fix(e2e): refresh latest sandbox image for docker runs (#1928)

This fixes an issue where you may run e.g. `mise run e2e:python`, then after
Python is upgraded in mise.toml, subsequent runs of `e2e:python` fail because
the Python version is out of sync.

Signed-off-by: Kris Hicks <khicks@nvidia.com>

Author: krishicks

e2e/with-docker-gateway.sh

@@ -13,6 +13,14 @@
 #
 # HTTPS endpoint-only mode is intentionally unsupported here. Use a named
 # gateway config when mTLS materials are needed.
+#
+# Sandbox image overrides:
+#   OPENSHELL_E2E_DOCKER_SANDBOX_IMAGE=...
+#   OPENSHELL_E2E_DOCKER_SANDBOX_IMAGE_PULL_POLICY=Always|IfNotPresent|Never
+#
+# The default community sandbox image uses :latest. This wrapper refreshes it
+# before starting the gateway, while the Docker driver defaults to IfNotPresent
+# so local Dockerfile-built images remain usable.
 
 set -euo pipefail
 
@@ -342,6 +350,41 @@ ensure_docker_supervisor_image() {
   exit 2
 }
 
+image_uses_latest_tag() {
+  local image=$1
+  local last_component
+
+  # Digest references are immutable even if the tag portion says latest.
+  if [[ "${image}" == *@* ]]; then
+    return 1
+  fi
+
+  last_component="${image##*/}"
+  # Docker treats an omitted tag as :latest.
+  if [[ "${last_component}" != *:* ]]; then
+    return 0
+  fi
+
+  [[ "${last_component}" == *:latest ]]
+}
+
+ensure_sandbox_image_available() {
+  local image=$1
+
+  if image_uses_latest_tag "${image}"; then
+    echo "Refreshing latest sandbox image ${image}..."
+    docker_pull_with_retry "${image}"
+    return
+  fi
+
+  if docker image inspect "${image}" >/dev/null 2>&1; then
+    return
+  fi
+
+  echo "Pulling ${image}..."
+  docker_pull_with_retry "${image}"
+}
+
 DAEMON_ARCH="$(normalize_arch "$(docker info --format '{{.Architecture}}' 2>/dev/null || true)")"
 SUPERVISOR_TARGET="$(linux_target_triple "${DAEMON_ARCH}")"
 HOST_OS="$(uname -s)"
@@ -386,12 +429,10 @@ fi
 
 DEFAULT_SANDBOX_IMAGE="ghcr.io/nvidia/openshell-community/sandboxes/base:latest"
 SANDBOX_IMAGE="${OPENSHELL_E2E_DOCKER_SANDBOX_IMAGE:-${OPENSHELL_SANDBOX_IMAGE:-${DEFAULT_SANDBOX_IMAGE}}}"
-if ! docker image inspect "${SANDBOX_IMAGE}" >/dev/null 2>&1; then
-  echo "Pulling ${SANDBOX_IMAGE}..."
-  if ! docker_pull_with_retry "${SANDBOX_IMAGE}"; then
-    echo "ERROR: sandbox image '${SANDBOX_IMAGE}' is not available." >&2
-    exit 2
-  fi
+SANDBOX_IMAGE_PULL_POLICY="${OPENSHELL_E2E_DOCKER_SANDBOX_IMAGE_PULL_POLICY:-${OPENSHELL_SANDBOX_IMAGE_PULL_POLICY:-IfNotPresent}}"
+if ! ensure_sandbox_image_available "${SANDBOX_IMAGE}"; then
+  echo "ERROR: sandbox image '${SANDBOX_IMAGE}' is not available." >&2
+  exit 2
 fi
 
 PKI_DIR="${WORKDIR}/pki"
@@ -420,6 +461,7 @@ else
 fi
 
 echo "Starting openshell-gateway on port ${HOST_PORT} (namespace: ${E2E_NAMESPACE})..."
+echo "Using sandbox image: ${SANDBOX_IMAGE} (pull policy: ${SANDBOX_IMAGE_PULL_POLICY})"
 e2e_generate_gateway_jwt "${JWT_DIR}"
 
 # Driver-specific options moved from CLI flags into a TOML config table
@@ -446,7 +488,7 @@ GATEWAY_CONFIG="${STATE_DIR}/gateway.toml"
   printf 'network_name = %s\n'         "$(toml_string "${DOCKER_NETWORK_NAME}")"
   printf 'grpc_endpoint = %s\n'        "$(toml_string "${GATEWAY_ENDPOINT}")"
   printf 'default_image = %s\n'        "$(toml_string "${SANDBOX_IMAGE}")"
-  printf 'image_pull_policy = "IfNotPresent"\n'
+  printf 'image_pull_policy = %s\n'    "$(toml_string "${SANDBOX_IMAGE_PULL_POLICY}")"
   printf 'guest_tls_ca = %s\n'         "$(toml_string "${PKI_DIR}/ca.crt")"
   printf 'guest_tls_cert = %s\n'       "$(toml_string "${PKI_DIR}/client/tls.crt")"
   printf 'guest_tls_key = %s\n'        "$(toml_string "${PKI_DIR}/client/tls.key")"