generator

Documentation

Index

• type Args
• type MonitoringAssignmentsGenerator
  • func (g MonitoringAssignmentsGenerator) Generate(args Args) ([]*core_xds.Resource, error)
• type ResourceGenerator

Types

type Args

type Args struct {
	Meshes     []*mesh_core.MeshResource
	Dataplanes []*mesh_core.DataplaneResource
}

type MonitoringAssignmentsGenerator

type MonitoringAssignmentsGenerator struct {
}

MonitoringAssignmentsGenerator knows how to generate MonitoringAssignment resources for a given set of Dataplanes.

Beware of the following constraints when it comes to integration with Prometheus:

1. Prometheus model for all `sd`s except for `file_sd` looks like this:

   // Group is a set of targets with a common label set(production , test, staging etc.). type Group struct { // Targets is a list of targets identified by a label set. Each target is // uniquely identifiable in the group by its address label. Targets []model.LabelSet // Labels is a set of labels that is common across all targets in the group. Labels model.LabelSet

   // Source is an identifier that describes a group of targets. Source string }

   That is why Kuma's MonitoringAssignment was designed to be close to that model.

2. However, `file_sd` uses different model for reading data from a file:

   struct { Targets []string `yaml:"targets"` Labels model.LabelSet `yaml:"labels"` }

   Notice that Targets is just a list of addresses rather than a list of model.LabelSet.

3. Because of that mismatch, some form of conversion is unavoidable on client side, e.g. inside `kuma-prometheus-sd`

4. The next component that imposes its constraints is `custom-sd`- adapter (https://github.com/prometheus/prometheus/tree/master/documentation/examples/custom-sd) that is recommended for use by all `file_sd`-based `sd`s.

   This adapter is doing conversion from Prometheus model into `file_sd` model and it expects that `Targets` field has only 1 label - `__address__` - and the rest of the labels must be a part of `Labels` field.

5. Therefore, we need to convert MonitoringAssignment into a model that `custom-sd` expects. It could happen on server side, it could happen on client side. Given that we're trying to minimize amount of logic on the client side, the choice was made in favour of server side.

   In practice, it means that generated MonitoringAssignment will look the following way:

   name: /meshes/default/dataplanes/backend-01 targets: - labels: __address__: 192.168.0.1:8080 labels: __scheme__: http __metrics_path__: /metrics job: backend instance: backend-01 mesh: default dataplane: backend-01 env: prod envs: ,prod, service: backend services: ,backend,

func (MonitoringAssignmentsGenerator) Generate

func (g MonitoringAssignmentsGenerator) Generate(args Args) ([]*core_xds.Resource, error)

type ResourceGenerator

type ResourceGenerator interface {
	Generate(Args) ([]*core_xds.Resource, error)
}