[libvirt] [PATCH v3] libxl: define a per-domain logger.
Jim Fehlig
jfehlig at suse.com
Tue Jan 10 00:49:14 UTC 2017
On 01/09/2017 08:20 AM, Cédric Bosdonnat wrote:
> libxl doesn't provide a way to write one log for each domain. Thus
> we need to demux the messages. If our logger doesn't know to which
> domain to attribute a message, then it will write it to the default
> log file.
>
> Starting with Xen 4.9 (commit f9858025 and following), libxl will
> write the domain ID in an easy to grab manner. The logger introduced
> by this commit will use it to demux the libxl log messages.
>
> Thanks to the default log file, this logger will also work with older
> versions of Xen.
> ---
> * v3: add JSON-formatted libxl_domain_config to the newly opened
> file when creating a guest.
BTW, this doesn't alleviate my fear of future "there's no debug info in my
domain log file" complaints. If we start seeing those I'll take you up on
delaying creation until first write :-).
> * v2: addressed Jim's comments
>
> src/Makefile.am | 1 +
> src/libxl/libxl_conf.c | 38 +-------
> src/libxl/libxl_conf.h | 4 +-
> src/libxl/libxl_domain.c | 7 ++
> src/libxl/libxl_driver.c | 2 +
> src/libxl/libxl_logger.c | 231 +++++++++++++++++++++++++++++++++++++++++++++++
> src/libxl/libxl_logger.h | 40 ++++++++
> 7 files changed, 286 insertions(+), 37 deletions(-)
> create mode 100644 src/libxl/libxl_logger.c
> create mode 100644 src/libxl/libxl_logger.h
>
> diff --git a/src/Makefile.am b/src/Makefile.am
> index 0dd2faaf6..58e3108a6 100644
> --- a/src/Makefile.am
> +++ b/src/Makefile.am
> @@ -851,6 +851,7 @@ LIBXL_DRIVER_SOURCES = \
> libxl/libxl_capabilities.c libxl/libxl_capabilities.h \
> libxl/libxl_domain.c libxl/libxl_domain.h \
> libxl/libxl_driver.c libxl/libxl_driver.h \
> + libxl/libxl_logger.c libxl/libxl_logger.h \
> libxl/libxl_migration.c libxl/libxl_migration.h
>
> UML_DRIVER_SOURCES = \
> diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c
> index b569ddad8..ac83b51c7 100644
> --- a/src/libxl/libxl_conf.c
> +++ b/src/libxl/libxl_conf.c
> @@ -76,9 +76,7 @@ libxlDriverConfigDispose(void *obj)
>
> virObjectUnref(cfg->caps);
> libxl_ctx_free(cfg->ctx);
> - xtl_logger_destroy(cfg->logger);
> - if (cfg->logger_file)
> - VIR_FORCE_FCLOSE(cfg->logger_file);
> + libxlLoggerFree(cfg->logger);
>
> VIR_FREE(cfg->configDir);
> VIR_FREE(cfg->autostartDir);
> @@ -1356,8 +1354,6 @@ libxlDriverConfigPtr
> libxlDriverConfigNew(void)
> {
> libxlDriverConfigPtr cfg;
> - char *log_file = NULL;
> - xentoollog_level log_level = XTL_DEBUG;
> char ebuf[1024];
> unsigned int free_mem;
>
> @@ -1386,9 +1382,6 @@ libxlDriverConfigNew(void)
> if (VIR_STRDUP(cfg->channelDir, LIBXL_CHANNEL_DIR) < 0)
> goto error;
>
> - if (virAsprintf(&log_file, "%s/libxl-driver.log", cfg->logDir) < 0)
> - goto error;
> -
> if (virFileMakePath(cfg->logDir) < 0) {
> virReportError(VIR_ERR_INTERNAL_ERROR,
> _("failed to create log dir '%s': %s"),
> @@ -1397,37 +1390,13 @@ libxlDriverConfigNew(void)
> goto error;
> }
>
> - if ((cfg->logger_file = fopen(log_file, "a")) == NULL) {
> - VIR_ERROR(_("Failed to create log file '%s': %s"),
> - log_file, virStrerror(errno, ebuf, sizeof(ebuf)));
> - goto error;
> - }
> - VIR_FREE(log_file);
> -
> - switch (virLogGetDefaultPriority()) {
> - case VIR_LOG_DEBUG:
> - log_level = XTL_DEBUG;
> - break;
> - case VIR_LOG_INFO:
> - log_level = XTL_INFO;
> - break;
> - case VIR_LOG_WARN:
> - log_level = XTL_WARN;
> - break;
> - case VIR_LOG_ERROR:
> - log_level = XTL_ERROR;
> - break;
> - }
> -
> - cfg->logger =
> - (xentoollog_logger *)xtl_createlogger_stdiostream(cfg->logger_file,
> - log_level, XTL_STDIOSTREAM_SHOW_DATE);
> + cfg->logger = libxlLoggerNew(cfg->logDir, virLogGetDefaultPriority());
> if (!cfg->logger) {
> VIR_ERROR(_("cannot create logger for libxenlight, disabling driver"));
> goto error;
> }
>
> - if (libxl_ctx_alloc(&cfg->ctx, LIBXL_VERSION, 0, cfg->logger)) {
> + if (libxl_ctx_alloc(&cfg->ctx, LIBXL_VERSION, 0, (xentoollog_logger *)cfg->logger)) {
> VIR_ERROR(_("cannot initialize libxenlight context, probably not "
> "running in a Xen Dom0, disabling driver"));
> goto error;
> @@ -1478,7 +1447,6 @@ libxlDriverConfigNew(void)
> return cfg;
>
> error:
> - VIR_FREE(log_file);
> virObjectUnref(cfg);
> return NULL;
> }
> diff --git a/src/libxl/libxl_conf.h b/src/libxl/libxl_conf.h
> index 851f3afb4..69d78851a 100644
> --- a/src/libxl/libxl_conf.h
> +++ b/src/libxl/libxl_conf.h
> @@ -41,6 +41,7 @@
> # include "locking/lock_manager.h"
> # include "virfirmware.h"
> # include "libxl_capabilities.h"
> +# include "libxl_logger.h"
>
> # define LIBXL_DRIVER_NAME "xenlight"
> # define LIBXL_VNC_PORT_MIN 5900
> @@ -74,8 +75,7 @@ struct _libxlDriverConfig {
> unsigned int version;
>
> /* log stream for driver-wide libxl ctx */
> - FILE *logger_file;
> - xentoollog_logger *logger;
> + libxlLoggerPtr logger;
> /* libxl ctx for driver wide ops; getVersion, getNodeInfo, ... */
> libxl_ctx *ctx;
>
> diff --git a/src/libxl/libxl_domain.c b/src/libxl/libxl_domain.c
> index 5cde576ef..fbe7ee5ff 100644
> --- a/src/libxl/libxl_domain.c
> +++ b/src/libxl/libxl_domain.c
> @@ -809,6 +809,8 @@ libxlDomainCleanup(libxlDriverPrivatePtr driver,
> VIR_FREE(xml);
> }
>
> + libxlLoggerCloseFile(cfg->logger, vm->def->id);
> +
> virDomainObjRemoveTransientDef(vm);
> virObjectUnref(cfg);
> }
> @@ -1127,6 +1129,7 @@ libxlDomainStart(libxlDriverPrivatePtr driver,
> libxl_asyncprogress_how aop_console_how;
> libxl_domain_restore_params params;
> unsigned int hostdev_flags = VIR_HOSTDEV_SP_PCI;
> + char *config_json = NULL;
>
> #ifdef LIBXL_HAVE_PVUSB
> hostdev_flags |= VIR_HOSTDEV_SP_USB;
> @@ -1290,6 +1293,9 @@ libxlDomainStart(libxlDriverPrivatePtr driver,
> * be cleaned up if there are any subsequent failures.
> */
> vm->def->id = domid;
> + config_json = libxl_domain_config_to_json(cfg->ctx, &d_config);
> +
> + libxlLoggerOpenFile(cfg->logger, domid, vm->def->name, config_json);
>
> /* Always enable domain death events */
> if (libxl_evenable_domain_death(cfg->ctx, vm->def->id, 0, &priv->deathW))
> @@ -1366,6 +1372,7 @@ libxlDomainStart(libxlDriverPrivatePtr driver,
>
> cleanup:
> libxl_domain_config_dispose(&d_config);
> + VIR_FREE(config_json);
> VIR_FREE(dom_xml);
> VIR_FREE(managed_save_path);
> virDomainDefFree(def);
> diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
> index 7e5d9b69e..325636c9a 100644
> --- a/src/libxl/libxl_driver.c
> +++ b/src/libxl/libxl_driver.c
> @@ -406,6 +406,8 @@ libxlReconnectDomain(virDomainObjPtr vm,
> /* Update domid in case it changed (e.g. reboot) while we were gone? */
> vm->def->id = d_info.domid;
>
> + libxlLoggerOpenFile(cfg->logger, vm->def->id, vm->def->name, NULL);
> +
> /* Update hostdev state */
> if (virHostdevUpdateActiveDomainDevices(hostdev_mgr, LIBXL_DRIVER_NAME,
> vm->def, hostdev_flags) < 0)
> diff --git a/src/libxl/libxl_logger.c b/src/libxl/libxl_logger.c
> new file mode 100644
> index 000000000..9ca745a93
> --- /dev/null
> +++ b/src/libxl/libxl_logger.c
> @@ -0,0 +1,231 @@
> +/*
> + * libxl_logger.c: libxl logger implementation
> + *
> + * Copyright (c) 2016 SUSE LINUX Products GmbH, Nuernberg, Germany.
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library. If not, see
> + * <http://www.gnu.org/licenses/>.
> + *
> + * Authors:
> + * Cédric Bosdonnat <cbosdonnat at suse.com>
> + */
> +#include <config.h>
> +
> +#include <string.h>
> +#include <libxl.h>
> +
> +#include "internal.h"
> +#include "libxl_logger.h"
> +#include "util/viralloc.h"
> +#include "util/virerror.h"
> +#include "util/virfile.h"
> +#include "util/virhash.h"
> +#include "util/virstring.h"
> +#include "util/virtime.h"
> +
> +#define VIR_FROM_THIS VIR_FROM_LIBXL
> +
> +VIR_LOG_INIT("libxl.libxl_logger");
> +
> +typedef struct xentoollog_logger_libvirt xentoollog_logger_libvirt;
> +
> +struct xentoollog_logger_libvirt {
> + xentoollog_logger vtable;
> + xentoollog_level minLevel;
> + const char *logDir;
> +
> + /* map storing the opened fds: "domid" -> FILE* */
> + virHashTablePtr files;
> + FILE *defaultLogFile;
> +};
> +
> +static void
> +libxlLoggerFileFree(void *payload, const void *key ATTRIBUTE_UNUSED)
> +{
> + FILE *file = payload;
> + VIR_FORCE_FCLOSE(file);
> + file = NULL;
> +}
> +
> +ATTRIBUTE_FMT_PRINTF(5, 0) static void
> +libvirt_vmessage(xentoollog_logger *logger_in,
> + xentoollog_level level,
> + int errnoval,
> + const char *context,
> + const char *format,
> + va_list args)
> +{
> + xentoollog_logger_libvirt *lg = (xentoollog_logger_libvirt *)logger_in;
> + FILE *logFile = lg->defaultLogFile;
> + char timestamp[VIR_TIME_STRING_BUFLEN];
> + char *message = NULL;
> + char *start, *end;
> + char ebuf[1024];
> +
> + VIR_DEBUG("libvirt_vmessage: context='%s' format='%s'", context, format);
> +
> + if (level < lg->minLevel)
> + return;
> +
> + if (virVasprintf(&message, format, args) < 0)
> + return;
> +
> + /* Should we print to a domain-specific log file? */
> + if ((start = strstr(message, ": Domain ")) &&
> + (end = strstr(start + 9, ":"))) {
> + FILE *domainLogFile;
> +
> + VIR_DEBUG("Found domain log message");
> +
> + start = start + 9;
> + *end = '\0';
> +
> + domainLogFile = virHashLookup(lg->files, start);
> + if (domainLogFile)
> + logFile = domainLogFile;
> +
> + *end = ':';
> + }
> +
> + /* Do the actual print to the log file */
> + if (virTimeStringNowRaw(timestamp) < 0)
> + timestamp[0] = '\0';
> +
> + fprintf(logFile, "%s: ", timestamp);
> + if (context)
> + fprintf(logFile, "%s: ", context);
> +
> + fprintf(logFile, "%s", message);
> +
> + if (errnoval >= 0)
> + fprintf(logFile, ": %s", virStrerror(errnoval, ebuf, sizeof(ebuf)));
> +
> + fputc('\n', logFile);
> + fflush(logFile);
> +
> + VIR_FREE(message);
> +}
> +
> +static void
> +libvirt_progress(xentoollog_logger *logger_in ATTRIBUTE_UNUSED,
> + const char *context ATTRIBUTE_UNUSED,
> + const char *doingwhat ATTRIBUTE_UNUSED,
> + int percent ATTRIBUTE_UNUSED,
> + unsigned long done ATTRIBUTE_UNUSED,
> + unsigned long total ATTRIBUTE_UNUSED)
> +{
> + /* This function purposedly does nothing: it's no logging info */
> +}
> +
> +static void
> +libvirt_destroy(xentoollog_logger *logger_in)
> +{
> + xentoollog_logger_libvirt *lg = (xentoollog_logger_libvirt*)logger_in;
> + VIR_FREE(lg);
> +}
> +
> +
> +libxlLoggerPtr libxlLoggerNew(const char *logDir,
> + virLogPriority minLevel)
The dominant pattern in libvirt is return type on its own line.
> +{
> + xentoollog_logger_libvirt logger;
> + libxlLoggerPtr logger_out = NULL;
> + char *path = NULL;
> +
> + switch (minLevel) {
> + case VIR_LOG_DEBUG:
> + logger.minLevel = XTL_DEBUG;
> + break;
> + case VIR_LOG_INFO:
> + logger.minLevel = XTL_INFO;
> + break;
> + case VIR_LOG_WARN:
> + logger.minLevel = XTL_WARN;
> + break;
> + case VIR_LOG_ERROR:
> + logger.minLevel = XTL_ERROR;
> + break;
> + }
> + logger.logDir = logDir;
> +
> + if ((logger.files = virHashCreate(3, libxlLoggerFileFree)) == NULL)
> + return NULL;
> +
> + if (virAsprintf(&path, "%s/libxl-driver.log", logDir) < 0)
> + goto error;
> +
> + if ((logger.defaultLogFile = fopen(path, "a")) == NULL)
> + goto error;
> +
> + logger_out = XTL_NEW_LOGGER(libvirt, logger);
> +
> + cleanup:
> + VIR_FREE(path);
> + return logger_out;
> +
> + error:
> + virHashFree(logger.files);
> + goto cleanup;
> +}
> +
> +void libxlLoggerFree(libxlLoggerPtr logger)
Same.
> +{
> + xentoollog_logger *xtl_logger = (xentoollog_logger*)logger;
> + if (logger->defaultLogFile)
> + VIR_FORCE_FCLOSE(logger->defaultLogFile);
> + virHashFree(logger->files);
> + xtl_logger_destroy(xtl_logger);
> +}
> +
> +void libxlLoggerOpenFile(libxlLoggerPtr logger, int id,
> + const char *name,
> + const char *domain_config)
Same.
> +{
> + char *path = NULL;
> + FILE *logFile = NULL;
> + char *domidstr = NULL;
> + char ebuf[1024];
> +
> + if (virAsprintf(&path, "%s/%s.log", logger->logDir, name) < 0 ||
> + virAsprintf(&domidstr, "%d", id) < 0)
> + goto cleanup;
> +
> + if (!(logFile = fopen(path, "a"))) {
> + VIR_WARN("Failed to open log file %s: %s",
> + path, virStrerror(errno, ebuf, sizeof(ebuf)));
> + goto cleanup;
> + }
> + ignore_value(virHashAddEntry(logger->files, domidstr, logFile));
> +
> + /* domain_config is non NULL only when starting a new domain */
> + if (domain_config) {
> + fprintf(logFile, "Domain start: %s\n", domain_config);
> + fflush(logFile);
> + }
> +
> + cleanup:
> + VIR_FREE(path);
> + VIR_FREE(domidstr);
> +}
> +
> +void libxlLoggerCloseFile(libxlLoggerPtr logger, int id)
Same.
> +{
> + char *domidstr = NULL;
> + if (virAsprintf(&domidstr, "%d", id) < 0)
> + return;
> +
> + ignore_value(virHashRemoveEntry(logger->files, domidstr));
> +
> + VIR_FREE(domidstr);
> +}
> diff --git a/src/libxl/libxl_logger.h b/src/libxl/libxl_logger.h
> new file mode 100644
> index 000000000..92b222578
> --- /dev/null
> +++ b/src/libxl/libxl_logger.h
> @@ -0,0 +1,40 @@
> +/*
> + * libxl_logger.h: libxl logger implementation
> + *
> + * Copyright (c) 2016 SUSE LINUX Products GmbH, Nuernberg, Germany.
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library. If not, see
> + * <http://www.gnu.org/licenses/>.
> + *
> + * Authors:
> + * Cédric Bosdonnat <cbosdonnat at suse.com>
> + */
> +
> +#ifndef __LIBXL_LOGGER_H
> +# define __LIBXL_LOGGER_H
> +
> +# include "util/virlog.h"
> +
> +typedef struct xentoollog_logger_libvirt libxlLogger;
> +typedef libxlLogger *libxlLoggerPtr;
> +
> +libxlLoggerPtr libxlLoggerNew(const char *logDir,
> + virLogPriority minLevel);
Indentation looks off here.
Beyond the small nits, ACK.
Regards,
Jim
> +void libxlLoggerFree(libxlLoggerPtr logger);
> +
> +void libxlLoggerOpenFile(libxlLoggerPtr logger, int id, const char *name,
> + const char *domain_config);
> +void libxlLoggerCloseFile(libxlLoggerPtr logger, int id);
> +
> +#endif /* __LIBXL_LOGGER_H */
>
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