mecano/lib/conditions.js

Common functions for system deployment.

// Generated by CoffeeScript 1.7.1
var each, exec, fs, misc;

each = require('each');

misc = require('./misc');

exec = require('ssh2-exec');

fs = require('ssh2-fs');


/*
Conditionnal properties
=======================
 */

module.exports = {

  /*
  
  `all(options, skip, succeed)` Run all conditions
  ---------------------------------------------------
  
  `opts`
  Command options
  
  `skip`
  Skip callback, called when a condition is not fulfill. May also be called with on error on failure
  
  `succeed`
  Succeed callback, only called if all the condition succeed
   */
  all: function(options, skip, succeed) {
    return each([this["if"], this.not_if, this.if_exists, this.not_if_exists, this.should_exist]).on('item', function(condition, next) {
      return condition(options, skip, next);
    }).on('error', skip).on('end', succeed);
  },

  /*
  `if` Run an action for a user defined condition
  -----------------------------------------------
  
  Work on the property `if` in `options`. When `if` 
  is a boolean, its value determine the output. If it's 
  a callback, the function is called with the `options`, 
  `skip` and `succeed` arguments. If it'a an array, all its element
  must positively resolve for the condition to pass.
  
  Updating the content of a file if we are the owner
  
      mecano.render
        source:'./file'
        if: (options, skip, succeed) ->
          fs.stat options.source, (err, stat) ->
             * File does not exists
            return skip err if err
             * Skip if we dont own the file
            return  skip() unless stat.uid is process.getuid()
             * Succeed if we own the file
            succeed()
   */
  "if": function(options, skip, succeed) {
    var ok;
    if (options["if"] == null) {
      return succeed();
    }
    ok = true;
    return each(options["if"]).on('item', function(si, next) {
      var type;
      if (!ok) {
        return next();
      }
      type = typeof si;
      if (type === 'boolean' || type === 'number') {
        if (!si) {
          ok = false;
        }
        return next();
      } else if (type === 'function') {
        return si(options, (function() {
          ok = false;
          return next.apply(null, arguments);
        }), next);
      } else {
        return next(new Error("Invalid condition type"));
      }
    }).on('both', function(err) {
      if (err || !ok) {
        return skip(err);
      }
      return succeed();
    });
  },

  /*
  `not_if` Run an action if false
  -------------------------------
  
  Work on the property `if` in `options`. When `if` 
  is a boolean, its value determine the output. If it's 
  a callback, the function is called with the `options`, 
  `skip` and `succeed` arguments. If it'a an array, all its element
  must positively resolve for the condition to pass.
   */
  not_if: function(options, skip, succeed) {
    var ok;
    if (options.not_if == null) {
      return succeed();
    }
    ok = true;
    return each(options.not_if).on('item', function(not_if, next) {
      var type;
      if (!ok) {
        return next();
      }
      type = typeof not_if;
      if (type === 'boolean' || type === 'number') {
        if (not_if) {
          ok = false;
        }
        return next();
      } else if (type === 'function') {
        return not_if(options, next, (function() {
          ok = false;
          return next.apply(null, arguments);
        }));
      } else {
        return next(new Error("Invalid condition type"));
      }
    }).on('both', function(err) {
      if (err || !ok) {
        return skip(err);
      }
      return succeed();
    });
  },

  /*
  
  `if_exists` Run an action if a file exists
  ----------------------------------------
  
  Work on the property `if_exists` in `options`. The value may 
  be a file path or an array of file paths. You could also set the
  value to `true`, in which case it will be set with the `destination`
  option.
  
  The callback `succeed` is called if all the provided paths 
  exists otherwise the callback `skip` is called.
   */
  if_exists: function(options, skip, succeed) {
    if (options.if_exists == null) {
      return succeed();
    }
    return each(options.if_exists).on('item', function(if_exists, next) {
      return fs.exists(options.ssh, if_exists, function(err, exists) {
        if (exists) {
          return next();
        } else {
          return skip();
        }
      });
    }).on('end', succeed);
  },

  /*
  
  `not_if_exists` Skip an action if a file exists
  -----------------------------------------------
  
  Work on the property `not_if_exists` in `options`. The value may 
  be a file path or an array of file paths. You could also set the
  value to `true`, in which case it will be set with the `destination`
  option.
  
  The callback `succeed` is called if none of the provided paths 
  exists otherwise the callback `skip` is called.
   */
  not_if_exists: function(options, skip, succeed) {
    if (options.not_if_exists == null) {
      return succeed();
    }
    return each(options.not_if_exists).on('item', function(not_if_exists, next) {
      return fs.exists(options.ssh, not_if_exists, function(err, exists) {
        if (exists) {
          return next(new Error);
        } else {
          return next();
        }
      });
    }).on('error', function() {
      return skip();
    }).on('end', succeed);
  },

  /*
  
  `if_exec` Run an action if a command is successfully executed
  -------------------------------------------------------------
  
  Work on the property `if_exec` in `options`. The value may 
  be a single shell command or an array of commands.   
  
  The callback `succeed` is called if all the provided command 
  were executed successfully otherwise the callback `skip` is called.
   */
  if_exec: function(options, skip, succeed) {
    if (options.if_exec == null) {
      return succeed();
    }
    return each(options.if_exec).on('item', function(cmd, next) {
      var run;
      if (typeof options.log === "function") {
        options.log("Execute condition: " + cmd);
      }
      options = {
        cmd: cmd,
        ssh: options.ssh
      };
      run = exec(options);
      if (options.stdout) {
        run.stdout.pipe(options.stdout, {
          end: false
        });
      }
      if (options.stderr) {
        run.stderr.pipe(options.stderr, {
          end: false
        });
      }
      return run.on("exit", function(code) {
        if (code === 0) {
          return next();
        } else {
          return skip();
        }
      });
    }).on('end', succeed);
  },

  /*
  
  `not_if_exec` Run an action unless a command is successfully executed
  ---------------------------------------------------------------------
  
  Work on the property `not_if_exec` in `options`. The value may 
  be a single shell command or an array of commands.   
  
  The callback `succeed` is called if all the provided command 
  were executed with failure otherwise the callback `skip` is called.
   */
  not_if_exec: function(options, skip, succeed) {
    if (options.not_if_exec == null) {
      return succeed();
    }
    return each(options.not_if_exec).on('item', function(cmd, next) {
      var run;
      if (typeof options.log === "function") {
        options.log("Execute condition: " + cmd);
      }
      options = {
        cmd: cmd,
        ssh: options.ssh
      };
      run = exec(options);
      if (options.stdout) {
        run.stdout.pipe(options.stdout, {
          end: false
        });
      }
      if (options.stderr) {
        run.stderr.pipe(options.stderr, {
          end: false
        });
      }
      return run.on("exit", function(code) {
        if (code === 0) {
          return next(new Error);
        } else {
          return next();
        }
      });
    }).on('error', function() {
      return skip();
    }).on('end', succeed);
  },

  /*
  
  `should_exist` Ensure a file exist
  ----------------------------------
  
  Ensure that an action run if all the files present in the 
  option "should_exist" exist. The value may 
  be a file path or an array of file paths.
  
  The callback `succeed` is called if all of the provided paths 
  exists otherwise the callback `skip` is called with an error.
   */
  should_exist: function(options, skip, succeed) {
    if (options.should_exist == null) {
      return succeed();
    }
    return each(options.should_exist).on('item', function(should_exist, next) {
      return fs.exists(options.ssh, should_exist, function(err, exists) {
        if (exists) {
          return next();
        } else {
          return next(new Error("File does not exist: " + should_exist));
        }
      });
    }).on('error', function(err) {
      return skip(err);
    }).on('end', succeed);
  },

  /*
  
  `should_not_exist` Ensure a file already exist
  ----------------------------------------------
  
  Ensure that an action run if none of the files present in the 
  option "should_exist" exist. The value may 
  be a file path or an array of file paths.
  
  The callback `succeed` is called if none of the provided paths 
  exists otherwise the callback `skip` is called with an error.
   */
  should_not_exist: function(options, skip, succeed) {
    if (options.should_not_exist == null) {
      return succeed();
    }
    return each(options.should_not_exist).on('item', function(should_not_exist, next) {
      return fs.exists(options.ssh, should_not_exist, function(err, exists) {
        if (exists) {
          return next(new Error("File does not exist: " + should_not_exist));
        } else {
          return next();
        }
      });
    }).on('error', function(err) {
      return skip(err);
    }).on('end', function() {
      return succeed();
    });
  }
};