[CRIU] [PATCH v5 2/3] tests: fix builds on alpine and centos

[Adrian Reber]

On Thu, Jun 28, 2018 at 03:20:36PM -0700, Andrei Vagin wrote:
> On Thu, Jun 28, 2018 at 12:43:28PM +0000, Adrian Reber wrote:
> > From: Adrian Reber <areber at redhat.com>
> > 
> > Install sudo, create test user with ID 1000, install bash,
> > fix pidfile creation and pidfile chmod.
> > 
> > v2:
> >  * use sleep to give the criu daemon some time to start up
> > 
> > v3:
> >  * Andrei is of course right and sleep is not good solution.
> >    After adding --status-fd support to criu service, this
> >    is how we now detect that criu is ready.
> > 
> > v4:
> >  * This was much more complicated than expected which is related
> >    to the different versions of the tools on the different travis
> >    test targets. There seems to be a bug in bash on Ubuntu
> >     https://lists.gnu.org/archive/html/bug-bash/2017-07/msg00039.html
> >    which prevents using 'read -n1' on Ubuntu. As a workaround
> >    the result from CRIU's status FD is now read via python.
> > 
> >    Another problem was discovered on alpine with the loop restore test.
> >    CRIU says to use setsid even if the process is already using setsid.
> >    As a workaround, still with setsid, this process is now using
> >    shell-job true for checkpoint and restore.
> > 
> > Parts of v2 have been committed before. So the changes from this commit
> > are partially already in another commit.
> > 
> > Signed-off-by: Adrian Reber <areber at redhat.com>
> > ---
> >  scripts/build/Dockerfile.centos |  4 ++++
> >  test/others/rpc/Makefile        | 17 +++++++++++++----
> >  test/others/rpc/read.py         | 18 ++++++++++++++++++
> >  test/others/rpc/restore-loop.py |  5 +++++
> >  test/others/rpc/run.sh          |  4 +++-
> >  5 files changed, 43 insertions(+), 5 deletions(-)
> >  create mode 100644 test/others/rpc/read.py
> > 
> > diff --git a/scripts/build/Dockerfile.centos b/scripts/build/Dockerfile.centos
> > index 0160b75..d8e70ac 100644
> > --- a/scripts/build/Dockerfile.centos
> > +++ b/scripts/build/Dockerfile.centos
> > @@ -40,4 +40,8 @@ WORKDIR /criu
> >  ENV CCACHE_DIR=/tmp/.ccache CCACHE_NOCOMPRESS=1 $ENV1=yes
> >  RUN mv .ccache /tmp && make mrproper && ccache -sz  && \
> >  	date && make -j $(nproc) CC="$CC" && date && ccache -s
> > +
> > +# The rpc test cases are running as user #1000, let's add the user
> > +RUN adduser -u 1000 test
> > +
> >  RUN make -C test/zdtm -j $(nproc)
> > diff --git a/test/others/rpc/Makefile b/test/others/rpc/Makefile
> > index 2b15873..50cd063 100644
> > --- a/test/others/rpc/Makefile
> > +++ b/test/others/rpc/Makefile
> > @@ -4,13 +4,22 @@ all: test-c rpc_pb2.py criu
> >  CFLAGS += -g -Werror -Wall -I.
> >  LDLIBS +=  -lprotobuf-c
> >  
> > +PYTHON ?= python
> > +
> >  run: all
> >  	mkdir -p build
> >  	chmod a+rwx build
> > -	@# need to start the criu daemon here to access the pidfile
> > -	sudo -g '#1000' -u '#1000' ./criu service -v4 -W build -o service.log --address criu_service.socket -d --pidfile pidfile
> > -	# Give the criu daemon some time to start up
> > -	sleep 0.5
> > +	rm -f build/status
> > +	sudo -g '#1000' -u '#1000' mkfifo build/status
> > +	@# Need to start the criu daemon here to access the pidfile.
> > +	@# The script read.py is used to wait until 'criu service'
> > +	@# is ready. As 'read -n 1' in some releases has a bug and does
> > +	@# not read correctly a \0, using python is a workaround.
> > +	sudo -g '#1000' -u '#1000' -- bash -c "exec 200<>build/status; \
> > +		./criu service -v4 -W build --address criu_service.socket \
> > +		-d --pidfile pidfile -o service.log --status-fd 200; \
> > +		$(PYTHON) read.py build/status"
> 
> criu service daemonizes after creating a socker, so I don't understand
> why do we need to wait something or why do we need to use status-fd?

The problem is not the socket, but the pidfile. The pidfile is written
after forking and sometimes I saw problems in the tests because the
pidfile did not yet exist. The status_fd is closed after the pidfile is
written.

		Adrian