我在尝试解决此依赖性问题时遇到问题。我在我的gemfile中有sqlite3，我可以看到它安装，即使我运行gem list（在我的docker容器内）。但是当我使用docker build生成我的依赖项，然后在容器中运行我的项目时，我在尝试运行时遇到以下错误rake test
root@401a61839c07:/app# rake test
rake aborted!
LoadError: cannot load such file -- sqlite3/sqlite3_native
这是构建，您可以清楚地看到已安装sqlite。
docker build -f DependenciesDockerfile -t visual-base .
.
.
.
Step 12 : RUN bundle install --without development
---> Running in 623d8b439808
Don't run Bundler as root. Bundler can ask for sudo if it is needed, and
installing your bundle as root will break this application for all non-root
users on this machine.
Fetching gem metadata from https://rubygems.org/...........
Fetching version metadata from https://rubygems.org/...
Fetching dependency metadata from https://rubygems.org/..
Installing rake 10.5.0
Installing i18n 0.7.0
Installing json 1.8.3
Installing minitest 5.8.4
Installing thread_safe 0.3.5
Installing tzinfo 1.2.2
Installing activesupport 4.1.6
Installing builder 3.2.2
Installing erubis 2.7.0
Installing actionview 4.1.6
Installing rack 1.5.5
Installing rack-test 0.6.3
Installing actionpack 4.1.6
Installing mime-types 2.99.1
Installing mail 2.6.3
Installing actionmailer 4.1.6
Installing activemodel 4.1.6
Installing arel 5.0.1.20140414130214
Installing activerecord 4.1.6
Installing execjs 2.6.0
Installing autoprefixer-rails 6.3.3.1
Installing bcrypt 3.1.11
Installing sass 3.2.19
Installing bootstrap-sass 3.3.5
Installing climate_control 0.0.3
Installing cocaine 0.5.8
Installing coffee-script-source 1.10.0
Installing coffee-script 2.4.1
Using thor 0.19.1
Installing railties 4.1.6
Installing coffee-rails 4.0.1
Installing jquery-rails 3.1.4
Using bundler 1.8.0
Installing hike 1.2.3
Installing multi_json 1.11.2
Installing tilt 1.4.1
Installing sprockets 2.12.4
Installing sprockets-rails 2.3.3
Installing rails 4.1.6
Installing commontator 4.10.5
Installing orm_adapter 0.5.0
Installing responders 1.1.2
Installing warden 1.2.6
Installing devise 3.5.6
Installing devise-bootstrap-views 0.0.8
Installing gretel 3.0.8
Installing jbuilder 2.4.1
Installing kgio 2.10.0
Installing mimemagic 0.3.0
Installing net-ldap 0.14.0
Installing paperclip 4.3.5
Installing pg 0.18.4
Installing polyamorous 1.1.0
Installing raindrops 0.16.0
Installing rdoc 4.2.2
Installing rmagick 2.13.3
Installing sass-rails 4.0.5
Installing sdoc 0.4.1
Installing sqlite3 1.3.11
Installing squeel 1.2.3
Installing turbolinks 2.5.3
Installing uglifier 2.7.2
Installing unicorn 5.0.1
Bundle complete! 28 Gemfile dependencies, 63 gems now installed.
Gems in the group development were not installed.
Use `bundle show [gemname]` to see where a bundled gem is installed.
Post-install message from rdoc:
Depending on your version of ruby, you may need to install ruby rdoc/ri data:
<= 1.8.6 : unsupported
= 1.8.7 : gem install rdoc-data; rdoc-data --install
= 1.9.1 : gem install rdoc-data; rdoc-data --install
>= 1.9.2 : nothing to do! Yay!
Post-install message from rmagick:
Please report any bugs. See https://github.com/gemhome/rmagick/compare/RMagick_2-13-2...master and https://github.com/rmagick/rmagick/issues/18
---> 901bbde8aa4f
Removing intermediate container 623d8b439808
Successfully built 901bbde8aa4f
2.2.3 in visual-automation/ on master
› docker build -t visual .
Sending build context to Docker daemon 112.3 MB
Step 1 : FROM visual-base
---> 901bbde8aa4f
Step 2 : MAINTAINER
---> Running in bd02c1f718e7
---> 02f76881207c
Removing intermediate container bd02c1f718e7
Step 3 : ADD . /app
---> 4f80ec7fccce
Removing intermediate container 6d73bdc55fde
Step 4 : RUN sed -i.bak 's/user www-data;/user root;/g' /etc/nginx/nginx.conf
---> Running in df22155ce2b7
---> aa9442d89c9e
Removing intermediate container df22155ce2b7
Step 5 : EXPOSE 80
---> Running in f839dd6707ce
---> d197974fa925
Removing intermediate container f839dd6707ce
Successfully built d197974fa925
2.2.3 in repo/ on master
› docker run -it visual /bin/bash
root@401a61839c07:/app# rake test
rake aborted!
LoadError: cannot load such file -- sqlite3/sqlite3_native
/app/vendor/cache/ruby/2.2.0/gems/sqlite3-1.3.11/lib/sqlite3.rb:6:in `require'
/app/vendor/cache/ruby/2.2.0/gems/sqlite3-1.3.11/lib/sqlite3.rb:6:in `rescue in <top (required)>'
/app/vendor/cache/ruby/2.2.0/gems/sqlite3-1.3.11/lib/sqlite3.rb:2:in `<top (required)>'
/app/config/application.rb:7:in `<top (required)>'
/app/Rakefile:4:in `<top (required)>'
LoadError: cannot load such file -- sqlite3/2.2/sqlite3_native
/app/vendor/cache/ruby/2.2.0/gems/sqlite3-1.3.11/lib/sqlite3.rb:4:in `require'
/app/vendor/cache/ruby/2.2.0/gems/sqlite3-1.3.11/lib/sqlite3.rb:4:in `<top (required)>'
/app/config/application.rb:7:in `<top (required)>'
/app/Rakefile:4:in `<top (required)>'
(See full trace by running task with --trace)
root@401a61839c07:/app#
以下是在容器
中运行时gem list的输出
root@69296d7eec2a:/app# gem list
*** LOCAL GEMS ***
actionmailer (4.1.6)
actionpack (4.1.6)
actionview (4.1.6)
activemodel (4.1.6)
activerecord (4.1.6)
activesupport (4.1.6)
arel (5.0.1.20140414130214)
autoprefixer-rails (5.2.1.1)
bcrypt (3.1.10)
bigdecimal (1.2.6)
bootstrap-sass (3.3.5)
builder (3.2.2)
bundler (1.8.0)
climate_control (0.0.3)
cocaine (0.5.8)
coffee-rails (4.0.1)
coffee-script (2.4.1)
coffee-script-source (1.9.1.1)
commontator (4.10.5)
devise (3.5.1)
devise-bootstrap-views (0.0.5)
dotenv (1.0.2)
erubis (2.7.0)
execjs (2.5.2)
foreman (0.77.0)
gretel (3.0.8)
hike (1.2.3)
i18n (0.7.0)
io-console (0.4.3)
jbuilder (2.3.1)
jquery-rails (3.1.3)
json (1.8.3, 1.8.1)
kgio (2.9.3)
mail (2.6.3)
mime-types (2.6.1)
mimemagic (0.3.0)
minitest (5.8.4, 5.4.3)
multi_json (1.11.2)
net-ldap (0.11)
orm_adapter (0.5.0)
paperclip (4.3.5)
pg (0.18.3)
polyamorous (1.1.0)
power_assert (0.2.2)
psych (2.0.8)
rack (1.5.5)
rack-test (0.6.3)
rails (4.1.6)
railties (4.1.6)
raindrops (0.15.0)
rake (10.4.2)
rdoc (4.2.0)
responders (1.1.2)
rmagick (2.13.3)
sass (3.2.19)
sass-rails (4.0.5)
sdoc (0.4.1)
sprockets (2.12.4)
sprockets-rails (2.3.2)
sqlite3 (1.3.11)
squeel (1.2.3)
test-unit (3.0.8)
thor (0.19.1)
thread_safe (0.3.5)
tilt (1.4.1)
turbolinks (2.5.3)
tzinfo (1.2.2)
uglifier (2.7.1)
unicorn (4.9.0)
warden (1.2.3)
我通过编辑gemspecs看到了临时解决方案，但是一旦你修复了gemspec，就会弹出另一个类似的错误。我必须遗漏一些东西，但看起来一切都井然有序。
非常感谢任何帮助
答案 0 :(得分：0)
来自ruby gem的文档https://github.com/sparklemotion/sqlite3-ruby它说
该模块允许Ruby程序与SQLite3数据库引擎（www.sqlite.org）连接。您必须安装SQLite引擎才能构建此模块。
我认为这里的问题是你的docker容器没有安装sqlite3引擎，所以当gem试图调用本机代码时它就不能。
确认您有类似的行
Dockerfile中的RUN apt-get sqlite3。