Hass.io install fails on ubuntu 16.04 cannot connect to SSL pages?

So I tried to install hass.io using the script on a ubuntu 16.04 host. (i.e. curl -sL https://raw.githubusercontent.com/home-assistant/hassio-build/master/install/hassio_install | bash -
Docker hello world is running without a problem.

But it seems that i cannot connect to any SSL page:

$ sudo docker logs hassio_supervisor
starting version 3.2.4
18-02-13 22:15:10 INFO (MainThread) [__main__] Initialize Hassio setup
18-02-13 22:15:10 INFO (MainThread) [__main__] Setup HassIO
18-02-13 22:15:10 WARNING (MainThread) [hassio.utils.dt] Can't fetch freegeoip data: Cannot connect to host freegeoip.io:443 ssl:True [Connection refused]
18-02-13 22:15:10 INFO (SyncWorker_0) [hassio.docker.supervisor] Attach to supervisor homeassistant/amd64-hassio-supervisor with version 0.88
18-02-13 22:15:11 INFO (SyncWorker_1) [hassio.docker.interface] Attach to image homeassistant/qemux86-64-homeassistant with version landingpage
18-02-13 22:15:11 INFO (MainThread) [hassio.addons.git] Clone addon https://github.com/home-assistant/hassio-addons repository
18-02-13 22:15:11 INFO (MainThread) [hassio.addons.git] Clone addon https://github.com/hassio-addons/repository repository
18-02-13 22:15:11 ERROR (MainThread) [hassio.addons.git] Can't clone https://github.com/home-assistant/hassio-addons repo: Cmd('git') failed due to: exit code(128)
  cmdline: git clone --recursive -v https://github.com/home-assistant/hassio-addons /data/addons/core
  stderr: 'Cloning into '/data/addons/core'...
fatal: unable to access 'https://github.com/home-assistant/hassio-addons/': Failed to connect to github.com port 443: Connection refused
'.
18-02-13 22:15:11 ERROR (MainThread) [hassio.addons] Can't load from repository core
18-02-13 22:15:11 ERROR (MainThread) [hassio.addons.git] Can't clone https://github.com/hassio-addons/repository repo: Cmd('git') failed due to: exit code(128)
  cmdline: git clone --recursive -v https://github.com/hassio-addons/repository /data/addons/git/a0d7b954
  stderr: 'Cloning into '/data/addons/git/a0d7b954'...
fatal: unable to access 'https://github.com/hassio-addons/repository/': Failed to connect to github.com port 443: Connection refused
'.
18-02-13 22:15:11 ERROR (MainThread) [hassio.addons] Can't load from repository https://github.com/hassio-addons/repository
18-02-13 22:15:11 INFO (MainThread) [hassio.addons] Load addons: 0 all - 0 new - 0 remove
18-02-13 22:15:11 INFO (MainThread) [hassio.updater] Fetch update data from https://raw.githubusercontent.com/home-assistant/hassio/master/version.json
18-02-13 22:15:11 WARNING (MainThread) [hassio.updater] Can't fetch versions from https://raw.githubusercontent.com/home-assistant/hassio/master/version.json: Cannot connect to host raw.githubusercontent.com:443 ssl:True [Connection refused]
18-02-13 22:15:11 INFO (MainThread) [hassio.snapshots] Found 0 snapshot files
18-02-13 22:15:11 INFO (MainThread) [hassio.addons] Startup initialize run 0 addons
18-02-13 22:15:11 INFO (MainThread) [__main__] Run HassIO
18-02-13 22:15:11 INFO (MainThread) [hassio.misc.dns] Start DNS port forwarding for host add-ons
18-02-13 22:15:11 INFO (MainThread) [hassio.supervisor] Update supervisor to version None
18-02-13 22:15:11 INFO (SyncWorker_1) [hassio.docker.interface] Pull image homeassistant/amd64-hassio-supervisor tag None.
18-02-13 22:15:12 ERROR (SyncWorker_1) [hassio.docker.interface] Can't install homeassistant/amd64-hassio-supervisor:None -> 404 Client Error: Not Found ("manifest for homeassistant/amd64-hassio-supervisor:None not found").
18-02-13 22:15:12 ERROR (MainThread) [hassio.supervisor] Update of hass.io fails!

I further checked and indeed the supervisor cannot connect to any SSL page.

$ sudo docker exec -i -t hassio_supervisor /bin/bash
bash-4.4# apk --no-cache add curl
fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/community/x86_64/APKINDEX.tar.gz
OK: 125 MiB in 40 packages
bash-4.4# curl https://google.com
curl: (35) error:1400410B:SSL routines:CONNECT_CR_SRVR_HELLO:wrong version number


$ bash-4.4# nslookup github.com
nslookup: can't resolve '(null)': Name does not resolve

Name:      github.com
Address 1: 192.30.253.112 lb-192-30-253-112-iad.github.com
Address 2: 192.30.253.113 lb-192-30-253-113-iad.github.com
bash-4.4# 

Has someone an idea?

Having the same issue but finding the same number of results frustrating

After some debugging I have finally found my issue, but never found the time to answer here. I had a portforwarding on my HA server that forwarded 443 to 8123 for SSL, such that I could easier connect to my HA instance. But I had made a mistake in the rules and as a result this was also set not only for incoming but also for OUTGOING connections, i.e. the NAT rerouted 443 to 8123, so it tried to connect to the wrong port.

So check all your network settings carefully, maybe you have something similar setup.