Question: I don't know what I was trying to do but I basically deleted `yum.conf`. I found an old config for yum on github but it still doesn't work. What do I do? I am using Centos 7.

Answer: 
Although I've no idea what was originally in your `/etc/yum.conf`, try placing this generic/vanilla content in there.

```
$ cat /etc/yum.conf
[main]
cachedir=/var/cache/yum/$basearch/$releasever
keepcache=0
debuglevel=2
logfile=/var/log/yum.log
exactarch=1
obsoletes=1
gpgcheck=1
plugins=1
installonly_limit=5
bugtracker_url=http://bugs.centos.org/set_project.php?project_id=23&ref=http://b                                                                                                                     
ugs.centos.org/bug_report_page.php?category=yum
distroverpkg=centos-release
$

```
If you prefer to restore to the original, you can reinstall the rpm that creates the `yum.conf`. First, find which rpm it comes from using `rpm -qf`.

On my system,

```
$ rpm -qf /etc/yum.conf 
yum-3.4.3-158.el7.centos.noarch

```

I found a copy here:

```
http://mirror.centos.org/centos/7/os/x86_64/Packages/yum-3.4.3-158.el7.centos.noarch.rpm

```

To reinstall,

```
$ sudo rpm --reinstall http://mirror.centos.org/centos/7/os/x86_64/Packages/yum-3.4.3-158.el7.centos.noarch.rpm

```

Alternatively, you could download the rpm, and pick it apart using `rpm2cpio`:

```
$ mkdir /tmp/yum
$ cd /tmp/yum
$ curl http://mirror.centos.org/centos/7/os/x86_64/Packages/yum-3.4.3-158.el7.centos.noarch.rpm | rpm2cpio | cpio -idmv

```

It will now be in `/tmp/yum/etc/yum.conf`

Meanwhile, you may wish to start using [etckeeper](https://www.digitalocean.com/community/tutorials/how-to-manage-etc-with-version-control-using-etckeeper-on-centos-7), which will at *least* keep a local backup of your `/etc` in version control.