Create a new ECS task set

  • Register a new task definition using our error container, and pointing to the crystal-sd-error virtual node.

    # Define variables #
TASK_DEF_ARN=$(aws ecs list-task-definitions | \
jq -r ' .taskDefinitionArns[] | select( . | contains("crystal"))' | tail -1)
TASK_DEF_OLD=$(aws ecs describe-task-definition --task-definition $TASK_DEF_ARN);
TASK_DEF_NEW=$(echo $TASK_DEF_OLD \
| jq ' .taskDefinition' \
| jq ' .containerDefinitions[0].image |= sub("epoch"; "error") ' \
| jq ' .containerDefinitions[].environment |= map(
    if .name=="APPMESH_VIRTUAL_NODE_NAME" then 
          .value="mesh/appmesh-workshop/virtualNode/crystal-sd-error" 
    else . end) ' \
| jq ' del(.status, .compatibilities, .taskDefinitionArn, .requiresAttributes, .revision, .registeredBy, .registeredAt) '
); \
TASK_DEF_FAMILY=$(echo $TASK_DEF_ARN | cut -d"/" -f2 | cut -d":" -f1);
echo $TASK_DEF_NEW > /tmp/$TASK_DEF_FAMILY.json && 
# Register ecs task definition #
aws ecs register-task-definition \
--cli-input-json file:///tmp/$TASK_DEF_FAMILY.json

  • Create a new task set.

    # Define variables #
CLUSTER_NAME=$(jq < cfn-output.json -r '.EcsClusterName');
SERVICE_ARN=$(aws ecs list-services --cluster $CLUSTER_NAME | \
jq -r ' .serviceArns[] | select( . | contains("sd"))' | tail -1)
TASK_DEF_ARN=$(aws ecs list-task-definitions | \
jq -r ' .taskDefinitionArns[] | select( . | contains("crystal"))' | tail -1)
SUBNET_ONE=$(jq < cfn-output.json -r '.PrivateSubnetOne');
SUBNET_TWO=$(jq < cfn-output.json -r '.PrivateSubnetTwo');
SUBNET_THREE=$(jq < cfn-output.json -r '.PrivateSubnetThree');
SECURITY_GROUP=$(jq < cfn-output.json -r '.ContainerSecurityGroup');
CMAP_SVC_ARN=$(aws servicediscovery list-services | \
jq -r '.Services[] | select(.Name == "crystal") | .Arn');
# Create ecs task set #
aws ecs create-task-set \
--service $SERVICE_ARN \
--cluster $CLUSTER_NAME \
--external-id error-task-set \
--task-definition "$(echo $TASK_DEF_ARN)" \
--service-registries "registryArn=$CMAP_SVC_ARN" \
--launch-type FARGATE \
--scale value=50,unit=PERCENT \
--network-configuration \
  "awsvpcConfiguration={subnets=[$SUBNET_ONE,$SUBNET_TWO,$SUBNET_THREE],
    securityGroups=[$SECURITY_GROUP],
    assignPublicIp=DISABLED}"

  • Wait for the service tasks to be in a running state and marked healthy for service discovery.

    # Define variables #
CLUSTER_NAME=$(jq < cfn-output.json -r '.EcsClusterName');
TASK_DEF_ARN=$(aws ecs list-task-definitions | \
jq -r ' .taskDefinitionArns[] | select( . | contains("crystal"))' | tail -1);
CMAP_SVC_ID=$(aws servicediscovery list-services | \
jq -r '.Services[] | select(.Name == "crystal") | .Id');
# Get task state #
_list_tasks() {
aws ecs list-tasks \
--cluster $CLUSTER_NAME \
--service crystal-service-sd | \
jq -r ' .taskArns | @text' | \
while read taskArns; do
  aws ecs describe-tasks --cluster $CLUSTER_NAME --tasks $taskArns;
done | \
jq -r --arg TASK_DEF_ARN $TASK_DEF_ARN \
' [.tasks[] | select( (.taskDefinitionArn == $TASK_DEF_ARN)
                and (.lastStatus == "RUNNING" ))] | length'
}
# Get instances health status #
_list_instances() {
aws servicediscovery get-instances-health-status \
--service-id $CMAP_SVC_ID | \
jq ' [.Status | to_entries[] | select( .value == "HEALTHY")] | length'
}
until [ $(_list_tasks) == "3" ]; do
echo "Tasks are starting ..."
sleep 10s
if [ $(_list_tasks) == "3" ]; then
echo "Tasks started"
break
fi
done
sleep 10s
until [ $(_list_instances) == "9" ]; do
echo "Instances are registering ..."
sleep 10s
if [ $(_list_instances) == "9" ]; then
echo "Instances registered"
break
fi
done