Add support for defining runner labels. Update README.md.

Author: novalu

README.md

@@ -75,6 +75,7 @@ The following environment variables allows you to control the configuration para
 | RUNNER_TOKEN | Runner token provided by GitHub in the Actions page. These tokens are valid for a short period. | Required if `GITHUB_ACCESS_TOKEN` is not provided
 | RUNNER_WORK_DIRECTORY | Runner's work directory | `"_work"`
 | RUNNER_NAME | Name of the runner displayed in the GitHub UI | Hostname of the container
+| RUNNER_LABELS | Extra labels in addition to the default: 'self-hosted,Linux,X64' (based on your OS and architecture) | `""`
 | RUNNER_REPLACE_EXISTING | `"true"` will replace existing runner with the same name, `"false"` will use a random name if there is conflict | `"true"`
 
 ## Runner Token

debian-buster/Dockerfile

@@ -8,6 +8,7 @@ ENV RUNNER_NAME=""
 ENV RUNNER_WORK_DIRECTORY="_work"
 ENV RUNNER_TOKEN=""
 ENV RUNNER_REPOSITORY_URL=""
+ENV RUNNER_LABELS=""
 ENV RUNNER_ALLOW_RUNASROOT=true
 ENV GITHUB_ACCESS_TOKEN=""
 

debian-buster/entrypoint.sh

@@ -33,6 +33,10 @@ if [ "$(echo $RUNNER_REPLACE_EXISTING | tr '[:upper:]' '[:lower:]')" == "true" ]
 	CONFIG_OPTS="--replace"
 fi
 
+if [[ -n $RUNNER_LABELS ]]; then
+    CONFIG_OPTS="${CONFIG_OPTS} --labels ${RUNNER_LABELS}"
+fi
+
 if [[ -f ".runner" ]]; then
     echo "Runner already configured. Skipping config."
 else