I am new to the Kubernetes and especially using helm. I installed the charts and it works fine with default values. I want to the add smtp server setting in the values.yml file for the chart. I am confused on how to inject the values while installing the chart. This is the chart that I am using https://github.com/helm/charts/tree/master/stable/prometheus-operator. After installing the helm chart with default values I see that there is a deployment called prometheus-operator-grafana which has values GF_SECURITY_ADMIN_USER and GF_SECURITY_ADMIN_PASSWORD but I am not sure where these values are coming from. Help with how these values work and how to inject them would be appreciated.
The interaction between parent and child chart values is summarize very well in this SO answer: helm overriding Chart and Values yaml from a base template chart
There are two separate grafana chart mechanisms that control such a thing: adminUser and adminPassword or admin.existingSecret along with admin.userKey and admin.passwordkey
Thus, helm ... --set grafana.adminUser=ninja --set grafana.adminPassword=hunter2 will do what you want. The fine manual even says they are using grafana as a subchart, and documents that exact setting as the first value underneath the grafana.enabled setting. Feel free to file an issue with the helm chart to spend the extra characters and document the grafana.adminUser setting, too