Fix bug of failed to up self-hosted runner (#11)

This commit is to fix the bug which be failed to up self-hosted runner,
because missing option of group setting.

Dockerfile

@@ -7,7 +7,8 @@ ENV http_proxy="" \
     owner="" \
     repo_name="" \
     runner_name="" \
-    label=""
+    label="" \
+    group=""
 
 WORKDIR /actions-runner
 

README.md

@@ -51,3 +51,7 @@ This token is generated by github.
 ### label [Optional]
 
 Labeled to Self-Hosted-runner. Details see [here](https://docs.github.com/en/actions/hosting-your-own-runners/using-labels-with-self-hosted-runners).
+
+### group [Optional]
+
+Add runner to specified self-hosted runner group. Self-hosted runner group is using Organization only.

autoconf.sh

@@ -17,17 +17,25 @@ if [ -z "${repo_name}" ]; then
   exit 1
 fi
 
-local LABEL=""
+LABEL=""
 
 if [ -z "${label}" ]; then
   LABEL=""
 else
   LABEL="${label}"
 fi
 
+if [ -z "${group}" ]; then
+  GROUP="Default"
+else
+  GROUP="${group}"
+fi
+
 expect -c "
 set timeout 10
 spawn ./config.sh --url https://github.com/${owner}/${repo_name} --token ${TOKEN}
+expect \"Enter the name of the runner group to add this runner to:\"
+send \"${GROUP}\n\"
 expect \"Enter the name of runner:\"
 send \"${runner_name}\n\"
 expect \"Enter any additional labels (ex. label-1,label-2):\"