/dev/notes

In the past I used to mess around with NFS over SSH but these days the FUSE options are much easier, except when you want to use a public key to authenticate with the remote host. In that case do this:

$ sshfs -o ssh_command="ssh -i ~/ssh_keys/[email protected]" [email protected]:/var/www/ ~/Sites/awshost

Actually, right after I posted this, I realised there's a better way to do it. That is, use the 'IdentityFile' option instead (as per the format of .ssh/config).

$ sshfs -o "IdentityFile=~/ssh_keys/[email protected]" [email protected]:/var/www/ ~/Sites/awshost
  

If you have any problems then add '-o debug' to the above command to help track it down.

It is 2013, we (still) don't have flying cars, or hoverboards, AND as developers, we still use terminals to interact with our operating system. So every so often I like to browse through commandlinefu.com and try and pick up any little tidbits which improve my command line efficiency.

Here's a small selection I have picked up recently that I didn't know.

sudo !! 
  

Run the previous command as sudo. This is great when you realise you needed to run something as root.

ctrl-x e
  

Open up $EDITOR to enter in a long command. In my setup it fires up vim. This is great for some of the long rails commands you need to create controllers or models.

cat /etc/passwd | column -s':' -t 
  

Column, columnates input, the -t argument will format standard input into a table and -s lets you specify an arbitrary field delimiter. For unformatted input this is very handy.

These next few are specific to zsh, and while I do love bash, since switching to zsh I haven't really looked back. It's things like this that when you work with a terminal every single day, you can't give up.

aaron@tempest ~ $ d                                 
  0    ~
  aaron@tempest ~ $ cd /etc
  aaron@tempest /etc $ d
  0    /etc
  1    ~
  aaron@tempest /etc $ 1
  ~
  aaron@tempest ~ $  
  

The 'd' command lists the directory stack, and then entering an integer will switch you directly to the directory index in the stack. It is a killer app.

Moving directories also is very pleasant in zsh. Use '..' to move up a directory, and simply type the name of the directory in, to move into a directory.

aaron@tempest ~ $ ..       
  aaron@tempest /Users $ aaron
  aaron@tempest ~ $ 
  

This last one is a trick I've know for a few years, I don't know how much time this has saved me exactly, but I use it every single day.

In vim, if you're editing a file that requires root (or any other user) permissions, you can write the file by doing

:w !sudo tee %
  

I use it so much that I've set up a leader key binding in my .vimrc

nnoremap <leader>sr :w !sudo tee %<CR>
  

There's nothing more annoying than making lengthy changes to a config file, go to write it and getting permission denied...

I make all my configs available online at github, if you're interested in seeing how I setup my environment.

Once you have Jenkins up and running you can manage most administrative tasks with a handy cli jar file or by using simple http requests.

Assuming you're running your server on port 8080, obtain the cli jar file like this:

$ wget http://localhost:8080/jnlpJars/jenkins-cli.jar
  

To see a list of available commands simply run the tool with the help argument:

$ java -jar jenkins-cli.jar -s http://localhost:8080 help
  > build
  >   Builds a job, and optionally waits until its completion.
  > clear-queue
  >   Clears the build queue
  > connect-node
  >   Reconnect to a node
  > copy-job
  >   Copies a job
  > ...
  

In recent versions of Jenkins, typical server operations have been decoupled from the cli tool and are now issued using simple http requests. For example to reload Jenkins instance's configuration, you would just fire a http request at it like this:

$ curl http://localhost:8080/reload
  

There are three commands of this sort:

• reload Reload server configuration
• restart Restart the server
• exit Close the server down

Issue these in the format:

$ curl http://[jenkins-server]/[command]