feat(runner): enhance runner name configuration options

- Introduces an option to use hostname as the runner name by setting `GITHUB_RUNNER_USE_HOSTNAME` to "true".
- Updates the behavior to prefer hostname over provided runner name when the flag is enabled.
- Provides fallback to hostname if no name is provided and the flag is not true.
- Improves documentation to clarify the new behavior and configuration options.

Author: winromulus

README.md

@@ -91,7 +91,8 @@ In ephemeral mode, the runner will:
 #### Environment Variables
 - `GITHUB_RUNNER_URL` (required): Repository, organization, or enterprise URL
 - `GITHUB_RUNNER_PAT` or `GITHUB_RUNNER_TOKEN` (required): Authentication token
-- `GITHUB_RUNNER_NAME` (optional): Runner name (defaults to hostname)
+- `GITHUB_RUNNER_NAME` (optional): Runner name (defaults to hostname, can be overridden by GITHUB_RUNNER_USE_HOSTNAME)
+- `GITHUB_RUNNER_USE_HOSTNAME` (optional): Set to "true" to always use container hostname as runner name, overriding GITHUB_RUNNER_NAME
 - `GITHUB_RUNNER_LABELS` (optional): Comma-separated list of labels
 - `GITHUB_RUNNER_GROUP` (optional): Runner group name
 - `GITHUB_RUNNER_WORKDIR` (optional): Working directory for jobs

src/entrypoint.sh

@@ -91,10 +91,15 @@ configure_runner() {
         exit 1
     fi
 
-    # Add runner name (use hostname as default)
-    if [ -n "${GITHUB_RUNNER_NAME}" ]; then
+    # Add runner name (with hostname preference option)
+    if [ "${GITHUB_RUNNER_USE_HOSTNAME}" = "true" ]; then
+        # When flag is true, always use hostname regardless of GITHUB_RUNNER_NAME
+        CONFIG_CMD="${CONFIG_CMD} --name \"$(hostname)\""
+    elif [ -n "${GITHUB_RUNNER_NAME}" ]; then
+        # Use provided name if flag is not true and name is provided
         CONFIG_CMD="${CONFIG_CMD} --name \"${GITHUB_RUNNER_NAME}\""
     else
+        # Fall back to hostname if no name provided and flag is not true
         CONFIG_CMD="${CONFIG_CMD} --name \"$(hostname)\""
     fi