[Libguestfs] [PATCH 2/2] customize: Improve the error messages when package manager is unknown or unsupported.

[Richard W.M. Jones]

On Wed, May 04, 2016 at 04:09:02PM +0200, Pino Toscano wrote:
> On Wednesday 04 May 2016 14:12:30 Richard W.M. Jones wrote:
> > For Windows, we now print:
> > 
> > $ virt-customize -a ./test-data/phony-guests/windows.img --install MSSQL
> > [   0.0] Examining the guest ...
> > [  14.2] Setting a random seed
> > virt-customize: warning: random seed could not be set for this type of
> > guest
> > [  14.2] Installing packages: MSSQL
> > virt-customize: error: '--install' failed because inspection could not
> > determine the package manager for this guest OS.
> > 
> > If this guest OS is a common one with ordinary package management then this
> > may have been caused by a failure of libguestfs inspection.
> > 
> > For OSes such as Windows that lack package management, this is not
> > possible.  Try using one of the '--firstboot*' flags instead (described in
> > the manual).
> > ---
> >  customize/customize_run.ml | 19 ++++++++++++++-----
> >  1 file changed, 14 insertions(+), 5 deletions(-)
> > 
> > diff --git a/customize/customize_run.ml b/customize/customize_run.ml
> > index 83e70a6..c0e1e44 100644
> > --- a/customize/customize_run.ml
> > +++ b/customize/customize_run.ml
> > @@ -94,7 +94,7 @@ exec >>%s 2>&1
> >    in
> >  
> >    (* http://distrowatch.com/dwres.php?resource=package-management *)
> > -  let guest_install_command packages =
> > +  let rec guest_install_command packages =
> >      let quoted_args = String.concat " " (List.map quote packages) in
> >      match g#inspect_get_package_management root with
> >      | "apk" ->
> > @@ -116,10 +116,11 @@ exec >>%s 2>&1
> >      | "urpmi" ->  sprintf "urpmi %s" quoted_args
> >      | "yum" ->    sprintf "yum -y install %s" quoted_args
> >      | "zypper" -> sprintf "zypper -n in -l %s" quoted_args
> > +
> >      | "unknown" ->
> > -      error (f_"--install is not supported for this guest operating system")
> > +      error_unknown_package_manager (s_"--install")
> >      | pm ->
> > -      error (f_"sorry, don't know how to use --install with the '%s' package manager") pm
> > +      error_unimplemented_package_manager (s_"--install") pm
> >  
> >    and guest_update_command () =
> >      match g#inspect_get_package_management root with
> > @@ -142,10 +143,18 @@ exec >>%s 2>&1
> >      | "urpmi" ->  "urpmi --auto-select"
> >      | "yum" ->    "yum -y update"
> >      | "zypper" -> "zypper -n update -l"
> > +
> >      | "unknown" ->
> > -      error (f_"--update is not supported for this guest operating system")
> > +      error_unknown_package_manager (s_"--update")
> >      | pm ->
> > -      error (f_"sorry, don't know how to use --update with the '%s' package manager") pm
> > +      error_unimplemented_package_manager (s_"--update") pm
> > +
> > +  (* Windows has package_management == "unknown". *)
> > +  and error_unknown_package_manager flag =
> > +    error (f_"'%s' failed because inspection could not determine the package manager for this guest OS.\n\nIf this guest OS is a common one with ordinary package management then this may have been caused by a failure of libguestfs inspection.\n\nFor OSes such as Windows that lack package management, this is not possible.  Try using one of the '--firstboot*' flags instead (described in the manual).") flag
> 
> what about
> "cannot run '%s' because no package management has been detected for 
> this guest OS.\n etc"
> 
> > +
> > +  and error_unimplemented_package_manager flag pm =
> > +      error (f_"sorry, '%s' with the '%s' package manager has not been implemented.\n\nIf this guest OS has ordinary package management then you will need to add support to virt-customize.\n\nFor OSes lack package management, this is not possible.\n\nYou can work around this by using one of the '--run*' or '--firstboot*' options instead (described in the manual).") flag pm
> 
> I'd shorten this message:
> "sorry, '%s' with the '%s' package manager has not been implemented yet.\n\nYou can work around this by using one of the '--run*' or '--firstboot*' options instead (described in the manual)."
> 
> rationale behind that:
> - telling users to add support for that is not exactly useful, and what
>   will happen in such cases is that we get reports with that
> - if the OS lacks package management, then the result will be "unknown"
>   and thus the other message will be shown
> - this would be shown in virt-builder, other than virt-customize (but
>   that's just a minor point)

Thanks - I pushed these with the changes you suggested.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
Fedora Windows cross-compiler. Compile Windows programs, test, and
build Windows installers. Over 100 libraries supported.
http://fedoraproject.org/wiki/MinGW