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Unverified Commit 6950f38f authored by Alessio Caiazza's avatar Alessio Caiazza
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Install k8s application with helm running inside the cluster

parent 48c4f1ea187f
module Clusters
module Concerns
end
end
module Clusters
module Concerns
module AppStatus
extend ActiveSupport::Concern
included do
state_machine :status, initial: :scheduled do
state :errored, value: -1
state :scheduled, value: 0
state :installing, value: 1
state :installed, value: 2
event :make_installing do
transition any - [:installing] => :installing
end
event :make_installed do
transition any - [:installed] => :installed
end
event :make_errored do
transition any - [:errored] => :errored
end
before_transition any => [:errored] do |app_status, transition|
status_reason = transition.args.first
app_status.status_reason = status_reason if status_reason
end
end
end
end
end
end
module Clusters
module Kubernetes
def self.table_name_prefix
'clusters_kubernetes_'
end
def self.app(app_name)
case app_name
when HelmApp::NAME
HelmApp
else
raise ArgumentError, "Unknown app #{app_name}"
end
end
end
end
module Clusters
module Kubernetes
class HelmApp < ActiveRecord::Base
NAME = 'helm'.freeze
include ::Clusters::Concerns::AppStatus
belongs_to :kubernetes_service, class_name: 'KubernetesService', foreign_key: :service_id
default_value_for :version, Gitlab::Clusters::Helm::HELM_VERSION
alias_method :cluster, :kubernetes_service
def name
NAME
end
end
end
end
......@@ -3,6 +3,8 @@ class KubernetesService < DeploymentService
include Gitlab::Kubernetes
include ReactiveCaching
has_one :helm_app, class_name: 'Clusters::Kubernetes::HelmApp', foreign_key: :service_id
self.reactive_cache_key = ->(service) { [service.class.model_name.singular, service.project_id] }
# Namespace defaults to the project path, but can be overridden in case that
......@@ -136,6 +138,10 @@ def calculate_reactive_cache
{ pods: read_pods }
end
def helm
Gitlab::Clusters::Helm.new(build_kubeclient!)
end
TEMPLATE_PLACEHOLDER = 'Kubernetes namespace'.freeze
private
......
module Clusters
class BaseHelmService
attr_accessor :app
def initialize(app)
@app = app
end
protected
def helm
return @helm if defined?(@helm)
@helm = @app.cluster.helm
end
end
end
module Clusters
class FetchAppInstallationStatusService < BaseHelmService
def execute
return unless app.installing?
phase = helm.installation_status(app)
log = helm.installation_log(app) if phase == 'Failed'
yield(phase, log) if block_given?
rescue KubeException => ke
app.make_errored!("Kubernetes error: #{ke.message}") unless app.errored?
end
end
end
module Clusters
class FinalizeAppInstallationService < BaseHelmService
def execute
helm.delete_installation_pod!(app)
app.make_errored!('Installation aborted') if aborted?
end
private
def aborted?
app.installing? || app.scheduled?
end
end
end
module Clusters
class InstallAppService < BaseHelmService
def execute
return unless app.scheduled?
begin
helm.install(app)
if app.make_installing
ClusterWaitForAppInstallationWorker.perform_in(
ClusterWaitForAppInstallationWorker::INITIAL_INTERVAL, app.name, app.id)
else
app.make_errored!("Failed to update app record; #{app.errors}")
end
rescue KubeException => ke
app.make_errored!("Kubernetes error: #{ke.message}")
rescue StandardError => e
Rails.logger.warn(e.message)
app.make_errored!("Can't start installation process")
end
end
end
end
module Clusters
class InstallTillerService < BaseService
def execute
ensure_namespace
install
end
private
def kubernetes_service
return @kubernetes_service if defined?(@kubernetes_service)
@kubernetes_service = project&.kubernetes_service
end
def ensure_namespace
kubernetes_service&.ensure_namespace!
end
def install
kubernetes_service&.helm_client&.init!
end
end
end
class ClusterInstallAppWorker
include Sidekiq::Worker
include ClusterQueue
include ClusterApp
def perform(app_name, app_id)
find_app(app_name, app_id) do |app|
Clusters::InstallAppService.new(app).execute
end
end
end
class ClusterWaitForAppInstallationWorker
include Sidekiq::Worker
include ClusterQueue
include ClusterApp
INITIAL_INTERVAL = 30.seconds
EAGER_INTERVAL = 10.seconds
TIMEOUT = 20.minutes
def perform(app_name, app_id)
find_app(app_name, app_id) do |app|
Clusters::FetchAppInstallationStatusService.new(app).execute do |phase, log|
case phase
when 'Succeeded'
if app.make_installed
Clusters::FinalizeAppInstallationService.new(app).execute
else
app.make_errored!("Failed to update app record; #{app.errors}")
end
when 'Failed'
app.make_errored!(log || 'Installation silently failed')
Clusters::FinalizeAppInstallationService.new(app).execute
else
if Time.now.utc - app.updated_at.to_time.utc > TIMEOUT
app.make_errored!('App installation timeouted')
else
ClusterWaitForAppInstallationWorker.perform_in(EAGER_INTERVAL, app.name, app.id)
end
end
end
end
end
end
module ClusterApp
extend ActiveSupport::Concern
included do
def find_app(app_name, id)
app = Clusters::Kubernetes.app(app_name).find(id)
yield(app) if block_given?
end
end
end
class CreateClustersKubernetesHelmApps < ActiveRecord::Migration
def change
create_table :clusters_kubernetes_helm_apps do |t|
t.integer :status, null: false
t.datetime_with_timezone :created_at, null: false
t.datetime_with_timezone :updated_at, null: false
t.references :service, index: true, null: false, foreign_key: { on_delete: :cascade }
t.string :version, null: false
t.text :status_reason
end
end
end
module Gitlab
module Clusters
class Helm
Error = Class.new(StandardError)
HELM_VERSION = '2.7.0'.freeze
NAMESPACE = 'gitlab-managed-apps'.freeze
COMMAND_SCRIPT = <<-EOS.freeze
set -eo pipefail
apk add -U ca-certificates openssl >/dev/null
wget -q -O - https://kubernetes-helm.storage.googleapis.com/helm-v${HELM_VERSION}-linux-amd64.tar.gz | tar zxC /tmp >/dev/null
mv /tmp/linux-amd64/helm /usr/bin/
helm init ${HELM_INIT_OPTS} >/dev/null
[[ -z "${HELM_COMMAND+x}" ]] || helm ${HELM_COMMAND} >/dev/null
EOS
def initialize(kubeclient)
@kubeclient = kubeclient
end
def init!
ensure_namespace!
@kubeclient.create_pod(pod_resource(OpenStruct.new(name: 'helm')))
end
def install(app)
ensure_namespace!
@kubeclient.create_pod(pod_resource(app))
end
##
# Returns Pod phase
#
# https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle/#pod-phase
#
# values: "Pending", "Running", "Succeeded", "Failed", "Unknown"
#
def installation_status(app)
@kubeclient.get_pod(pod_name(app), NAMESPACE).status.phase
end
def installation_log(app)
@kubeclient.get_pod_log(pod_name(app), NAMESPACE).body
end
def delete_installation_pod!(app)
@kubeclient.delete_pod(pod_name(app), NAMESPACE)
end
private
def pod_name(app)
"install-#{app.name}"
end
def pod_resource(app)
labels = { 'gitlab.org/action': 'install', 'gitlab.org/application': app.name }
metadata = { name: pod_name(app), namespace: NAMESPACE, labels: labels }
container = {
name: 'helm',
image: 'alpine:3.6',
env: generate_pod_env(app),
command: %w(/bin/sh),
args: %w(-c $(COMMAND_SCRIPT))
}
spec = { containers: [container], restartPolicy: 'Never' }
::Kubeclient::Resource.new(metadata: metadata, spec: spec)
end
def generate_pod_env(app)
env = {
HELM_VERSION: HELM_VERSION,
TILLER_NAMESPACE: NAMESPACE,
COMMAND_SCRIPT: COMMAND_SCRIPT
}
if app.name != 'helm'
env[:HELM_INIT_OPTS] = '--client-only'
env[:HELM_COMMAND] = helm_install_comand(app)
end
env.map { |key, value| { name: key, value: value } }
end
def helm_install_comand(app)
"install #{app.chart} --name #{app.name} --namespace #{NAMESPACE}"
end
def ensure_namespace!
begin
@kubeclient.get_namespace(NAMESPACE)
rescue KubeException => ke
raise ke unless ke.error_code == 404
namespace_resource = ::Kubeclient::Resource.new
namespace_resource.metadata = {}
namespace_resource.metadata.name = NAMESPACE
@kubeclient.create_namespace(namespace_resource)
end
end
end
end
end
require 'rails_helper'
require_relative '../kubernetes_spec'
RSpec.describe Clusters::Kubernetes::HelmApp, type: :model do
it_behaves_like 'a registered kubernetes app'
it { is_expected.to belong_to(:kubernetes_service) }
describe '#cluster' do
it 'is an alias to #kubernetes_service' do
expect(subject.method(:cluster).original_name).to eq(:kubernetes_service)
end
end
end
require 'rails_helper'
RSpec.shared_examples 'a registered kubernetes app' do
let(:name) { described_class::NAME }
it 'can be retrieved with Clusters::Kubernetes.app' do
expect(Clusters::Kubernetes.app(name)).to eq(described_class)
end
end
......@@ -7,8 +7,9 @@
let(:project) { build_stubbed(:kubernetes_project) }
let(:service) { project.kubernetes_service }
describe "Associations" do
describe 'Associations' do
it { is_expected.to belong_to :project }
it { is_expected.to have_one(:helm_app) }
end
describe 'Validations' do
......
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