title: How to set environment variables in Dockerized web app in Azure Devops release definition
body: <p>I currently have a build pipeline in Azure DevOps that builds a docker image with an Angular web app and pushes it to an Azure Container Registry. I also have a release pipeline that deploys that docker image to an Azure App Service for my DEV environment. The environment variables for DEV are currently hard-coded in the config file.</p>
  
  <p>I want to set up the release pipeline so that it can deploy to DEV, TST and PRD environments using the same image. For an on-prem app, I would normally just take the config file from with tokenized variables from the build artifact and use an ADO release task to replace the tokens with the environment specific variables. I don't think I can do that here since the config file now gets baked in with the Docker image during the build pipeline. Any ideas on how this is usually handled?</p>