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Version: 0.0.22

Deploy containerized app to ECS Fargate using IaSQL on Django (Python)

In this tutorial, we will run Django SQL migrations on top of IaSQL to deploy an HTTP server within a docker container on your AWS account using ECS, ECR and ELB. The container image will be hosted as a public repository in ECR and deployed to ECS using Fargate.

The code for this tutorial lives in this part of the repository.

Start managing an AWS account with a hosted IaSQL db

First, make sure you have an IAM user in AWS or create one with Programmatic access through the console/UI or CLI. Ensure that the IAM role has sufficient permissions to deploy and manage all your infrastructure resources.

There are two parts to each access key, which you’ll see in the IAM console/CLI after you create it, an id and a secret. Input these in the connect account modal:

If you use the AWS CLI, you can look at the credentials configured locally. In macOS and Linux this is as simple as:

$ cat ~/.aws/credentials
[default]
aws_access_key_id = <YOUR_ACCESS_KEY_ID>
aws_secret_access_key = <YOUR_SECRET_ACCESS_KEY>

You will be able to see your PostgreSQL connection information when you press Connect.

Make sure to copy the PostgreSQL connection string as you will not see it again.

Add the necessary cloud services to the hosted database

  1. Many different clients can be used to connect to a PostgreSQL database. For this tutorial, we'll use the standard psql CLI client. If you need to install psql, follow the instructions for your corresponding OS here.

  2. The first migration calls the iasql_install SQL function to install the ECS simplified module into the hosted database.

psql postgres://d0va6ywg:nfdDh#EP4CyzveFr@db.iasql.com/_4b2bb09a59a411e4 -c
SELECT * from iasql_install(
'aws_ecs_simplified'
);

If the function call is successful, it will return a virtual table with a record for each new table in your database under created_table_name and the number of existing resources or records imported from the account under record_count.

       module_name        |      created_table_name       | record_count
--------------------------+-------------------------------+--------------
aws_cloudwatch | log_group | 0
aws_ecr | public_repository | 0
aws_ecr | repository | 1
aws_ecr | repository_policy | 0
aws_security_group | security_group | 2
aws_security_group | security_group_rule | 0
aws_vpc | vpc | 1
aws_vpc | subnet | 3
aws_elb | load_balancer | 0
aws_elb | target_group | 0
aws_elb | listener | 0
aws_elb | load_balancer_security_groups | 0
aws_ecs_fargate | cluster | 0
aws_ecs_fargate | service | 0
aws_ecs_fargate | task_definition | 0
aws_ecs_fargate | container_definition | 0
aws_ecs_fargate | service_security_groups | 0
(17 rows)

Connect to the hosted db and provision cloud resources in your AWS account

  1. Get a local copy of the ECS Fargate examples

  2. (Optional) Create and activate a virtual environment to install python dependencies

    python -m venv <env-name>
    source <env-name>/bin/activate
  3. Install the project dependencies under the django/app folder

    pip install -r requirements.txt
  4. Create a .env file with the connection parameters provided on db creation. In this case:

    AWS_REGION=eu-west-2
    DB_NAME=_3ba201e349a11daf
    DB_USER=qpp3pzqb
    DB_PASSWORD=LN6jnHfhRJTBD6ia
  5. (Optional) Set the desired project name that your resources will be named after by changing the IASQL_PROJECT_NAME in the my_project/app/app/settings.py. If the name is not changed, quickstart will be used.

    note

    The project-name can only contain alphanumeric characters and hyphens(-) because it will be used to name the load balancer

  6. Per the Django database documentation, to connect to a new database you have to update the DATABASES in the my_project/app/app/settings.py file. This is already configure in the example project.

    django/app/app/settings.py
    DATABASES = {
    ...
    'infra': {
    'ENGINE': 'django.db.backends.postgresql',
    'NAME': env('DB_NAME'),
    'USER': env('DB_USER'),
    'PASSWORD': env('DB_PASSWORD'),
    'HOST': 'db.iasql.com',
    'PORT': '5432',
    }
    }

If you are using the template example go to step 9. The following steps explains how to instrospect an existing DB in Django.

  1. The second migration correspond to the Django models instrospected from the modules that have been installed in the database. To introspect the schema from your database run the following command. More information here.
python manage.py inspectdb --database=infra > infra/models.py
note

After running the inspectdb command you will need to tweak the models Django generated until they work the way you’d like. In our case you will have to modify the my_project/app/infra/models.py file as follow:

  1. Replace CharField with TextField
  2. Remove all max_length=-1. Helpful regex for a replacement: [\s,]*max_length=-1[,\s]*
  3. Add the following import from django.contrib.postgres.fields import ArrayField
  4. Replace in the Service class the subnets property with subnets = ArrayField(models.TextField())
  5. Add a default False value for the Service class force_new_deployment property (force_new_deployment = models.BooleanField(default=False)).
  6. Replace in the Role class the attached_policies_arns property with attached_policies_arns = ArrayField(models.TextField())
  7. Add related_name argument to the definition for IasqlDependencies.dependency. (dependency = models.ForeignKey('IasqlModule', models.DO_NOTHING, db_column='dependency', related_name='module'))
  8. Add related_name argument to the definition for TaskDefinition.execution_role_name. (execution_role_name = models.ForeignKey(Role, models.DO_NOTHING, db_column='execution_role_name', blank=True, null=True, related_name='execution_role_name'))
  9. Add related_name argument to the definition for TaskDefinition.task_role_name. (task_role_name = models.ForeignKey(Role, models.DO_NOTHING, db_column='task_role_name', blank=True, null=True, related_name='task_role_name'))
  1. After instrospecting the db you will need to generate the migration so you can have the my_project/app/infra/migrations/0002_inspectdb.py file.

    python manage.py makemigrations --name inspectdb infra
    caution

    If you install or uninstall IaSQL modules the database schema will change and you will need to run steps 7 and 8 to introspect the correct schema once again.

  2. Now you can use IaSQL models to create your resources. Run the existing migrations with:

    python manage.py migrate --database infra infra

    The operations of the my_project/app/infra/migrations/0003_initial.py migration will apply the changes described in the hosted db to your cloud account which will take a few minutes waiting for AWS

    my_project/app/infra/migrations/0003_initial.py
    ...
    operations = [
    migrations.RunPython(code=quickstart_up, reverse_code=apply),
    migrations.RunPython(code=apply, reverse_code=quickstart_down),
    ]

If the function call is successful, it will return a list of dicts with each cloud resource that has been created, deleted or updated.

[{'action': 'create', 'table_name': 'log_group', 'id': None, 'description': 'quickstart-log-group'}, {'action': 'create', 'table_name': 'repository', 'id': None, 'description': 'quickstart-repository'}, {'action': 'create', 'table_name': 'iam_role', 'id': None, 'description': 'quickstart-ecs-task-exec-role'}, {'action': 'create', 'table_name': 'security_group', 'id': 31, 'description': '31'}, {'action': 'create', 'table_name': 'security_group_rule', 'id': 48, 'description': '48'}, {'action': 'create', 'table_name': 'security_group_rule', 'id': 49, 'description': '49'}, {'action': 'create', 'table_name': 'listener', 'id': 16, 'description': '16'}, {'action': 'create', 'table_name': 'load_balancer', 'id': None, 'description': 'quickstart-load-balancer'}, {'action': 'create', 'table_name': 'target_group', 'id': None, 'description': 'quickstart-target'}, {'action': 'create', 'table_name': 'cluster', 'id': None, 'description': 'quickstart-cluster'}, {'action': 'create', 'table_name': 'task_definition', 'id': 16, 'description': '16'}, {'action': 'create', 'table_name': 'service', 'id': None, 'description': 'quickstart-service'}, {'action': 'delete', 'table_name': 'security_group_rule', 'id': None, 'description': 'sgr-024274a604968919e'}]

Login, build and push your code to the container registry

Previously, you needed to manually build and push your image to the ECR. But recently we've added the high-level ecr_build SQL function which does all those steps automatically. It will do the following:

  • Pull the code from your Github repository
  • Build the Docker image in the directory you've specified
  • Push the image to the ECR repository you've provided

All of these steps will be done in a CodeBuild project in your AWS account. To use the ecr_build function, you can run:

SELECT ecr_build(
'https://github.com/iasql/iasql-engine/', -- replace with your own Github repo if you want to use your own codebase
(SELECT id
FROM repository
WHERE repository_name = 'quickstart-repository')::varchar(255), -- replace quickstart if you've changed the project name
'./examples/ecs-fargate/django/app', -- the sub directory in the Github repo that the image should be built in
'main', -- the Github repo branch name
'' -- replace your github personal access token here if the repo is private
);

After running the above SQL command to completion, you can check the running app using the load balancer DNS name. To grab the name, run:

QUICKSTART_LB_DNS=$(psql -At 'postgres://d0va6ywg:nfdDh#EP4CyzveFr@db.iasql.com/_4b2bb09a59a411e4' -c "
SELECT dns_name
FROM load_balancer
WHERE load_balancer_name = '<project-name>-load-balancer';")

And then connect to your service!

curl ${QUICKSTART_LB_DNS}:8088/health

Delete Managed Cloud Resources

Delete the resources created by this tutorial using the following SQL code:

psql postgres://qpp3pzqb:LN6jnHfhRJTBD6ia@db.iasql.com/_3ba201e349a11daf -c
DELETE FROM repository_image WHERE private_repository_id = (SELECT id FROM repository WHERE repository_name = 'quickstart-repository');
DELETE FROM ecs_simplified WHERE app_name = 'quickstart';

Apply the changes described in the hosted db to your cloud account

psql postgres://qpp3pzqb:LN6jnHfhRJTBD6ia@db.iasql.com/_3ba201e349a11daf -c
 SELECT * from iasql_apply();

If the function call is successful, it will return a virtual table with a record for each cloud resource that has been created, deleted or updated.

 action |     table_name      |   id   |                                                         description                                                         
--------+---------------------+--------+-----------------------------------------------------------------------------------------------------------------------------
delete | cluster | [NULL] | arn:aws:ecs:sa-east-1:658401754851:cluster/quickstart-cluster
delete | task_definition | [NULL] | arn:aws:ecs:sa-east-1:658401754851:task-definition/quickstart-td:1
delete | service | [NULL] | arn:aws:ecs:sa-east-1:658401754851:service/quickstart-cluster/quickstart-service
delete | listener | [NULL] | arn:aws:elasticloadbalancing:sa-east-1:658401754851:listener/app/quickstart-load-balancer/3925cdb9acada7c1/7a459d6259dac5c9
delete | load_balancer | [NULL] | arn:aws:elasticloadbalancing:sa-east-1:658401754851:loadbalancer/app/quickstart-load-balancer/3925cdb9acada7c1
delete | target_group | [NULL] | arn:aws:elasticloadbalancing:sa-east-1:658401754851:targetgroup/quickstart-target/826f804f496d0a90
delete | security_group | [NULL] | sg-0015b0e07bd10b7d2
delete | security_group | [NULL] | sg-e0df1095
delete | security_group_rule | [NULL] | sgr-06aa0915b15fd23a9
delete | security_group_rule | [NULL] | sgr-02e2096ac9e77a5bf