SystemD util

Minimal dynamic bindings for libsystemd.so:

• int sd_notify(int unset_environment, const char* state)
• int sd_pid_notify(pid_t pid, int unset_environment, const char *state)
• int sd_journal_print(int priority, const char* fmt, ...)
• int sd_journal_send(const char* fmt, ...)
• int sd_journal_sendv(const iovec* data, int cnt)
• int sd_journal_perror(const char *message)

with minimal wraps:

• int sdNotify(int unset_environment, string state)
• int sdNotify_ready(int unset_environment=0) @nogc send state="READY=1"
• int sdNotify_reloading(int unset_environment=0) @nogc send state="RELOADING=1"
• int sdNotify_stopping(int unset_environment=0) @nogc send state="STOPPING=1"
• int sdNotify_watchdog(int unset_environment=0) @nogc send state="WATCHDOG=1"
• int sdPidNotify(pid_t pid, int unset_environment, string state)
• int sdNotifyf(Args...)(int unset_environment, string fmt, Args args) with D format
• int sdPidNotifyf(Args...)(pid_t pid, int unset_environment, string fmt, Args args) with D format

and 2 std.experimental.logger.Logger implementations:

• SDSimpleLogger not use libsystemd, only specific format output to stderr
• SDJournalLogger use sd_journal_sendv in writeLogMsg and call initSystemDLib in ctor. It also add custom fields as CODE_MODULE (exact module name), CODE_MODULE0 (first level), CODE_MODULE1 (second level) can be used as tags for filtering (read more)

See example