Files
hermes-agent/nix/nixosModules.nix
Siddharth Balyan ffdfeb91d8 fix(nix): unify directory and file permissions across all three layers (#3619)
Activation script, tmpfiles, and container entrypoint now agree on
0750 for all directories. Tighten config.yaml and workspace documents
from 0644 to 0640 (group-readable, no world access). Add explicit
chmod for .managed marker and container $TARGET_HOME to eliminate
umask dependence. Secrets (auth.json, .env) remain 0600.
2026-03-29 05:29:24 +05:30

755 lines
32 KiB
Nix

# nix/nixosModules.nix — NixOS module for hermes-agent
#
# Two modes:
# container.enable = false (default) → native systemd service
# container.enable = true → OCI container (persistent writable layer)
#
# Container mode: hermes runs from /nix/store bind-mounted read-only into a
# plain Ubuntu container. The writable layer (apt/pip/npm installs) persists
# across restarts and agent updates. Only image/volume/options changes trigger
# container recreation. Environment variables are written to $HERMES_HOME/.env
# and read by hermes at startup — no container recreation needed for env changes.
#
# Tool resolution: the hermes wrapper uses --suffix PATH for nix store tools,
# so apt/uv-installed versions take priority. The container entrypoint provisions
# extensible tools on first boot: nodejs/npm via apt, uv via curl, and a Python
# 3.11 venv (bootstrapped entirely by uv) at ~/.venv with pip seeded. Agents get
# writable tool prefixes for npm i -g, pip install, uv tool install, etc.
#
# Usage:
# services.hermes-agent = {
# enable = true;
# settings.model = "anthropic/claude-sonnet-4";
# environmentFiles = [ config.sops.secrets."hermes/env".path ];
# };
#
{ inputs, ... }: {
flake.nixosModules.default = { config, lib, pkgs, ... }:
let
cfg = config.services.hermes-agent;
hermes-agent = inputs.self.packages.${pkgs.system}.default;
# Deep-merge config type (from 0xrsydn/nix-hermes-agent)
deepConfigType = lib.types.mkOptionType {
name = "hermes-config-attrs";
description = "Hermes YAML config (attrset), merged deeply via lib.recursiveUpdate.";
check = builtins.isAttrs;
merge = _loc: defs: lib.foldl' lib.recursiveUpdate { } (map (d: d.value) defs);
};
# Generate config.yaml from Nix attrset (YAML is a superset of JSON)
configJson = builtins.toJSON cfg.settings;
generatedConfigFile = pkgs.writeText "hermes-config.yaml" configJson;
configFile = if cfg.configFile != null then cfg.configFile else generatedConfigFile;
configMergeScript = pkgs.callPackage ./configMergeScript.nix { };
# Generate .env from non-secret environment attrset
envFileContent = lib.concatStringsSep "\n" (
lib.mapAttrsToList (k: v: "${k}=${v}") cfg.environment
);
# Build documents derivation (from 0xrsydn)
documentDerivation = pkgs.runCommand "hermes-documents" { } (
''
mkdir -p $out
'' + lib.concatStringsSep "\n" (
lib.mapAttrsToList (name: value:
if builtins.isPath value || lib.isStorePath value
then "cp ${value} $out/${name}"
else "cat > $out/${name} <<'HERMES_DOC_EOF'\n${value}\nHERMES_DOC_EOF"
) cfg.documents
)
);
containerName = "hermes-agent";
containerDataDir = "/data"; # stateDir mount point inside container
containerHomeDir = "/home/hermes";
# ── Container mode helpers ──────────────────────────────────────────
containerBin = if cfg.container.backend == "docker"
then "${pkgs.docker}/bin/docker"
else "${pkgs.podman}/bin/podman";
# Runs as root inside the container on every start. Provisions the
# hermes user + sudo on first boot (writable layer persists), then
# drops privileges. Supports arbitrary base images (Debian, Alpine, etc).
containerEntrypoint = pkgs.writeShellScript "hermes-container-entrypoint" ''
set -eu
HERMES_UID="''${HERMES_UID:?HERMES_UID must be set}"
HERMES_GID="''${HERMES_GID:?HERMES_GID must be set}"
# Group: ensure a group with GID=$HERMES_GID exists
# Check by GID (not name) to avoid collisions with pre-existing groups
# (e.g. GID 100 = "users" on Ubuntu)
EXISTING_GROUP=$(getent group "$HERMES_GID" 2>/dev/null | cut -d: -f1 || true)
if [ -n "$EXISTING_GROUP" ]; then
GROUP_NAME="$EXISTING_GROUP"
else
GROUP_NAME="hermes"
if command -v groupadd >/dev/null 2>&1; then
groupadd -g "$HERMES_GID" "$GROUP_NAME"
elif command -v addgroup >/dev/null 2>&1; then
addgroup -g "$HERMES_GID" "$GROUP_NAME" 2>/dev/null || true
fi
fi
# User: ensure a user with UID=$HERMES_UID exists
PASSWD_ENTRY=$(getent passwd "$HERMES_UID" 2>/dev/null || true)
if [ -n "$PASSWD_ENTRY" ]; then
TARGET_USER=$(echo "$PASSWD_ENTRY" | cut -d: -f1)
TARGET_HOME=$(echo "$PASSWD_ENTRY" | cut -d: -f6)
else
TARGET_USER="hermes"
TARGET_HOME="/home/hermes"
if command -v useradd >/dev/null 2>&1; then
useradd -u "$HERMES_UID" -g "$HERMES_GID" -m -d "$TARGET_HOME" -s /bin/bash "$TARGET_USER"
elif command -v adduser >/dev/null 2>&1; then
adduser -u "$HERMES_UID" -D -h "$TARGET_HOME" -s /bin/sh -G "$GROUP_NAME" "$TARGET_USER" 2>/dev/null || true
fi
fi
mkdir -p "$TARGET_HOME"
chown "$HERMES_UID:$HERMES_GID" "$TARGET_HOME"
chmod 0750 "$TARGET_HOME"
# Ensure HERMES_HOME is owned by the target user
if [ -n "''${HERMES_HOME:-}" ] && [ -d "$HERMES_HOME" ]; then
chown -R "$HERMES_UID:$HERMES_GID" "$HERMES_HOME"
fi
# Provision apt packages (first boot only, cached in writable layer)
# sudo: agent self-modification
# nodejs/npm: writable node so npm i -g works (nix store copies are read-only)
# curl: needed for uv installer
if [ ! -f /var/lib/hermes-tools-provisioned ] && command -v apt-get >/dev/null 2>&1; then
echo "First boot: provisioning agent tools..."
apt-get update -qq
apt-get install -y -qq sudo nodejs npm curl
touch /var/lib/hermes-tools-provisioned
fi
if command -v sudo >/dev/null 2>&1 && [ ! -f /etc/sudoers.d/hermes ]; then
mkdir -p /etc/sudoers.d
echo "$TARGET_USER ALL=(ALL) NOPASSWD:ALL" > /etc/sudoers.d/hermes
chmod 0440 /etc/sudoers.d/hermes
fi
# uv (Python manager) not in Ubuntu repos, retry-safe outside the sentinel
if ! command -v uv >/dev/null 2>&1 && [ ! -x "$TARGET_HOME/.local/bin/uv" ] && command -v curl >/dev/null 2>&1; then
su -s /bin/sh "$TARGET_USER" -c 'curl -LsSf https://astral.sh/uv/install.sh | sh' || true
fi
# Python 3.11 venv gives the agent a writable Python with pip.
# Uses uv to install Python 3.11 (Ubuntu 24.04 ships 3.12).
# --seed includes pip/setuptools so bare `pip install` works.
_UV_BIN="$TARGET_HOME/.local/bin/uv"
if [ ! -d "$TARGET_HOME/.venv" ] && [ -x "$_UV_BIN" ]; then
su -s /bin/sh "$TARGET_USER" -c "
export PATH=\"\$HOME/.local/bin:\$PATH\"
uv python install 3.11
uv venv --python 3.11 --seed \"\$HOME/.venv\"
" || true
fi
# Put the agent venv first on PATH so python/pip resolve to writable copies
if [ -d "$TARGET_HOME/.venv/bin" ]; then
export PATH="$TARGET_HOME/.venv/bin:$PATH"
fi
if command -v setpriv >/dev/null 2>&1; then
exec setpriv --reuid="$HERMES_UID" --regid="$HERMES_GID" --init-groups "$@"
elif command -v su >/dev/null 2>&1; then
exec su -s /bin/sh "$TARGET_USER" -c 'exec "$0" "$@"' -- "$@"
else
echo "WARNING: no privilege-drop tool (setpriv/su), running as root" >&2
exec "$@"
fi
'';
# Identity hash — only recreate container when structural config changes.
# Package and entrypoint use stable symlinks (current-package, current-entrypoint)
# so they can update without recreation. Env vars go through $HERMES_HOME/.env.
containerIdentity = builtins.hashString "sha256" (builtins.toJSON {
schema = 3; # bump when identity inputs change
image = cfg.container.image;
extraVolumes = cfg.container.extraVolumes;
extraOptions = cfg.container.extraOptions;
});
identityFile = "${cfg.stateDir}/.container-identity";
# Default: /var/lib/hermes/workspace → /data/workspace.
# Custom paths outside stateDir pass through unchanged (user must add extraVolumes).
containerWorkDir =
if lib.hasPrefix "${cfg.stateDir}/" cfg.workingDirectory
then "${containerDataDir}/${lib.removePrefix "${cfg.stateDir}/" cfg.workingDirectory}"
else cfg.workingDirectory;
in {
options.services.hermes-agent = with lib; {
enable = mkEnableOption "Hermes Agent gateway service";
# ── Package ──────────────────────────────────────────────────────────
package = mkOption {
type = types.package;
default = hermes-agent;
description = "The hermes-agent package to use.";
};
# ── Service identity ─────────────────────────────────────────────────
user = mkOption {
type = types.str;
default = "hermes";
description = "System user running the gateway.";
};
group = mkOption {
type = types.str;
default = "hermes";
description = "System group running the gateway.";
};
createUser = mkOption {
type = types.bool;
default = true;
description = "Create the user/group automatically.";
};
# ── Directories ──────────────────────────────────────────────────────
stateDir = mkOption {
type = types.str;
default = "/var/lib/hermes";
description = "State directory. Contains .hermes/ subdir (HERMES_HOME).";
};
workingDirectory = mkOption {
type = types.str;
default = "${cfg.stateDir}/workspace";
defaultText = literalExpression ''"''${cfg.stateDir}/workspace"'';
description = "Working directory for the agent (MESSAGING_CWD).";
};
# ── Declarative config ───────────────────────────────────────────────
configFile = mkOption {
type = types.nullOr types.path;
default = null;
description = ''
Path to an existing config.yaml. If set, takes precedence over
the declarative `settings` option.
'';
};
settings = mkOption {
type = deepConfigType;
default = { };
description = ''
Declarative Hermes config (attrset). Deep-merged across module
definitions and rendered as config.yaml.
'';
example = literalExpression ''
{
model = "anthropic/claude-sonnet-4";
terminal.backend = "local";
compression = { enabled = true; threshold = 0.85; };
toolsets = [ "all" ];
}
'';
};
# ── Secrets / environment ────────────────────────────────────────────
environmentFiles = mkOption {
type = types.listOf types.str;
default = [ ];
description = ''
Paths to environment files containing secrets (API keys, tokens).
Contents are merged into $HERMES_HOME/.env at activation time.
Hermes reads this file on every startup via load_hermes_dotenv().
'';
};
environment = mkOption {
type = types.attrsOf types.str;
default = { };
description = ''
Non-secret environment variables. Merged into $HERMES_HOME/.env
at activation time. Do NOT put secrets here use environmentFiles.
'';
};
authFile = mkOption {
type = types.nullOr types.path;
default = null;
description = ''
Path to an auth.json seed file (OAuth credentials).
Only copied on first deploy existing auth.json is preserved.
'';
};
authFileForceOverwrite = mkOption {
type = types.bool;
default = false;
description = "Always overwrite auth.json from authFile on activation.";
};
# ── Documents ────────────────────────────────────────────────────────
documents = mkOption {
type = types.attrsOf (types.either types.str types.path);
default = { };
description = ''
Workspace files (SOUL.md, USER.md, etc.). Keys are filenames,
values are inline strings or paths. Installed into workingDirectory.
'';
example = literalExpression ''
{
"SOUL.md" = "You are a helpful AI assistant.";
"USER.md" = ./documents/USER.md;
}
'';
};
# ── MCP Servers ──────────────────────────────────────────────────────
mcpServers = mkOption {
type = types.attrsOf (types.submodule {
options = {
# Stdio transport
command = mkOption {
type = types.nullOr types.str;
default = null;
description = "MCP server command (stdio transport).";
};
args = mkOption {
type = types.listOf types.str;
default = [ ];
description = "Command-line arguments (stdio transport).";
};
env = mkOption {
type = types.attrsOf types.str;
default = { };
description = "Environment variables for the server process (stdio transport).";
};
# HTTP/StreamableHTTP transport
url = mkOption {
type = types.nullOr types.str;
default = null;
description = "MCP server endpoint URL (HTTP/StreamableHTTP transport).";
};
headers = mkOption {
type = types.attrsOf types.str;
default = { };
description = "HTTP headers, e.g. for authentication (HTTP transport).";
};
# Authentication
auth = mkOption {
type = types.nullOr (types.enum [ "oauth" ]);
default = null;
description = ''
Authentication method. Set to "oauth" for OAuth 2.1 PKCE flow
(remote MCP servers). Tokens are stored in $HERMES_HOME/mcp-tokens/.
'';
};
# Enable/disable
enabled = mkOption {
type = types.bool;
default = true;
description = "Enable or disable this MCP server.";
};
# Common options
timeout = mkOption {
type = types.nullOr types.int;
default = null;
description = "Tool call timeout in seconds (default: 120).";
};
connect_timeout = mkOption {
type = types.nullOr types.int;
default = null;
description = "Initial connection timeout in seconds (default: 60).";
};
# Tool filtering
tools = mkOption {
type = types.nullOr (types.submodule {
options = {
include = mkOption {
type = types.listOf types.str;
default = [ ];
description = "Tool allowlist only these tools are registered.";
};
exclude = mkOption {
type = types.listOf types.str;
default = [ ];
description = "Tool blocklist these tools are hidden.";
};
};
});
default = null;
description = "Filter which tools are exposed by this server.";
};
# Sampling (server-initiated LLM requests)
sampling = mkOption {
type = types.nullOr (types.submodule {
options = {
enabled = mkOption { type = types.bool; default = true; description = "Enable sampling."; };
model = mkOption { type = types.nullOr types.str; default = null; description = "Override model for sampling requests."; };
max_tokens_cap = mkOption { type = types.nullOr types.int; default = null; description = "Max tokens per request."; };
timeout = mkOption { type = types.nullOr types.int; default = null; description = "LLM call timeout in seconds."; };
max_rpm = mkOption { type = types.nullOr types.int; default = null; description = "Max requests per minute."; };
max_tool_rounds = mkOption { type = types.nullOr types.int; default = null; description = "Max tool-use rounds per sampling request."; };
allowed_models = mkOption { type = types.listOf types.str; default = [ ]; description = "Models the server is allowed to request."; };
log_level = mkOption {
type = types.nullOr (types.enum [ "debug" "info" "warning" ]);
default = null;
description = "Audit log level for sampling requests.";
};
};
});
default = null;
description = "Sampling configuration for server-initiated LLM requests.";
};
};
});
default = { };
description = ''
MCP server configurations (merged into settings.mcp_servers).
Each server uses either stdio (command/args) or HTTP (url) transport.
'';
example = literalExpression ''
{
filesystem = {
command = "npx";
args = [ "-y" "@modelcontextprotocol/server-filesystem" "/home/user" ];
};
remote-api = {
url = "http://my-server:8080/v0/mcp";
headers = { Authorization = "Bearer ..."; };
};
remote-oauth = {
url = "https://mcp.example.com/mcp";
auth = "oauth";
};
}
'';
};
# ── Service behavior ─────────────────────────────────────────────────
extraArgs = mkOption {
type = types.listOf types.str;
default = [ ];
description = "Extra command-line arguments for `hermes gateway`.";
};
extraPackages = mkOption {
type = types.listOf types.package;
default = [ ];
description = "Extra packages available on PATH.";
};
restart = mkOption {
type = types.str;
default = "always";
description = "systemd Restart= policy.";
};
restartSec = mkOption {
type = types.int;
default = 5;
description = "systemd RestartSec= value.";
};
addToSystemPackages = mkOption {
type = types.bool;
default = false;
description = "Add hermes CLI to environment.systemPackages.";
};
# ── OCI Container (opt-in) ──────────────────────────────────────────
container = {
enable = mkEnableOption "OCI container mode (Ubuntu base, full self-modification support)";
backend = mkOption {
type = types.enum [ "docker" "podman" ];
default = "docker";
description = "Container runtime.";
};
extraVolumes = mkOption {
type = types.listOf types.str;
default = [ ];
description = "Extra volume mounts (host:container:mode format).";
example = [ "/home/user/projects:/projects:rw" ];
};
extraOptions = mkOption {
type = types.listOf types.str;
default = [ ];
description = "Extra arguments passed to docker/podman run.";
};
image = mkOption {
type = types.str;
default = "ubuntu:24.04";
description = "OCI container image. The container pulls this at runtime via Docker/Podman.";
};
};
};
config = lib.mkIf cfg.enable (lib.mkMerge [
# ── Merge MCP servers into settings ────────────────────────────────
(lib.mkIf (cfg.mcpServers != { }) {
services.hermes-agent.settings.mcp_servers = lib.mapAttrs (_name: srv:
# Stdio transport
lib.optionalAttrs (srv.command != null) { inherit (srv) command args; }
// lib.optionalAttrs (srv.env != { }) { inherit (srv) env; }
# HTTP transport
// lib.optionalAttrs (srv.url != null) { inherit (srv) url; }
// lib.optionalAttrs (srv.headers != { }) { inherit (srv) headers; }
# Auth
// lib.optionalAttrs (srv.auth != null) { inherit (srv) auth; }
# Enable/disable
// { inherit (srv) enabled; }
# Common options
// lib.optionalAttrs (srv.timeout != null) { inherit (srv) timeout; }
// lib.optionalAttrs (srv.connect_timeout != null) { inherit (srv) connect_timeout; }
# Tool filtering
// lib.optionalAttrs (srv.tools != null) {
tools = lib.filterAttrs (_: v: v != [ ]) {
inherit (srv.tools) include exclude;
};
}
# Sampling
// lib.optionalAttrs (srv.sampling != null) {
sampling = lib.filterAttrs (_: v: v != null && v != [ ]) {
inherit (srv.sampling) enabled model max_tokens_cap timeout max_rpm
max_tool_rounds allowed_models log_level;
};
}
) cfg.mcpServers;
})
# ── User / group ──────────────────────────────────────────────────
(lib.mkIf cfg.createUser {
users.groups.${cfg.group} = { };
users.users.${cfg.user} = {
isSystemUser = true;
group = cfg.group;
home = cfg.stateDir;
createHome = true;
shell = pkgs.bashInteractive;
};
})
# ── Host CLI ──────────────────────────────────────────────────────
(lib.mkIf cfg.addToSystemPackages {
environment.systemPackages = [ cfg.package ];
})
# ── Directories ───────────────────────────────────────────────────
{
systemd.tmpfiles.rules = [
"d ${cfg.stateDir} 0750 ${cfg.user} ${cfg.group} - -"
"d ${cfg.stateDir}/.hermes 0750 ${cfg.user} ${cfg.group} - -"
"d ${cfg.stateDir}/home 0750 ${cfg.user} ${cfg.group} - -"
"d ${cfg.workingDirectory} 0750 ${cfg.user} ${cfg.group} - -"
];
}
# ── Activation: link config + auth + documents ────────────────────
{
system.activationScripts."hermes-agent-setup" = lib.stringAfter [ "users" ] ''
# Ensure directories exist (activation runs before tmpfiles)
mkdir -p ${cfg.stateDir}/.hermes
mkdir -p ${cfg.stateDir}/home
mkdir -p ${cfg.workingDirectory}
chown ${cfg.user}:${cfg.group} ${cfg.stateDir} ${cfg.stateDir}/.hermes ${cfg.stateDir}/home ${cfg.workingDirectory}
chmod 0750 ${cfg.stateDir} ${cfg.stateDir}/.hermes ${cfg.stateDir}/home ${cfg.workingDirectory}
# Merge Nix settings into existing config.yaml.
# Preserves user-added keys (skills, streaming, etc.); Nix keys win.
# If configFile is user-provided (not generated), overwrite instead of merge.
${if cfg.configFile != null then ''
install -o ${cfg.user} -g ${cfg.group} -m 0640 -D ${configFile} ${cfg.stateDir}/.hermes/config.yaml
'' else ''
${configMergeScript} ${generatedConfigFile} ${cfg.stateDir}/.hermes/config.yaml
chown ${cfg.user}:${cfg.group} ${cfg.stateDir}/.hermes/config.yaml
chmod 0640 ${cfg.stateDir}/.hermes/config.yaml
''}
# Managed mode marker (so interactive shells also detect NixOS management)
touch ${cfg.stateDir}/.hermes/.managed
chown ${cfg.user}:${cfg.group} ${cfg.stateDir}/.hermes/.managed
chmod 0644 ${cfg.stateDir}/.hermes/.managed
# Seed auth file if provided
${lib.optionalString (cfg.authFile != null) ''
${if cfg.authFileForceOverwrite then ''
install -o ${cfg.user} -g ${cfg.group} -m 0600 ${cfg.authFile} ${cfg.stateDir}/.hermes/auth.json
'' else ''
if [ ! -f ${cfg.stateDir}/.hermes/auth.json ]; then
install -o ${cfg.user} -g ${cfg.group} -m 0600 ${cfg.authFile} ${cfg.stateDir}/.hermes/auth.json
fi
''}
''}
# Seed .env from Nix-declared environment + environmentFiles.
# Hermes reads $HERMES_HOME/.env at startup via load_hermes_dotenv(),
# so this is the single source of truth for both native and container mode.
${lib.optionalString (cfg.environment != {} || cfg.environmentFiles != []) ''
ENV_FILE="${cfg.stateDir}/.hermes/.env"
install -o ${cfg.user} -g ${cfg.group} -m 0600 /dev/null "$ENV_FILE"
cat > "$ENV_FILE" <<'HERMES_NIX_ENV_EOF'
${envFileContent}
HERMES_NIX_ENV_EOF
${lib.concatStringsSep "\n" (map (f: ''
if [ -f "${f}" ]; then
echo "" >> "$ENV_FILE"
cat "${f}" >> "$ENV_FILE"
fi
'') cfg.environmentFiles)}
''}
# Link documents into workspace
${lib.concatStringsSep "\n" (lib.mapAttrsToList (name: _value: ''
install -o ${cfg.user} -g ${cfg.group} -m 0640 ${documentDerivation}/${name} ${cfg.workingDirectory}/${name}
'') cfg.documents)}
'';
}
# ══════════════════════════════════════════════════════════════════
# MODE A: Native systemd service (default)
# ══════════════════════════════════════════════════════════════════
(lib.mkIf (!cfg.container.enable) {
systemd.services.hermes-agent = {
description = "Hermes Agent Gateway";
wantedBy = [ "multi-user.target" ];
after = [ "network-online.target" ];
wants = [ "network-online.target" ];
environment = {
HOME = cfg.stateDir;
HERMES_HOME = "${cfg.stateDir}/.hermes";
HERMES_MANAGED = "true";
MESSAGING_CWD = cfg.workingDirectory;
};
serviceConfig = {
User = cfg.user;
Group = cfg.group;
WorkingDirectory = cfg.workingDirectory;
# cfg.environment and cfg.environmentFiles are written to
# $HERMES_HOME/.env by the activation script. load_hermes_dotenv()
# reads them at Python startup — no systemd EnvironmentFile needed.
ExecStart = lib.concatStringsSep " " ([
"${cfg.package}/bin/hermes"
"gateway"
] ++ cfg.extraArgs);
Restart = cfg.restart;
RestartSec = cfg.restartSec;
# Hardening
NoNewPrivileges = true;
ProtectSystem = "strict";
ProtectHome = false;
ReadWritePaths = [ cfg.stateDir ];
PrivateTmp = true;
};
path = [
cfg.package
pkgs.bash
pkgs.coreutils
pkgs.git
] ++ cfg.extraPackages;
};
})
# ══════════════════════════════════════════════════════════════════
# MODE B: OCI container (persistent writable layer)
# ══════════════════════════════════════════════════════════════════
(lib.mkIf cfg.container.enable {
# Ensure the container runtime is available
virtualisation.docker.enable = lib.mkDefault (cfg.container.backend == "docker");
systemd.services.hermes-agent = {
description = "Hermes Agent Gateway (container)";
wantedBy = [ "multi-user.target" ];
after = [ "network-online.target" ]
++ lib.optional (cfg.container.backend == "docker") "docker.service";
wants = [ "network-online.target" ];
requires = lib.optional (cfg.container.backend == "docker") "docker.service";
preStart = ''
# Stable symlinks container references these, not store paths directly
ln -sfn ${cfg.package} ${cfg.stateDir}/current-package
ln -sfn ${containerEntrypoint} ${cfg.stateDir}/current-entrypoint
# GC roots so nix-collect-garbage doesn't remove store paths in use
${pkgs.nix}/bin/nix-store --add-root ${cfg.stateDir}/.gc-root --indirect -r ${cfg.package} 2>/dev/null || true
${pkgs.nix}/bin/nix-store --add-root ${cfg.stateDir}/.gc-root-entrypoint --indirect -r ${containerEntrypoint} 2>/dev/null || true
# Check if container needs (re)creation
NEED_CREATE=false
if ! ${containerBin} inspect ${containerName} &>/dev/null; then
NEED_CREATE=true
elif [ ! -f ${identityFile} ] || [ "$(cat ${identityFile})" != "${containerIdentity}" ]; then
echo "Container config changed, recreating..."
${containerBin} rm -f ${containerName} || true
NEED_CREATE=true
fi
if [ "$NEED_CREATE" = "true" ]; then
# Resolve numeric UID/GID passed to entrypoint for in-container user setup
HERMES_UID=$(${pkgs.coreutils}/bin/id -u ${cfg.user})
HERMES_GID=$(${pkgs.coreutils}/bin/id -g ${cfg.user})
echo "Creating container..."
${containerBin} create \
--name ${containerName} \
--network=host \
--entrypoint ${containerDataDir}/current-entrypoint \
--volume /nix/store:/nix/store:ro \
--volume ${cfg.stateDir}:${containerDataDir} \
--volume ${cfg.stateDir}/home:${containerHomeDir} \
${lib.concatStringsSep " " (map (v: "--volume ${v}") cfg.container.extraVolumes)} \
--env HERMES_UID="$HERMES_UID" \
--env HERMES_GID="$HERMES_GID" \
--env HERMES_HOME=${containerDataDir}/.hermes \
--env HERMES_MANAGED=true \
--env HOME=${containerHomeDir} \
--env MESSAGING_CWD=${containerWorkDir} \
${lib.concatStringsSep " " cfg.container.extraOptions} \
${cfg.container.image} \
${containerDataDir}/current-package/bin/hermes gateway run --replace ${lib.concatStringsSep " " cfg.extraArgs}
echo "${containerIdentity}" > ${identityFile}
fi
'';
script = ''
exec ${containerBin} start -a ${containerName}
'';
preStop = ''
${containerBin} stop -t 10 ${containerName} || true
'';
serviceConfig = {
Type = "simple";
Restart = cfg.restart;
RestartSec = cfg.restartSec;
TimeoutStopSec = 30;
};
};
})
]);
};
}