Centos7: Can't install nginx (or epel)

Question

I have a clean install of Centos 7 on a RaspberryPi3b+. I am trying to install nginx and am running into problems with each approach.

Most of the research I've done points to installing epel, and then installing nginx. When I run yum install epel-release, I get the error:

No package epel-release available.
Error:  Nothing to do.

Some searching led me to wget it directly from fedora. I was able do that. I then ran rpm -ivh epel-release-latest-7.noarch.rpm successfully and then tried yum install nginx. That gave me this long error:

One of the configured repositories failed (Unknown),
 and yum doesn't have enough cached data to continue. At this point the only
 safe thing yum can do is fail. There are a few ways to work "fix" this:

     1. Contact the upstream for the repository and get them to fix the problem.

     2. Reconfigure the baseurl/etc. for the repository, to point to a working
        upstream. This is most often useful if you are using a newer
        distribution release than is supported by the repository (and the
        packages for the previous distribution release still work).

     3. Run the command with the repository temporarily disabled
            yum --disablerepo=<repoid> ...

     4. Disable the repository permanently, so yum won't use it by default. Yum
        will then just ignore the repository until you permanently enable it
        again or use --enablerepo for temporary usage:

            yum-config-manager --disable <repoid>
        or
            subscription-manager repos --disable=<repoid>

     5. Configure the failing repository to be skipped, if it is unavailable.
        Note that yum will try to contact the repo. when it runs most commands,
        so will have to try and fail each time (and thus. yum will be be much
        slower). If it is a very temporary problem though, this is often a nice
        compromise:

            yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true

Cannot retrieve metalink for repository: epel/armhfp. Please verify its path and try again

So, I found another method that doesn't require epel. I created a .repo file for nginx at /etc/yum.repos.d/nginx.repo, and added:

[nginx]
name=nginx repo
baseurl=http://nginx.org/packages/centos/$releasever/$basearch/
gpgcheck=0 
enabled=1

I ran yum repolist and got an error: http://nginx.org/packages/centos/7/armhfp/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found

For laughs, I tried installing nginx anyway and got an error similar to the long one above that the nginx repo failed.

Finally, I tried going to nginx.org and finding the correct link and hard-coding it in the repo file. That didn't work either, and now I am well and truly stuck.