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Plugin::Database - suggestion to read username/password from a different file
by Assaf Gordon 26 Sep '11

26 Sep '11

Hello Dancers, Somewhat related to the "sensitive" config data in SCM" topic discussed recently, I would like to suggest the followng small patch to "Dancer::Plugin::Database" : Instead of specifying "username/password" in your yml config file, I've added a new setting called "credentials". This one points to a simple text file that would contain the user name and password. With this one can checkin all the configuration files, never worrying about passwords. Samba uses similar option in "smbclient" . So my new config looks like this: ==== plugins: Database: driver: 'mysql' database: 'devdb' credentials: 'database.secret' ===== And the username password are stored in "database.secret": ===== $ cat database.secret username=myuser password=mypassword ==== The patch is available here: https://github.com/agordon/Dancer-Plugin-Database/commit/5564d0c729899c45b8… Comments are welcomed, -gordon

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serving static and dynamic content separately
by Mr. Puneet Kishor 18 Sep '11

18 Sep '11

Pursuant to my earlier post in which I expressed curiosity about serving static and dynamic content from different servers, I have the following (not directly Dancer related but causing me to sub-optimally serve Dancer content) problem. I am unable to configure apache2 frontend proxy to Starman and also serve apache2 content. My intent is to have apache2 serve some static content and some dynamic apps, both with domain names and those as sub-folders of the document root, and also serve some dynamic apps, both with domain names and without, proxied behind apache2. In other words, I want to do the following http://my.server.edu/ (served by apache2 from "/Users/me/Sites") http://my.server.edu/lib (served by apache2 from "/Users/me/Sites/lib") http://my.server.edu/app0 (served by apache2 from "/Users/me/Sites/app0" http://my.server.edu/app1 (served by Starman from "Users/me/Docs/www/app1") http://vapp1.org (served by Starman from "Users/me/Docs/www/vapp1") http://vapp1.org/lib (served by apache2 from "/Users/me/Sites") http://subapp.vapp1.org (served by Starman from "Users/me/Docs/www/subapp") http://subapp.vapp1.org/lib (served by apache2 from "/Users/me/Sites") Here is my (simplified) conf file with my intent and the unexpected exhibited behavior in the comments. #################################################### # Default settings for http://my.server.edu/ #################################################### Listen 80 ServerName my.server.edu:80 DocumentRoot "/Users/me/Sites" <Directory /> Options FollowSymLinks AllowOverride None Order deny,allow Deny from all </Directory> <Directory "/Users/me/Sites"> Options FollowSymLinks AllowOverride None Order allow,deny Allow from all </Directory> #################################################### # Static content for http://my.server.edu/lib #################################################### Alias /lib "/Users/me/Sites/lib" # The server responds with a "502 Bad gateway" error ScriptAlias /cgi-bin/ "/Users/me/cgi-bin/" <Directory "/Users/me/cgi-bin"> AllowOverride None Options None Order allow,deny Allow from all </Directory> #################################################### # Proxies #################################################### ProxyRequests Off <Proxy *> Order deny,allow Allow from all </Proxy> # The following app should get their static content # from http://my.server.edu/lib, but the server responds # with a "502 Bad gateway" error #################################################### # http://my.server.edu/app1 #################################################### ProxyPass /app1 http://127.0.0.1:5000 ProxyPassReverse /app1 http://127.0.0.1:5000 # The server responds with a "502 Bad gateway" error # when serving static content #################################################### # Virtual host http://vapp1.org #################################################### <VirtualHost *:80> ServerName vapp1.org #################################################### # Static content for http://vapp1.org/lib #################################################### Alias /lib "/Users/me/Sites/lib" ProxyRequests Off <Proxy *> Order deny,allow Allow from all </Proxy> ProxyPass / http://127.0.0.1:5001 ProxyPassReverse / http://127.0.0.1:5001 </VirtualHost> ##################################################### # Virtual host subdomain http://subapp.vapp1.org ##################################################### <VirtualHost *:80> ServerName subapp.vapp1.org # The server responds with a "502 Bad gateway" error # when serving static content #################################################### # Static content for http://subapp.vapp1.org/lib #################################################### Alias /lib "/Users/me/Sites/lib" ProxyRequests Off <Proxy *> Order deny,allow Allow from all </Proxy> ProxyPass / http://127.0.0.1:5002 ProxyPassReverse / http://127.0.0.1:5002 </VirtualHost> As you can see from above, if I have the virtual host segments in my conf file, the server responds with a "502 Bad gateway" error for everything that is supposed to come from http://my.server.edu. However, if I remove the virtual host segments, all other apps work just fine. I am sure I had this working on a previous machine, but now I am unable to reproduce that. What am I doing wrong?

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OT: sysadmins guys mock Dancers
by Dave Doyle 16 Sep '11

16 Sep '11

Hi Dancers, Sorry for the OT. Just thought this was amusing. My team came back from lunch yesterday to find the center of our pod newly decorated: http://i.imgur.com/umSpt.jpg Our SysAdmins have noticed my teams recent fetish for Dancer (2 restful API's, a new client facing dancer app and a new internal dancer app coming soon). This is the result. (for those not all to familiar with what's hanging there, see: http://en.wikipedia.org/wiki/Dance_Dance_Revolution ) Keep on dancin', meraxes -- dave.s.doyle(a)gmail.com

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Input-validation and Error-Handling in a fun 'dancer' way
by Assaf Gordon 15 Sep '11

15 Sep '11

Hello Dancers, I have another dancer-newbie question: Is there a recommended way to verify input (or general variables) and report errors to the user ? Common scenario: I have a form with 3 inputs, and they need to by in a certain format (verifiable by a simple regex). If the inputs do not conform, I want to: 1. Log the error for later inspection 2. Inform the user (e.g. using Plugin::Dancer::FlashMessage) (The error message reported to the user is not necessarily the same one written to the log, if I wish to include more technical details in the log, or be more descriptive and verbose to the user). 3. Stop processing the request. And I wish to do it in the most 'fun' dancer kind of way. Looking at a naive implementation (below), there's alot of redundant code for validating and reporting the error back to the user (and more validation code than actual processing code). Any suggestions ? Thanks! -gordon ==================== post '/dosomething' => sub { my $email = params->{email}; my $gene = params->{gene}; my $cutoff = param->{cutoff}; if (!defined $email) { warning "Missing email address"; flash error => 'Missing email address'; return template 'form_errors' ; } elsif (!valid_email($email)) { warning "Got Invalid email address: $email"; flash error => 'Invalid email address"; return template 'form_errors' ; } if (!defined $gene) { warning "Missing gene identifier"; flash error => 'Missing gene identifier'; return template 'form_errors' ; } elsif (!valid_gene_identifier($gene)) { warning "Got Invalid gene identifier: $gene"; flash error => 'Invalid gene identifier"; return template 'form_errors' ; } if (!defined $cutoff) { warning "Missing cutoff identifier"; flash error => 'Missing cutoff identifier'; return template 'form_errors' ; } elsif (!valid_cutoff_value($cutoff)) { warning "Got Invalid cutoff value: $cutoff"; flash error => 'Invalid Cutoff value: must a value between 0.1 and 0.55'; return template 'form_errors' ; } ## Input IS OK, do some processing and return the result my ($result, $error) = process($email, $gene, $cutoff); template 'result.tt', { email => $email, cutoff => $cutoff, gene => $gene, result => $result, error => $error, }; }

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Bug in Dancer::Request (+1-line patch)
by Richard Huxton 14 Sep '11

14 Sep '11

Current version of Dancer (1.3072) Line 52: sub forwarded_for_address { $_[0]->env->{X_FORWARDED_FOR} } Should read: sub forwarded_for_address { $_[0]->env->{HTTP_X_FORWARDED_FOR} } At least with my install of Apache on Debian. It's possible that the intention is to strip the HTTP_ from env entries, but it doesn't look like it here. I also suspect some of the other env vars might be missing a HTTP_ too. -- Richard Huxton Archonet Ltd

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deploying many, many apps
by Puneet Kishor 14 Sep '11

14 Sep '11

I have asked, or hinted at, other variants of the same question, but here again -- I am now developing and deploying many Dancer apps. Have been experimenting with, and am quite happy with Starman serving them hiding behind Apache2 proxies. My home grown, amateurish web_ctl [https://github.com/punkish/web_ctl] helps me manage them as well. However, with every app, I am starting an additional 10 Starman processes, so now already I have about 60 Starman processes running on my computer. 1. Why 10? I once tried 2 Starman processes for a very, very low traffic app, and found it coughing and sputtering, but surely, 10 is too many, isn't it? 2. Why not Apache2 with mod_perl or fastcgi or mod_psgi? Apache seems to launch 5-10 "children," but no matter how many apps are being served by it, that number of child processes seems to hover around that number. It doesn't get to n * 10 for Starman? The Starman approach does have one clear advantage -- each app can be turned off or on separately without having to restart Apache entirely. I want to get the crowd-wisdom on serving, say 50 different Dancer apps on the same computer. The apps will range from very, very low traffic to moderate traffic. However, all the apps will be data-intensive, in that, even if the number of user-hits on the server are few per hour, each hit does a fair bit of database work and sends back largish amounts of data. Data may be on the same or a different server -- that part is out of the scope for this thread. Many thanks in advance. Puneet.

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Dancer::Plugin::EncodeID
by Assaf Gordon 13 Sep '11

13 Sep '11

Hello dancers, My first attempt at a plugin: a simple utility to encode/obfuscate internal IDs in URLs. With this plugin, your users will see URLs such as: http://myserver.com/item/c98ea08a8e8ad715 instead of http://myserver.com/item/42 You can find it here: https://github.com/agordon/Dancer-Plugin-EncodeID Comments are very welcomed, -gordon

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Dancer::Plugin::Email problem with checking email failures
by Assaf Gordon 12 Sep '11

12 Sep '11

Hello, I'm having problems checking the return status of email sending with "Dancer::Plugin::Email" . The first example in the "code recipes" of "Dancer::Plugin::Email" shows the following: ---- post '/contact' => sub { my $msg = email { to => '...', subject => '...', message => $msg, encoding => 'base64', attach => [ '/path/to/file' ] }; warn $msg->{string} if $msg->{type} eq 'failure'; }; ---- This is the actual code I used: --- get '/emailtest' => sub { my $msg = email { to => 'gordon\(a)cshl.edu', subject => 'Dancer::PlugIn::Email Test', message => "Hello World from Dancer::Plugin::Email", }; warn $msg->{string} if $msg->{type} eq 'failure'; return "Email Sent!\n"; }; --- This is the error I get: ------------ Warning caught during route execution: Use of uninitialized value in string eq at /home/gordon/projects/perl_dancer_test/user_email_verification/lib/user_email_verification.pm line 80. /home/gordon/projects/perl_dancer_test/user_email_verification/lib/user_email_verification.pm around line 80 77 subject => 'Dancer::PlugIn::Email Test', 78 message => "Hello World from Dancer::Plugin::Email", 79 }; 80 warn $msg->{string} if $msg->{type} eq 'failure'; 81 return "Email Sent!\n"; 82 }; 83 ----------- Trying to dig a little deeper, it seems "$msg" is a "Return::Value" object, and that class is deprecated. Also, "$msg->{type}" returns an empty string (so it's not the problem), but "$msg->{string}" returns undef. and "Data::Dumper($msg)" gives: ----- $VAR1 = bless( { 'prop' => {}, 'string' => 'success', 'type' => 'success', 'errno' => undef }, 'Return::Value' ); ---- I'm using Perl 5.10.1 , Dancer 1.3702, Dancer::Plugin::Email 0.1300 . Any suggestions how to solve this ? Thanks! -gordon

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Dancer::Plugin::ValidateTiny
by Alexey Kolganov 09 Sep '11

09 Sep '11

Hello hackers! I just wrote a new plugin for validating forms, that using Validate::Tiny module. It's very simple and pretty for validating small forms on your site. You can find it here: https://github.com/kalgan/Dancer-Plugin-ValidateTiny Also, there you can find an example app for using this plugin. Any feedbacks and bug reports are welcome! -- Best regards, Alexey.

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"sensitive" config data in SCM
by Mr. Puneet Kishor 08 Sep '11

08 Sep '11

Not a Dancer question per se, but I am sure a few of you have encountered this, and it is a "best practice" issue I am encountering for my Dancer apps, so -- I have hard at work learning Git, striving to put all my work in a Git repo (including Github, where appropriate). Yesterday I realized that I would be committing my database and other passwords to the repo as well (I am using the most excellent Dancer::Plugin::Database). A little bit of searching brought me to the conclusion that I had to implement some kind of "smudge" and "clean" filters using .gitattributes -- so when I commit my work to the repo, the sensitive info would get replaced by **** (or other placeholders), and when I would checkout the work, the placeholders would get replaced by the real info. Before I waste too much time learning and implementing these smudge and clean filters, it would behoove me to ask if one of you already has those in place, and if you would kindly share them with me and the community... appropriately via Github. Many thanks in advance, Puneet.

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