¿Cómo depurar contenedores atascados en estado pendiente con programación fallida en Fargate?

Jan 02 2021

Objetivo

Mi objetivo es poder implementar en AWS EKS usando Fargate. He logrado que la implementación funcione con un node_group. Sin embargo, cuando pasé a usar Fargate, parece que todos los pods están bloqueados en el estado pendiente.

Cómo se ve mi código actual

Estoy aprovisionando usando Terraform (no necesariamente buscando una respuesta de Terraform). Así es como creo mi clúster EKS:

module "eks_cluster" {
  source                            = "terraform-aws-modules/eks/aws"
  version                           = "13.2.1"
  cluster_name                      = "${var.project_name}-${var.env_name}"
  cluster_version                   = var.cluster_version
  vpc_id                            = var.vpc_id
  cluster_enabled_log_types         = ["api", "audit", "authenticator", "controllerManager", "scheduler"]
  enable_irsa                       = true
  subnets                           = concat(var.private_subnet_ids, var.public_subnet_ids)
  create_fargate_pod_execution_role = false

  node_groups = {
    my_nodes = {
      desired_capacity = 1
      max_capacity     = 2
      min_capacity     = 1
      instance_type    = var.nodes_instance_type
      subnets          = var.private_subnet_ids
    }
  }
}

Y así es como aprovisiono el perfil de Fargate:

resource "aws_eks_fargate_profile" "airflow" {
  cluster_name           = module.eks_cluster.cluster_id
  fargate_profile_name   = "${var.project_name}-fargate-${var.env_name}"
  pod_execution_role_arn = aws_iam_role.fargate_iam_role.arn
  subnet_ids             = var.private_subnet_ids

  selector {
    namespace = "airflow"
  }
}

Y así es como creé y adjunto las políticas requeridas:

resource "aws_iam_role" "fargate_iam_role" {
  name                  = "${var.project_name}-fargate-${var.env_name}"
  force_detach_policies = true
  assume_role_policy    = jsonencode({
    Statement = [{
      Action    = "sts:AssumeRole"
      Effect    = "Allow"
      Principal = {
        Service = ["eks-fargate-pods.amazonaws.com", "eks.amazonaws.com"]
      }
    }]
    Version   = "2012-10-17"
  })
}

# Attach IAM Policy for Fargate
resource "aws_iam_role_policy_attachment" "fargate_pod_execution" {
  role       = aws_iam_role.fargate_iam_role.name
  policy_arn = "arn:aws:iam::aws:policy/AmazonEKSFargatePodExecutionRolePolicy"
}

Lo que he probado y no funciona

Intenté implementar los pods (estoy usando un gráfico de Helm) en el mismo espacio de nombres donde Fargate Profileexiste. Cuando corro kubectl get pods -n airflowveo todas mis vainas pendientes como:

NAME                                 READY   STATUS    RESTARTS   AGE
airflow-flower-79b5948677-vww5d      0/1     Pending   0          40s
airflow-redis-master-0               0/1     Pending   0          40s
airflow-scheduler-6b6bd4b6f6-j9qzg   0/2     Pending   0          41s
airflow-web-567b55fbbf-z8dsg         0/2     Pending   0          41s
airflow-worker-0                     0/2     Pending   0          40s
airflow-worker-1                     0/2     Pending   0          40s

Luego miro los eventos por kubectl get events -n airflow, a los que llego:

LAST SEEN   TYPE     REASON              OBJECT                                    MESSAGE
2m15s       Normal   LoggingEnabled      pod/airflow-flower-79b5948677-vww5d       Successfully enabled logging for pod
2m16s       Normal   SuccessfulCreate    replicaset/airflow-flower-79b5948677      Created pod: airflow-flower-79b5948677-vww5d
2m17s       Normal   ScalingReplicaSet   deployment/airflow-flower                 Scaled up replica set airflow-flower-79b5948677 to 1
2m15s       Normal   LoggingEnabled      pod/airflow-redis-master-0                Successfully enabled logging for pod
2m16s       Normal   SuccessfulCreate    statefulset/airflow-redis-master          create Pod airflow-redis-master-0 in StatefulSet airflow-redis-master successful
2m15s       Normal   LoggingEnabled      pod/airflow-scheduler-6b6bd4b6f6-j9qzg    Successfully enabled logging for pod
2m16s       Normal   SuccessfulCreate    replicaset/airflow-scheduler-6b6bd4b6f6   Created pod: airflow-scheduler-6b6bd4b6f6-j9qzg
2m17s       Normal   NoPods              poddisruptionbudget/airflow-scheduler     No matching pods found
2m17s       Normal   ScalingReplicaSet   deployment/airflow-scheduler              Scaled up replica set airflow-scheduler-6b6bd4b6f6 to 1
2m15s       Normal   LoggingEnabled      pod/airflow-web-567b55fbbf-z8dsg          Successfully enabled logging for pod
2m16s       Normal   SuccessfulCreate    replicaset/airflow-web-567b55fbbf         Created pod: airflow-web-567b55fbbf-z8dsg
2m17s       Normal   ScalingReplicaSet   deployment/airflow-web                    Scaled up replica set airflow-web-567b55fbbf to 1
2m15s       Normal   LoggingEnabled      pod/airflow-worker-0                      Successfully enabled logging for pod
2m15s       Normal   LoggingEnabled      pod/airflow-worker-1                      Successfully enabled logging for pod
2m16s       Normal   SuccessfulCreate    statefulset/airflow-worker                create Pod airflow-worker-0 in StatefulSet airflow-worker successful
2m16s       Normal   SuccessfulCreate    statefulset/airflow-worker                create Pod airflow-worker-1 in StatefulSet airflow-worker successful

Luego trato de describir una de las vainas (vía kubectl describe pod), y obtengo:

Name:                 airflow-redis-master-0
Namespace:            airflow
Priority:             2000001000
Priority Class Name:  system-node-critical
Node:                 <none>
Labels:               app=redis
                      chart=redis-10.5.7
                      controller-revision-hash=airflow-redis-master-588d57785d
                      eks.amazonaws.com/fargate-profile=airflow-fargate-airflow-dev
                      release=airflow
                      role=master
                      statefulset.kubernetes.io/pod-name=airflow-redis-master-0
Annotations:          CapacityProvisioned: 0.25vCPU 0.5GB
                      Logging: LoggingEnabled
                      checksum/configmap: 2b82c78fd9186045e6e2b44cfbb38460310697cf2f2f175c9d8618dd4d42e1ca
                      checksum/health: a5073935c8eb985cf8f3128ba7abbc4121cef628a9a1b0924c95cf97d33323bf
                      checksum/secret: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
                      cluster-autoscaler.kubernetes.io/safe-to-evict: true
                      kubernetes.io/psp: eks.privileged
Status:               Pending
IP:
IPs:                  <none>
Controlled By:        StatefulSet/airflow-redis-master
NominatedNodeName:    6f344dfd11-000a9c54e4e240a2a8b3dfceb5f8227e
Containers:
  airflow-redis:
    Image:      docker.io/bitnami/redis:5.0.7-debian-10-r32
    Port:       6379/TCP
    Host Port:  0/TCP
    Command:
      /bin/bash
      -c
      if [[ -n $REDIS_PASSWORD_FILE ]]; then password_aux=`cat ${REDIS_PASSWORD_FILE}`
        export REDIS_PASSWORD=$password_aux fi if [[ ! -f /opt/bitnami/redis/etc/master.conf ]];then cp /opt/bitnami/redis/mounted-etc/master.conf /opt/bitnami/redis/etc/master.conf fi if [[ ! -f /opt/bitnami/redis/etc/redis.conf ]];then cp /opt/bitnami/redis/mounted-etc/redis.conf /opt/bitnami/redis/etc/redis.conf fi ARGS=("--port" "${REDIS_PORT}")
      ARGS+=("--requirepass" "${REDIS_PASSWORD}") ARGS+=("--masterauth" "${REDIS_PASSWORD}")
      ARGS+=("--include" "/opt/bitnami/redis/etc/redis.conf")
      ARGS+=("--include" "/opt/bitnami/redis/etc/master.conf")
      /run.sh ${ARGS[@]}

    Liveness:   exec [sh -c /health/ping_liveness_local.sh 5] delay=5s timeout=5s period=5s #success=1 #failure=5
    Readiness:  exec [sh -c /health/ping_readiness_local.sh 5] delay=5s timeout=1s period=5s #success=1 #failure=5
    Environment:
      REDIS_REPLICATION_MODE:  master
      REDIS_PASSWORD:          <set to the key 'redis-password' in secret 'my-creds'>  Optional: false
      REDIS_PORT:              6379
    Mounts:
      /data from redis-data (rw)
      /health from health (rw)
      /opt/bitnami/redis/etc/ from redis-tmp-conf (rw)
      /opt/bitnami/redis/mounted-etc from config (rw)
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-dmwvn (ro)
Volumes:
  health:
    Type:      ConfigMap (a volume populated by a ConfigMap)
    Name:      airflow-redis-health
    Optional:  false
  config:
    Type:      ConfigMap (a volume populated by a ConfigMap)
    Name:      airflow-redis
    Optional:  false
  redis-data:
    Type:       EmptyDir (a temporary directory that shares a pod's lifetime)
    Medium:
    SizeLimit:  <unset>
  redis-tmp-conf:
    Type:       EmptyDir (a temporary directory that shares a pod's lifetime)
    Medium:
    SizeLimit:  <unset>
  default-token-dmwvn:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-dmwvn
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                 node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
  Type     Reason            Age    From               Message
  ----     ------            ----   ----               -------
  Normal   LoggingEnabled    3m12s  fargate-scheduler  Successfully enabled logging for pod
  Warning  FailedScheduling  12s    fargate-scheduler  Pod provisioning timed out (will retry) for pod: airflow/airflow-redis-master-0

Otras cosas que he probado

  • Etiquetar mis subredes con la etiqueta apropiada (condicional basado en subredes públicas / privadas):
    kubernetes_tags = map(
        "kubernetes.io/role/${var.type == "Public" ? "elb" : "internal-elb"}", 1,
        "kubernetes.io/cluster/${var.kubernetes_cluster_name}", "shared"
      )
  • Anotando mis pods con el perfil de Fargate (como infraestructura: fargate)
  • Configuración de depuración de VPC. A mi entender, las siguientes configuraciones deben describirse para Fargate (fuente aquí ):
  single_nat_gateway = true # needed for fargate (https://docs.aws.amazon.com/eks/latest/userguide/eks-ug.pdf#page=135&zoom=100,96,764)
  enable_nat_gateway = true # needed for fargate (https://docs.aws.amazon.com/eks/latest/userguide/eks-ug.pdf#page=135&zoom=100,96,764)
  enable_vpn_gateway = false
  enable_dns_hostnames = true # needed for fargate (https://docs.aws.amazon.com/eks/latest/userguide/eks-ug.pdf#page=135&zoom=100,96,764)
  enable_dns_support = true # needed for fargate (https://docs.aws.amazon.com/eks/latest/userguide/eks-ug.pdf#page=135&zoom=100,96,764)

Sin embargo, se me ha proporcionado una VPC de fácil creación y no estoy seguro de cómo comprobar si esta configuración ya se ha activado o desactivado.

¿Cuáles son los pasos que debo seguir para depurar este problema?

Respuestas

3 AsriBadlah Jan 02 2021 at 19:46

Para fines de prueba, creo que debe habilitar la conectividad desde las subredes privadas de vpc al mundo exterior mediante la puerta de enlace NAT. Por lo tanto, puede crear una puerta de enlace NAT en público y agregar a las subredes privadas una entrada adicional en su tabla de enrutamiento asociada que se ve así:

0.0.0.0/0 nat-xxxxxxxx

Si esto funcionó y desea mantener su salida restringida a través de su instancia de firewall, que es más segura, creo que debe comunicarse con el soporte del proveedor de firewall para preguntar cómo puede incluir el tráfico fuera de la lista blanca.