$ npm i npm -g

    $ npm install -g yarn

    $ yarn add global polymer-cli

    $ yarn add global bower

    $ npm install
    $ bower install

    $ polymer serve --open

    $ polymer build
    $ npm start

    $ polymer build

    $ polymer serve build/es6-bundled/ --open

    $ polymer lint --input src/**/*.html

    $ polymer test

    $ firebase deploy

   $ yarn global add prpl-server

   $ prpl-server --root ./build --config polymer.json --host 127.0.0.1

   $ prpl-server --root ./build --config polymer.json --host 127.0.0.1 --https-redirect

server {
<span class="pl-k">listen</span> <span class="pl-s">443</span>      ssl http2; 
<span class="pl-k">listen</span> [::]:443 ssl http2;
<span class="pl-k">server_name</span>     &lt;yourdomainname&gt;;

<span class="pl-k">if</span> (<span class="pl-smi">$scheme</span> != <span class="pl-s">"https"</span>) {
    <span class="pl-c1">return</span> <span class="pl-s">301</span> https://<span class="pl-smi">$host$request_uri</span>;
}  

<span class="pl-k">root</span>            /var/www/html;
<span class="pl-k">index</span>           index.html;
<span class="pl-k">charset</span>         utf-8;
<span class="pl-k">access_log</span>     <span class="pl-c1"> off</span>;
<span class="pl-k">error_log</span>       /var/log/nginx.error_log<span class="pl-c1"> error</span>;

<span class="pl-c"># SSL Certificate config</span>
<span class="pl-k">ssl_certificate</span> /etc/letsencrypt/live/&lt;yourdomainname&gt;/fullchain.pem; 
<span class="pl-k">ssl_certificate_key</span> /etc/letsencrypt/live/&lt;yourdomainname&gt;/privkey.pem;
<span class="pl-k">include</span> /etc/letsencrypt/options-ssl-nginx.conf; 

<span class="pl-k">ssl_session_timeout</span> <span class="pl-c1">10m</span>;
<span class="pl-k">ssl_session_cache</span> shared:SSL:10m;
<span class="pl-k">ssl_session_tickets</span> off;

<span class="pl-c"># Diffie-Hellman parameter for DHE ciphersuites, recommended 4096 bits</span>
<span class="pl-c"># to generate your dhparam.pem file, run $ openssl dhparam -out /etc/letsencrypt/live/&lt;yourdomainname&gt;/dhparam.pem 4096</span>
<span class="pl-k">ssl_dhparam</span>  /etc/letsencrypt/live/&lt;yourdomainname&gt;/dhparam.pem;

<span class="pl-c"># SSL Key exchanges</span>
<span class="pl-k">ssl_protocols</span> TLSv1.2 TLSv1.3; <span class="pl-c">#!! TLS 1.3 Requires nginx &gt;= 1.13.0 !!</span>
<span class="pl-k">ssl_ecdh_curve</span> secp384r1;
<span class="pl-k">ssl_ciphers</span> <span class="pl-s">'ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256'</span>;
<span class="pl-k">ssl_prefer_server_ciphers</span><span class="pl-c1"> on</span>;

<span class="pl-c"># OCSP Stapling - fetch OCSP records from URL in ssl_certificate and cache them for faster handshake</span>
<span class="pl-k">ssl_stapling</span> on;
<span class="pl-k">ssl_stapling_verify</span> on;
<span class="pl-k">ssl_trusted_certificate</span> /etc/letsencrypt/live/&lt;yourdomainname&gt;/fullchain.pem;

<span class="pl-c"># DNS for OSCP Resolver - to lookup your upstream domain name URL</span>
<span class="pl-k">resolver</span> <span class="pl-s">8.8.8.8</span> <span class="pl-s">4.4.4.4</span> valid=300s ipv6=off;
<span class="pl-k">resolver_timeout</span> <span class="pl-c1">10s</span>;

<span class="pl-c"># Security Header</span>
<span class="pl-k">add_header</span> Strict-Transport-Security <span class="pl-s">"max-age=31536000; includeSubdomains; preload"</span>;
<span class="pl-k">add_header</span> Referrer-Policy no-referrer-when-downgrade;
<span class="pl-k">add_header</span> X-Content-Type-Options nosniff;
<span class="pl-k">add_header</span> X-Frame-Options SAMEORIGIN;
<span class="pl-k">add_header</span> X-XSS-Protection <span class="pl-s">"1; mode=block"</span>;
<span class="pl-k">add_header</span> Content-Security-Policy upgrade-insecure-requests;

<span class="pl-c"># Required for LE certificate enrollment using certbot</span>
<span class="pl-k">location</span> <span class="pl-en">'/.well-known/acme-challenge' </span>{
    <span class="pl-k">default_type</span> <span class="pl-s">"text/plain"</span>;
    <span class="pl-k">root</span> /var/www/html;
}
<span class="pl-k">location</span> <span class="pl-en">/ </span>{
    <span class="pl-k">root</span> /var/www/html;
}

<span class="pl-c"># Reverse proxy</span>
<span class="pl-k">location</span> <span class="pl-en">/ </span>{
    <span class="pl-k">http2_push_preload</span> on;
    <span class="pl-k">proxy_pass</span> http://127.0.0.1:8080/;
    <span class="pl-k">proxy_set_header</span> X-Forwarded-Proto <span class="pl-smi">$scheme</span>;

#       proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Host $host:$server_port;
proxy_set_header X-Forwarded-Server $host;
proxy_read_timeout 3m;
proxy_send_timeout 3m;
proxy_buffer_size  128k;
proxy_buffers   32 32k;
proxy_busy_buffers_size 128k;
}
}

<clipboard-copy aria-label="Copy" class="ClipboardButton btn btn-invisible js-clipboard-copy m-2 p-0 tooltipped-no-delay d-flex flex-justify-center flex-items-center" data-copy-feedback="Copied!" data-tooltip-direction="w" value="server {

listen 443      ssl http2; 
listen [::]:443 ssl http2;
server_name     <yourdomainname>;

if ($scheme != &quot;https&quot;) {
    return 301 https://$host$request_uri;
}  

root            /var/www/html;
index           index.html;
charset         utf-8;
access_log      off;
error_log       /var/log/nginx.error_log error;

# SSL Certificate config
ssl_certificate /etc/letsencrypt/live/<yourdomainname>/fullchain.pem; 
ssl_certificate_key /etc/letsencrypt/live/<yourdomainname>/privkey.pem;
include /etc/letsencrypt/options-ssl-nginx.conf; 

ssl_session_timeout 10m;
ssl_session_cache shared:SSL:10m;
ssl_session_tickets off;

# Diffie-Hellman parameter for DHE ciphersuites, recommended 4096 bits
# to generate your dhparam.pem file, run $ openssl dhparam -out /etc/letsencrypt/live/<yourdomainname>/dhparam.pem 4096
ssl_dhparam  /etc/letsencrypt/live/<yourdomainname>/dhparam.pem;

# SSL Key exchanges
ssl_protocols TLSv1.2 TLSv1.3; #!! TLS 1.3 Requires nginx >= 1.13.0 !!
ssl_ecdh_curve secp384r1;
ssl_ciphers 'ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256';
ssl_prefer_server_ciphers on;

# OCSP Stapling - fetch OCSP records from URL in ssl_certificate and cache them for faster handshake
ssl_stapling on;
ssl_stapling_verify on;
ssl_trusted_certificate /etc/letsencrypt/live/<yourdomainname>/fullchain.pem;

# DNS for OSCP Resolver - to lookup your upstream domain name URL
resolver 8.8.8.8 4.4.4.4 valid=300s ipv6=off;
resolver_timeout 10s;

# Security Header
add_header Strict-Transport-Security &quot;max-age=31536000; includeSubdomains; preload&quot;;
add_header Referrer-Policy no-referrer-when-downgrade;
add_header X-Content-Type-Options nosniff;
add_header X-Frame-Options SAMEORIGIN;
add_header X-XSS-Protection &quot;1; mode=block&quot;;
add_header Content-Security-Policy upgrade-insecure-requests;

# Required for LE certificate enrollment using certbot
location '/.well-known/acme-challenge' {
    default_type &quot;text/plain&quot;;
    root /var/www/html;
}
location / {
    root /var/www/html;
}

# Reverse proxy
location / {
    http2_push_preload on;
    proxy_pass http://127.0.0.1:8080/;
    proxy_set_header X-Forwarded-Proto $scheme;

proxy_http_version 1.1;

    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection &quot;upgrade&quot;;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Host $host:$server_port;
    proxy_set_header X-Forwarded-Server $host;
    proxy_read_timeout 3m;
    proxy_send_timeout 3m;
    proxy_buffer_size  128k;
    proxy_buffers   32 32k;
    proxy_busy_buffers_size 128k;
}

}" tabindex="0" role="button">