[virt-tools-list] [vhostmd virtio PATCH v3 6/6] Add virtio support to vm-dump-metrics

Jim Fehlig jfehlig at suse.com
Fri Nov 30 18:31:59 UTC 2018


On 11/27/18 7:07 AM, Michael Trapp wrote:
> virtio functions are available in libmetrics
> and in libserialclient (with minimal dependencies).
> 
> ---
> We would like to have the serialclient code available in a library without
> additional dependencies, because linking against libmetrics requires libxml2.
> 
> virtio adds the 3rd transport method to vhostmd and the available
> '#ifdef WITH_XENSTORE' sections in vm-dump-metrics/main.c should be reviewed.
> 
>   libmetrics/Makefile.am       |  17 +++-
>   libmetrics/libmetrics.h      |   6 ++
>   libmetrics/libserialclient.c | 172 +++++++++++++++++++++++++++++++++++
>   libmetrics/libserialclient.h |  30 ++++++
>   vm-dump-metrics/main.c       |  29 ++++--
>   5 files changed, 246 insertions(+), 8 deletions(-)
>   create mode 100644 libmetrics/libserialclient.c
>   create mode 100644 libmetrics/libserialclient.h
> 
> diff --git a/libmetrics/Makefile.am b/libmetrics/Makefile.am
> index 28490ee..468f08f 100644
> --- a/libmetrics/Makefile.am
> +++ b/libmetrics/Makefile.am
> @@ -6,7 +6,7 @@ if WITH_XENSTORE
>   AM_CFLAGS += -DWITH_XENSTORE
>   endif
>   
> -lib_LTLIBRARIES=libmetrics.la
> +lib_LTLIBRARIES=libmetrics.la libserialclient.la
>   
>   libmetricsincdir=$(includedir)/vhostmd
>   libmetricsinc_HEADERS = libmetrics.h
> @@ -15,8 +15,21 @@ libmetrics_la_SOURCES =  \
>        libmetrics.c \
>        vm_metrics.c \
>        host_metrics.c \
> +     libserialclient.c \
>        libmetrics.h
>   
>   libmetrics_la_DEPENDENCIES = \
> -     libmetrics.h
> +     libmetrics.h \
> +     libserialclient.h
> +
> +
> +libserialclientincdir=
> +libserialclientinc_HEADERS = libserialclient.h
> +
> +libserialclient_la_SOURCES =  \
> +     libserialclient.c \
> +     libserialclient.h
> +
> +libserialclient_la_DEPENDENCIES = \
> +     libserialclient.h
>   
> diff --git a/libmetrics/libmetrics.h b/libmetrics/libmetrics.h
> index 717bc73..1908de8 100644
> --- a/libmetrics/libmetrics.h
> +++ b/libmetrics/libmetrics.h
> @@ -100,4 +100,10 @@ int dump_metrics(const char *dest_file);
>   /* dump metrics from xenstore to xml formatted file */
>   int dump_xenstore_metrics(const char *dest_file);
>   
> +/* dump metrics from virtio serial port to xml formatted file */
> +int dump_virtio_metrics(const char *dest_file);
> +
> +/* dump metrics from virtio serial port to buffer */
> +const char *get_virtio_metrics(const char *dev_name);
> +
>   #endif
> diff --git a/libmetrics/libserialclient.c b/libmetrics/libserialclient.c
> new file mode 100644
> index 0000000..61adc2b
> --- /dev/null
> +++ b/libmetrics/libserialclient.c
> @@ -0,0 +1,172 @@
> +/*
> + * Copyright (C) 2018 SAP SE
> + *
> + * 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, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
> + *
> + * Author: Michael Trapp <michael.trapp at sap.com>
> + */
> +
> +#include <config.h>
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <time.h>
> +#include <string.h>
> +#include <fcntl.h>
> +#include <unistd.h>
> +#include <errno.h>
> +
> +#include "libserialclient.h"
> +
> +
> +/*
> + * dump metrics from virtio serial port to xml formatted file
> + */
> +int dump_virtio_metrics(const char *dest_file)
> +{
> +    FILE *fp = stdout;
> +    char *response;
> +    size_t len;
> +
> +    response = get_virtio_metrics(NULL);
> +    if (response == NULL)
> +        goto error;
> +
> +    len = strlen(response);
> +
> +    if (dest_file) {
> +        fp = fopen(dest_file, "w");
> +        if (fp == NULL) {
> +            fprintf(stderr,
> +                    "LIB_SERIALCLIENT: Error, unable to dump metrics: fopen(%s) %s\n",
> +                    dest_file, strerror(errno));
> +            goto error;
> +        }
> +    }
> +
> +    if (fwrite(response, 1UL, len, fp) != len) {
> +        fprintf(stderr,
> +                "LIB_SERIALCLIENT: Error, unable to export metrics to file:%s - error:%s\n",
> +                dest_file ? dest_file : "STDOUT", strerror(errno));
> +        goto error;
> +    }
> +
> +    if (response)
> +        free(response);
> +
> +    return 0;
> +
> +  error:
> +    if (dest_file && fp)
> +        fclose(fp);
> +
> +    if (response)
> +        free(response);
> +
> +    return -1;
> +}
> +
> +/*
> + * dump metrics from virtio serial port to buffer
> + */
> +char *get_virtio_metrics(const char *dev_name)
> +{
> +    const char request[] = "GET /metrics/XML\n\n", end_token[] = "\n\n";
> +    const char *dev;
> +    char *response = NULL;
> +    int fd = -1;
> +    size_t pos;
> +    size_t buf_size = (1 << 16);
> +    const size_t req_len = (size_t) strlen(request);
> +    const time_t start_time = time(NULL);
> +
> +    if (dev_name)
> +        dev = dev_name;
> +    else
> +        dev = "/dev/virtio-ports/vhostmd";

This should be /dev/virtio-ports/org.github.vhostmd.1. I'll change it before 
pushing.

Regards,
Jim

> +
> +    response = calloc(1UL, buf_size);
> +    if (response == NULL)
> +        goto error;
> +
> +    fd = open(dev, O_RDWR | O_NONBLOCK);
> +
> +    if (fd < 0) {
> +        fprintf(stderr,
> +                "LIB_SERIALCLIENT: Error, unable to dump metrics: open(%s) %s\n",
> +                dev, strerror(errno));
> +        goto error;
> +    }
> +
> +    pos = 0;
> +    while (pos < req_len) {
> +        ssize_t len = write(fd, &request[pos], req_len - pos);
> +        if (len > 0)
> +            pos += (size_t) len;
> +        else {
> +            if (errno == EAGAIN)
> +                usleep(10000);
> +            else
> +                goto error;
> +        }
> +    }
> +
> +    pos = 0;
> +    do {
> +        ssize_t len = read(fd, &response[pos], buf_size - pos - 1);
> +        if (len > 0) {
> +            pos += (size_t) len;
> +            response[pos] = 0;
> +
> +            if ((pos + 1) >= buf_size) {
> +                buf_size = buf_size << 1;       // increase response buffer
> +                if (buf_size > (1 << 24))       // max 16MB
> +                    goto error;
> +
> +                response = realloc(response, buf_size);
> +                if (response == NULL)
> +                    goto error;
> +
> +                memset(&response[pos], 0, buf_size - pos);
> +            }
> +        } else {
> +            if (errno == EAGAIN) {
> +                usleep(10000);
> +                if (time(NULL) > (start_time + 30)) {
> +                    fprintf(stderr,
> +                            "LIB_SERIALCLIENT: Error, unable to read metrics"
> +                            " - timeout after 30s\n");
> +                    goto error;
> +                }
> +            } else
> +                goto error;
> +        }
> +    } while ((pos < (size_t) strlen(end_token) ||
> +              strcmp(end_token, &response[pos - (size_t) strlen(end_token)]) != 0) &&
> +             pos < buf_size);
> +
> +    if (fd >= 0)
> +        close(fd);
> +
> +    return response;
> +
> +  error:
> +    if (fd >= 0)
> +        close(fd);
> +    if (response)
> +        free(response);
> +
> +    return NULL;
> +}
> diff --git a/libmetrics/libserialclient.h b/libmetrics/libserialclient.h
> new file mode 100644
> index 0000000..887c6a5
> --- /dev/null
> +++ b/libmetrics/libserialclient.h
> @@ -0,0 +1,30 @@
> +/*
> + * Copyright (C) 2018 SAP SE
> + *
> + * 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, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
> + *
> + * Author: Michael Trapp <michael.trapp at sap.com>
> + */
> +
> +#ifndef __LIBSERIALCLIENT_H__
> +#define __LIBSERIALCLIENT_H__
> +
> +/* dump metrics from virtio serial port to xml formatted file */
> +int dump_virtio_metrics(const char *dest_file);
> +
> +/* dump metrics from virtio serial port to buffer */
> +char *get_virtio_metrics(const char *dev_name);
> +
> +#endif
> diff --git a/vm-dump-metrics/main.c b/vm-dump-metrics/main.c
> index 53874e8..aff92ad 100644
> --- a/vm-dump-metrics/main.c
> +++ b/vm-dump-metrics/main.c
> @@ -34,6 +34,7 @@ static void usage(const char *argv0)
>   #ifdef WITH_XENSTORE
>            "\t-x | --xenstore        Get metrics from xenstore.\n"
>   #endif
> +         "\t-i | --virtio          Get metrics from virtio channel.\n"
>            "\t-b | --vbd             Get metrics from vbd.\n";
>   
>      fprintf (stderr, "\nUsage: %s [options]\n\n%s\n", argv0, options_str);
> @@ -46,6 +47,7 @@ int main(int argc, char *argv[])
>   #ifdef WITH_XENSTORE
>      int xenstore = 0;
>   #endif
> +   int virtio = 0;
>      const char *dfile = NULL;
>   
>      struct option opts[] = {
> @@ -54,6 +56,7 @@ int main(int argc, char *argv[])
>   #ifdef WITH_XENSTORE
>         { "xenstore", no_argument, &xenstore, 1},
>   #endif
> +      { "virtio", no_argument, &virtio, 1},
>         { "help", no_argument, NULL, '?' },
>         { "dest", optional_argument, NULL, 'd'},
>         {0, 0, 0, 0}
> @@ -64,9 +67,9 @@ int main(int argc, char *argv[])
>         int c;
>   
>   #ifdef WITH_XENSTORE
> -      c = getopt_long(argc, argv, "d:vbx", opts, &optidx);
> +      c = getopt_long(argc, argv, "d:vbix", opts, &optidx);
>   #else
> -      c = getopt_long(argc, argv, "d:vb", opts, &optidx);
> +      c = getopt_long(argc, argv, "d:vbi", opts, &optidx);
>   #endif
>   
>         if (c == -1)
> @@ -82,6 +85,9 @@ int main(int argc, char *argv[])
>            case 'b':
>               vbd = 1;
>               break;
> +         case 'i':
> +            virtio = 1;
> +            break;
>   #ifdef WITH_XENSTORE
>            case 'x':
>               xenstore = 1;
> @@ -107,20 +113,31 @@ int main(int argc, char *argv[])
>      }
>   #endif
>   
> +   if (virtio) {
> +       if (dump_virtio_metrics(dfile) == -1)
> +           exit(1);
> +       exit(0);
> +   }
> +
>      if (vbd) {
>          if (dump_metrics(dfile) == -1)
>              exit(1);
>          exit(0);
>      }
>   
> -   /* If no metrics source is specfied, try disk first and then xenstore */
> +   /*
> +    * If no metrics source is specfied, try default order
> +    * disk, virtio, xenstore
> +    */
>      if (dump_metrics(dfile) == -1) {
> +       if (dump_virtio_metrics(dfile) == -1) {
>   #ifdef WITH_XENSTORE
> -       if (dump_xenstore_metrics(dfile) == -1)
> -	       exit(1);
> +           if (dump_xenstore_metrics(dfile) == -1)
> +               exit(1);
>   #else
> -       exit(1);
> +           exit(1);
>   #endif
> +       }
>      }
>   
>      exit(0);
> 




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