My Meteor app is not working in Ubuntu 16.04.
I'm stuck and would really appreciate any help.

I created a systemd service config for my Meteor app.
My app appears to start but I get a 502 in the browser.

It appears that my service is running

root@ubuntu# journalctl -f -u mymeteorapp
    Nov 06 22:33:52 ubuntu systemd[1]: Started mymeteorapp.service.

root@ubuntu:~# systemctl status mymeteorapp
    Nov 05 12:48:42 ubuntu systemd[1]: Started Meteor.js (NodeJS) mymeteorapp application.
    root@ubuntu:~#

But I get this nginx error

root@ubuntu:/lib/systemd/system# tail -f /var/log/nginx/error.log
    2016/11/06 22:34:29 [error] 13486#13486: *248 connect() failed (111: Connection refused) while connecting to upstream, client: 84.23.134.181, server: 36.102.142.66, request: "GET / HTTP/1.1", upstream: "http://127.0.0.1:8080/", host: "36.102.142.66"

Running netstat shows this:

root@ubuntu:/lib/systemd/system# netstat -plnt
    Active Internet connections (only servers)
    Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
    tcp 0 0 0.0.0.0:443 0.0.0.0:* LISTEN 4849/nginx -g daemo
    tcp 0 0 127.0.0.1:27017 0.0.0.0:* LISTEN 17393/mongod
    tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 4849/nginx -g daemo
    tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1467/sshd
    tcp6 0 0 :::80 :::* LISTEN 4849/nginx -g daemo
    tcp6 0 0 :::22 :::* LISTEN 1467/sshd

But I should see something here for 8080?

Nginx config is below:

    root@ubuntu:~# cat /etc/nginx/sites-available/mymeteorapp
    ================
    server_tokens off; # for security-by-obscurity: stop displaying nginx version

    # this section is needed to proxy web-socket connections
    map $http_upgrade $connection_upgrade {
    default upgrade;
    '' close;
    }

    # HTTP
    server {
    listen 80 default_server; # if this is not a default server, remove "default_server"
    listen [::]:80 default_server ipv6only=on;
    #listen 80;

    root /usr/share/nginx/html; # root is irrelevant
    index index.html index.htm; # this is also irrelevant

    server_name 36.102.142.66; # the domain on which we want to host the application. Since we set "default_server" previously, nginx will answer all hosts anyway.

    # redirect non-SSL to SSL
    location / {
    rewrite ^ https://$server_name$request_uri? permanent;
    }
    }

    # HTTPS server
    server {
    listen 443 ssl spdy; # we enable SPDY here
    server_name 36.102.142.66; # this domain must match Common Name (CN) in the SSL certificate

    root html; # irrelevant
    index index.html; # irrelevant

    ssl_certificate /etc/nginx/ssl/mymeteorapp.pem; # full path to SSL certificate and CA certificate concatenated together
    ssl_certificate_key /etc/nginx/ssl/mymeteorapp.key; # full path to SSL key

    # performance enhancement for SSL
    ssl_stapling on;
    ssl_session_cache shared:SSL:10m;
    ssl_session_timeout 5m;

    # safety enhancement to SSL: make sure we actually use a safe cipher
    ssl_prefer_server_ciphers on;
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    ssl_ciphers 'ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:ECDHE-RSA-RC4-SHA:ECDHE-ECDSA-RC4-SHA:RC4-SHA:HIGH:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK';

    # config to enable HSTS(HTTP Strict Transport Security) https://developer.mozilla.org/en-US/docs/Security/HTTP_Strict_Transport_Security
    # to avoid ssl stripping https://en.wikipedia.org/wiki/SSL_stripping#SSL_stripping
    add_header Strict-Transport-Security "max-age=31536000;";

    # If your application is not compatible with IE <= 10, this will redirect visitors to a page advising a browser update
    # This works because IE 11 does not present itself as MSIE anymore
    if ($http_user_agent ~ "MSIE" ) {
    return 303 https://browser-update.org/update.html;
    }

    # pass all requests to Meteor
    location / {
    proxy_pass http://127.0.0.1:8080 ;
    #proxy_pass http://0.0.0.0:8080;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade; # allow websockets
    proxy_set_header Connection $connection_upgrade;
    proxy_set_header X-Forwarded-For $remote_addr; # preserve client IP

    # this setting allows the browser to cache the application in a way compatible with Meteor
    # on every applicaiton update the name of CSS and JS file is different, so they can be cache infinitely (here: 30 days)
    # the root path (/) MUST NOT be cached
    if ($uri != '/') {
    expires 30d;
    }
    }
    }
    ================

Below is the script for systemd service:

root@ubuntu:~# cat /lib/systemd/system/mymeteorapp.service

    [Unit]
    Description=Meteor.js (NodeJS) mymeteorapp application
    # start the service after mongodb starts
    Requires=mongodb.service
    After=mongodb.service

    [Service]
    Type=forking
    # Automatically restart process if crashed
    Restart=on-failure
    RestartSec=10 5
    ##Restart=always
    StandardOutput=syslog
    StandardError=syslog
    SyslogIdentifier=mymeteorapp
    # drop root proviliges and switch to mymetorapp user
    User=mymeteorapp
    Group=mymeteorapp
    Environment=PATH=/opt/local/bin:/opt/local/sbin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
    Environment=NODE_PATH=/usr/lib/nodejs:/usr/lib/node_modules:/usr/share/javascript
    # set to home directory of the user Meteor will be running as
    Environment=PWD=/home/mymeteorapp
    Environment=HOME=/home/mymeteorapp
    # leave as 127.0.0.1 for security
    Environment=BIND_IP=127.0.0.1
    # the port nginx is proxying requests to
    Environment=PORT=8080
    # this allows Meteor to figure out correct IP address of visitors
    Environment=HTTP_FORWARDED_COUNT=1
    # MongoDB connection string using mymeteorapp as database name
    Environment=MONGO_URL=mongodb://localhost:27017/mymeteorapp
    # The domain name as configured previously as server_name in nginx
    Environment=NODE_ENV=production
    Environment=ROOT_URL=https://36.102.142.66
    # optional JSON config - the contents of file specified by passing "--settings" parameter to meteor command in development mode
    #Environment=METEOR_SETTINGS='{ "somesetting": "someval", "public": { "othersetting": "anothervalue" } }'
    # this is optional: http://docs.meteor.com/#email
    # commented out will default to no email being sent
    # you must register with MailGun to have a username and password there
    # export MAIL_URL=smtp://postmaster@mymetorapp.net:password123@smtp.mailgun.org
    # alternatively install "apt-get install default-mta" and uncomment:
    # export MAIL_URL=smtp://localhostEnvironment=statedir=/var/cache/foo
    ExecStart=/usr/bin/node /home/mymeteorapp/bundle/main.js

    [Install]
    WantedBy=multi-user.target

Some refs I have used:
how-to-deploy-a-meteor-js-application-on-ubuntu-14-04-with-nginx

run-your-meteor-app-on-production.html - purportedly an update for 16.04 on the 14.04 ref above though it still has the Upstart config instead of systemd.

run-meteor-app-as-a-service-on-ubuntu

how-to-deploy-node-js-applications-using-systemd-and-nginx

SystemdForUpstartUsers

initial-server-setup-with-ubuntu-16-04

how-to-install-node-js-on-ubuntu-16-04