discovery/kubernetes: expose label_selector and field_selector

Close #6807

Co-authored-by @shuttie
Signed-off-by: Aleksandra Gacek <algacek@google.com>
This commit is contained in:
Aleksandra Gacek 2020-02-07 15:13:44 +01:00 committed by Julien Pivotto
parent b4445ff03f
commit 8e53c19f9c
15 changed files with 168 additions and 86 deletions

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@ -806,7 +806,7 @@ var expectedErrors = []struct {
errMsg: "role",
}, {
filename: "kubernetes_selectors_endpoints.bad.yml",
errMsg: "endpoints role supports only pod, service and endpoints selectors",
errMsg: "endpoints role supports only pod, service, endpoints selectors",
}, {
filename: "kubernetes_selectors_ingress.bad.yml",
errMsg: "ingress role supports only ingress selectors",
@ -822,6 +822,12 @@ var expectedErrors = []struct {
}, {
filename: "kubernetes_namespace_discovery.bad.yml",
errMsg: "field foo not found in type kubernetes.plain",
}, {
filename: "kubernetes_selectors_duplicated_role.bad.yml",
errMsg: "duplicated selector role: pod",
}, {
filename: "kubernetes_selectors_incorrect_selector.bad.yml",
errMsg: "invalid selector: 'metadata.status-Running'; can't understand 'metadata.status-Running'",
}, {
filename: "kubernetes_bearertoken_basicauth.bad.yml",
errMsg: "at most one of basic_auth, bearer_token & bearer_token_file must be configured",

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@ -0,0 +1,11 @@
scrape_configs:
- job_name: prometheus
kubernetes_sd_configs:
- role: endpoints
selectors:
- role: "pod"
label: "foo=bar"
field: "metadata.status=Running"
- role: "pod"
label: "foo=bar"
field: "metadata.status=Running"

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@ -3,12 +3,12 @@ scrape_configs:
kubernetes_sd_configs:
- role: endpoints
selectors:
node:
label: "foo=bar"
field: "metadata.status=Running"
service:
label: "foo=bar"
field: "metadata.status=Running"
endpoints:
label: "foo=bar"
field: "metadata.status=Running"
- role: "node"
label: "foo=bar"
field: "metadata.status=Running"
- role: "service"
label: "foo=bar"
field: "metadata.status=Running"
- role: "endpoints"
label: "foo=bar"
field: "metadata.status=Running"

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@ -3,12 +3,12 @@ scrape_configs:
kubernetes_sd_configs:
- role: endpoints
selectors:
pod:
label: "foo=bar"
field: "metadata.status=Running"
service:
label: "foo=bar"
field: "metadata.status=Running"
endpoints:
label: "foo=bar"
field: "metadata.status=Running"
- role: "pod"
label: "foo=bar"
field: "metadata.status=Running"
- role: "service"
label: "foo=bar"
field: "metadata.status=Running"
- role: "endpoints"
label: "foo=bar"
field: "metadata.status=Running"

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@ -0,0 +1,7 @@
scrape_configs:
- job_name: prometheus
kubernetes_sd_configs:
- role: endpoints
selectors:
- role: "pod"
field: "metadata.status-Running"

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@ -3,6 +3,6 @@ scrape_configs:
kubernetes_sd_configs:
- role: ingress
selectors:
node:
- role: "node"
label: "foo=bar"
field: "metadata.status=Running"

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@ -3,6 +3,6 @@ scrape_configs:
kubernetes_sd_configs:
- role: ingress
selectors:
ingress:
- role: "ingress"
label: "foo=bar"
field: "metadata.status=Running"

View file

@ -3,6 +3,6 @@ scrape_configs:
kubernetes_sd_configs:
- role: node
selectors:
pod:
- role: "pod"
label: "foo=bar"
field: "metadata.status=Running"

View file

@ -3,6 +3,6 @@ scrape_configs:
kubernetes_sd_configs:
- role: node
selectors:
node:
- role: "node"
label: "foo=bar"
field: "metadata.status=Running"

View file

@ -3,6 +3,6 @@ scrape_configs:
kubernetes_sd_configs:
- role: pod
selectors:
node:
- role: "node"
label: "foo=bar"
field: "metadata.status=Running"

View file

@ -3,6 +3,6 @@ scrape_configs:
kubernetes_sd_configs:
- role: pod
selectors:
pod:
- role: "pod"
label: "foo=bar"
field: "metadata.status=Running"

View file

@ -3,6 +3,6 @@ scrape_configs:
kubernetes_sd_configs:
- role: service
selectors:
pod:
- role: "pod"
label: "foo=bar"
field: "metadata.status=Running"

View file

@ -3,6 +3,6 @@ scrape_configs:
kubernetes_sd_configs:
- role: service
selectors:
service:
- role: "service"
label: "foo=bar"
field: "metadata.status=Running"

View file

@ -16,6 +16,7 @@ package kubernetes
import (
"context"
"reflect"
"strings"
"sync"
"time"
@ -28,6 +29,7 @@ import (
apiv1 "k8s.io/api/core/v1"
extensionsv1beta1 "k8s.io/api/extensions/v1beta1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/fields"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/watch"
"k8s.io/client-go/kubernetes"
@ -91,22 +93,28 @@ type SDConfig struct {
Role Role `yaml:"role"`
HTTPClientConfig config_util.HTTPClientConfig `yaml:",inline"`
NamespaceDiscovery NamespaceDiscovery `yaml:"namespaces,omitempty"`
Selectors RoleSelectorConfig `yaml:"selectors,omitempty"`
Selectors []SelectorConfig `yaml:"selectors,omitempty"`
}
type RoleSelectorConfig struct {
Node ResourceSelectorConfig `yaml:"node,omitempty"`
Pod ResourceSelectorConfig `yaml:"pod,omitempty"`
Service ResourceSelectorConfig `yaml:"service,omitempty"`
Endpoints ResourceSelectorConfig `yaml:"endpoints,omitempty"`
Ingress ResourceSelectorConfig `yaml:"ingress,omitempty"`
type roleSelector struct {
node resourceSelector
pod resourceSelector
service resourceSelector
endpoints resourceSelector
ingress resourceSelector
}
type ResourceSelectorConfig struct {
type SelectorConfig struct {
Role Role `yaml:"role,omitempty"`
Label string `yaml:"label,omitempty"`
Field string `yaml:"field,omitempty"`
}
type resourceSelector struct {
label string
field string
}
// UnmarshalYAML implements the yaml.Unmarshaler interface.
func (c *SDConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
*c = SDConfig{}
@ -115,6 +123,9 @@ func (c *SDConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
if err != nil {
return err
}
if c.Role == "" {
return errors.Errorf("role missing (one of: pod, service, endpoints, node, ingress)")
}
err = c.HTTPClientConfig.Validate()
if err != nil {
return err
@ -122,29 +133,45 @@ func (c *SDConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
if c.APIServer.URL == nil && !reflect.DeepEqual(c.HTTPClientConfig, config_util.HTTPClientConfig{}) {
return errors.Errorf("to use custom HTTP client configuration please provide the 'api_server' URL explicitly")
}
switch c.Role {
case "pod":
if len(c.Selectors.Service.Field) > 0 || len(c.Selectors.Endpoints.Field) > 0 || len(c.Selectors.Ingress.Field) > 0 || len(c.Selectors.Node.Field) > 0 {
return errors.Errorf("pod role supports only pod selectors")
foundSelectorRoles := make(map[Role]struct{})
allowedSelectors := map[Role][]string{
RolePod: {string(RolePod)},
RoleService: {string(RoleService)},
RoleEndpoint: {string(RolePod), string(RoleService), string(RoleEndpoint)},
RoleNode: {string(RoleNode)},
RoleIngress: {string(RoleIngress)},
}
for _, selector := range c.Selectors {
if _, ok := foundSelectorRoles[selector.Role]; ok {
return errors.Errorf("duplicated selector role: %s", selector.Role)
}
case "service":
if len(c.Selectors.Pod.Field) > 0 || len(c.Selectors.Endpoints.Field) > 0 || len(c.Selectors.Ingress.Field) > 0 || len(c.Selectors.Node.Field) > 0 {
return errors.Errorf("service role supports only service selectors")
foundSelectorRoles[selector.Role] = struct{}{}
if _, ok := allowedSelectors[c.Role]; !ok {
return errors.Errorf("invalid role: %q, expecting one of: pod, service, endpoints, node or ingress", c.Role)
}
case "endpoints":
if len(c.Selectors.Ingress.Field) > 0 || len(c.Selectors.Node.Field) > 0 {
return errors.Errorf("endpoints role supports only pod, service and endpoints selectors")
var allowed bool
for _, role := range allowedSelectors[c.Role] {
if role == string(selector.Role) {
allowed = true
break
}
}
case "node":
if len(c.Selectors.Service.Field) > 0 || len(c.Selectors.Endpoints.Field) > 0 || len(c.Selectors.Ingress.Field) > 0 || len(c.Selectors.Pod.Field) > 0 {
return errors.Errorf("node role supports only node selectors")
if !allowed {
return errors.Errorf("%s role supports only %s selectors", c.Role, strings.Join(allowedSelectors[c.Role], ", "))
}
case "ingress":
if len(c.Selectors.Service.Field) > 0 || len(c.Selectors.Endpoints.Field) > 0 || len(c.Selectors.Node.Field) > 0 || len(c.Selectors.Pod.Field) > 0 {
return errors.Errorf("ingress role supports only ingress selectors")
_, err := fields.ParseSelector(selector.Field)
if err != nil {
return err
}
_, err = fields.ParseSelector(selector.Label)
if err != nil {
return err
}
default:
return errors.Errorf("role missing (one of: pod, service, endpoints, node, ingress)")
}
return nil
}
@ -196,7 +223,7 @@ type Discovery struct {
logger log.Logger
namespaceDiscovery *NamespaceDiscovery
discoverers []discoverer
selectors RoleSelectorConfig
selectors roleSelector
}
func (d *Discovery) getNamespaces() []string {
@ -247,10 +274,34 @@ func New(l log.Logger, conf *SDConfig) (*Discovery, error) {
role: conf.Role,
namespaceDiscovery: &conf.NamespaceDiscovery,
discoverers: make([]discoverer, 0),
selectors: conf.Selectors,
selectors: mapSelector(conf.Selectors),
}, nil
}
func mapSelector(rawSelector []SelectorConfig) roleSelector {
rs := roleSelector{}
for _, resourceSelectorRaw := range rawSelector {
switch resourceSelectorRaw.Role {
case RoleEndpoint:
rs.endpoints.field = resourceSelectorRaw.Field
rs.endpoints.label = resourceSelectorRaw.Label
case RoleIngress:
rs.ingress.field = resourceSelectorRaw.Field
rs.ingress.label = resourceSelectorRaw.Label
case RoleNode:
rs.node.field = resourceSelectorRaw.Field
rs.node.label = resourceSelectorRaw.Label
case RolePod:
rs.pod.field = resourceSelectorRaw.Field
rs.pod.label = resourceSelectorRaw.Label
case RoleService:
rs.service.field = resourceSelectorRaw.Field
rs.service.label = resourceSelectorRaw.Label
}
}
return rs
}
const resyncPeriod = 10 * time.Minute
// Run implements the discoverer interface.
@ -264,39 +315,39 @@ func (d *Discovery) Run(ctx context.Context, ch chan<- []*targetgroup.Group) {
e := d.client.CoreV1().Endpoints(namespace)
elw := &cache.ListWatch{
ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
options.FieldSelector = d.selectors.Endpoints.Field
options.LabelSelector = d.selectors.Endpoints.Label
options.FieldSelector = d.selectors.endpoints.field
options.LabelSelector = d.selectors.endpoints.label
return e.List(options)
},
WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
options.FieldSelector = d.selectors.Endpoints.Field
options.LabelSelector = d.selectors.Endpoints.Label
options.FieldSelector = d.selectors.endpoints.field
options.LabelSelector = d.selectors.endpoints.label
return e.Watch(options)
},
}
s := d.client.CoreV1().Services(namespace)
slw := &cache.ListWatch{
ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
options.FieldSelector = d.selectors.Service.Field
options.LabelSelector = d.selectors.Service.Label
options.FieldSelector = d.selectors.service.field
options.LabelSelector = d.selectors.service.label
return s.List(options)
},
WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
options.FieldSelector = d.selectors.Service.Field
options.LabelSelector = d.selectors.Service.Label
options.FieldSelector = d.selectors.service.field
options.LabelSelector = d.selectors.service.label
return s.Watch(options)
},
}
p := d.client.CoreV1().Pods(namespace)
plw := &cache.ListWatch{
ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
options.FieldSelector = d.selectors.Pod.Field
options.LabelSelector = d.selectors.Pod.Label
options.FieldSelector = d.selectors.pod.field
options.LabelSelector = d.selectors.pod.label
return p.List(options)
},
WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
options.FieldSelector = d.selectors.Pod.Field
options.LabelSelector = d.selectors.Pod.Label
options.FieldSelector = d.selectors.pod.field
options.LabelSelector = d.selectors.pod.label
return p.Watch(options)
},
}
@ -316,13 +367,13 @@ func (d *Discovery) Run(ctx context.Context, ch chan<- []*targetgroup.Group) {
p := d.client.CoreV1().Pods(namespace)
plw := &cache.ListWatch{
ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
options.FieldSelector = d.selectors.Pod.Field
options.LabelSelector = d.selectors.Pod.Label
options.FieldSelector = d.selectors.pod.field
options.LabelSelector = d.selectors.pod.label
return p.List(options)
},
WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
options.FieldSelector = d.selectors.Pod.Field
options.LabelSelector = d.selectors.Pod.Label
options.FieldSelector = d.selectors.pod.field
options.LabelSelector = d.selectors.pod.label
return p.Watch(options)
},
}
@ -338,13 +389,13 @@ func (d *Discovery) Run(ctx context.Context, ch chan<- []*targetgroup.Group) {
s := d.client.CoreV1().Services(namespace)
slw := &cache.ListWatch{
ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
options.FieldSelector = d.selectors.Service.Field
options.LabelSelector = d.selectors.Service.Label
options.FieldSelector = d.selectors.service.field
options.LabelSelector = d.selectors.service.label
return s.List(options)
},
WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
options.FieldSelector = d.selectors.Service.Field
options.LabelSelector = d.selectors.Service.Label
options.FieldSelector = d.selectors.service.field
options.LabelSelector = d.selectors.service.label
return s.Watch(options)
},
}
@ -360,13 +411,13 @@ func (d *Discovery) Run(ctx context.Context, ch chan<- []*targetgroup.Group) {
i := d.client.ExtensionsV1beta1().Ingresses(namespace)
ilw := &cache.ListWatch{
ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
options.FieldSelector = d.selectors.Ingress.Field
options.LabelSelector = d.selectors.Ingress.Label
options.FieldSelector = d.selectors.ingress.field
options.LabelSelector = d.selectors.ingress.label
return i.List(options)
},
WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
options.FieldSelector = d.selectors.Ingress.Field
options.LabelSelector = d.selectors.Ingress.Label
options.FieldSelector = d.selectors.ingress.field
options.LabelSelector = d.selectors.ingress.label
return i.Watch(options)
},
}
@ -380,13 +431,13 @@ func (d *Discovery) Run(ctx context.Context, ch chan<- []*targetgroup.Group) {
case RoleNode:
nlw := &cache.ListWatch{
ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
options.FieldSelector = d.selectors.Node.Field
options.LabelSelector = d.selectors.Node.Label
options.FieldSelector = d.selectors.node.field
options.LabelSelector = d.selectors.node.label
return d.client.CoreV1().Nodes().List(options)
},
WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
options.FieldSelector = d.selectors.Node.Field
options.LabelSelector = d.selectors.Node.Label
options.FieldSelector = d.selectors.node.field
options.LabelSelector = d.selectors.node.label
return d.client.CoreV1().Nodes().Watch(options)
},
}

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@ -860,10 +860,17 @@ namespaces:
# and https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/ to learn more about the possible
# filters that can be used. Endpoints role supports pod, service and endpoints selectors, other roles
# only support selectors matching the role itself (e.g. node role can only contain node selectors).
selectors:
<role>:
# Note: When making decision about using field/label selector make sure that this
# is the best approach - it will prevent Prometheus from reusing single list/watch
# for all scrape configs. This might result in a bigger load on the Kubernetes API,
# because per each selector combination there will be additional LIST/WATCH. On the other hand,
# if you just want to monitor small subset of pods in large cluster it's recommended to use selectors.
# Decision, if selectors should be used or not depends on the particular situation.
[ selectors:
[ - role: <role>
[ label: <string> ]
[ field: <string> ]
[ field: <string> ] ]]
```
Where `<role>` must be `endpoints`, `service`, `pod`, `node`, or