Upgrading from the version with setup-check

# Upgrading from the version with setup-check

Older versions of Repo Renderer had built-in default paths, a shared hooks
directory at `/usr/local/share/repo-render/hooks`, and `setup-check` and
`httpd-conf` commands. They also kept httpd and mirroring settings in the
renderer's config. The new version won't start until the config has been
updated, so do all of these steps together. Pushes made partway through
won't be rendered.

## 1. Install the new version

Follow step 1 of [openbsd.md](openbsd.md): build the package on your
machine with `make server`, copy it to the server, and run `install.sh`
there as root.

## 2. Update the renderer's config

On the server, as root, edit `/etc/repo-render/repo-render.yaml`.

Add the paths that used to be defaults, with your own host name in
`htdocs`:

```yaml
git_dir: /var/git
htdocs: /var/www/htdocs/code.example.com
spool_dir: /var/spool/repo-render
state_dir: /var/db/repo-render
log: syslog
git: /usr/local/bin/git
```

Then remove these settings, which the renderer no longer accepts:

- `listen`, `aliases` and `htpasswd`. These now go in httpd's config
  (step 4), so make a note of their values first.
- `ssh_key`.
- `mirrors` under each repository. Make a note of these too, for step 3.

Check the result:

```sh
su -s /bin/sh git -c 'repo-render --config /etc/repo-render/repo-render.yaml check'
```

If any old settings are left, `check` names them and says where they
belong now.

## 3. Rewire the repositories

Each repository needs to link to the new hook, and needs the config's
path and its mirrors stored in its own git config. Rewiring also removes
the old `core.hooksPath` setting.

If your mirrors are your own GitHub repositories, the migration script
can do all of this. On your machine:

```sh
tools/migrate-from-github --dry-run --key /etc/repo-render/mirror_key SERVER
tools/migrate-from-github --key /etc/repo-render/mirror_key SERVER
```

Use the path of your existing mirror key. Older versions used
`/etc/repo-render/mirror_key`, and before that
`/etc/repo-render/github_key`.

Otherwise, rewire each repository by hand. On the server, as root, run
this for each repository, with one `-m` for each of its mirrors:

```sh
su -s /bin/sh git -c 'repo-render-new-repo -c /etc/repo-render/repo-render.yaml -m URL /var/git/NAME.git'
su -s /bin/sh git -c 'git -C /var/git/NAME.git config core.sshCommand "ssh -o BatchMode=yes -o ConnectTimeout=30 -i /etc/repo-render/mirror_key"'
```

## 4. Replace httpd's config

Make a new `/etc/repo-render/httpd.conf` from
`/usr/local/share/examples/repo-render/httpd.conf`, as in step 4 of
[openbsd.md](openbsd.md). The example's paths don't include the host
name, but your existing site's do, so change `root` and `errdocs` to
`"/htdocs/YOUR.HOST"` and `"/htdocs/YOUR.HOST/err"`, and each private
site `root` to `"/private/YOUR.HOST"` if you have one. Put back the
`listen` address, any `alias` lines, and the htpasswd file path from the
old settings you noted in step 2. Then reload httpd:

```sh
httpd -n && rcctl reload httpd
```

## 5. Re-render and clean up

On the server, as root, render everything, then remove the files the old
version installed:

```sh
su -s /bin/sh git -c 'repo-render --config /etc/repo-render/repo-render.yaml render --all'
rm -r /usr/local/share/repo-render/hooks /usr/local/share/repo-render/lexers
rm -f /usr/local/share/repo-render/repo-render.yaml /usr/local/share/repo-render/httpd.conf
```

The syntax highlighters that used to live in `lexers/` are now built into
the renderer.