Deployed to AWS - 502 Bad Gateway

[AndryHTC]

We have followed every single step of the procedure but at the end of the day... Testing the deployment as suggested https://docs.serverpod.dev/deployments/deploying-to-aws#test-your-deployment we get a 502 Bad Gateway for all the endpoints.

Same problem with native AWS URL instead of DNS Domains... The connection to the database works, even with the subdomain database.[domain].[*]

[tusharbhambere]

Also Check this video https://youtu.be/zx2eh3t_98Q

[AndryHTC]

We have made the exact same steps

[yahu1031]

Maybe you have missed something buddy. My API works fine.

[AmoonPod]

Maybe you have missed something buddy. My API works fine.

Which OS are you currently using? Amazon Linux 2? Ubuntu?

[yahu1031]

@AndryHTC Okie So the bad gateway I got too but when I change the config file and deploy. Can I know What are you trying to access from the url? Like api.* or app.*?

[yahu1031]

@AmoonPod

Which OS are you currently using? Amazon Linux 2? Ubuntu?

Ubuntu is the default I guess. I don't specify anything.

[AndryHTC]

The problem was that we required in pubspec.yaml a different Dart SDK, and both aws/terraform/init-script.sh and the .github/workflows/deployment-aws.yml install a fixed SDK, and it does not take the same you define in the pubspec.yaml.

We actually had the entire infrastructure already installed, so @AmoonPod solved the issue by upgrading the Dart SDK manually in the EC2 instance through the Session Manager console

EDIT:
The permanent solution is to get the minimum version you choose from the pubspec.yaml and to put it in the other scripts aws/terraform/init-script.sh and .github/workflows/deployment-aws.yml. Then re-run the Terraform commands to avoid the regression of the problem in case you will need to terminate and re-start the instance in the future.

[yahu1031]

@AndryHTC @AmoonPod
Could you please be a little specific, like where should be changed and what?

Cause

The problem was that we required in pubspec.yaml a different Dart SDK, and both aws/terraform/init-script.sh and the .github/workflows/deployment-aws.yml install a fixed SDK, and it does not take the same you define in the pubspec.yaml.

This actually doesn't matter cause the pubspec will take the range of x.x.x - y.y.y versions.

solved the issue by upgrading the Dart SDK manually in the EC2 instance through the Session Manager console

Can you please guide me how to do it.

[AndryHTC]

@yahu1031 for upgrading manually the instance you can connect inside the AWS EC2 dashboard. If you chose your instance and click connect will appear terminal of that instance, then just update it as you do on your local machine.

Please share what you have done to the pubspec Dart SDK version for future reference.

The best way I found is to get the minimum version you choose from the pubspec.yaml and to put it in the other scripts aws/terraform/init-script.sh and .github/workflows/deployment-aws.yml. Then re-run the Terraform commands (the manual installation in the EC2 terminal will be replaced in case you will need to terminate and re-start the instance in the future, causing the same problems).

@vlidholt what is the minimum Dart SDK that Serverpod Server needs to run without problems? Does it match the default one when you create the serverpod project 2.18.0?

[yahu1031]

@AndryHTC I think min version is 2.17.0 where 2.18.0 has a lot of other upgrades. So I would recommend upgrading the pubspec version itself.

Please share what you have done to the pubspec Dart SDK version for future reference.

Sadly I've cleaned up my whole AWS 😢. So it wasn't hosted now. Waiting for certificate approval rn.

[layerzzzio]

I got the same error and @AndryHTC solution worked for me.
Let's start by describing my Dart/Flutter/Serverpod settings:

• serverpod 1.1.0
• flutter (web) 3.7.12
• dart 2.19.6

Note: with that configuration, my Flutter web app runs perfectly locally.

Objective

Changing dart version from 2.18.1 to 2.19.6 in order to fix the Bad Gateway 502 error

Note: it is possible the 502 error you encounter is not due to the version discrepancies. But in my case, this was the reason (I didn't know until I tried the solution).

Solution

1) Modify dart version in your EC2 instance

Log in to your AWS console and type EC2 in the search bar:

Click on the EC2 service and click on Instance and then on Instance ID:

Now you need to connect to your machine so you can modify the version manually:

• click first on Connect

• Choose your method (EC2 instance connect is recommended but do as you want here):

• you should see a terminal. In this terminal run the following script (that you can get from init-script.sh):

Note 1: I changed the version to 2.19.6 in the URL
Note 2: you might need to run the last command with sudo (but normally the export is already done)

echo "Installing dart"
wget -q https://storage.googleapis.com/dart-archive/channels/stable/release/2.19.6/sdk/dartsdk-linux-x64-release.zip
unzip -q dartsdk-linux-x64-release.zip
sudo mv dart-sdk/ /usr/lib/dart/
sudo chmod -R 755 /usr/lib/dart/
echo 'export PATH="$PATH:/usr/lib/dart/bin"' >> /etc/profile.d/script.sh

• Then I restarted my instance (normally not needed but I still did it - the website was not LIVE at that time)

WARNING 1: don't do that while users are using your website because it turns the webserver off. They won't have access to the website anymore.
WARNING 2: doing so scrapped the serverpod tables in the Postgres database. I recreated them by executing the tables-serverpod.pgsql script with Postico

• Connect again to your machine and in the terminal type dart --version. You should see version 2.19.6 or whatever your version should be.

2) Modify dart version in init-script.sh

So in <YOUR_PROJECT>_server/aws/terraform/init-script.sh, I changed wget -q https://storage.googleapis.com/dart-archive/channels/stable/release/2.18.1/sdk/dartsdk-linux-x64-release.zipby wget -q https://storage.googleapis.com/dart-archive/channels/stable/release/2.19.6/sdk/dartsdk-linux-x64-release.zip

3) Modify dart version in deployment-aws.yml

Changed:

      - name: Setup Dart SDK
        uses: dart-lang/setup-dart@v1.3
        with:
          sdk: 2.18.1

to

      - name: Setup Dart SDK
        uses: dart-lang/setup-dart@v1.3
        with:
          sdk: 2.19.6

4) Re-execute terraform commands

Note: I am not familiar with Terraform so the first command might not be necessary. But it doesn't hurt to do it.

Go to the following directory <YOUR_PROJECT>_server/aws/terraformand execute:

terraform init
terraform apply

5) Commit all this to GitHub and manually trigger an AWS Deployment.

Result: the Bad Gateway 502 error disappeared!

Final note: hopefully all the steps chain up well and you get your error fixed. If not, you might have to tweak a few things on your own. But most of it is in the above explanations. Credits to @AndryHTC 🙏

[vlidholt]

Converted this to a question so that more people potentially can get help from it.

[dongri727]

I’m still stuck in 502 bad gateway after these steps above
Any additional good advice ?

Serverpod 1.1.1
Flutter 3.13.9
Dart 3.1.5

I could terraform apply
I could deploy to AWS

502 on Chrome, Safari and Brave

[AndryHTC]

Any runtime error that prevents Serverpod from running will cause that error. Try to strip down and decompose your app piece by piece

[jblankenship5]

@AndryHTC when deploying to GCP I was able to view the logs from serverpod attempting to run, how can i do the same with aws?

[AndryHTC]

@AndryHTC when deploying to GCP I was able to view the logs from serverpod attempting to run, how can i do the same with aws?

I usually do a cat serverpod.log at the default ec2-user directory