": \"something\", \"something\": \"else\" }\n-- into\n-- { \"foobar\": \"hello world\", \"something\": \"else\" }\nreturn function (data)\nif type(data) ~= \"table\" then\n  return data\nend\n\n-- remove foo key\ndata[\"foo\"] = nil\n\n-- add a new key\ndata[\"foobar\"] = \"hello world\"\n\nreturn data\nend\n"
          ]
        }
      },
      "tags": []
    }
    '

Copied!

Make sure to replace the following placeholders with your own values:

consumerGroupName|Id: The id or name of the consumer group the plugin configuration will target.

Make the following request:

curl -X POST https://{region}.api.konghq.com/v2/control-planes/{controlPlaneId}/core-entities/consumer_groups/{consumerGroupId}/plugins/ \
    --header "accept: application/json" \
    --header "Content-Type: application/json" \
    --header "Authorization: Bearer $KONNECT_TOKEN" \
    --data '
    {
      "name": "response-transformer-advanced",
      "config": {
        "transform": {
          "functions": [
            "-- this function transforms\n-- { \"foo\": \"something\", \"something\": \"else\" }\n-- into\n-- { \"foobar\": \"hello world\", \"something\": \"else\" }\nreturn function (data)\nif type(data) ~= \"table\" then\n  return data\nend\n\n-- remove foo key\ndata[\"foo\"] = nil\n\n-- add a new key\ndata[\"foobar\"] = \"hello world\"\n\nreturn data\nend\n"
          ]
        }
      },
      "tags": []
    }
    '

Copied!

Make sure to replace the following placeholders with your own values:

region: Geographic region where your Kong Konnect is hosted and operates.
controlPlaneId: The id of the control plane.
KONNECT_TOKEN: Your Personal Access Token (PAT) associated with your Konnect account.
consumerGroupId: The id of the consumer group the plugin configuration will target.

See the Konnect API reference to learn about region-specific URLs and personal access tokens.

echo "
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: response-transformer-advanced
  namespace: kong
  annotations:
    kubernetes.io/ingress.class: kong
    konghq.com/tags: ''
config:
  transform:
    functions:
    - |
      -- this function transforms
      -- { 'foo': 'something', 'something': 'else' }
      -- into
      -- { 'foobar': 'hello world', 'something': 'else' }
      return function (data)
      if type(data) ~= 'table' then
        return data
      end

      -- remove foo key
      data['foo'] = nil

      -- add a new key
      data['foobar'] = 'hello world'

      return data
      end
plugin: response-transformer-advanced
" | kubectl apply -f -

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Next, apply the KongPlugin resource by annotating the KongConsumerGroup resource:

kubectl annotate -n kong  CONSUMERGROUP_NAME konghq.com/plugins=response-transformer-advanced

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Prerequisite: Configure your Personal Access Token

terraform {
  required_providers {
    konnect = {
      source  = "kong/konnect"
    }
  }
}

provider "konnect" {
  personal_access_token = "$KONNECT_TOKEN"
  server_url            = "https://us.api.konghq.com/"
}

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Add the following to your Terraform configuration to create a Konnect Gateway Plugin:

resource "konnect_gateway_plugin_response_transformer_advanced" "my_response_transformer_advanced" {
  enabled = true

  config = {

    transform = {
      functions = [<<EOF
-- this function transforms
-- { "foo": "something", "something": "else" }
-- into
-- { "foobar": "hello world", "something": "else" }
return function (data)
if type(data) ~= "table" then
  return data
end

-- remove foo key
data["foo"] = nil

-- add a new key
data["foobar"] = "hello world"

return data
end
EOF]
    }
  }
  tags = []

  control_plane_id = konnect_gateway_control_plane.my_konnect_cp.id
  consumer_group = {
    id = konnect_gateway_consumer_group.my_consumer_group.id
  }
}

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