[libvirt] [PATCH v3] screenshot: Expose the new API in virsh

Daniel Veillard veillard at redhat.com
Thu Jun 2 12:55:48 UTC 2011


On Thu, Jun 02, 2011 at 01:26:22PM +0200, Michal Privoznik wrote:
> * tools/virsh.c: Add screenshot command
> * tools/virsh.pod: Document new command
> * src/libvirt.c: Fix off-be-one error
> ---
> diff to v1:
> - make filename optional and generate filename when missing
> 
> diff to v2:
> - Eric's review suggestions included
> 
>  src/libvirt.c   |    2 +-
>  tools/virsh.c   |  187 +++++++++++++++++++++++++++++++++++++++++++++++++++---
>  tools/virsh.pod |    9 +++
>  3 files changed, 186 insertions(+), 12 deletions(-)
> 
> diff --git a/src/libvirt.c b/src/libvirt.c
> index ee5c7cd..eaae0ec 100644
> --- a/src/libvirt.c
> +++ b/src/libvirt.c
> @@ -2464,7 +2464,7 @@ error:
>   * The screen ID is the sequential number of screen. In case of multiple
>   * graphics cards, heads are enumerated before devices, e.g. having
>   * two graphics cards, both with four heads, screen ID 5 addresses
> - * the first head on the second card.
> + * the second head on the second card.
>   *
>   * Returns a string representing the mime-type of the image format, or
>   * NULL upon error. The caller must free() the returned value.
> diff --git a/tools/virsh.c b/tools/virsh.c
> index dfd5bd2..da10a0b 100644
> --- a/tools/virsh.c
> +++ b/tools/virsh.c
> @@ -264,6 +264,9 @@ static bool vshCmdGrpHelp(vshControl *ctl, const char *name);
>  static vshCmdOpt *vshCommandOpt(const vshCmd *cmd, const char *name);
>  static int vshCommandOptInt(const vshCmd *cmd, const char *name, int *value)
>      ATTRIBUTE_NONNULL(3) ATTRIBUTE_RETURN_CHECK;
> +static int vshCommandOptUInt(const vshCmd *cmd, const char *name,
> +                             unsigned int *value)
> +    ATTRIBUTE_NONNULL(3) ATTRIBUTE_RETURN_CHECK;
>  static int vshCommandOptUL(const vshCmd *cmd, const char *name,
>                             unsigned long *value)
>      ATTRIBUTE_NONNULL(3) ATTRIBUTE_RETURN_CHECK;
> @@ -1938,6 +1941,153 @@ cmdDump(vshControl *ctl, const vshCmd *cmd)
>      return ret;
>  }
>  
> +static const vshCmdInfo info_screenshot[] = {
> +    {"help", N_("take a screenshot of a current domain console and store it "
> +                "into a file")},
> +    {"desc", N_("screenshot of a current domain console")},
> +    {NULL, NULL}
> +};
> +
> +static const vshCmdOptDef opts_screenshot[] = {
> +    {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")},
> +    {"file", VSH_OT_DATA, VSH_OFLAG_NONE, N_("where to store the screenshot")},
> +    {"screen", VSH_OT_INT, VSH_OFLAG_NONE, N_("ID of a screen to take screenshot of")},
> +    {NULL, 0, 0, NULL}
> +};
> +
> +static int vshStreamSink(virStreamPtr st ATTRIBUTE_UNUSED,
> +                         const char *bytes, size_t nbytes, void *opaque)
> +{
> +    int *fd = opaque;
> +
> +    return safewrite(*fd, bytes, nbytes);
> +}
> +
> +/**
> + * Generate string: '<domain name>-<timestamp>[<extension>]'
> + */
> +static char *
> +vshGenFileName(vshControl *ctl, virDomainPtr dom, const char *mime)
> +{
> +    char timestr[100];
> +    struct timeval cur_time;
> +    struct tm time_info;
> +    const char *ext = NULL;
> +    char *ret = NULL;
> +
> +    /* We should be already connected, but doesn't
> +     * hurt to check */
> +    if (!vshConnectionUsability(ctl, ctl->conn))
> +        return NULL;
> +
> +    if (!dom) {
> +        vshError(ctl, "%s", _("Invalid domain supplied"));
> +        return NULL;
> +    }
> +
> +    if (STREQ(mime, "image/x-portable-pixmap"))
> +        ext = ".ppm";
> +    else if (STREQ(mime, "image/png"))
> +        ext = ".png";
> +    /* add mime type here */
> +
> +    gettimeofday(&cur_time, NULL);
> +    localtime_r(&cur_time.tv_sec, &time_info);
> +    strftime(timestr, sizeof(timestr), "%Y-%m-%d-%H:%M:%S", &time_info);
> +
> +    if (virAsprintf(&ret, "%s-%s%s", virDomainGetName(dom),
> +                    timestr, ext ? ext : "") < 0) {
> +        vshError(ctl, "%s", _("Out of memory"));
> +        return NULL;
> +    }
> +
> +    return ret;
> +}
> +
> +static bool
> +cmdScreenshot(vshControl *ctl, const vshCmd *cmd)
> +{
> +    virDomainPtr dom;
> +    const char *name = NULL;
> +    char *file = NULL;
> +    int fd = -1;
> +    virStreamPtr st = NULL;
> +    unsigned int screen = 0;
> +    unsigned int flags = 0; /* currently unused */
> +    int ret = false;
> +    bool created = true;
> +    bool generated = false;
> +    char *mime = NULL;
> +
> +    if (!vshConnectionUsability(ctl, ctl->conn))
> +        return false;
> +
> +    if (vshCommandOptString(cmd, "file", (const char **) &file) < 0) {
> +        vshError(ctl, "%s", _("file must not be empty"));
> +        return false;
> +    }
> +
> +    if (vshCommandOptUInt(cmd, "screen", &screen) < 0) {
> +        vshError(ctl, "%s", _("invalid screen ID"));
> +        return false;
> +    }
> +
> +    if (!(dom = vshCommandOptDomain(ctl, cmd, &name)))
> +        return false;
> +
> +    st = virStreamNew(ctl->conn, 0);
> +
> +    mime = virDomainScreenshot(dom, st, screen, flags);
> +    if (!mime) {
> +        vshError(ctl, _("could not take a screenshot of %s"), name);
> +        goto cleanup;
> +    }
> +
> +    if (!file) {
> +        if (!(file=vshGenFileName(ctl, dom, mime)))
> +            return false;
> +        generated = true;
> +    }
> +
> +    if ((fd = open(file, O_WRONLY|O_CREAT|O_EXCL, 0666)) < 0) {
> +        created = false;
> +        if (errno != EEXIST ||
> +            (fd = open(file, O_WRONLY|O_TRUNC, 0666)) < 0) {
> +            vshError(ctl, _("cannot create file %s"), file);
> +            goto cleanup;
> +        }
> +    }
> +
> +    if (virStreamRecvAll(st, vshStreamSink, &fd) < 0) {
> +        vshError(ctl, _("could not receive data from domain %s"), name);
> +        goto cleanup;
> +    }
> +
> +    if (VIR_CLOSE(fd) < 0) {
> +        vshError(ctl, _("cannot close file %s"), file);
> +        goto cleanup;
> +    }
> +
> +    if (virStreamFinish(st) < 0) {
> +        vshError(ctl, _("cannot close stream on domain %s"), name);
> +        goto cleanup;
> +    }
> +
> +    vshPrint(ctl, _("Screenshot saved to %s, with type of %s"), file, mime);
> +    ret = true;
> +
> +cleanup:
> +    if (!ret && created)
> +        unlink(file);
> +    if (generated)
> +        VIR_FREE(file);
> +    virDomainFree(dom);
> +    if (st)
> +        virStreamFree(st);
> +    VIR_FORCE_CLOSE(fd);
> +    return ret;
> +}
> +
>  /*
>   * "resume" command
>   */
> @@ -7451,16 +7601,6 @@ static const vshCmdOptDef opts_vol_download[] = {
>      {NULL, 0, 0, NULL}
>  };
>  
> -
> -static int
> -cmdVolDownloadSink(virStreamPtr st ATTRIBUTE_UNUSED,
> -                   const char *bytes, size_t nbytes, void *opaque)
> -{
> -    int *fd = opaque;
> -
> -    return safewrite(*fd, bytes, nbytes);
> -}
> -
>  static bool
>  cmdVolDownload (vshControl *ctl, const vshCmd *cmd)
>  {
> @@ -7510,7 +7650,7 @@ cmdVolDownload (vshControl *ctl, const vshCmd *cmd)
>          goto cleanup;
>      }
>  
> -    if (virStreamRecvAll(st, cmdVolDownloadSink, &fd) < 0) {
> +    if (virStreamRecvAll(st, vshStreamSink, &fd) < 0) {
>          vshError(ctl, _("cannot receive data from volume %s"), name);
>          goto cleanup;
>      }
> @@ -10945,6 +11085,7 @@ static const vshCmdDef domManagementCmds[] = {
>      {"resume", cmdResume, opts_resume, info_resume, 0},
>      {"save", cmdSave, opts_save, info_save, 0},
>      {"schedinfo", cmdSchedinfo, opts_schedinfo, info_schedinfo, 0},
> +    {"screenshot", cmdScreenshot, opts_screenshot, info_screenshot, 0},
>      {"setmaxmem", cmdSetmaxmem, opts_setmaxmem, info_setmaxmem, 0},
>      {"setmem", cmdSetmem, opts_setmem, info_setmem, 0},
>      {"setvcpus", cmdSetvcpus, opts_setvcpus, info_setvcpus, 0},
> @@ -11527,6 +11668,30 @@ vshCommandOptInt(const vshCmd *cmd, const char *name, int *value)
>      return ret;
>  }
>  
> +
> +/*
> + * Convert option to unsigned int
> + * See vshCommandOptInt()
> + */
> +static int
> +vshCommandOptUInt(const vshCmd *cmd, const char *name, unsigned int *value)
> +{
> +    vshCmdOpt *arg = vshCommandOpt(cmd, name);
> +    unsigned int ret = 0, num;
> +    char *end_p = NULL;
> +
> +    if ((arg != NULL) && (arg->data != NULL)) {
> +        num = strtoul(arg->data, &end_p, 10);
> +        ret = -1;
> +        if ((arg->data != end_p) && (*end_p == 0)) {
> +            *value = num;
> +            ret = 1;
> +        }
> +    }
> +    return ret;
> +}
> +
> +
>  /*
>   * Convert option to unsigned long
>   * See vshCommandOptInt()
> diff --git a/tools/virsh.pod b/tools/virsh.pod
> index 9251db6..e4a11d5 100644
> --- a/tools/virsh.pod
> +++ b/tools/virsh.pod
> @@ -596,6 +596,15 @@ Therefore, -1 is a useful shorthand for 262144.
>  B<Note>: The weight and cap parameters are defined only for the
>  XEN_CREDIT scheduler and are now I<DEPRECATED>.
>  
> +=item B<screenshot> I<domain-id> optional I<imagefilepath> I<--screen> B<screenID>
> +
> +Takes a screenshot of a current domain console and stores it into a file.
> +Optionally, if hypervisor supports more displays for a domain, I<screenID>
> +allows to specify which screen will be captured. It is the sequential number
> +of screen. In case of multiple graphics cards, heads are enumerated before
> +devices, e.g. having two graphics cards, both with four heads, screen ID 5
> +addresses the second head on the second card.
> +
>  =item B<setmem> I<domain-id> B<kilobytes> optional I<--config> I<--live>
>  I<--current>

  it's a bit late but it doesn't touch the API itself (except for fixing
the comment) and I think it would be good to have the virsh command
along with the API in 0.9.2,

  ACK,

Daniel

-- 
Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel at veillard.com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/




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