Re: [PATCH] nfsdclnts: Handle exceptions gracefully for "info" and "states" file.

[Steve Dickson <SteveD@RedHat.com>]

On 5/22/20 12:21 PM, Kenneth D'souza wrote:
> This patch makes sure that "info" and "states" file are sane.
> If "info" file is not sane this patch would populate the fields as "N/A".
> This helps us to go ahead and process next "states" file.
> 
> Signed-off-by: Kenneth D'souza <kdsouza@redhat.com>
Committed... (tag: nfs-utils-2-4-4-rc6)

steved.
> ---
>  tools/nfsdclnts/nfsdclnts.py | 75 +++++++++++++++++++++---------------
>  1 file changed, 43 insertions(+), 32 deletions(-)
> 
> diff --git a/tools/nfsdclnts/nfsdclnts.py b/tools/nfsdclnts/nfsdclnts.py
> index 2d0ad0ad..7370fede 100755
> --- a/tools/nfsdclnts/nfsdclnts.py
> +++ b/tools/nfsdclnts/nfsdclnts.py
> @@ -46,19 +46,18 @@ def init_worker():
>  # this function converts the info file to a dictionary format, sorta. 
>  def file_to_dict(path):
>      client_info = {}
> -    with open(path) as f:
> -        for line in f:
> -            try:
> -                (key, val) = line.split(':')
> -                client_info[key] = val
> -    # FIXME: There has to be a better way of converting the info file to a dictionary.
> -            except ValueError:
> +    try:
> +        with open(path) as f:
> +            for line in f:
>                  try:
> -                    (key, val) = line.split()
> -                    client_info[key] = val
> -                except:
> -                    pass
> -    return client_info
> +                    (key, val) = line.split(':', 1)
> +                    client_info[key] = val.strip()
> +                    # FIXME: There has to be a better way of converting the info file to a dictionary.
> +                except ValueError as reason:
> +                    print('%s' % reason)
> +        return client_info
> +    except OSError as reason:
> +        print('%s' % reason)
>  
>  # this function gets the paths from /proc/fs/nfsd/clients/
>  # returns a list of paths for each client which has nfs-share mounted.
> @@ -70,10 +69,10 @@ def getpaths():
>          exit('%s' % reason)
>      if len(dirs) !=0:
>  	    for i in dirs:
> -		    path.append('/proc/fs/nfsd/clients/' + i + '/states')
> +                path.append('/proc/fs/nfsd/clients/' + i + '/states')
>  	    return (path)
>      else:
> -	    exit('Nothing to process')
> +        exit('Nothing to process')
>  
>  # A single function to rule them all, in this function we gather all the data
>  # from already populated data_list and client_info.
> @@ -83,12 +82,11 @@ def printer(data_list, argument):
>      for i in data_list:
>          for key in i:
>              inode = i[key]['superblock'].split(':')[-1]
> -            # get the ip address from client_info as 'address:' note the extra
> -            # ':' as a suffix to address. If there is a better way to convert
> -            # the file to dictionary, please change the following value too.
> -            client_ip = client_info['address:']
>              # The ip address is quoted, so we dequote it.
> -            client_ip = client_ip[1:-1]
> +            try:
> +                client_ip = client_info['address'][1:-1]
> +            except:
> +                client_ip = "N/A"
>              try:
>                  # if the nfs-server reboots while the nfs-client holds the files open,
>                  # the nfs-server would print the filename as '/'. For such instaces we
> @@ -110,15 +108,25 @@ def printer(data_list, argument):
>                  deny = i[key]['deny']
>              except:
>                  deny = ''
> -            hostname = client_info['name'].split()[-1].split('"')[0]
> -            hostname =  hostname.split('.')[0]
> +            try:
> +                hostname = client_info['name'].split()[-1].split('"')[0]
> +                hostname =  hostname.split('.')[0]
> +                # if the hostname is too long, it messes up with the output being in columns,
> +                # therefore we truncate the hostname followed by two '..' as suffix.
> +                if len(hostname) > 20:
> +                    hostname = hostname[0:20] + '..'
> +            except:
> +                hostname = "N/A"
> +            try:
> +                clientid = client_info['clientid']
> +            except:
> +                clientid = "N/A"
> +            try:
> +                minorversion = "4." + client_info['minor version']
> +            except:
> +                minorversion = "N/A"
> +
>              otype = i[key]['type']
> -            # if the hostname is too long, it messes up with the output being in columns,
> -            # therefore we truncate the hostname followed by two '..' as suffix.
> -            if len(hostname) > 20:
> -                hostname = hostname[0:20] + '..'
> -            clientid = client_info['clientid'].strip()
> -            minorversion = client_info['minor version'].rstrip().rsplit()[0]
>              # since some fields do not have deny column, we drop those if -t is either
>              # layout or lock.
>              drop = ['layout', 'lock']
> @@ -138,17 +146,20 @@ def printer(data_list, argument):
>                     print('%-22s' %client_ip, end='| ')
>                  if (argument.clientinfo == True) :
>                      print('%-20s' %clientid, end='| ')
> -                    print('4.%-3s' %minorversion, end='| ')
> +                    print('%-5s' %minorversion, end='| ')
>                  print(fname)
>  
>  def opener(path):
>      try:
>          with open(path, 'r') as nfsdata:
> -            data = yaml.load(nfsdata, Loader = yaml.BaseLoader)
> -            if data is not None:
> -                clientinfo = path.rsplit('/', 1)[0] + '/info'
> -                data.append(clientinfo)
> +            try:
> +                data = yaml.load(nfsdata, Loader = yaml.BaseLoader)
> +                if data is not None:
> +                    clientinfo = path.rsplit('/', 1)[0] + '/info'
> +                    data.append(clientinfo)
>                  return data
> +            except:
> +                print("Exception occurred, Please make sure %s is a YAML file" %path)
>  
>      except OSError as reason:
>          print('%s' % reason)
>