I have just started experimenting with Helm kubernetes package manager.
But chart vs template topic seems a bit confusing to me.
I understand that by template I will create kubernetes yaml, which will create the objects and install them.
However the same is true for charts as well, but this latter is an abstraction over the yamls. And ./Charts containns standalone charts, while ./templates is valid only for the base chart. So I know that. But when should I include an other chart or just create a template?
Looking for different kind of charts through the web I still don't know which to use.
Say I have a project called MyApp, which has one component named MyServer which will communicate to MySql.
So I created a chart and put in it MyServer as a template :
./MyApp/templates/MyServer.yaml
What should I do with MySql?
I have seen both solutions in different projects, one just creates an other template:
./MyApp/templates/MySQL.yaml
on other project I saw a chart for MySql from a chart repository:
./MyApp/charts/mysql-version.tgz
On the top of that I have seen a bigdata project (hdfs,kafka,zookeeper,ELK,oracle db..etc) and one component was included as chart in ./charts other was created as a template in./templates.
This whole decision between chart and template seems random and confusing to me.
Could you explain it please when to use which?
A chart is a collection of templates, plus a little extra information like the metadata in the Chart.yaml file and the default values.yaml. In your example, MyApp is itself a chart.
For well-known dependencies (particularly things in the Helm charts repository and especially the stable charts) you're probably better off using the external chart; declare the dependency in your requirements.yaml or (Helm v3) Chart.yaml file and run helm dependency update. This lets you import the chart with two lines, rather than reproducing the StatefulSet, PersistentVolumeClaim, etc. that are included in the chart.
Related
lately I was experimenting with Skaffold with our Helm Charts and I am in little bit in a dilemma that our Helm Chart \ Sub Charts are compatible with Skaffold or not.
Our helm Charts are looking like the following
my-helm-charts
+-charts
+-project1
+-project2
+-project3
+-project4
+-infrastructure_kafka
+-charts
+-kafka
+-zookeeper
+-infrastructure_cassandra
+-infrastructure_elasticsearch
+-Charts.yaml
+-Values.yaml
The reason we choosed to structure the Helm Charts this way, is that if necessary to spin up extra stages for our project.
Now when I want to develop project2 with Google Cloud Code / Skaffold (which I configured correctly and I can start without problem in IntelliJ) I have to start whole my-helm-charts.
That is actually Ok but the problem is, if I use Debug in Kubernetes, I have a feeling Google Cloud Code/Skaffold can really locate the project2 and no debugging occurs.
My feeling is Google Cloud/Skaffold is more oriented to work with following contruct...
project2-helm
+-templates
+-Charts.yaml
+-Values.yaml
My Subcharts contructs starts in Google Cloud Code/Skaffold without any exception but I can't debug, is it possible to achieve want I want with my structure and if yes, how?
Or is it not possible at all...
Thx for answers...
We recently added a feature called config dependencies which might help here. It allows you to create more specific skaffold.yamls and then map them together with a "requires" field:
https://skaffold.dev/docs/design/config/#configuration-dependencies
Once you have the skaffold.yamls created and the right dependency mapping you can run skaffold with the -m flag to choose once slice of your services:
skaffold dev -m project3
Cloud Code support for modules is incoming.
Cloud Code IntelliJ and Cloud Code VS Code recently added preview level support for deploying and debugging modules of a larger application which uses Skaffold. See more here https://cloud.google.com/code/docs/intellij/skaffold-modules
I deployed the kube-prometheus-stack helm chart. While this chart offers a really nice starting point it has lots of default dashboards which I do not want to use. In the values.yaml of the chart, there is an option defaultDashboardsEnabled: true, which seems to be what I am looking for but if I set it to false using the code below in my values file, which I mount into the helm chart, the dashboards are still there. Does anyone know why this does not work?
A possibility which I thought of is that the chart has both a subchart called grafana and an option grafana, but I do not know how I could fix it or test if this is the issue.
grafana:
defaultDashboardsEnabled: false
I`m placing this answer to better visibility as community might interested in other solutions.
First way would be setting grafana.enable: to false in values.yaml.
## Using default values from https://github.com/grafana/helm-charts/blob/main/charts/grafana/values.yaml
grafana:
enabled: true
With this your chart will not install grafana.
Another way would be to helm pull the chart to your local directory and then just delete the template.grafana directory (to launch the chart locally you just need to helm install <name> ./prometheus-stack)
I solved the issue by removing the namespace where Grafana was located. Apparently, there has been some resource left which was not removed by uninstalling the helm chart.
Edit:
The problem seems to be with the configmaps. It appears that in some of these the old configuration is saved even though it has already been changed in the helm chart. Removing the Grafana deployment and all the config maps in the regarding namespace worked for me.
Surely it is not necessary to remove all configmaps but I did not have the time to find out which one is the problem.
I have a query related with prometheus-operator helm chart & alert manager combination.
Currently we are using prometheus-operator helm chart:
https://github.com/helm/charts/tree/master/stable/prometheus-operator
and I wrote a simple rule in values.yml (this is just a sample code) to generate an alert:
further I am using alertmanager config/routes/receivers to send alerts. It's working perfectly fine.
But as part of real-time implementation, I may be having so many alert rules. Is there any way where I can bring these all rules in separate rules file & configure the path (rule file path) in values.yml (under: additionalPrometheusRules section)
I also saw kube-prometheus-stack & additionalPrometheusRulesMap (in values.yml):
https://github.com/prometheus-community/helm-charts/blob/main/charts/kube-prometheus-stack/values.yaml
But didn't fine any solution. Anyone can help me on this?
So helm doesn't allow includes in values.yaml files typically. I read that there's a way to do it, but it depends on how the chart is built and typically upstream maintainers don't use templates that way afaik (could be wrong there, but I've never noticed it).
Your problem is exactly the same problem I've been trying to solve adequately, and I think I came up with something. It's not perfect, but it is better than having one huge monolithic values.yaml file.
helm allows the operator to specify multiple values.yaml files using the paradigm, -f values1.yaml -f values2.yaml -f some-more-values.yaml, so I broke my values file up into multiple logically-divided yaml files.
There might be gotchas, so be aware, but so far for this use-case, it seems to be working. I'm still testing things out. https://helm.sh/docs/helm/helm_install/
You can also add your own custom rules file using config maps. In this way, you can avoid over alerting and get notified for specific alerts only.
I look at this help requirement:
dependencies:
- name: postgresql
version: 8.6.2
repository: https://kubernetes-charts.storage.googleapis.com/
condition: postgresql.installdep.enable
Source: https://github.com/reportportal/kubernetes/blob/master/reportportal/v5/requirements.yaml
Postgres 8 is very very old. I guess this version is just the version of some package.
But how can I get more information about this package?
I look at https://kubernetes-charts.storage.googleapis.com/. But this URL seems made for robots, not for humans.
How can I (as a human) find more details about this dependency?
It looks like you can find the chart here: https://github.com/helm/charts/tree/master/stable/postgresql
It's current version is 8.6.4.
Your dependency looks like it references this PR and this version.
Also, as an aside that refers to the Chart version, not the postgres version. It looks like the current Chart is for postgres 11.
You can use helm dependency update locally: https://helm.sh/docs/helm/helm_dependency_update/
This will download all the dependencies to the ./charts subdir where you can check its contents and default vars.
Requirements.yaml is used to list Chart dependencies. Those dependencies can be built using helm dependency build from requirement.lock file.
Version describes chart version, not the image itself.
All necessary information about the chart are described in values.yaml- you can find there information about images to be installed, it's version etc. In this case it's postgresql:11.7.0.
You can retrieve information about the chart by using helm show values <chart_name> (chart doesn't have to be installed in the cluster) or it can be found on chart's github/ helm hub repository.
I'd like to check that my kubernetes helm chart does not define unused values in values.yaml. This should include any subcharts such that if you've defined subchart.foo.bar: ??? in the top-level values.yaml that key is definitely used in the subchart, or possibly as a short-cut mentioned in the subchart/values.yaml.
This is needed to prevent us from shipping bogus "documentation" in the values.yaml, for example if a key in a subchart has been changed or removed.
Ideally there would also be some possibility to report on which subchart values have not been overridden in the top-level chart, though this is less concerning.
Are there any existing tools that can help with this?
Since the Helm v3 release you can now define a schema for your values. On commands like helm install your provided values are automatically validated against the schema.
Please see the official documentation: https://helm.sh/docs/topics/charts/#schema-files
Schema validation works for subcharts too, this is also mentioned in the documentation on the link above.
AFAIK, there isn't a tool for that. However, it shouldn't be that hard to make one, even using bash. For example, you need to export all key/value pairs like this test.test1.test2 and grep for that string recursively in the templates folder. If you want to read yaml using bash, you can install shyaml. If you know how to code in Python, even better.
helm lint --detect-unused-values