[CLOUDP-350567] Automate PR creation to release helm chart using gh helm repo (#514)

# Summary

Per current process when we try to release a version of the helm chart
we create a PR to the `mongodb/helm-charts` repo. Since this is manual
task, it's time consuming and error prone.
This PR tries to automate that manual task.

## Proof of Work

The successful run
[here](https://spruce.mongodb.com/task/mongodb_kubernetes_create_chart_release_pr_create_chart_release_pr_patch_41049c8e970234d39de24bbfffeb6ac99e5c254f_68e8d76ce4a3ad00073c1ed3_25_10_10_09_52_45/logs?execution=0)
created [the PR](mongodb/helm-charts#516) on
helm chart repo successfully.

```
[2025/10/10 11:56:53.577] INFO     2025-10-10 09:56:53,577 [create_chart_release_pr]  Command succeeded
[2025/10/10 11:56:53.577] INFO     2025-10-10 09:56:53,577 [create_chart_release_pr]  Running command: git push -u origin mck-release-x.y.z in directory /data/mci/7faac8b315a48c50db2b095e7185d1ea/tmp/tmp0nfkyg_w/helm-charts
[2025/10/10 11:56:54.444] INFO     2025-10-10 09:56:54,443 [create_chart_release_pr]  Command succeeded
[2025/10/10 11:56:54.444] INFO     2025-10-10 09:56:54,444 [create_chart_release_pr]  Creating the pull request in the helm-charts repo.
[2025/10/10 11:56:55.762] INFO     2025-10-10 09:56:55,762 [create_chart_release_pr]  Successfully created Pull Request mongodb/helm-charts#516
[2025/10/10 11:56:55.801] Finished command 'subprocess.exec' in function 'create_chart_release_pr' (step 3.2 of 3) in 2.73136881s.
```

## 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

@@ -850,6 +850,23 @@ functions:
           unzip -u macos-notary.zip
           chmod 755 ./linux_amd64/macnotary
 
+  create_chart_release_pr:
+    - command: github.generate_token
+      params:
+        repo: helm-charts
+        expansion_name: GH_TOKEN
+    - command: subprocess.exec
+      type: setup
+      params:
+        working_dir: src/github.com/mongodb/mongodb-kubernetes
+        include_expansions_in_env:
+          - GH_TOKEN
+          - workdir
+          - OPERATOR_VERSION
+        env:
+          GH_TOKEN: ${GH_TOKEN}
+        binary: scripts/dev/run_python.sh scripts/release/create_chart_release_pr.py --chart_version ${OPERATOR_VERSION|*triggered_by_git_tag}
+
   release_kubectl_mongodb_plugin:
     - command: github.generate_token
       params:

.evergreen-release.yml

@@ -122,6 +122,13 @@ tasks:
       - func: install_goreleaser
       - func: install_macos_notarization_service
       - func: release_kubectl_mongodb_plugin
+    
+  - name: create_chart_release_pr
+    tags: [ "helm_chart_release_pr" ]
+    commands:
+      - func: clone
+      - func: python_venv
+      - func: create_chart_release_pr
 
 ### Release build variants
 buildvariants:
@@ -239,3 +246,12 @@ buildvariants:
     allowed_requesters: [ "patch", "github_tag" ]
     tasks:
       - name: release_kubectl_mongodb_plugin
+
+  - name: create_chart_release_pr
+    display_name: create_chart_release_pr
+    tags: [ "release" ]
+    run_on:
+      - release-ubuntu2404-small # This is required for CISA attestation https://jira.mongodb.org/browse/DEVPROD-17780
+    allowed_requesters: [ "patch", "github_tag" ]
+    tasks:
+      - name: create_chart_release_pr

requirements.txt

@@ -37,6 +37,7 @@ python-frontmatter==1.1.0
 python-on-whales==0.78.0
 yamale==6.0.0
 yamllint==1.37.1
+PyGithub==2.7.0
 
 # from kubeobject
 freezegun==1.5.5

scripts/release/create_chart_release_pr.py

@@ -0,0 +1,123 @@
+import argparse
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+from pathlib import Path
+from typing import List, Optional
+
+from github import Github, GithubException
+
+from lib.base_logger import logger
+
+REPO_URL = "https://github.com/mongodb/helm-charts.git"
+REPO_NAME = "mongodb/helm-charts"
+TARGET_CHART_SUBDIR = "charts/mongodb-kubernetes"
+BASE_BRANCH = "main"
+
+
+# run_command runs the command `command` from dir cwd
+def run_command(command: List[str], cwd: Optional[str] = None):
+    logger.debug(f"Running command: {' '.join(command)} in directory {cwd}")
+    result = subprocess.run(command, capture_output=True, text=True, cwd=cwd)
+    if result.returncode != 0:
+        raise RuntimeError(f"Command {' '.join(command)} failed. Stdout: {result.stdout}, stderr: {result.stderr}")
+    logger.debug("Command succeeded")
+    return result.stdout
+
+
+# create_pull_request creates the pull request to the helm-charts repo
+def create_pull_request(branch_name, chart_version, github_token):
+    logger.info("Creating the pull request in the helm-charts repo.")
+
+    try:
+        g = Github(github_token)
+        repo = g.get_repo(REPO_NAME)
+        pr_title = f"Release MCK {chart_version}"
+        body = f"This PR publishes the MCK chart version {chart_version}."
+
+        pr = repo.create_pull(
+            title=pr_title,
+            body=body,
+            head=branch_name,
+            base=BASE_BRANCH,
+        )
+        logger.info(f"Successfully created Pull Request {pr.html_url}")
+    except Exception as e:
+        pr_url = f"https://github.com/{REPO_NAME}/pull/new/{branch_name}"
+        raise Exception(
+            f"An unexpected error occurred while creating the PR: {e}. Please create the PR manually by following this link {pr_url}"
+        )
+
+
+def commit_and_push_chart(chart_version):
+    branch_name = f"mck-release-{chart_version}"
+
+    mck_dir = Path(".").resolve()
+    # source_chart_path is local helm chart in MCK repo
+    source_chart_path = os.path.join(mck_dir, "helm_chart")
+
+    if not os.path.isdir(source_chart_path):
+        raise Exception(f"The source chart path '{source_chart_path}' is not a valid directory.")
+
+    github_token = os.environ.get("GH_TOKEN")
+    if not github_token:
+        raise Exception("github token not found, git push will fail.")
+
+    with tempfile.TemporaryDirectory() as temp_dir:
+        helm_repo_path = os.path.join(temp_dir, "helm-charts")
+        logger.debug(f"Working in a temporary directory: {temp_dir}")
+
+        try:
+            run_command(["git", "clone", REPO_URL, helm_repo_path])
+            run_command(["git", "checkout", "-b", branch_name], cwd=helm_repo_path)
+
+            target_dir = os.path.join(helm_repo_path, TARGET_CHART_SUBDIR)
+            logger.debug(f"Clearing content from dir '{target_dir}'")
+            if os.path.exists(target_dir):
+                for item in os.listdir(target_dir):
+                    item_path = os.path.join(target_dir, item)
+                    if os.path.isdir(item_path):
+                        shutil.rmtree(item_path)
+                    else:
+                        os.remove(item_path)
+
+            logger.debug(f"Copying local MCK chart from '{source_chart_path}' to helm repo chart path {target_dir}")
+            shutil.copytree(source_chart_path, target_dir, dirs_exist_ok=True)
+
+            commit_message = f"Release MCK {chart_version}"
+            run_command(["git", "add", "."], cwd=helm_repo_path)
+            run_command(["git", "commit", "-m", commit_message], cwd=helm_repo_path)
+
+            logger.debug("Configuring remote URL for authenticated push...")
+            # Constructs a URL like https://x-access-token:[email protected]/owner/repo.git
+            authenticated_url = f"https://x-access-token:{github_token}@{REPO_URL.split('//')[1]}"
+            run_command(["git", "remote", "set-url", "origin", authenticated_url], cwd=helm_repo_path)
+            run_command(["git", "push", "-u", "origin", branch_name], cwd=helm_repo_path)
+
+            create_pull_request(branch_name, chart_version, github_token)
+
+        except Exception as e:
+            raise Exception(f"An error occurred while performing git commit and push, error: {e}")
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Automate PR creation to release MCK helm chart to github helm chart repo."
+    )
+    parser.add_argument(
+        "--chart_version", help="The version of the chart to be released (e.g., '1.3.0').", required=True
+    )
+    args = parser.parse_args()
+
+    chart_version = args.chart_version
+    try:
+        commit_and_push_chart(chart_version)
+    except Exception as e:
+        logger.error(f"Failed releasing helm chart, error: {e}")
+        raise e
+
+
+if __name__ == "__main__":
+    sys.exit(main())