Elixir Paris Meetup

Transcript

1. Nos premiers mois avec Elixir Joan Zapata @joanzap Raphaël Lustin @raphilustin
2. TrustBK
3. TrustBK Cible les PME From scratch, pas de dette technique Repense la relation banquier-client Confiance, technologie, éthique
4. On recrute ! trustbk.com/jobs
5. Nos premiers mois • Découvrir le langage et son écosystème • Trouver nos bonnes pratiques • Apprendre à tester et à livrer en production
6. Découvrir le langage
7. Scénario 1 Gestion d’erreur
8. Scénario 1 GET /api/accounts/1 authorization: Bearer 12345678 GET /api/accounts/1 authorization: Bearer WRONG_TOKEN 401 200 Controller Controller Controller Controller Plug SERVEUR
9. defmodule BackendWeb.Router do 
 scope "/api", BackendWeb do 
 get "/accounts/:id", AccountsController, :get_one 
 end 
 end
10. defmodule BackendWeb.Router do 
 
 
 
 
 scope "/api", BackendWeb do 
 get "/accounts/:id", AccountsController, :get_one 
 end 
 end
11. defmodule BackendWeb.Router do 
 pipeline :authenticate do 
 plug Backend.Plug.Authenticate 
 end 
 
 scope "/api", BackendWeb do 
 get "/accounts/:id", AccountsController, :get_one 
 end 
 end
12. defmodule BackendWeb.Router do 
 pipeline :authenticate do 
 plug Backend.Plug.Authenticate 
 end 
 
 scope "/api", BackendWeb do pipe_through :authenticate
 get "/accounts/:id", AccountsController, :get_one 
 end 
 end
13. Backend.Plug.Authenticate
14. defmodule Backend.Plug.Authenticate do 
 @behaviour Plug 
 
 def init(opts), do: opts 
 def call(conn, _opts \\ %{}) 
 end
15. def call(conn, _opts \\ %{}) do
 
 end
16. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 end
17. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 {:ok, token} = get_token(authorization_headers) 
 end
18. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 {:ok, token} = get_token(authorization_headers) 
 {:ok, session: session, user: user} = Auth.authenticate(token) 
 end
19. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 {:ok, token} = get_token(authorization_headers) 
 {:ok, session: session, user: user} = Auth.authenticate(token) 
 end
20. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 {:ok, token} = get_token(authorization_headers) 
 {:ok, session: session, user: user} = Auth.authenticate(token) 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) end
21. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 {:ok, token} = get_token(authorization_headers) 
 {:ok, session: session, user: user} = Auth.authenticate(token) 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) end
22. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 case get_token(authorization_headers) do 
 {:ok, token} -> 
 {:ok, session: session, user: user} = Auth.authenticate(token) 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 {:error, error} -> 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end 
 end
23. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 case get_token(authorization_headers) do 
 {:ok, token} -> 
 {:ok, session: session, user: user} = Auth.authenticate(token) 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 {:error, error} -> 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end 
 end
24. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 case get_token(authorization_headers) do 
 {:ok, token} -> 
 {:ok, session: session, user: user} = Auth.authenticate(token) 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 {:error, error} -> 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end 
 end
25. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 case get_token(authorization_headers) do 
 {:ok, token} -> 
 {:ok, session: session, user: user} = Auth.authenticate(token) 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 {:error, error} -> 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end 
 end
26. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 case get_token(authorization_headers) do 
 {:ok, token} -> 
 case Auth.authenticate(token) do 
 {:ok, session: session, user: user} -> 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 {:error, error} -> 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end 
 {:error, error} -> 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end 
 end
27. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 case get_token(authorization_headers) do 
 {:ok, token} -> 
 case Auth.authenticate(token) do 
 {:ok, session: session, user: user} -> 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 {:error, error} -> 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end 
 {:error, error} -> 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end 
 end
28. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 case get_token(authorization_headers) do 
 {:ok, token} -> 
 case Auth.authenticate(token) do 
 {:ok, session: session, user: user} -> 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 {:error, error} -> 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end 
 {:error, error} -> 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end 
 end
29. Please fix. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 case get_token(authorization_headers) do 
 {:ok, token} -> 
 case Auth.authenticate(token) do 
 {:ok, session: session, user: user} -> 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 {:error, error} -> 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end 
 {:error, error} -> 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end 
 end
30. |>
31. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 {:ok, token} = get_token(authorization_headers) 
 {:ok, session: session, user: user} = Auth.authenticate(token) 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) end
32. def call(conn, _opts \\ %{}) do 
 {:ok, session: session, user: user} = 
 conn 
 |> get_req_header("authorization") 
 |> get_token() 
 |> Auth.authenticate() 
 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session)
 end
33. def call(conn, _opts \\ %{}) do 
 conn 
 |> get_req_header("authorization") 
 |> get_token() 
 |> Auth.authenticate() 
 |> handle_authentication(conn) 
 end
34. def call(conn, _opts \\ %{}) do 
 conn 
 |> get_req_header("authorization") 
 |> get_token() 
 |> Auth.authenticate() 
 |> handle_authentication(conn) 
 end 
 
 def handle_authentication({:ok, session: session, user: user}, conn) do 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 end
35. def call(conn, _opts \\ %{}) do 
 conn 
 |> get_req_header("authorization") 
 |> get_token() 
 |> Auth.authenticate() 
 |> handle_authentication(conn) 
 end 
 
 def handle_authentication({:ok, session: session, user: user}, conn) do 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 end 
 
 def handle_authentication({:error, error}, conn) do 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end
36. def call(conn, _opts \\ %{}) do 
 conn 
 |> get_req_header("authorization") 
 |> get_token() 
 |> Auth.authenticate() 
 |> handle_authentication(conn) 
 end 
 
 def handle_authentication({:ok, session: session, user: user}, conn) do 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 end 
 
 def handle_authentication({:error, error}, conn) do 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end
37. def call(conn, _opts \\ %{}) do 
 conn 
 |> get_req_header("authorization") 
 |> get_token() 
 |> Auth.authenticate() 
 |> handle_authentication(conn) 
 end 
 
 def handle_authentication({:ok, session: session, user: user}, conn) do 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 end 
 
 def handle_authentication({:error, error}, conn) do 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end {:ok, token} @spec authenticate(String.t) :: … X
38. def call(conn, _opts \\ %{}) do 
 conn 
 |> get_req_header("authorization") 
 |> get_token() 
 |> Auth.authenticate() 
 |> handle_authentication(conn) 
 end 
 
 def handle_authentication({:ok, session: session, user: user}, conn) do 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 end 
 
 def handle_authentication({:error, error}, conn) do 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end @spec authenticate({:ok, String.t} | {:error, atom}) :: … {:ok, token} @spec authenticate(String.t) :: … X
39. def call(conn, _opts \\ %{}) do 
 conn 
 |> get_req_header("authorization") 
 |> get_token() 
 |> Auth.authenticate() 
 |> handle_authentication(conn) 
 end 
 
 def handle_authentication({:ok, session: session, user: user}, conn) do 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 end 
 
 def handle_authentication({:error, error}, conn) do 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end {:ok, token} @spec authenticate(String.t) :: … X @spec authenticate({:ok, String.t} | {:error, atom}) :: … Please fix.
42. def call(conn, _opts \\ %{}) do 
 authorization_headers = get_req_header(conn, "authorization") 
 {:ok, token} = get_token(authorization_headers) 
 {:ok, session: session, user: user} = Auth.authenticate(token) 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) end
43. def call(conn, _opts \\ %{}) do 
 with authorization_headers <- get_req_header(conn, "authorization"), 
 {:ok, token} <- get_token(authorization_headers), 
 {:ok, session: session, user: user} <- Auth.authenticate(token) 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) end
44. def call(conn, _opts \\ %{}) do 
 with authorization_headers <- get_req_header(conn, "authorization"), 
 {:ok, token} <- get_token(authorization_headers), 
 {:ok, session: session, user: user} <- Auth.authenticate(token) 
 do conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) end end
45. def call(conn, _opts \\ %{}) do 
 with authorization_headers <- get_req_header(conn, "authorization"), 
 {:ok, token} <- get_token(authorization_headers), 
 {:ok, session: session, user: user} <- Auth.authenticate(token) 
 do conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session)
 else pattern -> instructions pattern -> instructions pattern -> instructions end end
46. def call(conn, _opts \\ %{}) do 
 with authorization_headers <- get_req_header(conn, "authorization"), 
 {:ok, token} <- get_token(authorization_headers), 
 {:ok, session: session, user: user} <- Auth.authenticate(token) 
 do conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session)
 else end end
47. def call(conn, _opts \\ %{}) do 
 with authorization_headers <- get_req_header(conn, "authorization"), 
 {:ok, token} <- get_token(authorization_headers), 
 {:ok, session: session, user: user} <- Auth.authenticate(token) 
 do 
 conn 
 |> assign(:current_user, user) 
 |> assign(:current_session, session) 
 else {:error, _reason} -> 
 conn 
 |> put_status(:unauthorized) 
 |> render(ErrorView, "401.json", %{}) 
 |> halt() 
 end 
 end
48. Scénario 2 Pagination
49. Scénario 2 GET ?page=0 [{…}, {…}, {…}, {…}] Serveur Prestataire
50. Scénario 2 GET ?page=0 [{…}, {…}, {…}, {…}] Serveur Prestataire GET ?page=1 [{…}, {…}]
51. Scénario 2 GET ?page=0 [{…}, {…}, {…}, {…}] Serveur Prestataire GET ?page=1 [{…}, {…}] GET ?page=2 []
52. defmodule Client 
 def resources(page) do 
 ... 
 end 
 end
53. [%{…}, %{…}, %{…}] defmodule Client 
 def resources(page) do 
 ... 
 end 
 end
54. def get_resources do 
 end
55. def get_resources do 
 page = 0 
 acc = [] end
56. def get_resources do 
 page = 0 
 acc = [] 
 do 
 result = Client.resources(page) page = page + 1
 acc = acc ++ result 
 while(result != []) 
 
 acc 
 end 

57. Récursivité
58. def get_resources do 
 end
59. def get_resources do Client.resources(0)
 end
60. def get_resources do do_get_resources(0, Client.resources(0))
 end
61. def get_resources do 
 do_get_resources(0, Client.resources(0)) 
 end 
 
 defp do_get_resources(_page, []), 
 do: :ok
62. def get_resources do 
 do_get_resources(0, Client.resources(0)) 
 end 
 
 defp do_get_resources(_page, []), 
 do: :ok
 defp do_get_resources(page, resources), 
 do: do_get_resources( page + 1, Client.resources(page + 1) )
63. def get_resources do 
 do_get_resources(0, Client.resources(0)) 
 end 
 
 defp do_get_resources(_page, []), 
 do: :ok
 defp do_get_resources(page, resources), 
 do: do_get_resources( page + 1, Client.resources(page + 1) )
64. def get_resources do 
 do_get_resources([], 0, Client.resources(0)) 
 end 
 
 defp do_get_resources(acc, _page, []), 
 do: acc
 defp do_get_resources(acc, page, resources), 
 do: do_get_resources( acc + resources, page + 1, Client.resources(page + 1) )
65. def get_resources do 
 do_get_resources([], 0, Client.resources(0)) 
 end 
 
 defp do_get_resources(acc, _page, []), 
 do: acc
 defp do_get_resources(acc, page, resources), 
 do: do_get_resources( acc + resources, page + 1, Client.resources(page + 1) )
66. Utilisation
67. get_resources() 
 |> Enum.each(&process_resource/1)
68. get_resources() 
 |> Enum.each(&process_resource/1)
69. get_resources() 
 |> Enum.each(&process_resource/1)
70. get_resources() 
 |> Stream.each(&process_resource/1) |> Stream.run()
71. get_resources() 
 |> Stream.each(&process_resource/1) |> Stream.run()
72. get_resources() 
 |> Stream.each(&process_resource/1) |> Stream.run()
73. get_resources() 
 |> Stream.each(&process_resource/1) |> Stream.run()
74. def get_resources do
 end
75. def get_resources do 
 Stream.unfold()
 end
76. unfold(initial_acc, (acc -> {element, acc} | nil))
77. def get_resources do 
 Stream.unfold()
 end
78. def get_resources do 
 Stream.unfold(0, fn page -> 
 end) 
 end
79. def get_resources do 
 Stream.unfold(0, fn page ->
 resources = Client.resources(page) 
 {resources, page + 1} 
 end) 
 end
80. def get_resources do 
 Stream.unfold(0, fn page -> 
 case Client.resources(page) do 
 [] -> nil 
 resources -> {resources, page + 1} 
 end 
 end) 
 end
81. get_resources |> Enum.to_list() [
 [ %{id: 1, …}, %{id: 2, …}, %{id: 3, …} ], 
 [ %{id: 4, …}, %{id: 5, …}, %{id: 6, …} ], 
 [ %{id: 7, …}, %{id: 8, …}, %{id: 9, …} ] 
 ] iex>
82. def get_resources do 
 Stream.unfold(0, fn page -> 
 case Client.resources(page) do 
 [] -> nil 
 resources -> {resources, page + 1} 
 end 
 end)
 end
83. def get_resources do 
 Stream.unfold(0, fn page -> 
 case Client.resources(page) do 
 [] -> nil 
 resources -> {resources, page + 1} 
 end 
 end) |> Stream.flat_map(& &1) 
 end
84. [
 %{id: 1, …}, %{id: 2, …}, %{id: 3, …},
 %{id: 4, …}, %{id: 5, …}, %{id: 6, …}, 
 %{id: 7, …}, %{id: 8, …}, %{id: 9, …}
 ] get_resources |> Enum.to_list() iex>
85. def get_resources do 
 Stream.unfold(0, fn page -> 
 case Client.resources(page) do 
 [] -> nil 
 resources -> {resources, page + 1} 
 end 
 end) |> Stream.flat_map(& &1) 
 end
86. Intégration et livraison continues Retour d’expérience
91. .gitlab-ci.yml
92. image: elixir:1.5.1 services: - postgres:9.6 variables: MIX_ENV: test stages: - build - test - package - deploy before_script: - mix local.hex --force - mix local.rebar --force - mix deps.get --only test cache: paths: - "_build" - "deps" .gitlab-ci.yml
93. image: elixir:1.5.1 services: - postgres:9.6 variables: MIX_ENV: test stages: - build - test - package - deploy before_script: - mix local.hex --force - mix local.rebar --force - mix deps.get --only test cache: paths: - "_build" - "deps" .gitlab-ci.yml
94. image: elixir:1.5.1 services: - postgres:9.6 variables: MIX_ENV: test stages: - build - test - package - deploy before_script: - mix local.hex --force - mix local.rebar --force - mix deps.get --only test cache: paths: - "_build" - "deps" .gitlab-ci.yml
95. image: elixir:1.5.1 services: - postgres:9.6 variables: MIX_ENV: test stages: - build - test - package - deploy before_script: - mix local.hex --force - mix local.rebar --force - mix deps.get --only test cache: paths: - "_build" - "deps" .gitlab-ci.yml
96. build: stage: build script: - mix compile doc: stage: build script: - mix docs .gitlab-ci.yml
97. .gitlab-ci.yml lint: stage: test script: - mix credo - mix dialyzer --halt-exit-status migrations: stage: test script: - mix ecto.reset - mix ecto.rollback --all test: stage: test script: - mix ecto.reset - mix test
98. .gitlab-ci.yml lint: stage: test script: - mix credo - mix dialyzer --halt-exit-status migrations: stage: test script: - mix ecto.reset - mix ecto.rollback --all test: stage: test script: - mix ecto.reset - mix test
99. .gitlab-ci.yml lint: stage: test script: - mix credo - mix dialyzer --halt-exit-status migrations: stage: test script: - mix ecto.reset - mix ecto.rollback --all test: stage: test script: - mix ecto.reset - mix test
100. .gitlab-ci.yml lint: stage: test script: - mix credo - mix dialyzer --halt-exit-status migrations: stage: test script: - mix ecto.reset - mix ecto.rollback --all test: stage: test script: - mix ecto.reset - mix test
101. .gitlab-ci.yml package: stage: package script: - bin/package.sh artifacts: expire_in: 1 month paths: - artifact/
102. .gitlab-ci.yml package: stage: package script: - bin/package.sh artifacts: expire_in: 1 month paths: - artifact/
103. .gitlab-ci.yml deploy:integration: stage: deploy environment: name: $CI_BUILD_REF_NAME url: https://$CI_BUILD_REF_NAME.integration only: - master@trustbk/backend script: - bin/deploy.sh
104. .gitlab-ci.yml deploy:integration: stage: deploy environment: name: $CI_BUILD_REF_NAME url: https://$CI_BUILD_REF_NAME.integration only: - master@trustbk/backend script: - bin/deploy.sh
105. .gitlab-ci.yml deploy:integration: stage: deploy environment: name: $CI_BUILD_REF_NAME url: https://$CI_BUILD_REF_NAME.integration only: - master@trustbk/backend script: - bin/deploy.sh
106. bin/package.sh
107. bin/package.sh distillery A pure Elixir implementation of release packaging functionality for the Erlang VM.
108. rel/config.exs Path.join(["rel", "plugins", "*.exs"]) |> Path.wildcard() |> Enum.map(&Code.eval_file(&1)) use Mix.Releases.Config, default_release: :backend, default_environment: Mix.env() environment :prod do set include_erts: true set include_src: false set include_system_libs: true end release :backend do set version: current_version(:backend) set applications: [ :backend, … ] end
109. bin/package.sh $ mix release ==> Assembling release.. ==> Building release backend:0.0.1 using environment prod ==> Including ERTS 9.0.4 from /usr/local/Cellar/erlang/20.0/lib/erlang/erts-9.0.4 ==> Packaging release.. ==> Release successfully built! You can run it in one of the following ways: Interactive: _build/prod/rel/backend/bin/backend console Foreground: _build/prod/rel/backend/bin/backend foreground Daemon: _build/prod/rel/backend/bin/backend start
110. bin/package.sh _build/prod/rel/backend/releases/0.0.1/backend.tar.gz
111. bin/package.sh $ tree -L 2 _build/prod/rel/backend _build/prod/rel/backend ├── bin │ ├── backend │ ├── backend.bat │ ├── backend_loader.sh │ ├── release_utils.escript │ └── start_clean.boot ├── erts-9.0 │ ├── bin │ ├── include │ ├── lib │ └── src ├── lib │ ├── backend-0.0.1 │ └── […dependencies…] ├── releases │ ├── 0.0.1 │ ├── RELEASES │ └── start_erl.data └── var ├── WARNING_README ├── log ├── sys.config └── vm.args bin/backend start bin/backend stop
112. bin/package.sh #!/bin/bash -ex MIX_ENV=prod mix release —warnings-as-errors […preparing a tarball from _build/prod/rel/backend]
113. bin/package.sh #!/bin/bash -ex MIX_ENV=prod mix release —warnings-as-errors […preparing a tarball from _build/prod/rel/backend]
114. bin/package.sh
115. lib/backend/release_tasks.ex defmodule Elixir.Backend.ReleaseTasks do alias Backend.Repo alias Ecto.Migrator @start_apps [:ecto, :postgrex] def migrate do :ok = Application.load(:backend) Enum.each(@start_apps, &Application.ensure_all_started/1) {:ok, _} = Repo.start_link(pool_size: 1) path = Application.app_dir(:backend, "priv/repo/migrations") Migrator.run(Repo, path, :up, all: true) Enum.each(@start_apps, &Application.stop/1) :init.stop() end end
116. lib/backend/release_tasks.ex defmodule Elixir.Backend.ReleaseTasks do alias Backend.Repo alias Ecto.Migrator @start_apps [:ecto, :postgrex] def migrate do :ok = Application.load(:backend) Enum.each(@start_apps, &Application.ensure_all_started/1) {:ok, _} = Repo.start_link(pool_size: 1) path = Application.app_dir(:backend, "priv/repo/migrations") Migrator.run(Repo, path, :up, all: true) Enum.each(@start_apps, &Application.stop/1) :init.stop() end end
117. lib/backend/release_tasks.ex defmodule Elixir.Backend.ReleaseTasks do alias Backend.Repo alias Ecto.Migrator @start_apps [:ecto, :postgrex] def migrate do :ok = Application.load(:backend) Enum.each(@start_apps, &Application.ensure_all_started/1) {:ok, _} = Repo.start_link(pool_size: 1) path = Application.app_dir(:backend, "priv/repo/migrations") Migrator.run(Repo, path, :up, all: true) Enum.each(@start_apps, &Application.stop/1) :init.stop() end end
118. rel/commands/migrate.sh #!/bin/sh bin/backend command Elixir.Backend.ReleaseTasks migrate
119. rel/config.exs release :backend do set version: current_version(:backend) set applications: [ :backend, … ] set commands: [ "migrate": "rel/commands/migrate.sh" ] end
120. bin/deploy.sh
121. config/prod.exs use Mix.Config config :backend, Backend.Repo, adapter: Ecto.Adapters.Postgres, username: System.get_env("TBK_BACKEND_DB_USER"), password: System.get_env("TBK_BACKEND_DB_PASSWORD"), database: System.get_env("TBK_BACKEND_DB_DATABASE"), hostname: System.get_env("TBK_BACKEND_DB_HOSTNAME"), pool_size: 10 Evaluated at compile-time!
122. config/prod.exs use Mix.Config config :backend, Backend.Repo, adapter: Ecto.Adapters.Postgres, username: "${TBK_BACKEND_DB_USER}", password: "${TBK_BACKEND_DB_PASSWORD}", database: "${TBK_BACKEND_DB_DATABASE}", hostname: "${TBK_BACKEND_DB_HOSTNAME}", pool_size: 10 Evaluated at runtime by Erlang VM with REPLACE_OS_VARS=true
123. bin/deploy.sh […copy tarball to server by SSH] […expand] vcour/bin/backend stop ln -sfT versions/20170921102241_8f41acc1 vcour vcour/bin/backend migrate vcour/bin/backend start
124. • Idempotent • Stateless • Zero-downtime deployment bin/deploy.sh
126. Questions Joan Zapata @joanzap Raphaël Lustin @raphilustin