crossplane-fn-network-discovery

README

function-network-discovery

A [Crossplane] Composition Function for discovery of VPC architecture

Provide this function with a VPC name, region and provider configuration to use and it will discover components of the VPC including:

• VPC ID
• CIDR Block
• Additional CIDRS
• Subnets
• Route Tables
• Internet Gateway
• NAT Gateways
• VPC Peering connections
• Transit gateways
• Security groups

This information will then be patched to the status of the XR. To understand the structure required for the XR status, see package/composite

Composition integration

This function is placed in the pipeline with a reference to the cluster object for that composition and an additional reference of where to patch information about the subnets it is generating for that provider.

This should be specified in your composition, for example

  - step: network-discovery
    functionRef:
      name: function-network-discovery
    input:
      apiVersion: nd.fn.giantswarm.io
      kind: Input
      metadata:
        namespace: crossplane
      spec:
        vpcNameRef: spec.vpcs
        regionRef: spec.region
        providerConfigRef: spec.providerConfigRef.name
        patchTo: status.vpcs

Input parameters

• enabledRef optional Reference to a boolean parameter that optionally tells the function to skip discovery. Use this in complex composition structures where discovery may or may not be required.
• providerConfigRef required A reference to an AWS providerConfig
• regionRef required The default region being used by the XR
• vpcNameRef required a path to a location on the XR containing the name of one or more VPCs. The referenced location may be a single string or a list of objects
• groupingTagRef optional If specified, the location of the reference will be used as a tag filter for grouping subnets and route tables together

vpcNameRef

If the location pointed to by vpcNameRef is a list, it must match the following format:

• name required The name of the VPC to discover
• region optional The region to discover the VPC in - if not defined falls back to the default region specified above
• providerConfigRef optional A provider config reference to use for discovery of this specific VPC. Useful for cross account VPC discovery

groupingTagRef

The location for groupingTagRef should match the following format:

• key string the key for the tag

The value of the tag key on the AWS resource should be numeric. If it is not it is ignored.

tags:
  subnetsets.xnetworks.crossplane.giantswarm.io: 1

[!NOTE] This is not an AWS tag filter. It is used to group the output of subnets and route tables into sets were defined together. If not defined, a single list will be output

eg.

subnets:
- subnet-1: sn-123456
  subnet-2: sn-234567
  ...
  subnet-10: sn-012345

If defined, this would otherwise result in the following:

subnets:
- subnet-1: sn-123456
  subnet-2: sn-234567
  subnet-3: sn-345678
- subnet-4: sn-456789
  subnet-5: sn-567890
  subnet-6: sn-678901

For information such as transit gateways, nat gateways and peering connections a unique name tag is expected to prevent resources overwriting each other.

If a name tag cannot be found, the ID will not be returned for that item so if you are expecting an id to be returned when it isn't appearing in the status, check that a unique name tag is assigned to the resource in AWS.

Documentation

Overview

Package main implements a Composition Function.