Re: [Qemu-devel] [PATCH v2] docker: Don't enable networking as a side-effect of DEBUG=1

[Daniel P. Berrange]

On Fri, Jul 14, 2017 at 10:29:30AM +0800, Fam Zheng wrote:
> On Thu, 07/13 15:43, Daniel P. Berrange wrote:
> > When trying to debug problems with tests it is natural to set
> > DEBUG=1 when starting the docker environment. Unfortunately
> > this has a side-effect of enabling an eth0 network interface
> > in the container, which changes the operating environment of
> > the test suite. IOW tests with fail may suddenly start
> > working again if DEBUG=1 is set, due to changed network setup.
> > 
> > Add a separate NETWORK variable to allow enablement of
> > networking separately from DEBUG=1. This can be used in two
> > ways. To enable the default docker network backend
> > 
> >   make address@hidden NETWORK=1
> > 
> > while to enable a specific network backend, eg join the network
> > associated with the container 'wibble':
> > 
> >   make address@hidden NETWORK=container:wibble
> > 
> > Signed-off-by: Daniel P. Berrange <address@hidden>
> > ---
> > 
> > Changed in v2:
> > 
> >  - Remove reference to eth0
> >  - Allow arbitrary docker network backend to be given
> > 
> >  tests/docker/Makefile.include | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/tests/docker/Makefile.include b/tests/docker/Makefile.include
> > index 037cb9e9e7..ec8e8d935d 100644
> > --- a/tests/docker/Makefile.include
> > +++ b/tests/docker/Makefile.include
> > @@ -106,6 +106,8 @@ docker:
> >     @echo '                         (default is 1)'
> >     @echo '    DEBUG=1              Stop and drop to shell in the created 
> > container'
> >     @echo '                         before running the command.'
> > +   @echo '    NETWORK=1            Enable virtual network interface with 
> > default backend.'
> > +   @echo '    NETWORK=$BACKEND     Enable virtual network interface with 
> > $BACKEND.'
> >     @echo '    NOUSER               Define to disable adding current user 
> > to containers passwd.'
> >     @echo '    NOCACHE=1            Ignore cache when build images.'
> >     @echo '    EXECUTABLE=<path>    Include executable in image.'
> > @@ -132,7 +134,8 @@ docker-run: docker-qemu-src
> >             $(SRC_PATH)/tests/docker/docker.py run                  \
> >                     $(if $(NOUSER),,-u $(shell id -u)) -t           \
> >                     $(if $V,,--rm)                                  \
> > -                   $(if $(DEBUG),-i,--net=none)                    \
> > +                   $(if $(DEBUG),-i,)                              \
> > +                   $(if $(NETWORK),$(if $(subst $(NETWORK),,1)$(subst 
> > 1,,$(NETWORK)),--net=$(NETWORK),),--net=none) \
> 
> Isn't the first subst enough? We already know $(NETWORK) is non-empty. If it 
> is
> "1", $(subst 1,,1) is empty; otherwise, $(subst foo,,1) is non-empty:
> 
>                       $(if $(NETWORK),$(if $(subst 
> $(NETWORK),,1),,--net=$(NETWORK)),--net=none) \

This looks inverted to me - NETWORK=1, will generate --net=1 and
NETWORK=foo generates empty string.


Regards,
Daniel
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