Build parent images checking the Dockerfile directive. Fixes makeusab…

…rew#1

lib/decking.js

@@ -169,44 +169,72 @@ Decking.prototype._build = function(image, done) {
   }
 
   var targetPath = target + "/Dockerfile";
-  this.logger.log("Building image " + image + " from " + targetPath);
 
   // @TODO for now, always assume we want to build from a Dockerfile
   // @TODO need a lot of careful validation here
-  var readStream = fs.createReadStream(targetPath);
-  var writeStream = fs.createWriteStream("./Dockerfile");
   var self = this;
+  var buildDep = false;
 
-  // ensure we don't try and create the tarball until the local Dockerfile exists
-  writeStream.on("close", function() {
-    var options = {t: image};
-    if(self.hasArg("--no-cache")) {
-      self.logger.log("Not using image cache");
-      options.nocache = true;
+  if(self.hasArg("--no-dependencies")) {
+    self.logger.log("Not building dependencies");
+  } else {
+    // Detecting local dependency
+    var dockerfileContent = fs.readFileSync(targetPath);
+    var fromRe = /^\s*from\s*(\S*)/i;
+    var fromMatch = fromRe.exec(dockerfileContent);
+    if (fromMatch) {
+      var dependency = fromMatch[1];
+      if (this.config.images[dependency]) {
+        // the dependency is declared in the local images, let's build that one first
+        buildDep = true;
+        self.logger.log("Found dependency : " + dependency);
+        self._build(dependency, function(err) {
+          if (err) return done(err);
+          continueFn();
+        });
+      }
     }
+  }
 
-    self.logger.log("Uploading compressed context...");
+  if (!buildDep) continueFn();
 
-    // @TODO allow user to specifiy --exclude params to avoid unnecessarily huge tarballs
-    var tar = child_process.spawn("tar", ["-c", "-", "./"]);
+  function continueFn() {
+    self.logger.log("Building image " + image + " from " + targetPath);
 
-    return self.docker.buildImage(tar.stdout, options, function(err, res) {
-      fs.unlink("./Dockerfile", function(err) {
-        if(err) return self.logger.log("[WARN] Could not remove Dockerfile");
-      });
-      if(err) return done(err);
-      if(res.headers["content-type"] === "application/json") {
-        res.pipe(JSONStream.parse("stream")).pipe(process.stdout);
-      } else {
-        // we don't need an if/else but let's keep it for clarity; it'd be too easy to
-        // skim-read the code and misinterpret the first pipe otherwise
-        res.pipe(process.stdout);
+    var readStream = fs.createReadStream(targetPath);
+    var writeStream = fs.createWriteStream("./Dockerfile");
+
+    // ensure we don't try and create the tarball until the local Dockerfile exists
+    writeStream.on("close", function() {
+      var options = {t: image};
+      if(self.hasArg("--no-cache")) {
+        self.logger.log("Not using image cache");
+        options.nocache = true;
       }
-      return res.on("end", done);
+
+      self.logger.log("Uploading compressed context...");
+
+      // @TODO allow user to specifiy --exclude params to avoid unnecessarily huge tarballs
+      var tar = child_process.spawn("tar", ["-c", "-", "./"]);
+
+      return self.docker.buildImage(tar.stdout, options, function(err, res) {
+        fs.unlink("./Dockerfile", function(err) {
+          if(err) return self.logger.log("[WARN] Could not remove Dockerfile");
+        });
+        if(err) return done(err);
+        if(res.headers["content-type"] === "application/json") {
+          res.pipe(JSONStream.parse("stream")).pipe(process.stdout);
+        } else {
+          // we don't need an if/else but let's keep it for clarity; it'd be too easy to
+          // skim-read the code and misinterpret the first pipe otherwise
+          res.pipe(process.stdout);
+        }
+        return res.on("end", done);
+      });
     });
-  });
 
-  readStream.pipe(writeStream);
+    readStream.pipe(writeStream);
+  }
 };
 
 // ----------