My Puppet VimRC

January 12, 2016

Those who know me, know that I’m a Vim user. I’ve been using Vim exclusively for over ten years. I’ve tried different editors, and this isn’t the place to start the editor-holy-war-debate, but I’ve always found myself drawn back to Vim for its extensibility, flexibility and power. When I started at FanDuel, I left behind configuration management with Chef and began my journey to understanding Puppet. The excerpt below comes from my ~/.vimrc Vim configuration file, and defines the settings applied to Puppet .pp files.

...
Plugin 'rodjek/vim-puppet'
...
""" puppet files
au BufNewFile,BufRead *.pp set syntax=puppet
au BufNewFile,BufRead *.pp setlocal tabstop=2
au BufNewFile,BufRead *.pp setlocal shiftwidth=2
au BufNewFile,BufRead *.pp setlocal noexpandtab
au FileType puppet setlocal isk+=:
au FileType puppet nnoremap <c-]> :exe "tag " . substitute(expand("<cword>"), "^::", "", "")<CR>  
au FileType puppet nnoremap <c-w><c-]> :tab split<CR>:exe "tag " . substitute(expand("<cword>"), "^::", "", "")<CR>
let g:syntastic_mode_map = { 'passive_filetypes': ['puppet']  }
let g:tagbar_type_puppet = {
    \ 'ctagstype': 'puppet',
    \ 'kinds': [
        \'c:class',
        \'s:site',
        \'n:node',
        \'d:definition'
      \]
    \}

Line 2 uses Vundle to load rodjek/vim-puppet, a plugin to provide some conveniences when editing Puppet code. In this case, some nice syntax highlighting and automatic formatting, and automatic alignment of hash rockets among other things.

Lines 5 through 8 set some local defaults for editing: enabling Puppet syntax, making tabs two spaces wide and using hard tabs. Yup, hard tabs. Don’t ask.

Line 9 makes sure that the ‘:’ colon character is treated as a keyword separator for Puppet files. This is useful because of the way Puppet uses ‘::’ as a namespace separator, e.g. foo::bar::baz refers to a class baz, defined within a class bar, defined within a class foo. I can use Vim movements to move between the different segments of that identifier etc.

To remove ambiguity when scoping identifiers in Puppet, top-scoping can be used. Top-scoping involves preceding an identifier with a pair of colon characters, e.g. ::foo::bar::baz. This syntax ensures the Puppet parser does not try to locate foo::bar::baz relative to the scope in which its defined, rather to locate it from the top level of its symbol table.

I use ctags extensively in Vim to let me move around source code quickly. Ctags is used to build a map of identifiers in code, and the files where those identifiers are defined. With a proper tags file, I can use Ctrl+] on an identifier, and Vim will open up the current buffer with the file and location where that identifier is defined. The problem is, for top-scoped puppet identifiers, the identifier doesn’t map to a file location directly, because of the leading ‘::’. The key binding defined on lines 10 and 11 (courtesy of Marius Gedminas, @mgedmin) remaps the default tag movement key, to first strip any leading ‘::’ from the identifier under my cursor, before trying to locate and move to the corresponding definition. Line 10 follows the tag in the current buffer, and line 11 opens the tag in a new tab.

Line 12 disables active Syntastic syntax checking. Puppet syntax checking can be done by shelling out to the Puppet parser, but that’s quite an expensive operation. I prefer to just do an explicit syntax check before I commit changes to Git. If anybody knows of a non-expensive way to leave active syntax checking turned on without causing Vim to run like a snail, let me know!

Line 13 onwards makes sure that when Tagbar is toggled, I can see, and navigate using any tags available for the Puppet file I’m editing.

My Puppet VimRC

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