max/nix-super
1
0
Fork 0
mirror of https://github.com/privatevoid-net/nix-super.git synced 2024-11-23 06:26:15 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

Support socket-based, on-demand activation of the Nix daemon with systemd

Browse source 
Systemd can start the Nix daemon on demand when the Nix daemon socket
is first accessed.  This is signalled through the LISTEN_FDS
environment variable, so all we need to do is check for that and then
use file descriptor 3 as the listen socket instead of creating one
ourselves.
This commit is contained in:
Eelco Dolstra 2012-06-18 23:01:46 -04:00
parent 02fb6323e0
commit 2f3f413e91
1 changed files with 53 additions and 37 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

90
src/nix-worker/nix-worker.cc
View file

@ -695,51 +695,67 @@ static void setSigChldAction(bool autoReap)
} }
#define SD_LISTEN_FDS_START 3
static void daemonLoop() static void daemonLoop()
{ {
/* Get rid of children automatically; don't let them become /* Get rid of children automatically; don't let them become
zombies. */ zombies. */
setSigChldAction(true); setSigChldAction(true);
AutoCloseFD fdSocket;
/* Handle socket-based activation by systemd. */
if (getEnv("LISTEN_FDS") != "") {
if (getEnv("LISTEN_PID") != int2String(getpid()) || getEnv("LISTEN_FDS") != "1")
throw Error("unexpected systemd environment variables");
fdSocket = SD_LISTEN_FDS_START;
}
/* Otherwise, create and bind to a Unix domain socket. */
else {
/* Create and bind to a Unix domain socket. */ /* Create and bind to a Unix domain socket. */
AutoCloseFD fdSocket = socket(PF_UNIX, SOCK_STREAM, 0); fdSocket = socket(PF_UNIX, SOCK_STREAM, 0);
if (fdSocket == -1) if (fdSocket == -1)
throw SysError("cannot create Unix domain socket"); throw SysError("cannot create Unix domain socket");
string socketPath = nixStateDir + DEFAULT_SOCKET_PATH;
createDirs(dirOf(socketPath));
/* Urgh, sockaddr_un allows path names of only 108 characters.
So chdir to the socket directory so that we can pass a
relative path name. */
chdir(dirOf(socketPath).c_str());
Path socketPathRel = "./" + baseNameOf(socketPath);
struct sockaddr_un addr;
addr.sun_family = AF_UNIX;
if (socketPathRel.size() >= sizeof(addr.sun_path))
throw Error(format("socket path `%1%' is too long") % socketPathRel);
strcpy(addr.sun_path, socketPathRel.c_str());
unlink(socketPath.c_str());
/* Make sure that the socket is created with 0666 permission
(everybody can connect --- provided they have access to the
directory containing the socket). */
mode_t oldMode = umask(0111);
int res = bind(fdSocket, (struct sockaddr *) &addr, sizeof(addr));
umask(oldMode);
if (res == -1)
throw SysError(format("cannot bind to socket `%1%'") % socketPath);
chdir("/"); /* back to the root */
if (listen(fdSocket, 5) == -1)
throw SysError(format("cannot listen on socket `%1%'") % socketPath);
}
closeOnExec(fdSocket); closeOnExec(fdSocket);
string socketPath = nixStateDir + DEFAULT_SOCKET_PATH;
createDirs(dirOf(socketPath));
/* Urgh, sockaddr_un allows path names of only 108 characters. So
chdir to the socket directory so that we can pass a relative
path name. */
chdir(dirOf(socketPath).c_str());
Path socketPathRel = "./" + baseNameOf(socketPath);
struct sockaddr_un addr;
addr.sun_family = AF_UNIX;
if (socketPathRel.size() >= sizeof(addr.sun_path))
throw Error(format("socket path `%1%' is too long") % socketPathRel);
strcpy(addr.sun_path, socketPathRel.c_str());
unlink(socketPath.c_str());
/* Make sure that the socket is created with 0666 permission
(everybody can connect --- provided they have access to the
directory containing the socket). */
mode_t oldMode = umask(0111);
int res = bind(fdSocket, (struct sockaddr *) &addr, sizeof(addr));
umask(oldMode);
if (res == -1)
throw SysError(format("cannot bind to socket `%1%'") % socketPath);
chdir("/"); /* back to the root */
if (listen(fdSocket, 5) == -1)
throw SysError(format("cannot listen on socket `%1%'") % socketPath);
/* Loop accepting connections. */ /* Loop accepting connections. */
while (1) { while (1) {