How can we override dependencies "version" in helm chart Chart.yaml file? - kubernetes-helm

Question

I am wondering and apparently have not yet found anywhere if there is a way via which I can specifically override the value of "version" key's value from the dependencies chart in Helm
# Chart.yaml
dependencies:
- name: bitnami/postgresql
version: **"8.10.5"**
repository: "https://charts.bitnami.com/bitnami"
I tried something like below:
# Chart.yaml
dependencies:
- name: bitnami/postgresql
version: "{{.Values.postgresql.version}}"
repository: "https://charts.bitnami.com/bitnami"
and
# Values.yaml
postgreSQL:
version: "8.10.5"
But I am getting below error:
Error: cannot load Chart.yaml: error converting YAML to JSON: yaml: invalid map key: map[interface {}]interface {}{".Values.postgresql.version":interface {}(nil)}
If this is currently not possible then can someone advise how do you update the "version" of dependencies in Charts.yaml whenever new version is available of them?

Answer 1

It's not super well documented in the Helm documentation – the generic helm dependency command documentation mentions it, but not the main discussion of chart dependencies – but the version: field is optional, and it uses semantic versioning if it is present. Helm maintains a separate Chart.lock file that lists precise versions of chart dependencies, and the helm dependency update command will update that file.
So for your uses you might say:
dependencies:
- name: bitnami/postgresql
version: '^8' # Any 8.x.x version, but not version 7 or 9
repository: "https://charts.bitnami.com/bitnami"
Or, if you're not configuring the dependency chart at all, just leave out the version: line entirely and use whatever the latest version is.
# Install the chart using the specific Chart.lock version
helm install myservice .
# Get a newer version in Chart.lock and upgrade the database
rm Chart.lock
helm dependency update
helm upgrade myservice .
Do check the Chart.lock file into source control, so you have reproducible deployments.
All of this is also true if you're using the older, Helm v2-compatible layout that lists dependencies in a separate requirements.yaml file. In this case the lock file is requirements.lock, but version: is still a semantic version constraint and the same helm dependency commands update the lock file.

Answer 2

Your approach won't work, because the template engine ({{ .Values.myvar }}) works only in the template folder.
# Chart.yaml
dependencies:
- name: bitnami/postgresql
version: "{{.Values.postgresql.version}}" # Won't be replaced
repository: "https://charts.bitnami.com/bitnami"
I am afraid that the helm team won't change this behaviour according to this discussion:
https://github.com/helm/helm/issues/2492
Apperantly the only way I can think of, is to replace the version with a shell script and afterwards calling the helm commando.
sed -i 's/version: "[0-9].[0-9].[0-9]"/version: "9.9.9"/' Chart.yaml
helm install ....