docker-proxy - Error starting userland proxy while trying to bind on 443
<p>I'm trying to install discourse with docker in an Ubuntu 16.04 LTS with Apache listening to port 80 and 443.</p>

<p><a href="https://i.stack.imgur.com/iyPoG.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/iyPoG.jpg" alt="enter image description here"></a></p>

<p>When I try to lunch the app I get the following error:</p>

<blockquote>
  <p>starting up existing container
  + /usr/bin/docker start app Error response from daemon: driver failed programming external connectivity on endpoint app
  (dade361e77fbf29f4d9667febe57a06f168f916148e10cc1365093d8f97026bb):
  <strong>Error starting userland proxy: listen tcp 0.0.0.0:443</strong>: listen: address
  already in use Error: failed to start containers: app</p>
</blockquote>

<p>For what I'v found docker-proxy is the one that is trying to bind on 443.</p>

<p><a href="https://i.stack.imgur.com/EEQdW.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EEQdW.jpg" alt="netstat -tulpn | grep 443"></a></p>

<p>How can I solve this?</p>

<p>Some details...</p>

<pre><code>docker version
Client:
 Version:      1.11.2
 API version:  1.23
 Go version:   go1.5.4
 Git commit:   b9f10c9
 Built:        Wed Jun  1 22:00:43 2016
 OS/Arch:      linux/amd64

Server:
 Version:      1.11.2
 API version:  1.23
 Go version:   go1.5.4
 Git commit:   b9f10c9
 Built:        Wed Jun  1 22:00:43 2016
 OS/Arch:      linux/amd64


docker info
Containers: 1
 Running: 0
 Paused: 0
 Stopped: 1
Images: 4
Server Version: 1.11.2
Storage Driver: aufs
 Root Dir: /var/lib/docker/aufs
 Backing Filesystem: extfs
 Dirs: 25
 Dirperm1 Supported: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: null host bridge
Kernel Version: 4.4.0-28-generic
Operating System: Ubuntu 16.04 LTS
OSType: linux
Architecture: x86_64
CPUs: 4
Total Memory: 31.39 GiB
Name: sd-12345
ID: 6OLH:SAG5:VWTW:BL7U:6QYH:4BBS:QHBN:37MY:DLXA:W64E:4EVZ:WBAK
Docker Root Dir: /var/lib/docker
Debug mode (client): false
Debug mode (server): false
Registry: https://index.docker.io/v1/
WARNING: No swap limit support
</code></pre>