vercel-labs / blue-green Goto Github PK

Hi Vercel Team,

Thank you for providing this template! We've gone through the official detailed guide and got an unexpected behavior. Hopefully you'll be able to bring a little more clarity to it.

Here are the steps we've performed:

• Deployed the project from template
• Activated Skew Protection (set it to 12 hours just in case)
• Activated Deployment Protection Bypass
• Disabled Auto-Assign Custom Production Domains
• Created an edge config with the given structure and assigned it to the project

After configuring the template:

• Made 1st commit (blue)
• Got a new staged deployment for blue (name: kpta06k8s, deployment_id: 3hLGq19X25VdZJRJb4GgrZKj8uZB)
• Promoted it to production (let's assume it's our current production version now), assigned domain: bg-deployment.vercel.app
• Made 2nd commit (green)
• Got a new staged deployment for green (name: dvlhqub4s, deployment_id: APj98qJsXj7KkUVZ6uNerj2it18o)
• Left it in a staged (let's assume it's our next production version, which we'd like to test on a limited number of users).

Finally, we've made changes to edge config:

{
  "blue-green-configuration": {
    "deploymentDomainBlue": "bg-deployment-kpta06k8s-xxx.vercel.app",
    "deploymentDomainGreen": "bg-deployment-dvlhqub4s-xxx.vercel.app",
    "trafficGreenPercent": 50
  }
}

Now, according to the guide, that should be it - green deployment is still staged, but we've already started splitting the traffic.

Expected result:

• We continue working with default domain for current production: bg-deployment.vercel.app
• We have both deployments working

Observed result:

• Blue deployment continues working fine under https://bg-deployment.vercel.app/

• Green deployment loads the page, but fails to load static assets:

And the most curios thing is

• If we go to staged green deployment dvlhqub4s and access it under https://bg-deployment-xxx.vercel.app/
• Both blue and green will work:
  
  

What we've also learned

• If we will go and promote green deployment to be active production
• Both blue and green will start working under https://bg-deployment.vercel.app/ (though on a previous step they did not work)
• Good! but it contradicts with an idea of testing green deployment first, and only after that making it active

PS:

• We've checked the latest commit from May 15th (commit id: 5d4ce15)
• With all the same steps above, green staged deployment stopped serving blue-green at all (bc of the new condition added)

We will appreciate you can clarify this behavior and let us know how to make this schema work like it is described in the guide, or let us know if there is smth that is slipping away from us.

Thanks in advance!
Alex