How to see what has changed in new helm chart relase

Question

I would like to see the changes made to the helm chart compared to its previous release - running helm list i see there were xx revisions - any way to see differences ? I know about rollback helm rollback <RELEASE> 0 but just wanted to know what's changed

Anni

Answer 1

On helm website you can find some plugins. One of them called helm-diff, and it can generate diffs between releases.

Here is how to use this plugin:

$ helm diff release -h

This command compares the manifests details of a different releases created from the same chart

It can be used to compare the manifests of

 - release1 with release2
    $ helm diff release [flags] release1 release2
   Example:
    $ helm diff release my-prod my-stage

Here is explained how to install the plugin. TLDR: if you are using helm version > 2.3.x jest run:

helm plugin install https://github.com/databus23/helm-diff

Let me know it this solves your problem. If you have any further questions I'd be happy to answer them.

Humour

not really what I was looking for - comparing two different release of the same chart, but rather two revisions of the same release – Anni

Well, then use helm diff revision. Its the same plugin. – Humour

Please note that you need to have a cluster running for helm diff revision to work. Otherwise, you will get dial tcp ...: connect: connection refused and the plugin exits – Podagra

Answer 2

Diff against the previous release, using the traefik chart as example:

First, get the previous release revision number, assuming there is more than one (Note: Beware of edge cases, e.g. when there's no release or only one release):

previous_release="$(helm history -n kube-system traefik | tail -2 | head -1 | cut -f 1 -d' ')"

Then compare it against the latest one:

helm diff -n kube-system revision traefik "$previous_release"

Undercurrent