Add env hostname information

Approximation in case of hostname change or in case of
contextualisation, but it does the job for 95% of use-cases.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/lttng-events.c b/lttng-events.c
index bbff1c9df2b352167c80317853669590fb893dda..7a1be7295a7ef33d1e61f692d9a2926c0ed03d77 100644 (file)
--- a/lttng-events.c
+++ b/lttng-events.c
@@ -903,6 +903,7 @@ int _lttng_session_metadata_statedump(struct lttng_session *session)
        unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
        struct lttng_channel *chan;
        struct lttng_event *event;
+       char hostname[__NEW_UTS_LEN + 1];
        int ret = 0;
 
        if (!ACCESS_ONCE(session->active))
@@ -959,8 +960,14 @@ int _lttng_session_metadata_statedump(struct lttng_session *session)
        if (ret)
                goto end;
 
+       rcu_read_lock();
+       memcpy(hostname, task_nsproxy(current)->uts_ns->name.nodename,
+               sizeof(hostname));
+       rcu_read_unlock();
+
        ret = lttng_metadata_printf(session,
                "env {\n"
+               "       hostname = \"%s\";\n"
                "       domain = \"kernel\";\n"
                "       sysname = \"%s\";\n"
                "       kernel_release = \"%s\";\n"
@@ -970,6 +977,7 @@ int _lttng_session_metadata_statedump(struct lttng_session *session)
                "       tracer_minor = %d;\n"
                "       tracer_patchlevel = %d;\n"
                "};\n\n",
+               hostname,
                utsname()->sysname,
                utsname()->release,
                utsname()->version,