On Tue, 2017-01-10 at 12:21 +0000, Joao Martins wrote:
> Hey Cedric,
>
> On 01/10/2017 09:03 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.
>
> This is great stuff!
>
> BTW, while applying the patch in my local repo, I noticed some issues (and
> confirmed make syntax-check is failing with them as well). But I assume those
> could be fixed on commit.
Indeed, fixed it locally. Thanks for the heads up.
--
Cedric
> Joao
>
> > ---
> > * v4: delay the log file opening to the first message write.
> >
> > * v3: add JSON-formatted libxl_domain_config to the newly opened
> > file when creating a guest.
> >
> > * 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 | 257 +++++++++++++++++++++++++++++++++++++++++++++++
> > src/libxl/libxl_logger.h | 40 ++++++++
> > 7 files changed, 312 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..437dbb34b
> > --- /dev/null
> > +++ b/src/libxl/libxl_logger.c
> > @@ -0,0 +1,257 @@
> > +/*
> > + * 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@xxxxxxxx>
> > + */
> > +#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;
> > +
> > +typedef struct {
> > + FILE *handle;
> > + char *path;
> > +} libxlLoggerFile;
> > +
> > +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)
> > +{
> > + libxlLoggerFile *file = payload;
> > + if (file->handle) {
> > + VIR_FORCE_FCLOSE(file->handle);
> > + file->handle = NULL;
> > + }
> > + VIR_FREE(file->path);
> > +}
> > +
> > +static int
> > +libxlLoggerFileOpen(libxlLoggerFile *file) {
>
> ^^^^ newline here?
> > + int ret = 0;
> > + char ebuf[1024];
> > +
> > + if (!file->handle && !(file->handle = fopen(file->path, "a"))) {
> > + VIR_WARN("Failed to open log file %s: %s",
> > + file->path, virStrerror(errno, ebuf, sizeof(ebuf)));
> > + ret = -1;
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +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, ":"))) {
> > + libxlLoggerFile *file = NULL;
> > +
> > + start = start + 9;
> > + *end = '\0';
> > +
> > + file = virHashLookup(lg->files, start);
> > + if (file) {
> > + ignore_value(libxlLoggerFileOpen(file));
> > + logFile = file->handle;
> > + }
> > +
> > + *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 */
>
> Wasn't migration code seeing progress reported using this xentoollog function?
> (see tools/libxl/libxl_save_callout.c:418) But then this is the save helper and
> I recall there was a pipe between libxl and the save helper child process which
> would send the output to the parent and libxl would wrap some other way. So I
> assume this is of no concern and the migration logging ends up in the same
> domain file (as one would expect) ?
>
> > +}
> > +
> > +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)
> > +{
> > + 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)
> > +{
> > + 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)
> > +{
> > + FILE *logFile = NULL;
> > + char *domidstr = NULL;
> > + libxlLoggerFile *file;
> > +
>
> ^^^^ Nit: spurious whitespace here
>
> > + if (VIR_ALLOC(file) < 0)
> > + return;
> > +
> > + if (virAsprintf(&file->path, "%s/%s.log", logger->logDir, name) < 0 ||
> > + virAsprintf(&domidstr, "%d", id) < 0)
> > + goto error;
> > +
> > + ignore_value(virHashAddEntry(logger->files, domidstr, file));
> > +
> > + /* domain_config is non NULL only when starting a new domain */
> > + if (domain_config) {
> > + if (libxlLoggerFileOpen(file) < 0)
> > + goto cleanup;
> > +
> > + fprintf(logFile, "Domain start: %s\n", domain_config);
> > + fflush(logFile);
> > + }
> > + goto cleanup;
> > +
> > + error:
> > + VIR_FREE(file->path);
> > + VIR_FREE(file);
> > +
> > + cleanup:
> > + VIR_FREE(domidstr);
> > +}
> > +
> > +void libxlLoggerCloseFile(libxlLoggerPtr logger, int id)
> > +{
> > + 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@xxxxxxxx>
> > + */
> > +
> > +#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);
> > +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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