Installing ArgoCD (gitops tool) on AKS and monitoring using Datadog

We’ll create the AKS and acr using terraform.

Create child modules in a folder “High5infra_aksPOC“.

a) acr

########################## main.tf ###############################

resource "azurerm_container_registry" "main" {
  name                = "highregistry"
  location            = var.location
  resource_group_name = var.resource_group_name
  sku                 = "Premium"
  admin_enabled       = true

  identity {
    type         = "UserAssigned"
    identity_ids = [var.identity_id]
  }

  tags = {
    "Created By" = var.tag_CreatedBy
    "Created Date" = var.tag_CreatedDate
  }

  lifecycle {
    prevent_destroy = true               # Reference link https://developer.hashicorp.com/terraform/tutorials/state/resource-lifecycle#prevent-resource-deletion
  }  

}

resource "azurerm_role_assignment" "acr_pull" {
  scope              = azurerm_container_registry.main.id
  role_definition_name = "AcrPull"
  principal_id       = var.principal_id
}

output "login_server" {
  value = azurerm_container_registry.main.login_server
}

########################## variables.tf ##########################

variable "location" {}
variable "resource_group_name" {}
variable "identity_id" {}
variable "principal_id" {}
variable "tag_CreatedBy" {}
variable "tag_CreatedDate" {}

b) aks

########################## main.tf ###############################

resource "azurerm_kubernetes_cluster" "aks" {
  name                = var.name
  location            = var.location
  resource_group_name = var.resource_group_name
  dns_prefix          = "exampleaks1"


  default_node_pool {
    name       = "default"
    node_count = 1
    vm_size    = "Standard_D2_v2"
    vnet_subnet_id = var.subnet_id
  }

  identity {
    type = "UserAssigned"
    identity_ids = [var.identity_id]
  }

  tags = {
    Created_By = var.tag_CreatedBy
    Created_Date = var.tag_CreatedDate
  }
}

########################## variables.tf ##########################

variable "name" {}
variable "identity_id" {}
variable "tag_CreatedBy" {}
variable "tag_CreatedDate" {}
variable "location" {}
variable "resource_group_name" {}
variable "subnet_id" {}

c) LogAnalytics

########################## main.tf ###############################
resource "azurerm_log_analytics_workspace" "main" {
  name                = var.name
  location            = var.location
  resource_group_name = var.resource_group_name
  sku                 = "PerGB2018"
  retention_in_days   = 30

  tags = {
    "Created By" = var.tag_CreatedBy
    "Created Date" = var.tag_CreatedDate
  }

}

output "workspace_id" {
  value = azurerm_log_analytics_workspace.main.id
}

########################## variables.tf ##########################

variable "location" {}
variable "resource_group_name" {}
variable "name" {}
variable "tag_CreatedBy" {}
variable "tag_CreatedDate" {}

d) user_assigned_identity

########################## main.tf ###############################

resource "azurerm_user_assigned_identity" "main" {
  name                = "Test-containerPull"
  location            = var.location
  resource_group_name = var.resource_group_name

  lifecycle {
    prevent_destroy = true
  }
}

output "id" {
  value = azurerm_user_assigned_identity.main.id
}

output "principal_id" {
  value = azurerm_user_assigned_identity.main.principal_id
}

########################## variables.tf ##########################

variable "location" {}
variable "resource_group_name" {}

e) vnet

########################## main.tf ###############################

resource "azurerm_virtual_network" "main" {
  name                = var.virtual_network_name
  location            = var.location
  resource_group_name = var.resource_group_name
  address_space       = ["10.7.0.0/16"]

  tags = {
    "Created By" = var.tag_CreatedBy
    "Created Date" = var.tag_CreatedDate
  }

}

resource "azurerm_subnet" "main" {
  name                 = "AksSubnet"
  resource_group_name  = var.resource_group_name
  virtual_network_name = azurerm_virtual_network.main.name
  address_prefixes     = ["10.7.0.0/23"]

#   delegation {
#     name = "appservices-delegation"
#     service_delegation {
#       name = "Microsoft.App/environments"
#       actions = [
#         "Microsoft.Network/virtualNetworks/subnets/join/action",
#         "Microsoft.Network/virtualNetworks/subnets/prepareNetworkPolicies/action",
#       ]
#     }
#   }

}

output "vnet_id" {
  value = azurerm_virtual_network.main.id
}

output "subnet_id" {
  value = azurerm_subnet.main.id
}

########################## variables.tf ##########################


variable "location" {}
variable "resource_group_name" {}
variable "tag_CreatedBy" {}
variable "tag_CreatedDate" {}
variable "virtual_network_name" {}

Now write the remaining terraform file in the root of the folder “High5infra_aksPOC”.

 ########################## main.tf ###############################

 resource "azurerm_resource_group" "aks" {
   name     = var.resource_group_name
   location = var.location
   tags = {
     Status = "Running application"
   }
 }

 module "log_analytics" {
   source              = "./modules/LogAnalytics"
   name                = var.log_analytics_name
   resource_group_name = azurerm_resource_group.aks.name
   location            = azurerm_resource_group.aks.location
   tag_CreatedBy       = var.tag_CreatedBy
   tag_CreatedDate     = var.tag_CreatedDate

   depends_on = [azurerm_resource_group.aks]

 }

 module "user_assigned_identity" {
   source              = "./modules/user_assigned_identity"
   resource_group_name = "High-ACR-RG"
   location            = azurerm_resource_group.aks.location

   depends_on = [azurerm_resource_group.aks]
 }

 module "acr" {
   source              = "./modules/acr"
   resource_group_name = "High-ACR-RG"
   location            = "centralus"
   identity_id         = module.user_assigned_identity.id
   principal_id        = module.user_assigned_identity.principal_id
   tag_CreatedBy       = var.tag_CreatedBy
   tag_CreatedDate     = var.tag_CreatedDate

   depends_on = [module.user_assigned_identity]

 }

 module "vnet" {
   source               = "./modules/vnet"
   resource_group_name  = var.resource_group_name
   location             = var.location
   virtual_network_name = var.vnet_name
   tag_CreatedBy        = var.tag_CreatedBy
   tag_CreatedDate      = var.tag_CreatedDate

   depends_on = [ module.user_assigned_identity ]

 }

 module "aks" {
   source              = "./modules/aks"
   resource_group_name = azurerm_resource_group.aks.name
   location            = azurerm_resource_group.aks.location
   name                = var.aksname
   subnet_id           = module.vnet.subnet_id
   identity_id         = module.user_assigned_identity.id
   tag_CreatedBy       = var.tag_CreatedBy
   tag_CreatedDate     = var.tag_CreatedDate

   depends_on = [module.vnet]
 }

 ########################## variables.tf ############################

 variable "location" {
   description = "The Azure region where the resources should be created."
   type        = string
 }

 variable "resource_group_name" {
   description = "The name of the resource group."
   type        = string
 }

 variable "aksname" {
   description = "The ingress port for the first container app."
   type        = string
 }

 variable "app2_ingress_port" {
   description = "The ingress port for the second container app."
   type        = number
 }

 variable "log_analytics_name" {
   description = "Log Analytics name."
   type        = string
 }

 variable "tag_CreatedBy" {
   description = "Created By ___"
   type        = string
 }

 variable "tag_CreatedDate" {
   description = "Enter Date of creation tag"
 }

 variable "vnet_name" {
   description = "Enter the name of the vnet"
   type        = string
 }

 ########################## terraform.tfvars #########################

 location            = "centralus"
 resource_group_name = "High-AKS"
 log_analytics_name  = "akslogAnalyticsWorkspace"
 aksname             = "testAKS"
 app2_ingress_port   = 5001
 tag_CreatedBy       = "Tara Prasad Sarangi"
 tag_CreatedDate     = "21-10-2024"
 vnet_name           = "AKSVNet"

 ############################## backend.tf ###########################
 # Here we will store terraform state file in the Azure storage 

 terraform {
    backend "azurerm" {
      storage_account_name = "terraformiacstorage"
      resource_group_name  = "DevOps_Tools"
      container_name       = "terraform-backend"
      key                  = "aks.terraform.tfstate"
      access_key           = "<your_access_key>"
    }
  }

Now the AKS will be created with all the resources mentioned in terraform file.
We will connect to AKS using our terminal.

a) Install AzureCLI by following steps in the given link.

b) Log into azure using az login command.

c) Set the subscription using az account set --subscription "your-subscription-name-or-id" command if you have multiple subscriptions.

d) Install kubectl using az aks install-cli command.

e) Get the aks credential using az aks get-credentials --resource-group --name command.

f) Verify the connection using kubectl get nodes command.

Now install ArgoCD using below commands.

 kubectl create ns argocd-stage #create namespace argocd-stage

 kubectl apply -n argocd-stage -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml #download and install argocd in argocd-stage namespace

 kubectl get pods -n argocd-stage #list all the pods in argo-stage namespace

 kubectl edit svc argocd-server -n argocd-stage -o yaml #change the service from ClusterIP to LoadBalancer

 kubect get svc argocd-server -n argocd-stage -o yaml #check if service type is changed 

 kubectl -n argocd-stage get secret argocd-initial-admin-secret -o jsonpath="{.data.password}" | base64 --decode  #(for Password, Username- admin)

Now copy the Loadbalancer IP and paste it in browser. Argocd will open and paste the decoded password. Username is admin.

Now we will create Datadog account for monitoring kubernetes
a) Create a datadog account for free by clicking on this link. Per email account gets 14 days free trial period.

b) To install the agent in the Kubernetes, In the Agents, choose kubernetes from left dock and follow the instruction.

c) Create datadog-agent.yaml locally and write in the below format
```
apiVersion: datadoghq.com/v2alpha1
kind: DatadogAgent
metadata:
  name: datadog
spec:
  global:
    clusterName: <CLUSTER_NAME> # in my case this is testAKS
    site: <DATADOG_SITE> # in my case this is us5.datadoghq.com
    credentials:
      apiSecret:
        secretName: datadog-secret
        keyName: api-key
```
d) Save the yaml and run the command kubectl apply -f datadog-agent.yaml.

e) Now you will be able to see finish option at the bottom of the page.

f) Now search “Kubernetes Overview”

We can see all the details about the k8s.