Register a service with haproxy¶

Ensure that the salt-master and loadbalancer can be brought up with vagrant locally:
```
vagrant up salt-master
vagrant up loadbalancer
```
In the local repository, create a new state/directory to manage files for your service:
```
touch salt/base/salt.sls
```

Additionally, add an nginx configuration state and consul service state that exposes that directory over HTTP:

This configuration might look similar to an existing haproxy service like letsencrypt

/etc/nginx/sites.d/letsencrypt-well-known.conf:
  file.managed:
    - source: salt://base/config/letsencrypt-well-known-nginx.conf
    - user: root
    - group: root
    - mode: "0644"
    - require:
      - file: /etc/nginx/sites.d/
      - sls: tls.lego

/etc/consul.d/service-letsencrypt-well-known.json:
  file.managed:
    - source: salt://consul/etc/service.jinja
    - template: jinja
    - context:
        name: letsencrypt-well-known
        port: 9000
    - user: root
    - group: root
    - mode: "0644"
    - require:
      - pkg: consul-pkgs

In your local repository, navigate to salt/base/config and add an nginx configuration file: This configuration file might look similarly to the one of the letsencrypt service:

server {
  listen 9000 ssl default_server;

  ssl_certificate /etc/ssl/private/salt.psf.io.pem;
  ssl_certificate_key /etc/ssl/private/salt.psf.io.pem;

  server_name _;

  location /.well-known/acme-challenge/ {
      alias /etc/lego/.well-known/acme-challenge/;
      try_files $uri =404;
  }
}
~

Add an entry in pillar/base/haproxy.sls to create the haproxy configuration:
```
letsencrypt-well-known:
  domains: []
  verify_host: salt.psf.io
  check: "GET /.well-known/acme-challenge/sentinel HTTP/1.1\\r\\nHost:\\ salt.psf.io"
```
This will render given the template in salt/haproxy/config/haproxy.cfg.jinja to create a service which has two “slots” that will be filled based on the DNS resolution of the consul service registered in step 3.
Prepare an SSH configuration file to access the host with native ssh commands:
```
vagrant ssh-config salt-master loadbalancer >> vagrant-ssh
```
Open an SSH session with port forwarding to the haproxy status page:
```
ssh -L 4646:127.0.0.1:4646 -F vagrant-ssh loadbalancer
```
- Open http://localhost:4646/haproxy?stats to see haproxy status
You will see the two “slots” registered in haproxy, with one host found via Consul DNS.
- Green indicates the host exists, was resolved, and is passing health check.
- Brown indicates that a slot does not have a host, in other words not enough hosts were resolved, so it is reserved in “maintenance” state.
- Red would indicate that a host exists, was resolved, and is failing health check.
In a new window run:
```
ssh -F sshconfig -L 8500:127.0.0.1:8500 salt-master
```
- Open http://localhost:8500/ui/vagrant/services to see what consul services are registered
You can browse to see what services have been registered, and what nodes are advertising that service.