README
¶
package tagger
The Tagger is the central source of truth for client-side entity tagging. It
subscribes to workloadmeta to get updates for all the entity kinds (containers,
kubernetes pods, kubernetes nodes, etc.) and extracts the tags for each of them.
Tags are then stored in memory (by the TagStore) and can be queried by the
tagger.Tag() method. Calling once tagger.Start() after the config
package is ready is needed to enable collection.
The package methods use a common defaultTagger object, but we can create a custom Tagger object for testing.
The package implements an IPC mechanism (a server and a client) to allow other
agents to query the DefaultTagger and avoid duplicating the information in
their process. Check the remote package for more details.
The tagger is also available to python checks via the tagger module exporting
the get_tags() function. This function accepts the same arguments as the Go Tag()
function, and returns an empty list on errors.
Workloadmeta
The entities that need to be tagged are collected by workloadmeta. The tagger subscribes to workloadmeta to get updates for all the entity kinds (containers, kubernetes pods, kubernetes nodes, etc.) and extracts the tags for each of them.
TagStore
The TagStore reads types.TagInfo structs and stores them in an in-memory cache. Cache invalidation is triggered by the collectors (or source) by either:
- sending new tags for the same
Entity, all the tags from thisSourcewill be removed and replaced by the new tags. - sending a types.TagInfo with DeleteEntity set, all the tags collected for this entity by the specified source (but not others) will be deleted when prune() is called.
TagCardinality
types.TagInfo accepts and store tags that have different cardinality. TagCardinality can be:
- LowCardinality: in the host count order of magnitude
- OrchestratorCardinality: tags that change value for each pod or task
- HighCardinality: typically tags that change value for each web request, user agent, container, etc.
Entity IDs
Tagger entities are identified by a string-typed ID, with one of the following forms:
| Entity | ID |
|---|---|
| workloadmeta.KindContainer | container_id://<sha> |
| workloadmeta.KindContainerImageMetadata | container_image_metadata://<sha> |
| workloadmeta.KindECSTask | ecs_task://<task-id> |
| workloadmeta.KindHost | host |
| workloadmeta.KindKubernetesDeployment | deployment://<namespace>/<name> |
| workloadmeta.KindKubernetesNamespace | namespace://<name> |
| workloadmeta.KindKubernetesNode | kubernetes_node_uid://<name> |
| workloadmeta.KindKubernetesPod | kubernetes_pod_uid://<uid> |
| workloadmeta.KindProcess | process://<pid> |
Tagger
The Tagger handles the glue between the workloadmeta collector and the TagStore.
For convenience, the package creates a defaultTagger object that is used
when calling the tagger.Tag() method.
+--------------+
| Workloadmeta |
+---+----------+
|
|
+--------+ +--+-------+ +-------------+
| User <------+ Tagger +-------> IPC handler |
|packages| +--+-----^-+ +-------------+
+--------+ | |
| |
+--v-----+-+
| TagStore |
+----------+
Documentation
¶
Overview ¶
Package tagger provides the tagger component for the Datadog Agent
Index ¶
- Variables
- func AccumulateTagsFor(entity string, cardinality types.TagCardinality, tb tagset.TagsAccumulator) error
- func AgentTags(cardinality types.TagCardinality) ([]string, error)
- func EnrichTags(tb tagset.TagsAccumulator, originInfo taggertypes.OriginInfo)
- func GetEntity(entityID string) (*types.Entity, error)
- func GetEntityHash(entity string, cardinality types.TagCardinality) string
- func GlobalTags(cardinality types.TagCardinality) ([]string, error)
- func List() types.TaggerListResponse
- func ResetCaptureTagger()
- func SetGlobalTaggerClient(t Component)
- func SetNewCaptureTagger(newCaptureTagger Component)
- func StandardTags(entity string) ([]string, error)
- func Tag(entity string, cardinality types.TagCardinality) ([]string, error)
- func UnlockGlobalTaggerClient()
- type AgentTypeForTagger
- type Component
- type Params
Constants ¶
This section is empty.
Variables ¶
var ( // ChecksCardinality defines the cardinality of tags we should send for check metrics // this can still be overridden when calling get_tags in python checks. ChecksCardinality types.TagCardinality // DogstatsdCardinality defines the cardinality of tags we should send for metrics from // dogstatsd. DogstatsdCardinality types.TagCardinality )
Functions ¶
func AccumulateTagsFor ¶
func AccumulateTagsFor(entity string, cardinality types.TagCardinality, tb tagset.TagsAccumulator) error
AccumulateTagsFor is an interface function that queries taggerclient singleton
func AgentTags ¶
func AgentTags(cardinality types.TagCardinality) ([]string, error)
AgentTags is an interface function that queries taggerclient singleton
func EnrichTags ¶
func EnrichTags(tb tagset.TagsAccumulator, originInfo taggertypes.OriginInfo)
EnrichTags is an interface function that queries taggerclient singleton
func GetEntityHash ¶
func GetEntityHash(entity string, cardinality types.TagCardinality) string
GetEntityHash is an interface function that queries taggerclient singleton
func GlobalTags ¶
func GlobalTags(cardinality types.TagCardinality) ([]string, error)
GlobalTags is an interface function that queries taggerclient singleton
func SetGlobalTaggerClient ¶
func SetGlobalTaggerClient(t Component)
SetGlobalTaggerClient sets the global taggerClient instance
func SetNewCaptureTagger ¶
func SetNewCaptureTagger(newCaptureTagger Component)
SetNewCaptureTagger will set capture tagger in global tagger instance by using provided capture tagger
func StandardTags ¶
StandardTags is an interface function that queries taggerclient singleton
func Tag ¶
func Tag(entity string, cardinality types.TagCardinality) ([]string, error)
Tag is an interface function that queries taggerclient singleton
func UnlockGlobalTaggerClient ¶
func UnlockGlobalTaggerClient()
UnlockGlobalTaggerClient releases the initOnce lock on the global tagger. For testing only.
Types ¶
type AgentTypeForTagger ¶
type AgentTypeForTagger uint8
AgentTypeForTagger represents agent types that tagger is used for
const ( LocalTaggerAgent AgentTypeForTagger = 1 << iota NodeRemoteTaggerAgent CLCRunnerRemoteTaggerAgent FakeTagger )
Define agent type for tagger
type Component ¶
type Component interface {
Start(ctx context.Context) error
Stop() error
Tag(entity string, cardinality types.TagCardinality) ([]string, error)
AccumulateTagsFor(entity string, cardinality types.TagCardinality, tb tagset.TagsAccumulator) error
Standard(entity string) ([]string, error)
List() types.TaggerListResponse
GetEntity(entityID string) (*types.Entity, error)
Subscribe(cardinality types.TagCardinality) chan []types.EntityEvent
Unsubscribe(ch chan []types.EntityEvent)
GetEntityHash(entity string, cardinality types.TagCardinality) string
AgentTags(cardinality types.TagCardinality) ([]string, error)
GlobalTags(cardinality types.TagCardinality) ([]string, error)
SetNewCaptureTagger(newCaptureTagger Component)
ResetCaptureTagger()
EnrichTags(tb tagset.TagsAccumulator, originInfo taggertypes.OriginInfo)
}
Component is the component type.
func GetTaggerInstance ¶
func GetTaggerInstance() Component
GetTaggerInstance returns the global Tagger instance
type Params ¶
type Params struct {
AgentTypeForTagger AgentTypeForTagger
FallBackToLocalIfRemoteTaggerFails bool
}
Params provides the kind of agent we're instantiating workloadmeta for
func NewCLCRunnerRemoteTaggerParams ¶
func NewCLCRunnerRemoteTaggerParams() Params
NewCLCRunnerRemoteTaggerParams creates a Params struct with the CLCRunnerRemoteTagger type
func NewFakeTaggerParams ¶
func NewFakeTaggerParams() Params
NewFakeTaggerParams creates a Params struct with the FakeTagger type and for testing purposes
func NewNodeRemoteTaggerParams ¶
func NewNodeRemoteTaggerParams() Params
NewNodeRemoteTaggerParams creates a Params struct with the NodeRemoteTagger type
func NewNodeRemoteTaggerParamsWithFallback ¶
func NewNodeRemoteTaggerParamsWithFallback() Params
NewNodeRemoteTaggerParamsWithFallback creates a Params struct with the NodeRemoteTagger type and fallback to local tagger if remote tagger fails
func NewTaggerParams ¶
func NewTaggerParams() Params
NewTaggerParams creates a Params struct with the default LocalTagger type
func NewTaggerParamsForCoreAgent ¶
NewTaggerParamsForCoreAgent is a constructor function for creating core agent tagger params
Source Files
Directories
¶
| Path | Synopsis |
|---|---|
|
Package taggerimpl contains the implementation of the tagger component.
|
Package taggerimpl contains the implementation of the tagger component. |
|
api
Package api implements the Tagger API.
|
Package api implements the Tagger API. |
|
collectors
Package collectors implements a collector for the Tagger component that subscribes to workloadmeta
|
Package collectors implements a collector for the Tagger component that subscribes to workloadmeta |
|
empty
Package empty implements empty functions for the tagger component interface.
|
Package empty implements empty functions for the tagger component interface. |
|
local
Package local implements a local Tagger.
|
Package local implements a local Tagger. |
|
remote
Package remote implements a remote Tagger.
|
Package remote implements a remote Tagger. |
|
replay
Package replay implements the Tagger replay.
|
Package replay implements the Tagger replay. |
|
server
Package server implements a gRPC server that streams Tagger entities.
|
Package server implements a gRPC server that streams Tagger entities. |
|
subscriber
Package subscriber implements the functionality needed to subscribe to events generated by the Tagger component.
|
Package subscriber implements the functionality needed to subscribe to events generated by the Tagger component. |
|
tagstore
Package tagstore implements the TagStore which is the component of the Tagger responsible for storing the tags in memory.
|
Package tagstore implements the TagStore which is the component of the Tagger responsible for storing the tags in memory. |
|
telemetry
Package telemetry defines the telemetry for the Tagger component.
|
Package telemetry defines the telemetry for the Tagger component. |
|
Package types defines types used by the Tagger component.
|
Package types defines types used by the Tagger component. |
|
Package utils defines several helpers used by the Tagger component.
|
Package utils defines several helpers used by the Tagger component. |