[libvirt] [PATCH 3/8] daemon: Hook up the virLog{Get, Set}DefaultOutput to the daemon's init routine

[Erik Skultety]

Now that virLog{Get,Set}DefaultOutput routines are introduced we can wire them
up to the daemon's logging initialization code. As part of this process,
refactor the daemonSetupLoggingDefaults method, since the code isn't
particularly easy to read (due to the condition below). However, this refactor
changes the logic of the selection of the default logging output in the way
demonstrated below. Long story short, we should really only care if we're
running daemonized or not, disregarding the fact of (not) having a TTY
completely as that should be of the libvirtd's parent concern (what FD it will
pass to it).

Before:
if (godaemon || !hasTTY):
    if (journald):
        use journald

if (godaemon):
    if (privileged):
        use SYSCONFIG/libvirtd.log
    else:
        use XDG_CONFIG_HOME/libvirtd.log
else:
    use stderr

After:
if (godaemon):
    if (journald):
        use journald

    else:
        if (privileged):
            use SYSCONFIG/libvirtd.log
        else:
            use XDG_CONFIG_HOME/libvirtd.log
else:
    use stderr

Signed-off-by: Erik Skultety <eskultet at redhat.com>
---
 daemon/libvirtd.c | 86 ++++++++++++++-----------------------------------------
 1 file changed, 21 insertions(+), 65 deletions(-)

diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c
index 9a5f193..3af4ea1 100644
--- a/daemon/libvirtd.c
+++ b/daemon/libvirtd.c
@@ -660,65 +660,24 @@ daemonSetupNetworking(virNetServerPtr srv,
 static int
 daemonSetupLoggingDefaults(bool godaemon, bool privileged)
 {
-    if (virLogGetOutputs() == 0 &&
-        (godaemon || !isatty(STDIN_FILENO))) {
-        char *tmp;
+    /* If we're running as a daemon, the try to direct the output to systemd
+     * journal first (if it exists), otherwise fallback to libvirtd.log. If not
+     * running as a daemon, use stderr as default.
+     */
+    if (!godaemon) {
+        if (virLogSetDefaultOutput(VIR_LOG_TO_STDERR, privileged) < 0)
+            return -1;
+    } else {
         if (access("/run/systemd/journal/socket", W_OK) >= 0) {
-            virLogPriority priority = virLogGetDefaultPriority();
-
-            /* By default we don't want to log too much stuff into journald as
-             * it may employ rate limiting and thus block libvirt execution. */
-            if (priority == VIR_LOG_DEBUG)
-                priority = VIR_LOG_INFO;
-
-            if (virAsprintf(&tmp, "%d:journald", priority) < 0)
-                goto error;
-            virLogSetOutputs(tmp);
-            VIR_FREE(tmp);
-        }
-    }
-
-    if (virLogGetOutputs() == 0) {
-        char *tmp = NULL;
-
-        if (godaemon) {
-            if (privileged) {
-                if (virAsprintf(&tmp, "%d:file:%s/log/libvirt/libvirtd.log",
-                                virLogGetDefaultPriority(),
-                                LOCALSTATEDIR) == -1)
-                    goto error;
-            } else {
-                char *logdir = virGetUserCacheDirectory();
-                mode_t old_umask;
-
-                if (!logdir)
-                    goto error;
-
-                old_umask = umask(077);
-                if (virFileMakePath(logdir) < 0) {
-                    umask(old_umask);
-                    goto error;
-                }
-                umask(old_umask);
-
-                if (virAsprintf(&tmp, "%d:file:%s/libvirtd.log",
-                                virLogGetDefaultPriority(), logdir) == -1) {
-                    VIR_FREE(logdir);
-                    goto error;
-                }
-                VIR_FREE(logdir);
-            }
+            if (virLogSetDefaultOutput(VIR_LOG_TO_JOURNALD, privileged) < 0)
+                return -1;
         } else {
-            if (virAsprintf(&tmp, "%d:stderr", virLogGetDefaultPriority()) < 0)
-                goto error;
+            if (virLogSetDefaultOutput(VIR_LOG_TO_FILE, privileged) < 0)
+                return -1;
         }
-        virLogSetOutputs(tmp);
-        VIR_FREE(tmp);
     }
 
     return 0;
- error:
-    return -1;
 }
 
 /*
@@ -733,6 +692,9 @@ daemonSetupLogging(struct daemonConfig *config,
                    bool verbose,
                    bool godaemon)
 {
+    if (daemonSetupLoggingDefaults(godaemon, privileged) < 0)
+        return -1;
+
     virLogReset();
 
     /*
@@ -767,20 +729,14 @@ daemonSetupLogging(struct daemonConfig *config,
         virLogSetDefaultPriority(VIR_LOG_INFO);
 
     /*
-     * If no defined outputs, and either running
-     * as daemon or not on a tty, then first try
-     * to direct it to the systemd journal
-     * (if it exists), otherwise fallback to libvirtd.log. If both not running
-     * as daemon and having a tty, use stderr as default.
-     */
-    if (virLogGetNbOutputs() == 0 &&
-        daemonSetupLoggingDefaults(godaemon, privileged) < 0)
-        goto error;
+     * If there are no outputs defined, use the default one */
+    if (!virLogGetNbOutputs()) {
+        char *tmp = virLogGetDefaultOutput();
+        virLogSetOutputs(tmp);
+        VIR_FREE(tmp);
+    }
 
     return 0;
-
- error:
-    return -1;
 }
 
 
-- 
2.5.5