Homework

Apply validation and linting skills to a realistic chart with comprehensive schema enforcement.

Task 1 — Comprehensive values.schema.json

Create a new Helm chart (helm create webapp) and write a values.schema.json that enforces all of the following constraints:

• replicaCount is a required integer between 1 and 50
• image.repository is a required non-empty string
• image.tag must match semver pattern: ^v?[0-9]+\.[0-9]+\.[0-9]+(-[a-zA-Z0-9.]+)?$
• image.pullPolicy must be one of Always, IfNotPresent, or Never
• service.type must be one of ClusterIP, NodePort, or LoadBalancer
• service.port must be an integer between 1 and 65535
• ingress.enabled must be a boolean
• resources.limits and resources.requests are objects with optional cpu (string) and memory (string) fields

After writing the schema:

1. Run helm lint . with the default values.yaml — fix any issues until it passes
2. Create a test-bad-values.yaml with at least 5 distinct schema violations and verify they are all reported

Task 2 — Full Validation Pipeline Script

Write a shell script called ci-validate.sh that implements the complete validation pipeline for any chart directory passed as an argument:

1. Stage 1: helm lint --strict
2. Stage 2: helm template renders without errors
3. Stage 3: kubeconform -strict validates rendered YAML against a configurable Kubernetes version (default 1.29.0, overridable via K8S_VERSION environment variable)

Requirements:

• The script must exit immediately on the first stage failure (set -euo pipefail)
• Each stage must print a clear header (e.g., ==> Stage 1: Linting...)
• On success, print a summary line; on failure, print which stage failed
• Support an optional -f values-file.yaml flag to pass a custom values file to all stages

Test the script against your Task 1 chart with both valid and invalid values.

Task 3 — Error Catalogue

Create a document (text file or markdown) that catalogues at least 8 distinct Helm chart errors, organized by which tool catches them. For each error, provide:

• The exact code or configuration that causes the error
• Which tool detects it (helm lint, helm template, kubeconform, or helm install --dry-run=server)
• The error message produced
• The fix

Your catalogue must include at least two errors from each of these categories:

• Structural: missing Chart.yaml fields, invalid YAML syntax
• Template: nil pointers, scope errors, wrong indentation
• Schema: type mismatches, enum violations, missing required fields
• Kubernetes: misspelled fields, deprecated APIs, invalid resource specs

Grading Rubric