Use channel server for install script

install.sh

@@ -33,8 +33,8 @@ set -e
 #     If set to true will not start k3s service.
 #
 #   - INSTALL_K3S_VERSION
-#     Version of k3s to download from github. Will attempt to download the
-#     latest version if not specified.
+#     Version of k3s to download from github. Will attempt to download from the
+#     stable channel if not specified.
 #
 #   - INSTALL_K3S_COMMIT
 #     Commit of k3s to download from temporary cloud storage.
@@ -75,6 +75,14 @@ set -e
 #
 #   - INSTALL_K3S_SELINUX_WARN
 #     If set to true will continue if k3s-selinux policy is not found.
+#
+#   - INSTALL_K3S_CHANNEL_URL
+#     Channel URL for fetching k3s download URL.
+#     Defaults to 'https://update.k3s.io/v1-release/channels'.
+#
+#   - INSTALL_K3S_CHANNEL
+#     Channel to use for fetching k3s download URL.
+#     Defaults to 'stable'.
 
 GITHUB_URL=https://github.com/rancher/k3s/releases
 STORAGE_URL=https://storage.googleapis.com/k3s-ci-builds
@@ -229,6 +237,10 @@ setup_env() {
     if [ "${INSTALL_K3S_BIN_DIR_READ_ONLY}" = true ]; then
         INSTALL_K3S_SKIP_DOWNLOAD=true
     fi
+
+    # --- setup channel values
+    INSTALL_K3S_CHANNEL_URL=${INSTALL_K3S_CHANNEL_URL:-'https://update.k3s.io/v1-release/channels'}
+    INSTALL_K3S_CHANNEL=${INSTALL_K3S_CHANNEL:-'stable'}
 }
 
 # --- check if skip download environment variable set ---
@@ -301,20 +313,21 @@ setup_tmp() {
     trap cleanup INT EXIT
 }
 
-# --- use desired k3s version if defined or find latest ---
+# --- use desired k3s version if defined or find version from channel ---
 get_release_version() {
     if [ -n "${INSTALL_K3S_COMMIT}" ]; then
         VERSION_K3S="commit ${INSTALL_K3S_COMMIT}"
     elif [ -n "${INSTALL_K3S_VERSION}" ]; then
         VERSION_K3S=${INSTALL_K3S_VERSION}
     else
-        info "Finding latest release"
+        info "Finding release for channel ${INSTALL_K3S_CHANNEL}"
+        version_url="${INSTALL_K3S_CHANNEL_URL}/${INSTALL_K3S_CHANNEL}"
         case $DOWNLOADER in
             curl)
-                VERSION_K3S=$(curl -w '%{url_effective}' -I -L -s -S ${GITHUB_URL}/latest -o /dev/null | sed -e 's|.*/||')
+                VERSION_K3S=$(curl -w '%{url_effective}' -L -s -S ${version_url} -o /dev/null | sed -e 's|.*/||')
                 ;;
             wget)
-                VERSION_K3S=$(wget -SqO /dev/null ${GITHUB_URL}/latest 2>&1 | grep -i Location | sed -e 's|.*/||')
+                VERSION_K3S=$(wget -SqO /dev/null ${version_url} 2>&1 | grep -i Location | sed -e 's|.*/||')
                 ;;
             *)
                 fatal "Incorrect downloader executable '$DOWNLOADER'"