Document the required varlink build args

The API document incorrectly documented the wrong varlink build
arguments.  The output attribute is required.

Fixes: #3204

Signed-off-by: baude <bbaude@redhat.com>

1 files changed, 36 insertions, 1 deletions

diff --git a/API.md b/API.md
index f0e5cf18f..3d2a6b01f 100755
--- a/API.md
+++ b/API.md
@@ -304,8 +304,43 @@ method AttachControl(name: [string](https://godoc.org/builtin#string)) </div>
 
 method BuildImage(build: [BuildInfo](#BuildInfo)) [MoreResponse](#MoreResponse)</div>
 BuildImage takes a [BuildInfo](#BuildInfo) structure and builds an image.  At a minimum, you must provide the
-'dockerfile' and 'tags' options in the BuildInfo structure. It will return a [MoreResponse](#MoreResponse) structure
+contextDir tarball path, the 'dockerfiles' path, and 'output' option in the BuildInfo structure.  The 'output'
+options is the name of the of the resulting build. It will return a [MoreResponse](#MoreResponse) structure
 that contains the build logs and resulting image ID.
+#### Example
+~~~
+$ sudo varlink call -m unix:///run/podman/io.podman/io.podman.BuildImage '{"build":{"contextDir":"/tmp/t/context.tar","dockerfiles":["Dockerfile"], "output":"foobar"}}'
+{
+ "image": {
+   "id": "",
+   "logs": [
+     "STEP 1: FROM alpine\n"
+   ]
+ }
+}
+{
+ "image": {
+   "id": "",
+   "logs": [
+     "STEP 2: COMMIT foobar\n"
+   ]
+ }
+}
+{
+ "image": {
+   "id": "",
+   "logs": [
+     "b7b28af77ffec6054d13378df4fdf02725830086c7444d9c278af25312aa39b9\n"
+   ]
+ }
+}
+{
+ "image": {
+   "id": "b7b28af77ffec6054d13378df4fdf02725830086c7444d9c278af25312aa39b9",
+   "logs": []
+ }
+}
+~~~
 ### <a name="BuildImageHierarchyMap"></a>func BuildImageHierarchyMap
 <div style="background-color: #E8E8E8; padding: 15px; margin: 10px; border-radius: 10px;">