Merge pull request #616 from resin-io/no-docker-warning

Provide a helpful warning when Docker is not installed

CHANGELOG.md

@@ -7,6 +7,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Changed
 
+- Provide a helpful warning when Docker is not installed (or is unaccessible)
 - Added a link to the Node download page in the warning for users with old Node versions
 
 ## [6.3.1] - 2017-08-08

build/utils/docker.js

@@ -1,5 +1,5 @@
 // Generated by CoffeeScript 1.12.7
-var QEMU_BIN_NAME, QEMU_VERSION, cacheHighlightStream, copyQemu, generateConnectOpts, getQemuPath, hasQemu, installQemu, parseBuildArgs, platformNeedsQemu, tarDirectory;
+var QEMU_BIN_NAME, QEMU_VERSION, cacheHighlightStream, copyQemu, ensureDockerSeemsAccessible, generateConnectOpts, getQemuPath, hasQemu, installQemu, parseBuildArgs, platformNeedsQemu, tarDirectory;
 
 QEMU_VERSION = 'v2.5.50-resin-execve';
 
@@ -266,7 +266,9 @@ exports.runBuild = function(params, options, getBundleInfo, logger) {
           return newStream.pipe(logThroughStream).pipe(cacheHighlightStream()).pipe(logger.streams.build);
         }
       };
-      return generateConnectOpts(options).then(function(connectOpts) {
+      return generateConnectOpts(options).tap(function(connectOpts) {
+        return ensureDockerSeemsAccessible(connectOpts);
+      }).then(function(connectOpts) {
         var builder, opts;
         logger.logDebug('Connecting with the following options:');
         logger.logDebug(JSON.stringify(connectOpts, null, '  '));
@@ -309,12 +311,26 @@ exports.getDocker = function(options) {
   var Docker, Promise;
   Docker = require('dockerode');
   Promise = require('bluebird');
-  return generateConnectOpts(options).then(function(connectOpts) {
+  return generateConnectOpts(options).tap(function(connectOpts) {
+    return ensureDockerSeemsAccessible(connectOpts);
+  }).then(function(connectOpts) {
     connectOpts['Promise'] = Promise;
     return new Docker(connectOpts);
   });
 };
 
+ensureDockerSeemsAccessible = function(options) {
+  var fs;
+  fs = require('mz/fs');
+  if (options.socketPath != null) {
+    return fs.access(options.socketPath, fs.constants.R_OK | fs.constants.W_OK)["return"](true)["catch"](function(err) {
+      throw new Error("Docker seems to be unavailable (using socket " + options.socketPath + "). Is it installed, and do you have permission to talk to it?");
+    });
+  } else {
+    return Promise.resolve(true);
+  }
+};
+
 hasQemu = function() {
   var fs;
   fs = require('mz/fs');

lib/utils/docker.coffee

@@ -175,7 +175,6 @@ parseBuildArgs = (args, onError) ->
 # Pass in the command line parameters and options and also
 # a function which will return the information about the bundle
 exports.runBuild = (params, options, getBundleInfo, logger) ->
-
 	Promise = require('bluebird')
 	dockerBuild = require('resin-docker-build')
 	resolver = require('resin-bundle-resolve')
@@ -277,8 +276,9 @@ exports.runBuild = (params, options, getBundleInfo, logger) ->
 
 			# Create a builder
 			generateConnectOpts(options)
+			.tap (connectOpts) ->
+				ensureDockerSeemsAccessible(connectOpts)
 			.then (connectOpts) ->
-
 				# Allow degugging output, hidden behind an env var
 				logger.logDebug('Connecting with the following options:')
 				logger.logDebug(JSON.stringify(connectOpts, null, '  '))
@@ -317,11 +317,29 @@ exports.getDocker = (options) ->
 	Promise = require('bluebird')
 
 	generateConnectOpts(options)
+	.tap (connectOpts) ->
+		ensureDockerSeemsAccessible(connectOpts)
 	.then (connectOpts) ->
 		# Use bluebird's promises
 		connectOpts['Promise'] = Promise
 		new Docker(connectOpts)
 
+ensureDockerSeemsAccessible = (options) ->
+	fs = require('mz/fs')
+
+	if options.socketPath?
+		# If we're trying to use a socket, check it exists and we have access to it
+		fs.access(options.socketPath, fs.constants.R_OK | fs.constants.W_OK)
+		.return(true)
+		.catch (err) ->
+			throw new Error(
+				"Docker seems to be unavailable (using socket #{options.socketPath}). Is it
+				installed, and do you have permission to talk to it?"
+			)
+	else
+		# Otherwise, we think we're probably ok
+		Promise.resolve(true)
+
 hasQemu = ->
 	fs = require('mz/fs')