EC2インスタンスでEPELがエラーになる

##対象
Amazon Linux AMI release 2013.03
Amazon Linux AMI release 2014.09

##事象

いつ頃からか、新しく作ったインスタンスが軒並みエラーになるように。

```
$ sudo yum list --enablerepo=epel
Loaded plugins: priorities, security, update-motd, upgrade-helper
Error: Cannot retrieve repository metadata (repomd.xml) for repository: epel. Please verify its path and try again
```

ミラーじゃなくbaseurlを使うとエラーはなくなる。SSLの接続がおかしいくさい。

```epel.repo
[epel]
name=Extra Packages for Enterprise Linux 6 - $basearch
#baseurl=http://download.fedoraproject.org/pub/epel/6/$basearch
mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-6&arch=$basearch
failovermethod=priority
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6

[epel-debuginfo]
name=Extra Packages for Enterprise Linux 6 - $basearch - Debug
#baseurl=http://download.fedoraproject.org/pub/epel/6/$basearch/debug
mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-debug-6&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6
gpgcheck=1

[epel-source]
name=Extra Packages for Enterprise Linux 6 - $basearch - Source
#baseurl=http://download.fedoraproject.org/pub/epel/6/SRPMS
mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-source-6&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6
gpgcheck=1
```

##対応

[linux - EPEL Repo for CentOS 6 causing error - Server Fault](http://serverfault.com/questions/637549/epel-repo-for-centos-6-causing-error)

SSL証明書を更新すればOKとのこと

```
$ sudo yum list ca-certificates
Loaded plugins: priorities, security, update-motd, upgrade-helper
amzn-main                                                                                                                                                                                                 | 2.1 kB     00:00
amzn-updates                                                                                                                                                                                              | 2.3 kB     00:00
devel-sg2-base                                                                                                                                                                                            | 1.3 kB     00:00
zabbix                                                                                                                                                                                                    |  951 B     00:00
zabbix-non-supported                                                                                                                                                                                      |  951 B     00:00
10 packages excluded due to repository priority protections
Installed Packages
ca-certificates.noarch                                                                                     2010.63-3.7.amzn1                                                                                            installed
Available Packages
ca-certificates.noarch                                                                                     2014.1.98-65.0.11.amzn1                                                                                      amzn-main
```
めちゃめちゃ古い・・・

```
$ sudo yum upgrade ca-certificates --disablerepo=epel
```
ありがとうございましたm(_ _)m