What?

Cortex-k8s-sidecar is based on kiwigrid/k8s-sidecar (a sidecar to mount configmap/secret fields into a pod). This sidecar implementation however doesn't make the fields available over the filesystem, but posts the content to the Cortex API directly.

Why?

This sidecar improves the original kiwigrid/k8s-sidecar on following aspects:

1. kiwigrid/k8s-sidecar only works with the local storage backend while this project allows to use the s3 storage backend for the ruler and alertmanager. This also enables the use of sharding for the ruler.
2. kiwigrid/k8s-sidecar requires rules configmaps to be tagged with a label (for instance cortex_rules: "1"). That is difficult to integrate with the prometheus-operator which watches PrometheusRule resources and writes the rules to configmaps that don't support custom labels (as per operator configuration). This project however applies an additional filter based on the resource naming (prometheus-<name>-rulefiles-<postfix>) so label filtering can take place simply on the hardcoded label (managed-by: prometheus-operator).
3. kiwigrid/k8s-sidecar required the x-scope-orgid to be specified (implicitly) in the annotation k8s-sidecar-target-directory (where the x-scope-orgid is the name of the directory). This project however takes the x-scope-orgid from a configurable namespace label; as organizations/tenants are typically assigned a namespace in which rules and alerts are created this is a much simpler setup to integrate.

Images

Images are available at:

• docker.io/paul424/cortex-k8s-sidecar

All are identical multi-arch images built for amd64, arm64, arm/v7, ppc64le and s390x

Features

• Support for configmaps only
• Filter based on label
• Update/Delete on change of configmap

Build

docker build --network=host -t cortex-k8s-sidecar:0.1 .

Configuration Environment Variables

name	description	required	default	type
FUNCTION	Specifies the Cortex function to push configuration for; either rules or alerts.	false	rules	string
LABEL	Label that should be used for filtering	true	-	string
LABEL_VALUE	The value for the label you want to filter your resources on. Don't set a value to filter by any value	false	-	string
X_SCOPE_ORGID_DEFAULT	The default x-scope-orgid to use	false	system	string
X_SCOPE_ORGID_NAMESPACE_LABEL	The namespace label that contains the x-scope-orgid. Notice when the label isn't found on the namespace, the value of X_SCOPE_ORGID_DEFAULT is used.	false	-	string
RULES_URL	The Cortex ruler endpoint , for instance http://cortex-ruler.cortex.svc.cluster.local:8080/api/v1/rules	true	-	string
ALERTS_URL	The Cortex alertmanager endpoint, for instance http://cortex-alertmanager.cortex.svc.cluster.local:8080/api/v1/alerts	true	-	string
SYNC_SLEEP	Every SYNC_SLEEP seconds, update the rules or alerts (depends on FUNCTION) against the found resources.	false	60	string
NAMESPACE	Comma separated list of namespaces. If specified, the sidecar will search for config-maps inside these namespaces. It's also possible to specify ALL to search in all namespaces.	false	namespace in which the sidecar is running	string
KUBECONFIG	if this is given and points to a file or ~/.kube/config is mounted k8s config will be loaded from this file, otherwise "incluster" k8s configuration is tried.	false	-	string
LOG_LEVEL	Set the logging level. (DEBUG, INFO, WARN, ERROR, CRITICAL)	false	INFO	string
LOG_FORMAT	Set a log format. (JSON or LOGFMT)	false	JSON	string
LOG_TZ	Set the log timezone. (LOCAL or UTC)