Hi everyone I am still having the same issue with A load bal

Question

Hi everyone I am still having the same issue with A load balancer cannot be attached to multiple subnets in the same Availability Zone Service AmazonElasticLoadBalancing Status Code 400 Error Code InvalidConfigurationRequest Request ID lt id redacted gt Proxy null when trying to deploy I am trying with the example code I was wondering if someone could help me understand how the load balancer is created and or point me to source for the ecs run launcher module Since I am just using the example code I am confused about what could be happening there is no load balancer created as far as I can see

Mike Atlas · Answer

I m not using the docker compose example myself but am using ECS and an ALB is needed to route http requests to the Dagit ECS task service

Lindsay S · Answer

I think that the module creates a load balancer if it doesn t exist

Lindsay S · Answer

I wanted to see how that is done

Mike Atlas · Answer

I m guessing your VPC has multiple subnets defined for the same AZ and the script here is trying naively to associate to all available subnets in the VPC

Mike Atlas · Answer

I suppose you could try making a dedicated VPC for running Dagster in ECS and only one subnet for it

Mike Atlas · Answer

The error messages and ALB are created for you by docker compose not by Dagster

Mike Atlas · Answer

gt One of the resources Docker creates is an AWS ELB Load Balancer You can access Dagit on port 3000 of the Load Balancer s URL To find the Load Balancer s URL look for the

Lindsay S · Answer

I see yes i m looking at the subnets for the default vpc now and I see the issue I will try to specify the subnets in the docker compose

Lindsay S · Answer

if I did want to create another vpc for just running dagster where would I set the vpc I want to use also in the docker compose file

Mike Atlas · Answer

yeah looks like `x aws vpc` is the key

Mike Atlas · Answer

<https docs docker com cloud ecs compose examples > under Load Balancers

Lindsay S · Answer

thank you so much trying to set subnets for the default first and if that doesn t work I will try creating a new vpc I don t want to mess with the current vpc because I have no idea what is using that this is really helpful though

Mike Atlas · Answer

Yeah That docker link ^ gave me another idea which is that you could define an ALB that you made separately and just refer to it with `x aws loadbalancer`

Mike Atlas · Answer

that might make it possible to stay in the same VPC

Mike Atlas · Answer

but you can also specify ALB subnets it seems anyways another solution is the section in <https github com docker compose cli issues 921 issuecomment 998704609>

Mike Atlas · Answer

``` LoadBalancer Properties Subnets subnet xxxxxxxxx```

Mike Atlas · Answer

So maybe you can just pick 1 subnet from your default main VPC and be all set ^

Lindsay S · Answer

yaaasss this worked Thank you so much I am still getting errors deploying but they are different errors so I think this piece at least is solved I ended up using the last solution adding something like this to the end of my docker compose file

Lindsay S · Answer

```x aws cloudformation Resources LoadBalancer Properties Subnets subnet xxxxxxx subnet xxxxxxx```

Mike Atlas · Answer

Awesome