fix(config): ensure the docker context is passed image builds

The `dockerContext` options was documented but never implemented making
it always utilize the default value of `.` or cwd. update steps to pass
the context which the docker Image class will resolve against the
current working directory

Fixes: #13

lib/build-config.js

@@ -19,6 +19,7 @@ async function buildConfig(build_id, config, context) {
   , dockerLogin: login = true
   , dockerImage: image
   , dockerPublish: publish = true
+  , dockerContext = '.'
   } = config
 
   let name = null
@@ -58,6 +59,6 @@ async function buildConfig(build_id, config, context) {
   , build: build_id
   , login: login
   , env: context.env
-  , context: config.context || '.'
+  , context: dockerContext
   }
 }

lib/docker/image.js

@@ -53,7 +53,7 @@ class Image {
   }
 
   get context() {
-    return this.opts.context
+    return path.resolve(this.opts.cwd, this.opts.context)
   }
 
   set context(ctx) {

lib/prepare.js

@@ -16,6 +16,7 @@ async function dockerPrepare(opts, context) {
   , dockerfile: opts.dockerfile
   , build_id: opts.build
   , cwd: cwd
+  , context: opts.context
   })
 
   const args = {

lib/publish.js

@@ -15,6 +15,7 @@ async function publish(opts, context) {
   , dockerfile: opts.dockerfile
   , build_id: opts.build
   , cwd: cwd
+  , context: opts.context
   })
 
   const vars = buildTemplateVars(opts, context)

lib/verify.js

@@ -17,7 +17,8 @@ async function verify(opts, context) {
     const error = new SemanticError(
       'Docker image name not found'
     , 'EINVAL'
-    , 'Image name parsed from package.json name if possible. Or via the "image" option.'
+    , 'Image name parsed from package.json name if possible. '
+        + 'Or via the "dockerImage" option.'
     )
     throw error
   }
@@ -29,6 +30,7 @@ async function verify(opts, context) {
   , dockerfile: opts.dockerfile
   , build_id: opts.build
   , cwd: cwd
+  , context: opts.context
   })
 
   debug('docker options', opts)