title: How do you push updated container images to AWS ECR?
body: <p>So my understanding of containers and the associated terminology is tenuous at best, so if I say anything completely off please correct me.</p>
  <p>I have a Lambda function that I am publishing as a container instance.  I successfully pushed my container and ran my Lambda code, which had a bug (side note:  Is there really no other way to test minor code changes rather than rebuild and push the entire container every time?  I'm not using SAM, which is a decision I regret and am stuck with).</p>
  <p>I went to fix the bug, and the absolute only thing I can find is the original commands:</p>
  <pre><code>docker build -T CONTAINER-NAME .
  
  aws ecr create-repository --repository-name CONTAINER-NAME --image-scanning-configuration scanOnPush=true
  docker tag CONTAINER-NAME:latest 1234.dkr.ecr.us-west-2.amazonaws.com/CONTAINER-NAME:latest
  aws ecr get-login-password | docker login --username AWS --password-stdin 1234.dkr.ecr.us-west-2.amazonaws.com
  docker push 1234.dkr.ecr.us-west-2.amazonaws.com/CONTAINER-NAME:latest
  </code></pre>
  <p>These worked fine the first time around but now run without error, but do not update my image.  I suspect it has to do with the tags, which the documentation is very unclear about--are they just tags like the rest of AWS resources', or something more?.  I've experimented with different combinations of changing tags, which generally leads to errors about a given tag or repo not existing.</p>