Refresh Traefik static config instead of seeding it once

commands/doctor.cmd

@@ -43,6 +43,22 @@ echo -e "\033[32mWarden global .env:\033[0m"
 cat ${WARDEN_HOME_DIR}/.env
 echo
 
+echo -e "\033[32mTraefik version in use:\033[0m"
+docker container inspect traefik --format '{{ .Config.Image }} ({{ .State.Status }})' 2>/dev/null \
+    || echo "traefik container is not present"
+echo
+
+echo -e "\033[32mTraefik static configuration:\033[0m"
+if [[ ! -f "${WARDEN_HOME_DIR}/etc/traefik/traefik.yml" ]]; then
+    echo "not present; run 'warden svc up'"
+elif cmp -s "${WARDEN_DIR}/config/traefik/traefik.yml" "${WARDEN_HOME_DIR}/etc/traefik/traefik.yml"; then
+    echo "in sync with ${WARDEN_DIR}/config/traefik/traefik.yml"
+else
+    echo "differs from ${WARDEN_DIR}/config/traefik/traefik.yml (shipped < | > in use):"
+    diff "${WARDEN_DIR}/config/traefik/traefik.yml" "${WARDEN_HOME_DIR}/etc/traefik/traefik.yml"
+fi
+echo
+
 echo -e "\033[32mWarden service override via Docker compose file:\033[0m"
 if [[ -f ${WARDEN_HOME_DIR}/docker-compose.yml ]]; then
     echo -e "\033[33mWarden services have additional service configuration added or overridden via ${WARDEN_HOME_DIR}/docker-compose.yml file.\033[0m"

commands/env.cmd

@@ -10,6 +10,12 @@ if [[ "${WARDEN_PARAMS[0]}" == "up" ]]; then
     assertSvcRunning
 fi
 
+## keep Traefik's static configuration current on environment lifecycle commands, since
+## these are reached far more often than 'warden svc up' after an upgrade
+if containsElement "${WARDEN_PARAMS[0]}" up start restart; then
+    assertTraefikStaticConfig
+fi
+
 HOST_UID=$(id -u)
 HOST_GID=$(id -g)
 

commands/svc.cmd

@@ -67,6 +67,11 @@ if [[ -f "${WARDEN_HOME_DIR}/docker-compose.yml" ]]; then
     DOCKER_COMPOSE_ARGS+=("${WARDEN_HOME_DIR}/docker-compose.yml")
 fi
 
+## keep Traefik's static configuration current whenever global services are (re)started
+if containsElement "${WARDEN_PARAMS[0]}" up start restart; then
+    assertTraefikStaticConfig
+fi
+
 ## special handling when 'svc up' is run
 if [[ "${WARDEN_PARAMS[0]}" == "up" ]]; then
 
@@ -84,11 +89,6 @@ if [[ "${WARDEN_PARAMS[0]}" == "up" ]]; then
         mkdir -p "${WARDEN_HOME_DIR}/etc/traefik"
     fi
 
-    ## copy configuration files into location where they'll be mounted into containers from
-    if [[ ! -f "${WARDEN_HOME_DIR}/etc/traefik/traefik.yml" ]]; then
-        cp "${WARDEN_DIR}/config/traefik/traefik.yml" "${WARDEN_HOME_DIR}/etc/traefik/traefik.yml"
-    fi
-
     ## generate dynamic traefik ssl termination configuration
     cat > "${WARDEN_HOME_DIR}/etc/traefik/dynamic.yml" <<-EOT
 		tls:

utils/svc.sh

@@ -1,6 +1,64 @@
 #!/usr/bin/env bash
 [[ ! ${WARDEN_DIR} ]] && >&2 echo -e "\033[31mThis script is not intended to be run directly!\033[0m" && exit 1
 
+## Warden owns ${WARDEN_HOME_DIR}/etc/traefik/traefik.yml; it is generated configuration,
+## not user state. After a Traefik major upgrade some settings, such as the router rule
+## syntax, have to be adjusted globally for backward compatibility, and seeding the file
+## once meant existing installs never received them.
+##
+## Override the service's volumes via ${WARDEN_HOME_DIR}/docker-compose.yml if you need
+## Traefik to run against a hand-written static config.
+##
+## Returns 0 when the file was replaced, otherwise 1.
+function refreshTraefikStaticConfig() {
+    local source="${WARDEN_DIR}/config/traefik/traefik.yml"
+    local target="${WARDEN_HOME_DIR}/etc/traefik/traefik.yml"
+
+    if cmp -s "${source}" "${target}"; then
+        return 1
+    fi
+
+    mkdir -p "$(dirname "${target}")"
+
+    if [[ -f "${target}" ]]; then
+        ## timestamped so a later refresh cannot clobber an earlier backup
+        local backup
+        backup="${target}.$(date +%Y%m%d-%H%M%S).bak"
+        cp "${target}" "${backup}"
+        echo "==> Refreshing ${target} from ${source}"
+        echo "    Previous version saved as ${backup}"
+    fi
+
+    cp "${source}" "${target}"
+
+    return 0
+}
+
+## Resolve the container id of Warden's own running Traefik. Matching on the Compose
+## project labels keeps this scoped to the services 'warden svc' orchestrates, so a
+## Traefik belonging to something else on the same daemon is never restarted.
+function wardenTraefikContainerId() {
+    docker container ls -q \
+        --filter label=com.docker.compose.project=warden \
+        --filter label=com.docker.compose.service=traefik \
+        --filter status=running 2>/dev/null || true
+}
+
+## Refresh Traefik's static configuration, restarting Traefik when it changed. Traefik
+## never reloads static configuration, and Compose will not recreate the container just
+## because a bind mounted file changed, so the restart has to be explicit.
+function assertTraefikStaticConfig() {
+    refreshTraefikStaticConfig || return 0
+
+    local traefikId
+    traefikId="$(wardenTraefikContainerId)"
+
+    if [[ -n "${traefikId}" ]]; then
+        echo "==> Restarting traefik to apply the updated static configuration"
+        docker restart "${traefikId}" >/dev/null
+    fi
+}
+
 function assertSvcRunning() {
     ## test for global services running
     wardenNetworkName=$(cat ${WARDEN_DIR}/docker/docker-compose.yml | grep -A3 'networks:' | tail -n1 | sed -e 's/[[:blank:]]*name:[[:blank:]]*//g')