AWS ECS (Fargate) + ALB (Application Load Balancer)

Warning

When using Fargate or vanilla ECS, you should set the number of worker carefully. Setting too high a number of workers could lead to extra charges due to a bug in fastapi (https://github.com/developmentseed/titiler/issues/119, https://github.com/tiangolo/fastapi/issues/253).

Deploy

The example handles tasks such as generating a docker image and setting up an application load balancer (ALB) and ECS services.

1. Install CDK and connect to your AWS account. This step is only necessary once per AWS account.

   # Download titiler repo
   $ git clone https://github.com/developmentseed/titiler.git
   
   # Create a virtual environment
   python -m pip install --upgrade virtualenv
   virtualenv .venv
   source .venv/bin/activate
   
   # Install CDK dependencies
   python -m pip install -r requirements-cdk.txt
   
   # Install NodeJS dependencies
   npm install
   
   $ npm run cdk -- bootstrap # Deploys the CDK toolkit stack into an AWS environment
   
   # or in specific region
   $ npm run cdk -- bootstrap aws://${AWS_ACCOUNT_ID}/eu-central-1
   

2. Generate CloudFormation template

   $ npm run cdk -- synth  # Synthesizes and prints the CloudFormation template for this stack
   

3. Update settings (see intro.md)

   export TITILER_STACK_NAME="mytiler"
   export TITILER_STACK_STAGE="dev"
   export TITILER_STACK_MIN_ECS_INSTANCES=10
   

   Available settings for ECS:

   min_ecs_instances: int = 5
   max_ecs_instances: int = 50
   
   # CPU value      |   Memory value
   # 256 (.25 vCPU) | 0.5 GB, 1 GB, 2 GB
   # 512 (.5 vCPU)  | 1 GB, 2 GB, 3 GB, 4 GB
   # 1024 (1 vCPU)  | 2 GB, 3 GB, 4 GB, 5 GB, 6 GB, 7 GB, 8 GB
   # 2048 (2 vCPU)  | Between 4 GB and 16 GB in 1-GB increments
   # 4096 (4 vCPU)  | Between 8 GB and 30 GB in 1-GB increments
   task_cpu: int = 256
   task_memory: int = 512
   
   # GUNICORN configuration
   # Ref: https://github.com/developmentseed/titiler/issues/119
   
   # WORKERS_PER_CORE
   # This image will check how many CPU cores are available in the current server running your container.
   # It will set the number of workers to the number of CPU cores multiplied by this value.
   workers_per_core: int = 1
   
   # MAX_WORKERS
   # You can use it to let the image compute the number of workers automatically but making sure it's limited to a maximum.
   # should depends on `task_cpu`
   max_workers: int = 1
   
   # WEB_CONCURRENCY
   # Override the automatic definition of number of workers.
   # Set to the number of CPU cores in the current server multiplied by the environment variable WORKERS_PER_CORE.
   # So, in a server with 2 cores, by default it will be set to 2.
   web_concurrency: Optional[int]
   

4. Deploy

   # Deploys the stack(s) mytiler-ecs-dev in cdk/app.py
   $ npm run cdk -- deploy mytiler-ecs-dev