Back in 2009, whilst freelancing, I applied to join both the teams of PledgeMusic and Songkick . I was lucky enough to join PledgeMusic and I am still there today. SongKick are still a cool company though and their product is a very simple one. They harvest gig listing data from thousands of sources and build a list of venues, bands and gigs (historical and upcoming).

This data is very simple yet very powerful, you can use their website or their app to select your city (Brighton) or cities you’d travel to (hell anywhere cool in Europe) and import your favourite artists from Facebook, Spotify or your music from your phone. That’s it, but this means you can now easily search for what bands that you like are coming up and track those events, announce you’re going or if they have tickets buy them from Songkick or via one of their partner vendors (the usual suspects).

Having travelled to Europe plenty in the last 10 years this services makes it really easy to add a gig to our sightseeing itinerary. Last year it was D-A-D in Gothenberg, Conny Bloom in Oreboro and then into Stockholm for a pootle around the city before home. And before that we travelled to Brussels to see Messer Chups after getting similar notifications.

This service is not only powerful for Consumers but Bands and Promoters should take the time to ensure their events are listed on the site, add them if not or just ensure the bands are listed properly and date and venue are accurate. And this guarantees that little bit more exposure and your target customers don’t end up missing Messer Chups when they come to Brighton. This may have happened :(

Having decided to attend Mammothfest 2017 this year. I took a look at the listing and it appeared that over 20 bands (both established and new on the scene) were not listed. Since any user can edit a listing I added in the missing ones and one day later the app is notifying me about new gigs for ‘Hole In The Sky’ and ‘Mutually Assured Destruction". Excellent, so not only is the gig listing more accurate but fans are automatically notified that new bands are added to the bill. Potentially making that push in sales that any artists, promoter, gig needs. Don’t miss out on that little bit more exposure because just a Facebook Event just doesn’t cut it anymore

So why not pop on over and let me know if you’re also going to Damnation 2017

Getting Too Many Connections errors from MySQL. At the point where couldn’t determine why so many additional connections had appears from nowhere we had to immediately raise this limit. Fortunately you can do it while MySQL is still running.

mysql> show variables like 'max_connections';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| max_connections | 300   |
+-----------------+-------+
1 row in set (0.00 sec)

mysql> SET GLOBAL max_connections = 500;
Query OK, 0 rows affected (0.00 sec)

mysql> show variables like 'max_connections';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| max_connections | 500   |
+-----------------+-------+
1 row in set (0.00 sec)

You can also check how many connections there are at a given time.

mysql> show status where `variable_name` = 'Threads_connected';
+-------------------+-------+
| Variable_name     | Value |
+-------------------+-------+
| Threads_connected | 275   |
+-------------------+-------+
1 row in set (0.00 sec)

Be sure to memorialise your config change in my.cnf because restarting the server will loose this change.

[mysqld]
max_connections                 = 500

I recently changed the default SSH port of one of my client’s servers. It appears that the first time I tried to deploy via Capistrano it hanged and I had to kill the task.

export GIT_ASKPASS="/bin/echo" GIT_SSH="/tmp/somerepo/git-ssh.sh" ; /usr/bin/env git ls-remote git@github.com:someuser/somerepo.git

I added the GIT_SSH_COMMAND export to give some debug.

export GIT_SSH_COMMAND="ssh -vvv" export GIT_ASKPASS="/bin/echo" GIT_SSH="/tmp/somerepo/git-ssh.sh" ; /usr/bin/env git ls-remote git@github.com:someuser/somerepo.git

It appears to be connecting on the custom port for that new server.

export GIT_SSH_COMMAND="ssh -vvv" export GIT_ASKPASS="/bin/echo" GIT_SSH="/tmp/somerepo/git-ssh.sh" ; /usr/bin/env git ls-remote git@github.com:someuser/somerepo.git
OpenSSH_6.9p1, OpenSSL 1.0.2d 9 Jul 2015
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to github.com [192.30.253.112] port 1234.

So for some inexplicable reason it’s trying to forward using the same port as the initial connection is made from. I can’t find an option to turn this off in the Capistrano 3 config so I am going to force the port to be 22. Editing ~/.ssh/config on the server with the following fixes it. Be sure if this is a new file to chmod permissions to 644.

Host github.com
Port 22

Sublime 3 keeps opening files and hanging and generally telling me it’s reloading open files, kill Sublime, re-open and those files are still being loaded up on start up.

Need to just nuke that session….

rm ~/Library/Application\ Support/Sublime\ Text\ 3/Local/Session.sublime_session

Boom!

Came across and interesting problem. We decode a base64 string that is received as a parameter and decode it to work out where to build a new path. The problem here is that the extra characters \xDB\x9D\x00 shouldn’t be there and cause YAML to blow up

2.2.2 :017 > Base64.decode64('LS0tCi0gOnBvbHltb3JwaGljX3BhdGgKLSAhcnVieS9BY3RpdmVSZWNvcmQ6%250AUHJvamVjdAogIGF0dHJpYnV0ZXM6CiAgICBpZDogODAyNQo=%250A')
 => "---\n- :polymorphic_path\n- !ruby/ActiveRecord:\xDB\x9D\x00Project\n  attributes:\n    id: 8025\n"
2.2.2 :023 > YAML.load("---\n- :polymorphic_path\n- !ruby/ActiveRecord:\xDB\x9D\x00Project\n  attributes:\n    id: 8025\n")
Psych::SyntaxError: (<unknown>): control characters are not allowed at line 1 column 1

Somehow control characters are appearing in our Base64 string and we need to strip them. It just doesn’t seem as simple as

2.2.2 :025 > "---\n- :polymorphic_path\n- !ruby/ActiveRecord:\xDB\x9D\x00Project\n  attributes:\n    id: 8025\n".gsub("\xDB\x98\x00",'')
 => "---\n- :polymorphic_path\n- !ruby/ActiveRecord:۝\u0000Project\n  attributes:\n    id: 8025\n"

I found that if you call ord on a single string character you get the ASCII code

2.2.2 :042 > Base64.decode64('LS0tCi0gOnBvbHltb3JwaGljX3BhdGgKLSAhcnVieS9BY3RpdmVSZWNvcmQ6%250AUHJvamVjdAogIGF0dHJpYnV0ZXM6CiAgICBpZDogODAyNQo=%250A').chars[45..47].map(&:ord)
 => [219, 157, 0]

So if I strip those ASCII characters from my string I should be good? Right?

class String
  def without_extended_characters
    chars.select {|s| (1..127).include?(s.ord) }.join
  end
end

and then

2.2.2 :043 > Base64.decode64('LS0tCi0gOnBvbHltb3JwaGljX3BhdGgKLSAhcnVieS9BY3RpdmVSZWNvcmQ6%250AUHJvamVjdAogIGF0dHJpYnV0ZXM6CiAgICBpZDogODAyNQo=%250A').without_extended_characters
 => "---\n- :polymorphic_path\n- !ruby/ActiveRecord:Project\n  attributes:\n    id: 8025\n"

That’s much better and now YAML can decode this successfully.

It is at this stage I notice…. %250A in the Base64 string and at the end of the string. This represents a carriage return, that can happen in parameters easily enough, so I am decoding a carriage return and then stripping it from the string. I should just strip the carriage returns in the first place.

2.2.2 :045 > Base64.decode64('LS0tCi0gOnBvbHltb3JwaGljX3BhdGgKLSAhcnVieS9BY3RpdmVSZWNvcmQ6%250AUHJvamVjdAogIGF0dHJpYnV0ZXM6CiAgICBpZDogODAyNQo=%250A'.gsub('%250A',''))
 => "---\n- :polymorphic_path\n- !ruby/ActiveRecord:Project\n  attributes:\n    id: 8025\n"

Oh well, I learnt about String#ord all the same.

----------- SCAN SUMMARY -----------
Known viruses: 6288879
Engine version: 0.98.7
Scanned directories: 79272
Scanned files: 257567
Infected files: 14
Total errors: 18985
Data scanned: 4639.85 MB
Data read: 5473.88 MB (ratio 0.85:1)
Time: 692.947 sec (11 m 32 s)

/tmp/clamav
/tmp/clamav/maldetect-1.6.tar.gz.001
/tmp/clamav/rfxn.yara.002.001
/tmp/clamav/rfxn.yara.004.001
/tmp/clamav/rfxn.yara.001
/tmp/clamav/rfxn.yara.001.001
/tmp/clamav/rfxn.yara.003.001
/tmp/clamav/x86_64.h.001

rails@epic-invite-staging:~/apps/epic-invite/staging/current$ bundle exec pumactl -P tmp/pids/puma.pid restart
Command restart sent success

rails@snarf:/var/www/mini-epic/current$ sudo -u postgres createuser --interactive
Enter name of role to add: rails
Shall the new role be a superuser? (y/n) y
rails@snarf:/var/www/mini-epic/current$ RAILS_ENV=staging rake db:create
rails@snarf:/var/www/mini-epic/current$ psql epic_invite_staging < /tmp/mini-epic.pgsql

class Dave
  def monitor; end
end

Dave.method_defined?(:monitor)
 => true 
Dave.method_defined?(:iareweasel)
 => false

-- C level backtrace information -------------------------------------------
0   libruby.2.2.0.dylib                 0x0000000103e6e885 rb_vm_bugreport + 149
1   libruby.2.2.0.dylib                 0x0000000103d0dbb4 rb_bug + 468
2   libruby.2.2.0.dylib                 0x0000000103d0deac rb_bug_errno + 92
3   libruby.2.2.0.dylib                 0x0000000103e7cb2c thread_timer + 588
4   libsystem_pthread.dylib             0x00007fffbb4ac9af _pthread_body + 180
5   libsystem_pthread.dylib             0x00007fffbb4ac8fb _pthread_body + 0

-- Other runtime information -----------------------------------------------

* Loaded script: bin/rails

* Loaded features:

    0 enumerator.so
    1 rational.so
    2 complex.so