FedoraにRailsを入れた時に躓いたメモ

FedoraにRailsをインストールしようとしたらちょっと躓いたのでメモ

###環境
Fedora26
ruby 2.4.1p111 (2017-03-22 revision 58053) [x86_64-linux]
Rails 5.1.4

###Rubyインストール
```
su -
dnf install ruby
```
ここは普通に問題なし。
余談ですがfedoraではyumの後継としてdnfってのがあるようですね。
###Railsインストール(take1)
```
[root@localhost ~]# gem install -N rails
Fetching: i18n-0.8.6.gem (100%)
Successfully installed i18n-0.8.6
Fetching: thread_safe-0.3.6.gem (100%)
Successfully installed thread_safe-0.3.6
Fetching: tzinfo-1.2.3.gem (100%)
Successfully installed tzinfo-1.2.3
Fetching: minitest-5.10.3.gem (100%)
Successfully installed minitest-5.10.3
Fetching: concurrent-ruby-1.0.5.gem (100%)
Successfully installed concurrent-ruby-1.0.5
Fetching: activesupport-5.1.4.gem (100%)
Successfully installed activesupport-5.1.4
Fetching: rack-2.0.3.gem (100%)
Successfully installed rack-2.0.3
Fetching: rack-test-0.7.0.gem (100%)
Successfully installed rack-test-0.7.0
Fetching: mini_portile2-2.3.0.gem (100%)
Successfully installed mini_portile2-2.3.0
Fetching: nokogiri-1.8.1.gem (100%)
Building native extensions.  This could take a while...
ERROR:  Error installing rails:
	ERROR: Failed to build gem native extension.

    current directory: /usr/local/share/gems/gems/nokogiri-1.8.1/ext/nokogiri
/usr/bin/ruby -r ./siteconf20171014-2850-5yzwpu.rb extconf.rb
mkmf.rb can't find header files for ruby at /usr/share/include/ruby.h

extconf failed, exit code 1

Gem files will remain installed in /usr/local/share/gems/gems/nokogiri-1.8.1 for inspection.
Results logged to /usr/local/lib64/gems/ruby/nokogiri-1.8.1/gem_make.out
```
エラーが出ました。
出力されたログを確認。

```:/usr/local/lib64/gems/ruby/nokogiri-1.8.1/gem_make.out
current directory: /usr/local/share/gems/gems/nokogiri-1.8.1/ext/nokogiri
/usr/bin/ruby -r ./siteconf20171014-2850-5yzwpu.rb extconf.rb
mkmf.rb can't find header files for ruby at /usr/share/include/ruby.h

extconf failed, exit code 1
```
rubyのヘッダーファイルがない模様。
なのでruby-develをインストール
`dnf install ruby-devel`
###Railsインストール(take2)
```
[root@localhost ~]# gem install -N rails
Building native extensions.  This could take a while...
ERROR:  Error installing rails:
	ERROR: Failed to build gem native extension.

    current directory: /usr/local/share/gems/gems/nokogiri-1.8.1/ext/nokogiri
/usr/bin/ruby -r ./siteconf20171014-2904-13v3c3.rb extconf.rb
checking if the C compiler accepts ... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
	--with-opt-dir
	--without-opt-dir
	--with-opt-include
	--without-opt-include=${opt-dir}/include
	--with-opt-lib
	--without-opt-lib=${opt-dir}/lib64
	--with-make-prog
	--without-make-prog
	--srcdir=.
	--curdir
	--ruby=/usr/bin/$(RUBY_BASE_NAME)
	--help
	--clean
/usr/share/ruby/mkmf.rb:457:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
	from /usr/share/ruby/mkmf.rb:572:in `block in try_compile'
	from /usr/share/ruby/mkmf.rb:523:in `with_werror'
	from /usr/share/ruby/mkmf.rb:572:in `try_compile'
	from extconf.rb:138:in `nokogiri_try_compile'
	from extconf.rb:162:in `block in add_cflags'
	from /usr/share/ruby/mkmf.rb:630:in `with_cflags'
	from extconf.rb:161:in `add_cflags'
	from extconf.rb:407:in `<main>'

To see why this extension failed to compile, please check the mkmf.log which can be found here:

  /usr/local/lib64/gems/ruby/nokogiri-1.8.1/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in /usr/local/share/gems/gems/nokogiri-1.8.1 for inspection.
Results logged to /usr/local/lib64/gems/ruby/nokogiri-1.8.1/gem_make.out
```
再度エラー。
ログファイル確認、今度は↓を見てみる。
/usr/local/lib64/gems/ruby/nokogiri-1.8.1/mkmf.log 

```:/usr/local/lib64/gems/ruby/nokogiri-1.8.1/mkmf.log 
"gcc -o conftest -I/usr/include -I/usr/include/ruby/backward -I/usr/include -I.    -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -mtune=generic -fPIC  conftest.c  -L. -L/usr/lib64 -L. -Wl,-z,relro -specs=/usr/lib/rpm/redhat/redhat-hardened-ld -fstack-protector -rdynamic -Wl,-export-dynamic  -m64   -lruby  -lpthread -ldl -lcrypt -lm   -lc "
gcc: エラー: /usr/lib/rpm/redhat/redhat-hardened-cc1: No such file or directory
checked program was:
/* begin */
1: #include "ruby.h"
2: 
3: int main(int argc, char **argv)
4: {
5:   return 0;
6: }
/* end */
```
また足りないファイルがある模様、
調べたところ下記パッケージが必要みたい。
`dnf install redhat-rpm-config`
###Railsインストール(take3)
```
[root@localhost ~]# gem install -N railsBuilding native extensions.  This could take a while...
Successfully installed nokogiri-1.8.1
Fetching: crass-1.0.2.gem (100%)
Successfully installed crass-1.0.2
…
Fetching: rails-5.1.4.gem (100%)
Successfully installed rails-5.1.4
30 gems installed
```
無事インストール完了しました。