How to get missing critical values in the helm chart?

186    Asked by DavidPiper in Devops , Asked on Jul 17, 2024

 There is a particular scenario where I am unable to handle a scenario where I need to deploy a helm chart by using a Configuration file however the file is missing some critical values that are required for successful deployment. How can I handle this particular scenario? 

Answered by David EDWARDS

 In the context of DevOps, here are the steps given of how you can get the missing critical values in the helm chart:-

Identify the missing values

You can use the helm template command to render the helm chart locally and identify which values are missing from your Configuration file.

  Helm template my-release my-chart -f my-values.yaml –debug

Merging default values

You can create a new Configuration file which would help in merging the default values with your custom or existing values. This can be done by using a tool such as yq or even you can manually edit this YAML file.

  Yq eval-all ‘select(fileIndex == 0) * select(fileIndex == 1)’ values.yaml my-values.yaml > merged-values.yaml

Validation of Configuration

You should try to ensure that the merged Configuration file should include all the required values. You can use the helm’s lunging feature for this validation.

Helm lint my-chart -f merged-values.yaml

Deploy with the merged Configuration

Now you can deploy the helm chart by using the newly created Configuration file.

  Helm install my-release my-chart -f merged-values.yaml

Here is an example code given in Java of how you can handle this particular scenario:-

Import com.fasterxml.jackson.databind.ObjectMapper;
Import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
Import org.yaml.snakeyaml.DumperOptions;
Import org.yaml.snakeyaml.Yaml;
Import org.yaml.snakeyaml.constructor.Constructor;
Import java.io.File;
Import java.io.IOException;
Import java.util.Map;
Public class HelmConfigurationMerger {
    Public static void main(String[] args) {
        String defaultConfigPath = “default-values.yaml”;
        String customConfigPath = “custom-values.yaml”;
        String mergedConfigPath = “merged-values.yaml”;
        Try {
            // Load default and custom configurations
            Map defaultConfig = loadYaml(defaultConfigPath);
            Map customConfig = loadYaml(customConfigPath);
            // Merge configurations
            Map mergedConfig = mergeConfigurations(defaultConfig, customConfig);
            // Validate merged configuration
            validateConfiguration(mergedConfig);
            // Save merged configuration
            saveYaml(mergedConfig, mergedConfigPath);
            System.out.println(“Merged configuration saved to: “ + mergedConfigPath);
        } catch (Exception e) {
            System.err.println(“Error: “ + e.getMessage());
        }
    }
    // Load YAML file into a Map
    Private static Map loadYaml(String filePath) throws IOException {
        ObjectMapper mapper = new ObjectMapper(new YAMLFactory());
        Return mapper.readValue(new File(filePath), Map.class);
    }
    // Merge custom configuration into default configuration
    Private static Map mergeConfigurations(Map defaultConfig, Map customConfig) {
        defaultConfig.putAll(customConfig);
        return defaultConfig;
    }
    // Validate that all required keys are present in the configuration
    Private static void validateConfiguration(Map config) throws Exception {
        String[] requiredKeys = {“replicaCount”, “image.repository”, “image.tag”, “service.port”};
        For (String key : requiredKeys) {
            If (!hasKey(config, key)) {
                Throw new Exception(“Missing required configuration key: “ + key);
            }
        }
    }
    // Check if a key exists in the nested configuration
    Private static boolean hasKey(Map config, String key) {
        String[] parts = key.split(\.);
        Map current = config;
        For (String part : parts) {
            If (current.containsKey(part)) {
                Object value = current.get(part);
                If (value instanceof Map) {
                    Current = (Map) value;
                } else {
                    Return true;
                }
            } else {
                Return false;
            }
        }
        Return true;
    }
    // Save configuration to a YAML file
    Private static void saveYaml(Map config, String filePath) throws IOException {
        DumperOptions options = new DumperOptions();
        Options.setDefaultFlowStyle(DumperOptions.FlowStyle.BLOCK);
        Yaml yaml = new Yaml(new Constructor(Map.class), options);
        Yaml.dump(config, new java.io.FileWriter(filePath));
    }
}

The provided Java-based code would provide you the robust solution for your given scenario where the critical values are missing in a helm chart configuration. This particular method would not only simplify the management of configuration files but also help in you reducing the risk of deployment failures due to missing or incorrect values. If you implement this particular solution to your scenario then it would help you in streamlining the process of deployment and also help in enhancing of the reliability of your helm based Kubernetes based application.



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