README.adoc

SKS variant

This folder contains the variant to use when deploying in Exoscale using an SKS cluster.

Usage

This module can be declared by adding the following block on your Terraform configuration:

module "thanos" {
  source = "git::https://github.com/camptocamp/devops-stack-module-thanos//sks?ref=<RELEASE>"

  cluster_name     = module.sks.cluster_name
  base_domain      = module.sks.base_domain
  cluster_issuer   = local.cluster_issuer
  cluster_id       = module.sks.cluster_id
  argocd_namespace = module.argocd_bootstrap.argocd_namespace

  metrics_storage = {
    bucket_name = resource.aws_s3_bucket.this["thanos"].id
    region      = resource.aws_s3_bucket.this["thanos"].region
    access_key  = resource.exoscale_iam_access_key.s3_iam_key["thanos"].key
    secret_key  = resource.exoscale_iam_access_key.s3_iam_key["thanos"].secret
  }

  thanos = {
    oidc = module.oidc.oidc
  }

  dependency_ids = {
    argocd       = module.argocd_bootstrap.id
    traefik      = module.traefik.id
    cert-manager = module.cert-manager.id
    keycloak     = module.keycloak.id
    oidc         = module.oidc.id
    longhorn     = module.longhorn.id
  }
}

Important

You are in charge of creating a S3 bucket for Thanos to store the archived metrics. We’ve decided to keep the creation of this bucket outside of this module, mainly because the persistence of the data should not be related to the instantiation of the module itself.

Tip	Check the SKS deployment example to see how to create the S3 bucket and to better understand the values passed on the example above.

Note	Do not forget that the bucket configuration also needs to be passed to the module kube-prometheus-stack.

OIDC

Note	This module was developed with OIDC in mind.

There is an OIDC proxy container deployed as a sidecar on each pod that has a web interface. Consequently, the thanos variable is expected to have a map oidc containing at least the Issuer URL, the Client ID, and the Client Secret.

You can pass these values by pointing an output from another module (as above), or by defining them explicitly:

module "thanos" {
  ...
  thanos = {
    oidc = {
      issuer_url    = "<URL>"
      client_id     = "<ID>"
      client_secret = "<SECRET>"
    }
  }
  ...
}

Resource Configuration

Since the resource requirements are not the same on every deployment and because the consumed resources also influence the cost associated, we refrained from configuring default resource requirements for the components of Thanos. We did, however, set memory limits for some of the pods (query, storegateway and compactor all have a 1 GB memory limit). These values should be customized as you see fit, although there is not really a need in a test deployment.

Technical Reference

Dependencies

module.argocd_bootstrap.id

Obviously, the module depends on an already running Argo CD in the cluster in order for the application to be created.

module.traefik.id and module.cert-manager.id

This module has multiple ingresses and consequently it must be deployed after the module traefik and cert-manager.

module.keycloak.id and module.oidc.id

When using Keycloak as an OIDC provider for the Longhorn Dashboard, you need to add Keycloak and the OIDC module as dependencies.

module.longhorn.id

This module requires a Persistent Volume so it needs to be deployed after the module Longhorn.

Requirements

The following requirements are needed by this module:

• argocd (>= 5)

• null (>= 3)

• random (>= 3)

• utils (>= 1)

Modules

The following Modules are called:

thanos

Source: ../

Version:

Required Inputs

The following input variables are required:

cluster_id

Description: ID of the SKS cluster.

Type: string

metrics_storage

Description: Exoscale SOS bucket configuration values for the bucket where the archived metrics will be stored.

Type:

object({
    bucket_name = string
    region      = string
    access_key  = string
    secret_key  = string
  })

cluster_name

Description: Name given to the cluster. Value used for the ingress' URL of the application.

Type: string

base_domain

Description: Base domain of the cluster. Value used for the ingress' URL of the application.

Type: string

Optional Inputs

The following input variables are optional (have default values):

argocd_namespace

Description: Namespace used by Argo CD where the Application and AppProject resources should be created.

Type: string

Default: "argocd"

argocd_project

Description: Name of the Argo CD AppProject where the Application should be created. If not set, the Application will be created in a new AppProject only for this Application.

Type: string

Default: null

argocd_labels

Description: Labels to attach to the Argo CD Application resource.

Type: map(string)

Default: {}

destination_cluster

Description: Destination cluster where the application should be deployed.

Type: string

Default: "in-cluster"

target_revision

Description: Override of target revision of the application chart.

Type: string

Default: "v2.5.0"

cluster_issuer

Description: SSL certificate issuer to use. Usually you would configure this value as letsencrypt-staging or letsencrypt-prod on your root *.tf files.

Type: string

Default: "ca-issuer"

namespace

Description: Namespace where the applications’s Kubernetes resources should be created. Namespace will be created in case it doesn’t exist.

Type: string

Default: "thanos"

helm_values

Description: Helm chart value overrides. They should be passed as a list of HCL structures.

Type: any

Default: []

deep_merge_append_list

Description: A boolean flag to enable/disable appending lists instead of overwriting them.

Type: bool

Default: false

app_autosync

Description: Automated sync options for the Argo CD Application resource.

Type:

object({
    allow_empty = optional(bool)
    prune       = optional(bool)
    self_heal   = optional(bool)
  })

Default:

{
  "allow_empty": false,
  "prune": true,
  "self_heal": true
}

dependency_ids

Description: IDs of the other modules on which this module depends on.

Type: map(string)

Default: {}

thanos

Description: Most frequently used Thanos settings. This variable is merged with the local value thanos_defaults, which contains some sensible defaults. You can check the default values on the local.tf file. If there still is anything other that needs to be customized, you can always pass on configuration values using the variable helm_values.

Type: any

Default: {}

Outputs

The following outputs are exported:

id

Description: ID to pass other modules in order to refer to this module as a dependency. It takes the ID that comes from the main module and passes it along to the code that called this variant in the first place.

Reference in table format

Show tables

= Requirements

Name	Version
argocd	>= 5
null	>= 3
random	>= 3
utils	>= 1

= Modules

Name	Source	Version
thanos

= Inputs

Name	Description	Type	Default	Required
cluster_id	ID of the SKS cluster.	string	n/a	yes
metrics_storage	Exoscale SOS bucket configuration values for the bucket where the archived metrics will be stored.	object({ bucket_name = string region = string access_key = string secret_key = string })	n/a	yes
cluster_name	Name given to the cluster. Value used for the ingress' URL of the application.	string	n/a	yes
base_domain	Base domain of the cluster. Value used for the ingress' URL of the application.	string	n/a	yes
argocd_namespace	Namespace used by Argo CD where the Application and AppProject resources should be created.	string	"argocd"	no
argocd_project	Name of the Argo CD AppProject where the Application should be created. If not set, the Application will be created in a new AppProject only for this Application.	string	null	no
argocd_labels	Labels to attach to the Argo CD Application resource.	map(string)	{}	no
destination_cluster	Destination cluster where the application should be deployed.	string	"in-cluster"	no
target_revision	Override of target revision of the application chart.	string	"v2.5.0"	no
cluster_issuer	SSL certificate issuer to use. Usually you would configure this value as letsencrypt-staging or letsencrypt-prod on your root *.tf files.	string	"ca-issuer"	no
namespace	Namespace where the applications’s Kubernetes resources should be created. Namespace will be created in case it doesn’t exist.	string	"thanos"	no
helm_values	Helm chart value overrides. They should be passed as a list of HCL structures.	any	[]	no
deep_merge_append_list	A boolean flag to enable/disable appending lists instead of overwriting them.	bool	false	no
app_autosync	Automated sync options for the Argo CD Application resource.	object({ allow_empty = optional(bool) prune = optional(bool) self_heal = optional(bool) })	{ "allow_empty": false, "prune": true, "self_heal": true }	no
dependency_ids	IDs of the other modules on which this module depends on.	map(string)	{}	no
thanos	Most frequently used Thanos settings. This variable is merged with the local value thanos_defaults, which contains some sensible defaults. You can check the default values on the local.tf file. If there still is anything other that needs to be customized, you can always pass on configuration values using the variable helm_values.	any	{}	no

= Outputs

Name	Description
id	ID to pass other modules in order to refer to this module as a dependency. It takes the ID that comes from the main module and passes it along to the code that called this variant in the first place.