verdnatura-mirror
/
tini
mirror of https://github.com/krallin/tini.git
0
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Add Tini Handoff Capability 

This makes it so that after tini is initialized, it will handoff pid 1 to the
user's program, in the presence of the TINI_HANDOFF variable.
This commit is contained in:
Sargun Dhillon 2017-08-29 17:02:29 -07:00
parent 391dac855a
commit 9fa32c78e8
1 changed files with 42 additions and 38 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

80
src/tini.c
View File

@ -31,6 +31,7 @@
#define REDIRECT_STDOUT "TITUS_REDIRECT_STDOUT"
#define TITUS_CB_PATH "TITUS_UNIX_CB_PATH"
#define TITUS_CONFIRM "TITUS_CONFIRM"
#define TINI_HANDOFF "TINI_HANDOFF"
const char stdioattr[] = "user.stdio";
@ -145,6 +146,44 @@ int isolate_child() {
return 0;
}
int do_execvp(char* const argv[], int new_stdout_fd, int new_stderr_fd, const signal_configuration_t* const sigconf_ptr) {
// Restore all signal handlers to the way they were before we touched them.
if (restore_signals(sigconf_ptr)) {
return 1;
}
// Do the FD swap
// No need to set CLO_EXEC on existing stdout, stderr FDs, because we're closing them anyway
if (dup2(new_stdout_fd, 1) == -1) {
PRINT_FATAL("Failed to duplicate stdout FD: %s", strerror(errno));
return 1;
}
if (dup2(new_stderr_fd, 2) == -1) {
PRINT_FATAL("Failed to duplicate stdout FD: %s", strerror(errno));
return 1;
}
// Unset TINI specific environment variables
unsetenv(REDIRECT_STDERR);
unsetenv(REDIRECT_STDOUT);
unsetenv(TITUS_CB_PATH);
unsetenv(TITUS_CONFIRM);
unsetenv(TINI_HANDOFF);
execvp(argv[0], argv);
// execvp will only return on an error so make sure that we check the errno
// and exit with the correct return status for the error that we encountered
// See: http://www.tldp.org/LDP/abs/html/exitcodes.html#EXITCODESREF
switch (errno) {
case ENOENT:
return 127;
case EACCES:
return 126;
}
PRINT_FATAL("exec %s failed: %s", argv[0], strerror(errno));
return 1;
}
int spawn(const signal_configuration_t* const sigconf_ptr, char* const argv[], int* const child_pid_ptr) {
int new_stdout_fd = 1;
@ -180,6 +219,8 @@ int spawn(const signal_configuration_t* const sigconf_ptr, char* const argv[], i
return 1;
}
}
if (getenv(TINI_HANDOFF))
return do_execvp(argv, new_stdout_fd, new_stderr_fd, sigconf_ptr);
// TODO: check if tini was a foreground process to begin with (it's not OK to "steal" the foreground!")
@ -194,44 +235,7 @@ int spawn(const signal_configuration_t* const sigconf_ptr, char* const argv[], i
return 1;
}
// Restore all signal handlers to the way they were before we touched them.
if (restore_signals(sigconf_ptr)) {
return 1;
}
// Do the FD swap
// No need to set CLO_EXEC on existing stdout, stderr FDs, because we're closing them anyway
if (dup2(new_stdout_fd, 1) == -1) {
PRINT_FATAL("Failed to duplicate stdout FD: %s", strerror(errno));
return 1;
}
if (dup2(new_stderr_fd, 2) == -1) {
PRINT_FATAL("Failed to duplicate stdout FD: %s", strerror(errno));
return 1;
}
// Unset TINI specific environment variables
unsetenv(REDIRECT_STDERR);
unsetenv(REDIRECT_STDOUT);
unsetenv(TITUS_CB_PATH);
unsetenv(TITUS_CONFIRM);
execvp(argv[0], argv);
// execvp will only return on an error so make sure that we check the errno
// and exit with the correct return status for the error that we encountered
// See: http://www.tldp.org/LDP/abs/html/exitcodes.html#EXITCODESREF
int status = 1;
switch (errno) {
case ENOENT:
status = 127;
break;
case EACCES:
status = 126;
break;
}
PRINT_FATAL("exec %s failed: %s", argv[0], strerror(errno));
return status;
return do_execvp(argv, new_stdout_fd, new_stderr_fd, sigconf_ptr);
} else {
// Parent
if (new_stdout_fd != 1)