[PATCH 3/6] nss: Make logging conditional on an envvar

From: Michal Privoznik <mprivozn(a)redhat.com&gt; As promised in previous commit, make NSS modules silent by default and enable debug printings if LIBVIRT_NSS_DEBUG envvar is set. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- docs/nss.rst | 13 +++++++++++++ tools/nss/libvirt_nss_log.c | 4 ++++ tools/nss/libvirt_nss_log.h | 2 ++ 3 files changed, 19 insertions(+) diff --git a/docs/nss.rst b/docs/nss.rst index be137d987b..3df85cee0a 100644 --- a/docs/nss.rst +++ b/docs/nss.rst @@ -111,6 +111,19 @@ their IP addresses in any other way (usermode networking, assigned network devices and so on) will not be able to have their hostnames resolved through it. +Debugging +--------- + +:since:`Since 11.5.0` both NSS modules check for ``LIBVIRT_NSS_DEBUG`` +environment variable¸ which if set to any value turns on printing of debug and +error messages onto standard error output. This can be useful when debugging +either of the module. + +:: + + $ LIBVIRT_NSS_DEBUG=1 getent hosts mydomain + + Alternatives ------------ diff --git a/tools/nss/libvirt_nss_log.c b/tools/nss/libvirt_nss_log.c index 0863897c07..9a28a91800 100644 --- a/tools/nss/libvirt_nss_log.c +++ b/tools/nss/libvirt_nss_log.c @@ -24,6 +24,7 @@ #include <stdio.h> #include <string.h> #include <stdarg.h> +#include <stdlib.h> #include "libvirt_nss_log.h" #include "libvirt_nss.h" @@ -54,6 +55,9 @@ nssLog(nssLogPriority prio, g_autofree char *ebuf = NULL; va_list ap; + if (!getenv(NSS_LOG_ENV_VAR)) + return; + fprintf(stderr, "%s %s:%d : ", nssLogPriorityToString(prio), func, linenr); va_start(ap, fmt); diff --git a/tools/nss/libvirt_nss_log.h b/tools/nss/libvirt_nss_log.h index bac64d4bc7..25926fb6de 100644 --- a/tools/nss/libvirt_nss_log.h +++ b/tools/nss/libvirt_nss_log.h @@ -31,6 +31,8 @@ typedef enum { #define ERROR(...) \ nssLog(NSS_ERROR, __FUNCTION__, __LINE__, __VA_ARGS__) +#define NSS_LOG_ENV_VAR "LIBVIRT_NSS_DEBUG" + void nssLog(nssLogPriority prio, const char *func, -- 2.49.0