[CLOUDP-343558] Run helm chart-testing tool ct as part of CI (lint_repo) (#450)

# Summary

Whenever we raised PR in to helm chart repo CI failed there because we
had linting issues in our helm chart. A previous PR that [I
raised](#445) fixed
the linting problem. But we should have a linting mechanism in our CI
that would consistently check if we have made any mistake in our charts.
This PR does that.

The `chart_schema.yaml` and `lintconf.yaml` are the default yaml files
using which `ct` should be run. And `ct` is the tool that is used for
linting in our helm charts repo.

## Proof of Work

Passing `lint_repo` task here
https://spruce.mongodb.com/version/68c43aae1d5d5d000770c624/tasks?sorts=STATUS%3AASC%3BBASE_STATUS%3ADESC
and in this PR as well.

## Checklist

- [x] Have you linked a jira ticket and/or is the ticket in the title?
- [x] Have you checked whether your jira ticket required DOCSP changes?
- [x] Have you added changelog file?
    - use `skip-changelog` label if not needed
- refer to [Changelog files and Release
Notes](https://github.com/mongodb/mongodb-kubernetes/blob/master/CONTRIBUTING.md#changelog-files-and-release-notes)
section in CONTRIBUTING.md for more details

Author: viveksinghggits

.evergreen-functions.yml

@@ -250,6 +250,13 @@ functions:
         add_to_path:
           - ${workdir}/bin
         command: scripts/evergreen/setup_yq.sh
+    - command: subprocess.exec
+      type: setup
+      params:
+        working_dir: src/github.com/mongodb/mongodb-kubernetes
+        add_to_path:
+          - ${workdir}/bin
+        command: scripts/dev/setup_chart_testing_cli.sh
     - command: subprocess.exec
       type: test
       params:

.githooks/pre-commit

@@ -163,6 +163,10 @@ lint_code() {
   scripts/evergreen/lint_code.sh
 }
 
+lint_helm_chart() {
+  scripts/dev/lint_helm_chart.sh
+}
+
 function validate_snippets() {
   scripts/code_snippets/validate_snippets.py
 }
@@ -222,6 +226,7 @@ pre_commit() {
   run_job_in_background "python_formatting"
   run_job_in_background "check_erroneous_kubebuilder_annotations"
   run_job_in_background "validate_snippets"
+  run_job_in_background "lint_helm_chart"
 
   if wait_for_all_background_jobs; then
     echo -e "${GREEN}pre-commit: All checks passed!${NO_COLOR}"

Makefile

@@ -420,3 +420,7 @@ prepare-local-olm-e2e:
 
 prepare-operator-configmap: # prepares the local environment to run a local operator
 	source scripts/dev/set_env_context.sh && source scripts/funcs/printing && source scripts/funcs/operator_deployment && prepare_operator_config_map "$(kubectl config current-context)"
+
+# Lint the helm chart using helm chart-testing tool (`ct`) using the default configuration available at `helm_chart/tests/schemas/`
+lint-chart:
+	scripts/dev/lint_helm_chart.sh

helm_chart/tests/schemas/chart_schema.yaml

@@ -0,0 +1,37 @@
+name: str()
+home: str(required=False)
+version: str()
+apiVersion: str()
+appVersion: any(str(), num(), required=False)
+description: str(required=False)
+keywords: list(str(), required=False)
+sources: list(str(), required=False)
+maintainers: list(include('maintainer'), required=False)
+dependencies: list(include('dependency'), required=False)
+icon: str(required=False)
+engine: str(required=False)
+condition: str(required=False)
+tags: str(required=False)
+deprecated: bool(required=False)
+kubeVersion: str(required=False)
+annotations: map(str(), str(), required=False)
+type: str(required=False)
+---
+maintainer:
+  name: str()
+  email: str(required=False)
+  url: str(required=False)
+---
+dependency:
+  name: str()
+  version: str()
+  repository: str(required=False)
+  condition: str(required=False)
+  tags: list(str(), required=False)
+  enabled: bool(required=False)
+  import-values: list(any(str(), include('import-value')), required=False)
+  alias: str(required=False)
+---
+import-value:
+  child: str()
+  parent: str()

helm_chart/tests/schemas/lintconf.yaml

@@ -0,0 +1,42 @@
+---
+rules:
+  braces:
+    min-spaces-inside: 0
+    max-spaces-inside: 0
+    min-spaces-inside-empty: -1
+    max-spaces-inside-empty: -1
+  brackets:
+    min-spaces-inside: 0
+    max-spaces-inside: 0
+    min-spaces-inside-empty: -1
+    max-spaces-inside-empty: -1
+  colons:
+    max-spaces-before: 0
+    max-spaces-after: 1
+  commas:
+    max-spaces-before: 0
+    min-spaces-after: 1
+    max-spaces-after: 1
+  comments:
+    require-starting-space: true
+    min-spaces-from-content: 2
+  document-end: disable
+  document-start: disable           # No --- to start a file
+  empty-lines:
+    max: 2
+    max-start: 0
+    max-end: 0
+  hyphens:
+    max-spaces-after: 1
+  indentation:
+    spaces: consistent
+    indent-sequences: whatever      # - list indentation will handle both indentation and without
+    check-multi-line-strings: false
+  key-duplicates: enable
+  line-length: disable              # Lines can be any length
+  new-line-at-end-of-file: enable
+  new-lines:
+    type: unix
+  trailing-spaces: enable
+  truthy:
+    level: warning

requirements.txt

@@ -35,6 +35,8 @@ botocore==1.40.7
 boto3==1.40.7
 python-frontmatter==1.1.0
 python-on-whales==0.78.0
+yamale==6.0.0
+yamllint==1.37.1
 
 # from kubeobject
 freezegun==1.5.5

scripts/dev/install.sh

@@ -4,7 +4,7 @@ set -Eeou pipefail
 source scripts/funcs/printing
 source scripts/dev/set_env_context.sh
 
-tools="kubectl helm coreutils kind jq shellcheck python@${PYTHON_VERSION}"
+tools="kubectl helm coreutils kind jq shellcheck python@${PYTHON_VERSION} chart-testing"
 echo "The following tools will be installed using homebrew: ${tools}"
 echo "Note, that you must download 'go' and Docker by yourself"
 
@@ -28,6 +28,9 @@ elif [ "$(uname)" = "Linux" ] ; then # Ubuntu only
 
   sudo snap install --channel=edge shellcheck
 
+  # install helm chart testing tool chart-testing (ct)
+  ./setup_chart_testing_cli.sh
+
 else
   echo "This only works on OSX & Ubuntu - please install the tools yourself. Sorry!"
   exit 1

scripts/dev/lint_helm_chart.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+set -Eeou pipefail
+
+source scripts/dev/set_env_context.sh
+
+if ! command -v ct &> /dev/null; then
+  echo "Error: 'ct' command not found in PATH. Please download it from here https://github.com/helm/chart-testing" >&2
+  exit 1
+fi
+
+if [ -z "${PROJECT_DIR}" ]; then
+  echo "Error: PROJECT_DIR environment variable is not set. Please set a context or set it (PROJECT_DIR var) to your local MCK repo manually." >&2
+  exit 1
+fi
+
+# the binaries yamale and yamllint required by ct are available at `${PROJECT_DIR}/venv/bin`
+export PATH=${PROJECT_DIR}/venv/bin:${PATH}
+
+ct lint --charts="${PROJECT_DIR}/helm_chart/" \
+    --chart-yaml-schema "${PROJECT_DIR}/helm_chart/tests/schemas/chart_schema.yaml" \
+    --lint-conf "${PROJECT_DIR}/helm_chart/tests/schemas/lintconf.yaml"

scripts/dev/setup_chart_testing_cli.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+# A script Evergreen will use to setup helm chart testing CLI (https://github.com/helm/chart-testing)
+#
+# This should be executed from root of the evergreen build dir
+
+set -Eeou pipefail
+
+source scripts/dev/set_env_context.sh
+
+if [[ -n "${PROJECT_DIR:-}" ]]; then
+  bindir="${PROJECT_DIR}/bin"
+  tmpdir="${PROJECT_DIR}/tmp"
+else
+  bindir="${GOPATH}/bin"
+  tmpdir="${GOPATH}/tmp"
+fi
+
+mkdir -p "${bindir}" "${tmpdir}"
+
+curl -s --retry 3 -L -o "${tmpdir}/chart-testing_3.13.0_linux_amd64.tar.gz" "https://github.com/helm/chart-testing/releases/download/v3.13.0/chart-testing_3.13.0_linux_amd64.tar.gz"
+tar xvf "${tmpdir}/chart-testing_3.13.0_linux_amd64.tar.gz" -C "${tmpdir}/"
+mv "${tmpdir}/ct" "${bindir}"