diff --git a/misc/build.func b/misc/build.func index 9c7d6a93..a0510eda 100644 --- a/misc/build.func +++ b/misc/build.func @@ -146,6 +146,52 @@ pve_check() { fi } +# When a node is running tens of containers, it's possible to exceed the kernel's cryptographic key storage allocations. +# These are tuneable, so verify if the currently deployment is approaching the limits, advise the user on how to tune the limits, and exit the script. +# https://cleveruptime.com/docs/files/proc-key-users | https://docs.kernel.org/security/keys/core.html +maxkeys_check() { + # Read kernel parameters + per_user_maxkeys=$(cat /proc/sys/kernel/keys/maxkeys 2>/dev/null || echo 0) + per_user_maxbytes=$(cat /proc/sys/kernel/keys/maxbytes 2>/dev/null || echo 0) + + # Exit if kernel parameters are unavailable + if [[ "$per_user_maxkeys" -eq 0 || "$per_user_maxbytes" -eq 0 ]]; then + echo -e "${CROSS}${RD} Error: Unable to read kernel parameters. Ensure proper permissions.${CL}" + exit 1 + fi + + # Fetch key usage for user ID 100000 (typical for containers) + used_lxc_keys=$(awk '/100000:/ {print $2}' /proc/key-users 2>/dev/null || echo 0) + used_lxc_bytes=$(awk '/100000:/ {split($5, a, "/"); print a[1]}' /proc/key-users 2>/dev/null || echo 0) + + # Calculate thresholds and suggested new limits + threshold_keys=$((per_user_maxkeys - 100)) + threshold_bytes=$((per_user_maxbytes - 1000)) + new_limit_keys=$((per_user_maxkeys * 2)) + new_limit_bytes=$((per_user_maxbytes * 2)) + + # Check if key or byte usage is near limits + failure=0 + if [[ "$used_lxc_keys" -gt "$threshold_keys" ]]; then + echo -e "${CROSS}${RD} Warning: Key usage is near the limit (${used_lxc_keys}/${per_user_maxkeys}).${CL}" + echo -e "${INFO} Suggested action: Set ${GN}kernel.keys.maxkeys=${new_limit_keys}${CL} in ${BOLD}/etc/sysctl.d/98-community-scripts.conf${CL}." + failure=1 + fi + if [[ "$used_lxc_bytes" -gt "$threshold_bytes" ]]; then + echo -e "${CROSS}${RD} Warning: Key byte usage is near the limit (${used_lxc_bytes}/${per_user_maxbytes}).${CL}" + echo -e "${INFO} Suggested action: Set ${GN}kernel.keys.maxbytes=${new_limit_bytes}${CL} in ${BOLD}/etc/sysctl.d/98-community-scripts.conf${CL}." + failure=1 + fi + + # Provide next steps if issues are detected + if [[ "$failure" -eq 1 ]]; then + echo -e "${INFO} To apply changes, run: ${BOLD}service procps force-reload${CL}" + exit 1 + fi + + echo -e "${CM}${GN} All kernel key limits are within safe thresholds.${CL}" +} + # This function checks the system architecture and exits if it's not "amd64". arch_check() { if [ "$(dpkg --print-architecture)" != "amd64" ]; then @@ -687,6 +733,7 @@ install_script() { root_check arch_check ssh_check + maxkeys_check if systemctl is-active -q ping-instances.service; then systemctl -q stop ping-instances.service