Kubernetes-native Ruby development

Imaging you develop your application onto Kubernetes cluster with all the infrastructure got up.

Here are my thoughts about the way to get there and the tooling to use for it.

Transcript

1. Kubernetes-native Ruby development (Salahutdinov Dmitry) Saint P Ruby Meetup, “RubyDay", 29/02/2020 1
2. Hey, my name is Dmitry 2
3. About myself :) 3
4. 4 Learn Ruby with kids
5. AMPLIFR 5 SPRING30 30% discount coupon
6. 6 Introduction
7. 2008: ruby application $ gem install -v 2.1.0 rails Fetching actionmailer-2.1.0.gem Fetching rails-2.1.0.gem Fetching activesupport-2.1.0.gem Fetching activeresource-2.1.0.gem Fetching actionpack-2.1.0.gem Fetching activerecord-2.1.0.gem Successfully installed activesupport-2.1.0 Successfully installed activeresource-2.1.0 Successfully installed actionpack-2.1.0 Successfully installed actionmailer-2.1.0 Successfully installed activerecord-2.1.0 Successfully installed rails-2.1.0 6 gems installed $ rails new brand_new_2008 No isolation, hard to manage several gemsets 7
8. https://www.cloudcity.io/blog/2015/07/10/how-bundler-works-a-history-of-ruby-dependency-management/ 2009: Bundler 8
9. 2009: isolated gem sets 9
10. 2010: RVM (+gemsets) 10
11. 2014: Docker 11
12. 2014: isolated environment 12
13. 2016: Amplifr With one of two micro services 13
14. 2015: Kubernetes 14
15. 2016: Amplifr 15
16. 2016: Amplifr on Kubernetes 16
17. 2020: micro-service paradise 17
18. 2020: IaC 18
19. 2020: independent deploy 19
20. 2020: development 20
21. 2020: development $ cd amplifr && docker-compose up server 21
22. 2020: development $ cd amplifr-front && docker-compose up server 22
23. 2020: development $ cd amplifr-logux && docker-compose up server 23
24. DC: incomplete environment We run critical services only 24
25. DC: dummy dependencies $ cd amplifr && docker-compose up server $ cd ../amplifr-front && docker-compose up server $ cd ../amplifr-logux && docker-compose up server $ … $ cd ../amplifr-screenshot ERROR: Can't find a suitable configuration file in this directory or any parent. Are you in the right directory? Supported filenames: docker-compose.yml, docker-compose.yaml 25
26. Docker compose: duplication FROM gcr.io/amplifr.com/amplifr/amplifr-baseimage:latest AS builder LABEL maintaner="hosting@evilmartians.com" RUN apt-get update RUN apt-get -y install build-essential git libidn11-dev libpq-dev libxml2-dev libxslt1-dev ADD . /app WORKDIR /app RUN gem update --system && bundle config build.nokogiri --use-system- libraries RUN bundle install --without development:test -j4 --deployment -- path /usr/local/bundle FROM gcr.io/amplifr.com/amplifr/amplifr-baseimage:latest LABEL maintaner="hosting@evilmartians.com" COPY --from=builder /usr/local/bundle/ /usr/local/bundle/ COPY --chown=nobody:nogroup . /app WORKDIR /app RUN bundle exec rake assets:precompile && bundle exec rake assets:clean CMD ["bundle", "exec", "puma", "-C", "config/puma.rb"] FROM ruby:2.7 RUN apt-get update -qq \ && apt-get install -yq --no-install-recommends \ … && apt-get clean \ && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* ENV LANG=C.UTF-8 \ GEM_HOME=/bundle \ BUNDLE_JOBS=4 \ BUNDLE_RETRY=3 ENV BUNDLE_PATH $GEM_HOME ENV BUNDLE_APP_CONFIG=$BUNDLE_PATH \ BUNDLE_BIN=$BUNDLE_PATH/bin ENV PATH $BUNDLE_BIN:$PATH RUN mkdir -p /app WORKDIR /app Dockerfile Dockerfile.dev 26
27. Docker compose: duplication Kubernetes manifests vs. docker-compose.yml version: '3.4' services: app: &app build: context: . dockerfile: Dockerfile.dev args: PG_VERSION: '9.6' NODE_VERSION: '12.0.0' image: amplifr-dev:0.1.0 volumes: - .:/app:cached - bundle:/bundle … mail: image: drujensen/mailcatcher:latest ports: - '1025:1025' - '1080:1080' imgproxy: image: darthsim/imgproxy ports: - '8080:8080' 27
28. Kubernetes for development? RAILS_ENV=development NODE_ENV=development LOG_LEVEL=debug DOMAIN=amplifr.local 28
29. Todo • Deploy the whole infrastructure locally/remote • Redeploy/sync cycle • Debug • Interactive: REPL/bash (+ generators) 29 To run development on top of Kubernetes
30. 30 Deploy
31. https://amplifr.local 31
32. Parametrize K8s manifest • RAILS_ENV=production/development • MAIN_DOMAIN=amplifr.com/amplifr.local • REPLICAS (web,sidekiq)=12/1 • Memory/CPU limits • NODE_ENV=production/development • DEBUG_LEVEL=info/debug Raw manifest, helm charts, kustomize 32
33. Kustomize 33
34. Helm 34
35. Fail #1: helm charts {{- if and .Values.ingress.enable .Values.production.enable }} apiVersion: v1 kind: List items: - apiVersion: networking.k8s.io/v1beta1 kind: Ingress metadata: annotations: kubernetes.io/ingress.allow-http: "false" kubernetes.io/tls-acme: "false" nginx.ingress.kubernetes.io/proxy-body-size: 32m labels: app: {{ template "amplifr.name" . }} chart: "{{ .Chart.Name }}-{{ .Chart.Version | replace "+" "_" }}" release: {{ .Release.Name | quote }} heritage: {{ .Release.Service | quote }} name: app-amplifr-com spec: rules: - host: app.amplifr.com http: paths: - backend: serviceName: {{ .Release.Name | quote }} servicePort: 80 path: / - backend: serviceName: {{ .Release.Name | quote }} servicePort: 80 Dry helm charts 35
36. Fail #2: certificates Manage certificates $ cfssl gencert -initca \ builder/ca-csr.json | cfssljson -bare ca - $ cfssl gencert -ca=ca.pem -ca-key=ca-key.pem \ -config=builder/ca-config.json -profile=server \ builder/ca-server.json | cfssljson -bare server $ mv *.{csr,pem} ./builder { "CN": “amplifr.local”, "key": { "algo": "rsa", "size": 2048 }, 36
37. minikube config set memory 8192 minikube config set cpus 2 minikube start minikube ip # 192.168.64.7 echo "$(minikube ip) \ amplifr.local” | sudo tee -a /etc/hosts minikube addons enable ingress Fail #3: resources 37
38. Fail #4: ENV variables $ env | wc -l 160 Prioritize, reduce, generalize, dry env variables $ env | grep amplifr | grep com RAILS_ASSET_HOST=https://app.amplifr.com AMPLIFR_MAIN_DOMAIN=app.amplifr.com DIRECT_UPLOAD_URL=https://direct.amplifr.com IMGPROXY_URL=https://imgproxy.amplifr.com LANDING_URL=https://amplifr.com LOGUX_WSS_URL=wss://logux.amplifr.com 38
39. Sane defaults DEFAULTS_SET = "defaults/#{ENV['DEFAULTS_SET'] || 'kubernetes'}" require_relative DEFAULTS_SET # Defaults module is a container for general purpose constants and # configuration options used as sane defaults for the Settings object # (config/settings.yml). Environment variables defined by .env file # will always have precedence over a default. # # A value belongs here if: # # 1. It is not a secret (like an API key). # 2. It is not specific to a personal development environment. # 3. It does not depend on dev environment (RAILS_ENV). # NOTE: Use this module for common constants for all presets module Defaults # Inherit preset-specific constants include DEFAULTS_SET.camelize.constantize AMPLIFR_MAIN_PROTOCOL = 'https' IMGPROXY_MAX_SRC_RESOLUTION = 67.2 end module Defaults module Kubernetes # TODO SCREENSHOT_URL = 'http://screenshot.screenshot' end end module Defaults module Local AMPLIFR_MAIN_DOMAIN = 'localhost.amplifr.com:3001' LANDING_URL = 'https://localhost.amplifr.com:3001' # TODO end end module Defaults module DockerCompose AMPLIFR_MAIN_DOMAIN = 'localhost.amplifr.com:3001' LANDING_URL = 'https://localhost.amplifr.com:3001' SCREENSHOT_URL = 'http://screenshot' # TODO end end https://dev.to/amplifr/sane-defaults-25pe 39
40. Deployed -infrastructure review (all the services) -dried helm-charts/k8s manifests -dried ENV variables (12 factors?) -K8s experience -deploy anywhere(g.e. for any branch with ci) 40
41. Debug 41
42. Telepresence 42
43. Telepresence 43
44. Attach to container As it runs in development mode with debugger support # Switch to raw terminal mode, sends stdin to #’bash' in ruby-container from pod 123456-7890 # and sends stdout/stderr from 'bash' back to # the client kubectl attach 123456-7890 \ -c ruby-container -i -t 44
45. Remote debugger Expose port of deployments, just as raw docker port exposing 45
46. Re-deploy 46
47. Continuous deployment FROM ruby:2.7 WORKDIR /app ADD Gemfile* ./ RUN bundle install ADD . ./ require 'rack/lobster' run Rack::Lobster.new Dockerfile Source code Sync changes Rebuild/redeploy Speeds up development feedback cycle response time 47
48. Google Skaffold 48
49. Skaffold config apiVersion: skaffold/v2alpha1 kind: Config build: artifacts: - image: ruby-example context: backend sync: infer: - '*.rb' - 'config.ru' https://dev.to/amplifr/continuous-deployment-to-minikube-with-skaffold-18ib 49
50. Skaffold dev-mode 50
51. Skaffold features •Helm/Kustomize/Docker-compose •Profiles support •Dev mode (rebuild/sync files) •Build strategies 51
54. Tilt manages dependencies In fact you manage dependencies with python code Titl microservices demo source code 54
55. Titl team is user-friendly Great 2 minutes Titl introduction video! And human-friendly 55
56. Tilt features • Tiltfile is a code • Dependencies • WebUI, manage all from one window • Helm/Kustomize/Docker-compose 56
57. 57 Interactive
58. Clone manifest 58
59. Run “utility pod” kubectl run -it ruby-utility \ --image=ruby-example:7c021a795 \ --env RACK_ENV=development \ -- bash 59
60. Sync files back: ksync $ ksync create --selector app.kubernetes.io/ksync="true" \ —reload=false -n default $(pwd)/backend /app/ # start ksync $ ksync watch --log-level=debug 60
61. Kubedude One ruby script to manage them all 61
62. Final solution 62
63. 63 npm install Tools on top of Kubernetes
64. Good news 64
65. Manual copy files 65
66. Conclusion -Deep dive into Kubernetes (developer skill) -Review on your project infrastructure -Dry you application config -Cleanup helm-charts/k8s-manifests -Remote-development - idea of the future -Fun 66
67. Thank you ❤ @dsalahutdinov1 @dsalahutdinov https://dev.to/amplifr https://amplifr.com 67