cli: add release-helm command

* Closes reanahub#363.

reana/reana_dev/release.py

@@ -8,23 +8,28 @@
 
 """`reana-dev`'s release commands."""
 
+import os
+import re
 import sys
 from time import sleep
 
 import click
 import semver
 
 from reana.reana_dev.docker import docker_push
+from reana.config import REPO_LIST_CLUSTER
 from reana.reana_dev.git import (
     git_clean,
     git_is_current_version_tagged,
     is_last_commit_release_commit,
 )
 from reana.reana_dev.utils import (
+    bump_component_version,
     display_message,
     fetch_latest_pypi_version,
     get_current_component_version_from_source_files,
     get_current_tag,
+    get_srcdir,
     is_component_dockerised,
     parse_pep440_version,
     run_command,
@@ -68,6 +73,26 @@ def is_component_releasable(component, exit_code=False, display=False):
     return is_releasable
 
 
+def get_component_version_as_semver2(component):
+    """Get Docker release friendly component version (semver2)."""
+    docker_tag = ""
+    current_tag = get_current_tag(component)
+
+    if parse_pep440_version(current_tag):
+        docker_tag = translate_pep440_to_semver2(current_tag)
+    elif semver.VersionInfo.isvalid(current_tag):
+        docker_tag = current_tag
+    else:
+        display_message(
+            f"The component's latest tag ({current_tag}) is not a "
+            "valid version (nor PEP440 nor semver2 compliant).",
+            component,
+        )
+        sys.exit(1)
+
+    return docker_tag
+
+
 @click.group()
 def release_commands():
     """Release commands group."""
@@ -112,21 +137,8 @@ def release_docker(ctx, component, user, image_name):  # noqa: D301
             cannot_release_on_dockerhub.append(component_)
         is_component_releasable(component_, exit_code=True, display=True)
 
-        current_tag = get_current_tag(component_)
         full_image_name = f"{user}/{image_name or component_}"
-        docker_tag = ""
-
-        if parse_pep440_version(current_tag):
-            docker_tag = translate_pep440_to_semver2(current_tag)
-        elif semver.VersionInfo.isvalid(current_tag):
-            docker_tag = current_tag
-        else:
-            display_message(
-                f"The component's latest tag ({current_tag}) is not a "
-                "valid version (nor PEP440 nor semver2 compliant).",
-                component_,
-            )
-            sys.exit(1)
+        docker_tag = get_component_version_as_semver2(component_)
 
         run_command(
             f"docker tag {full_image_name}:latest {full_image_name}:{docker_tag}",
@@ -202,4 +214,82 @@ def release_pypi(ctx, component, timeout):  # noqa: D301
         click.secho(f"{component} successfully released on PyPI", fg="green")
 
 
+@click.option(
+    "--version", "-v", help="REANA version to release, e.g. 0.7.0a1",
+)
+@click.option("--user", "-u", default="reanahub", help="DockerHub user name [reanahub]")
+@release_commands.command(name="release-helm")
+@click.pass_context
+def release_helm(ctx, version, user):  # noqa: D30
+    """Release REANA as a Helm chart.
+
+    \b
+    :param components: The option ``component`` can be repeated. The value may
+                       consist of:
+                         * (1) standard component name such as
+                               'reana-workflow-controller';
+                         * (2) short component name such as 'r-w-controller';
+                         * (3) special value '.' indicating component of the
+                               current working directory;
+                         * (4) special value 'CLUSTER' that will expand to
+                               cover all REANA cluster components [default];
+                         * (5) special value 'CLIENT' that will expand to
+                               cover all REANA client components;
+                         * (6) special value 'DEMO' that will expand
+                               to include several runable REANA demo examples;
+                         * (7) special value 'ALL' that will expand to include
+                               all REANA repositories.
+    :type component: str
+    """
+
+    def _update_values_yaml(new_docker_images):
+        """Update all images in ``values.yaml``, skipping the ones up to date."""
+        update_images_cmds = []  # FIXME
+        values_yaml_relative_path = "helm/reana/values.yaml"
+        values_yaml_abs_path = os.path.join(
+            get_srcdir("reana"), values_yaml_relative_path
+        )
+        values_yaml = ""
+
+        with open(values_yaml_abs_path) as f:
+            values_yaml = f.read()
+            for docker_image in new_docker_images:
+                image_name, _ = docker_image.split(":")
+                if image_name in values_yaml:
+                    values_yaml = re.sub(
+                        f"{image_name}:.*", lambda _: docker_image, values_yaml, count=1
+                    )
+
+        with open(values_yaml_abs_path, "w") as f:
+            f.write(values_yaml)
+
+    remaining_docker_releases = []
+    new_docker_images = []
+    for component in REPO_LIST_CLUSTER:
+        if not is_component_dockerised(component):
+            continue
+        if not git_is_current_version_tagged(component):
+            remaining_docker_releases.append(component)
+        else:
+            new_docker_images.append(
+                f"{user}/{component}:{get_component_version_as_semver2(component)}"
+            )
+
+    if remaining_docker_releases:
+        line_by_line_missing_releases = "\n".join(remaining_docker_releases)
+        click.secho(
+            "The following components are missing to be released:\n"
+            f"{line_by_line_missing_releases}",
+            fg="red",
+        )
+        sys.exit(1)
+
+    _update_values_yaml(new_docker_images)
+    version = bump_component_version(
+        "reana",
+        get_current_component_version_from_source_files("reana"),
+        next_version=version,
+    )
+
+
 release_commands_list = list(release_commands.commands.values())