如何使用Phoenix Guides中的示例在生产模式下运行Elixir Phoenix Docker？

Question

Elixir Phoenix Guides上给出的示例Dockerfile似乎已过时且损坏。可以在此处找到示例：https://hexdocs.pm/phoenix/releases.html#containers

我像这样创建了一个香草应用程序：mix phx.new hello_world

破碎的Dockerfile：

# FROM elixir:1.9.0-alpine as build

# install build dependencies
RUN apk add --update git build-base nodejs yarn python

# prepare build dir
RUN mkdir /app
WORKDIR /app

# install hex + rebar
RUN mix local.hex --force && \
    mix local.rebar --force

# set build ENV
ENV MIX_ENV=prod

# install mix dependencies
COPY mix.exs mix.lock ./
COPY config config
RUN mix deps.get
RUN mix deps.compile

# build assets
COPY assets assets
RUN cd assets && npm install && npm run deploy
RUN mix phx.digest

# build project
COPY priv priv
COPY lib lib
RUN mix compile

# build release
COPY rel rel
RUN mix release

# prepare release image
FROM alpine:3.9 AS app
RUN apk add --update bash openssl

RUN mkdir /app
WORKDIR /app

COPY --from=build /app/_build/prod/rel/my_app ./
RUN chown -R nobody: /app
USER nobody

ENV HOME=/app

我正在尝试从原始的Phoenix应用安装中运行Dockerfile，并且遇到了许多问题，包括：

# FROM elixir:1.9.0-alpine as build
# Needs to be uncommented

RUN cd assets && npm install && npm run deploy
# npm install failed, had to add nodejs-npm

COPY rel rel
# errors here, there is no rel, should I remove?

More errors later because DATABASE_URL and SECRET_KEY_BASE are not declared

我不是专家，到目前为止，Dockerfile现在看起来像这样：

FROM elixir:1.9.1-alpine as build

# install build dependencies
# modified: is this correct?
RUN apk add --update git build-base nodejs nodejs-npm yarn python

# prepare build dir
RUN mkdir /app
WORKDIR /app

# install hex + rebar
RUN mix local.hex --force && \
    mix local.rebar --force

# set build ENV
# modified: is this correct?
ENV DATABASE_URL=${DATABASE_URL} \
  SECRET_KEY_BASE=${SECRET_KEY_BASE} \
  MIX_ENV=prod

# install mix dependencies
COPY mix.exs mix.lock ./
COPY config config
RUN mix deps.get
RUN mix deps.compile

# build assets
COPY assets assets
RUN cd assets && npm install && npm run deploy

# build project
COPY priv priv
COPY lib lib
RUN mix compile

# build release
# removed next line, is that correct?
# COPY rel rel
RUN mix release

# prepare release image
FROM alpine:3.9 AS app
RUN apk add --update bash openssl

RUN mkdir /app
WORKDIR /app

COPY --from=build /app/_build/prod/rel/hello_world ./
RUN chown -R nobody: /app
USER nobody

ENV HOME=/app

ENTRYPOINT ["./bin/hello_world", "start"]

我尝试使用此命令运行容器：

docker run -it -e DATABASE_URL='ecto://postgres:123456@localhost/hello_world_dev' -e SECRET_KEY_BASE='blargblargblarg' hello_world:latest

但我收到此错误：

05:20:34.841 [error] GenServer #PID<0.1380.0> terminating
** (RuntimeError) connect raised KeyError exception: key :database not found. The exception details are hidden, as they may contain sensitive data such as database credentials. You may set :show_sensitive_data_on_connection_error to true when starting your connection if you wish to see all of the details
    (elixir) lib/keyword.ex:393: Keyword.fetch!/2
    (postgrex) lib/postgrex/protocol.ex:92: Postgrex.Protocol.connect/1
    (db_connection) lib/db_connection/connection.ex:69: DBConnection.Connection.connect/2
    (connection) lib/connection.ex:622: Connection.enter_connect/5
    (stdlib) proc_lib.erl:249: :proc_lib.init_p_do_apply/3
Last message: nil

..... repeat a lot

05:48:41.296 [info] Application hello_world exited: shutdown

这对我来说是很新的。我已经轻松地部署到了Heroku，但希望使用Docker的幸福之路可以部署到AWS，GCP等...

Answer 1

看起来像出现问题，因为您没有正确设置配置。

例外：密钥：找不到数据库

为了使用通过环境变量注入的数据库，您需要显式获取它。根据配置的组织方式，您应该为存储库配置一个配置。默认情况下，仓库的配置是：

config :yourserver_api, YourServer.Repo,
  username: "postgres",
  password: "postgres",
  database: "yourserver_api_prod",
  hostname: "localhost",
  pool_size: 10

如果您确定例如将注入数据库，则需要将其更改为：

database: System.get_env("DATABASE_URL")