view release on metacpan or  search on metacpan

lib/Dancer/Deployment.pod  view on Meta::CPAN

C<HAProxy> is a reliable high-performance TCP/HTTP load balancer written in C available from
L<http://haproxy.1wt.eu/>.

Suppose we want to run an application at C<app.example.com:80> and would to use two
backends listen on hosts C<app-be1.example.com:3000> and C<app-be2.example.com:3000>.

Here is HAProxy configuration file (haproxy.conf):

    global
        nbproc  1
        maxconn 4096
        user    nobody
        group   nobody
        # haproxy logs will be collected by syslog
        # syslog: unix socket path or tcp pair (ipaddress:port)
        log     /var/run/log local0
        daemon
        # enable compression (haproxy v1.5-dev13 and above required)
        tune.comp.maxlevel  5

    defaults
        log     global
        option  httpclose
        option  httplog
        option  dontlognull
        option  forwardfor
        option  abortonclose
        mode    http
        balance roundrobin
        retries 3
        timeout connect         5s
        timeout server          30s
        timeout client          30s
        timeout http-keep-alive 200m
        # enable compression (haproxy v1.5-dev13 and above required)
        compression algo gzip
        compression type text/html application/javascript text/css application/x-javascript text/javascript

    # application frontend (available at http://app.example.com)
    frontend app.example.com
        bind                  :80
        # modify request headers
        reqadd                X-Forwarded-Proto:\ http
        reqadd                X-Forwarded-Port:\ 80
        # modify response headers
        rspdel                ^Server:.*
        rspdel                ^X-Powered-By:.*
        rspadd                Server:\ Dethklok\ (Unix/0.2.3)
        rate-limit sessions   1024
        acl is-haproxy-stats  path_beg /stats
        # uncomment if you'd like to get haproxy usage statistics
        # use_backend haproxy   if is-haproxy-stats
        default_backend       dynamic

    # haproxy statistics (available at http://app.example.com/stats)
    backend haproxy
        stats uri             /stats
        stats refresh         180s
        stats realm           app.example.com\ haproxy\ statistics
        # change credentials
        stats auth            admin1:password1
        stats auth            admin2:password2
        stats hide-version
        stats show-legends

    # application backends
    backend dynamic
        # change path_info to check and value of the Host header sent to application server
        option httpchk HEAD / HTTP/1.1\r\nHost:\ app.example.com
        server app1 app-be1.example.com:3000 check inter 30s
        server app2 app-be2.example.com:3000 check inter 30s

We will need to start the workers on each backend of our application. This can be done by starman utility:

    # on app-be1.example.com
    $ starman --workers=2 --listen :3000 /path/to/app.pl
    # on app-be2.example.com
    $ starman --workers=2 --listen :3000 /path/to/app.pl

Then start the haproxy itself:

    # check the configuration..
    $ sudo haproxy -c -f haproxy.conf
    # now really start it..
    $ sudo haproxy -f haproxy.conf

=head3 Plackup Chef Cookbook

A psgi chef cookbook supporting Dancer (as well as I<Catalyst>)
written by Alexey Melezhik is available
at L<http://community.opscode.com/cookbooks/psgi>.

=head2 Running from Apache

You can run your Dancer app from Apache using the following examples:

=head3 Running from Apache with Plack

You can run your app from Apache using PSGI (Plack), with a config like the
following:

    <VirtualHost myapp.example.com>
        ServerName www.myapp.example.com
        ServerAlias myapp.example.com
        DocumentRoot /websites/myapp.example.com

        <Directory /websites/myapp.example.com>
            AllowOverride None
            Order allow,deny
            Allow from all
        </Directory>

        <Location />
            SetHandler perl-script
            PerlResponseHandler Plack::Handler::Apache2
            PerlSetVar psgi_app /websites/myapp.example.com/app.pl
        </Location>

        ErrorLog  /websites/myapp.example.com/logs/error_log
        CustomLog /websites/myapp.example.com/logs/access_log common