[PostgreSQL] List running queries

In psql, run this command

select * from pg_stat_activity where datname = YOUR_DB_NAME and state = 'active'

 You might also what to order the result by query_start or state_change

Start lein repl with test profile

When you try to run lein repl with test profile, you'll get warning/error message similar to this.

$ lein with-profile test repl

Warning: no nREPL dependency detected.

Be sure to include org.clojure/tools.nrepl in :dependencies of your profile.

... 

Error loading clojure.tools.nrepl.server: Could not locate clojure/tools/nrepl/server__init.class or clojure/tools/nrepl/server.clj on classpath: 

Error loading complete.core: Could not locate complete/core__init.class or complete/core.clj on classpath: 

Exception in thread "main" java.lang.ClassNotFoundException: clojure.tools.nrepl.server, compiling:(/private/var/folders/7d/98yf91rn0yz6wbh56h5q7rkh0000gn/T/form-init2792809345387087761.clj:1:1340)

The reason is because unlike default profile, tools.nrepl isn't added as dependency for test profile. You can verify this by comparing the output between lein pprint (or lein with-profile default pprint) and lein with-profile test pprint.

To fix this error, you can use the feature that lein provided combining profile like so;

$ lein with-profile default,test repl

With the command above, lein should start the repl without any errors.

[VIM] Not jumping to half of the screen when scroll to the right (horizontally) in a long line

:set sidescroll=1

Credit: In vim, how to scroll horizontally, by just one character, when cursor reaches end of the window? [duplicate]

Thanks @iporsut for triggered my curiosity

Set bash completion when aliasing docker to d

After you installed docker bash completion, either by sourcing it from your .bash_profile or installing it to bash-completion, add this line to the end of your docker-completion.sh file.

complete -F _docker d

Reload your shell. And that's it!

Note: change the last d to other character you aliased docker to

[VIM] Move screen before cursor reaching top or bottom

It's interesting that I didn't realize I had been living without this feature for years as a vim user. Thanks to @tenderlove and @searls for publishing their vim setup session video. In the beginning of this video, @tenderlove adds set scrolloff=2 to vimrc. scrolloff is a good config that everyone who's using vim should have in their vimrc.

What it does is to tell vim to move screen before cursor reaching 2 top or bottom lines (2 is an arbitrary number). Give it a try. I bet you'll like it.

I went observe on JetBrains' IDE, they are configured to behave the same with setting scrolloff=1 on vim.

Sample config for rabbitmq_auth_mechanism_ssl that works

This is a sample rabbitmq.config for enabling both client-side certificate and ssl authentication.

[
    {rabbit, [{auth_mechanisms, ['EXTERNAL']},
              {ssl_listeners, [5671]},
              {ssl_cert_login_from, common_name},
              {ssl_options, [{cacertfile,"/path/to/ca-cert"},
                             {certfile,"/path/to/client-cert"},
                             {keyfile,"/path/to/client-key"},
                             {verify,verify_peer},
                             {fail_if_no_peer_cert,true}                           
              ]}  
    ]}  
].

Notes:

1. Make sure that you enabled rabbitmq_auth_mechanism_ssl plugin with 
   rabbitmq-plugins enable rabbitmq_auth_mechanism_ssl. It will be target for the EXTERNAL auth mechanim.
2.  In your process of creating client certificate, set your rabbitmq client username as CN. i.e. CN=client_username. You don't need to provide client's login name anymore when creating rabbitmq connection in your client code.

Tested with RabbitMQ version 3.4.2

[Docker] Look inside running container

docker exec -t -i <container-name> /bin/bash

For looking inside an image, use

docker run -t -i <image-name> /bin/bash

credit: http://stackoverflow.com/a/20816397