feat(action,install): add GitHub Enterprise support with optional authentication

Support GitHub Enterprise Server by allowing custom API and server URLs via GITHUB_API_URL and GITHUB_SERVER_URL environment variables. Add optional authentication support using GH_TOKEN or GITHUB_TOKEN environment variables in both the GitHub Action and install script.

This enables the sr action and installer to work in GitHub Enterprise environments and respects user-provided tokens for API rate limit benefits.

Author: urmzd

action.yml

@@ -110,8 +110,6 @@ runs:
         # Resolve the action ref to a concrete release tag.
         # Floating tags (e.g. v1) are git tags — not releases — so we resolve
         # them to the latest release sharing the same major version.
-        # API calls use no auth — the repo is public and the caller's token
-        # may be scoped to a different repository (e.g. GitHub App tokens).
         resolve_release_tag() {
           local api="$1" ref="$2"
 
@@ -120,10 +118,15 @@ runs:
             exit 1
           fi
 
+          local auth_args=()
+          if [ -n "${GH_TOKEN:-}" ]; then
+            auth_args+=(-H "Authorization: token ${GH_TOKEN}")
+          fi
+
           # Try exact tag match (works for non-floating refs like v1.2.3).
           # curl without -f so a 404 returns JSON instead of exit 22.
           local tag
-          tag=$(curl -sSL -H "Accept: application/vnd.github+json" \
+          tag=$(curl -sSL "${auth_args[@]}" -H "Accept: application/vnd.github+json" \
             "${api}/releases/tags/${ref}" 2>/dev/null \
             | jq -r '.tag_name // empty') || true
 
@@ -134,7 +137,7 @@ runs:
 
           echo "No exact release for ref=${ref}, searching by major version..." >&2
           local releases
-          releases=$(curl -fsSL -H "Accept: application/vnd.github+json" \
+          releases=$(curl -fsSL "${auth_args[@]}" -H "Accept: application/vnd.github+json" \
             "${api}/releases?per_page=20")
 
           local major
@@ -153,7 +156,7 @@ runs:
           echo "$tag"
         }
 
-        API="https://api.github.com/repos/${SR_REPO}"
+        API="${GITHUB_API_URL:-https://api.github.com}/repos/${SR_REPO}"
         echo "Resolving ref=${SR_REF} via ${API}"
         RELEASE_TAG=$(resolve_release_tag "$API" "$SR_REF")
 
@@ -163,7 +166,7 @@ runs:
         fi
 
         echo "Resolved release tag: ${RELEASE_TAG}"
-        URL="https://github.com/${SR_REPO}/releases/download/${RELEASE_TAG}/${BINARY_NAME}"
+        URL="${GITHUB_SERVER_URL:-https://github.com}/${SR_REPO}/releases/download/${RELEASE_TAG}/${BINARY_NAME}"
         echo "Downloading from ${URL}"
         curl -fsSL -H "Authorization: token $GH_TOKEN" "$URL" -o "$DEST"
 

install.sh

@@ -13,6 +13,16 @@ set -eu
 
 REPO="urmzd/sr"
 
+# curl with optional auth — uses GH_TOKEN or GITHUB_TOKEN if set.
+gh_curl() {
+    token="${GH_TOKEN:-${GITHUB_TOKEN:-}}"
+    if [ -n "$token" ]; then
+        curl -fsSL -H "Authorization: token $token" "$@"
+    else
+        curl -fsSL "$@"
+    fi
+}
+
 main() {
     os=$(uname -s)
     arch=$(uname -m)
@@ -43,7 +53,7 @@ main() {
     if [ -n "${SR_VERSION:-}" ]; then
         tag="$SR_VERSION"
     else
-        tag=$(curl -fsSL "https://api.github.com/repos/$REPO/releases/latest" \
+        tag=$(gh_curl "https://api.github.com/repos/$REPO/releases/latest" \
             | sed -n 's/.*"tag_name": *"\([^"]*\)".*/\1/p')
         if [ -z "$tag" ]; then
             err "Failed to fetch latest release tag"
@@ -57,7 +67,7 @@ main() {
     mkdir -p "$install_dir"
 
     echo "Downloading sr $tag for $target..."
-    curl -fsSL "$url" -o "$install_dir/sr"
+    gh_curl "$url" -o "$install_dir/sr"
 
     if [ -n "${SR_SHA256:-}" ]; then
         if command -v sha256sum >/dev/null 2>&1; then