running bazel remote executor test on separate machines

Question

The remote worker guide of bazel (here) explains how to start the remote-worker locally and then run bazel against it.

I tried it and indeed that worked (with bugs that reported in GH)

Another attempt was to create run the remote worker on a virtual separate machine, by running it inside docker container and running bazel against it. But it failed in a different way - and I think this time I'm using it wrong.

Here's my docker file:

FROM openjdk:8

# install release bazel from apt
RUN echo "deb [arch=amd64] http://storage.googleapis.com/bazel-apt stable jdk1.8" | tee /etc/apt/sources.list.d/bazel.list
RUN curl https://bazel.build/bazel-release.pub.gpg |  apt-key add -
RUN apt-get update && apt-get install -y zip bazel

# compile dev bazel from sources
RUN mkdir -p /usr/src/bazel
# "bazel" has the latest development code of bazel from github
COPY bazel /usr/src/bazel
WORKDIR /usr/src/bazel
RUN bazel build src/bazel

# compile remote_worker using latest development bazel
RUN bazel-bin/src/bazel build //src/tools/remote_worker

# prepare cache folder
RUN mkdir -p /tmp/test

# Run remote-worker
CMD ["bazel-bin/src/tools/remote_worker/remote_worker","--work_path=/tmp/test","--listen_port=3030"]

After building it I simply ran the docker binding the port to the localhost:

$ docker build -t bazel-worker .
$ docker run -p 3030:3030 bazel-worker

Then ran bazel java test to run using the remote worker: (Can check out my test repo here)

$ bazel --host_jvm_args=-Dbazel.DigestFunction=SHA1 test \
      --spawn_strategy=remote \
      --remote_executor=localhost:3030 \
      --remote_cache=localhost:3030 \
      --strategy=Javac=remote \
      --remote_local_fallback=false \
      --remote_timeout=600 \
      //src/main/java/com/example/...

But I got this weird error message:

____Loading package: src/main/java/com/example
____Loading package: @bazel_tools//tools/cpp
____Loading package: @local_jdk//
____Loading package: @local_config_xcode//
____Loading package: @local_config_cc//
____Loading complete.  Analyzing...
____Loading package: tools/defaults
____Loading package: @bazel_tools//third_party/java/jdk/langtools
____Loading package: @junit//jar
____Found 1 test target...
____Building...
____[0 / 2] BazelWorkspaceStatusAction stable-status.txt
____[2 / 4] Creating source manifest for //src/main/java/com/example:my_test
____From Extracting interface @junit//jar:jar:
/tmp/test/build-80057300-ffd2-49ea-a20b-3f234d9963db/external/bazel_tools/tools/jdk/ijar/ijar: 1: /tmp/test/build-80057300-ffd2-49ea-a20b-3f234d9963db/external/bazel_tools/tools/jdk/ijar/ijar: �����0��!H__PAGEZEROx__TEXTpp__text__TEXT/��__stubs__TEXT0p�__stub_helper__TEXT���__gcc_except_tab__TEXT�: not found
/tmp/test/build-80057300-ffd2-49ea-a20b-3f234d9963db/external/bazel_tools/tools/jdk/ijar/ijar: 2: /tmp/test/build-80057300-ffd2-49ea-a20b-3f234d9963db/external/bazel_tools/tools/jdk/ijar/ijar: Syntax error: word unexpected (expecting ")")
ERROR: /private/var/tmp/_bazel_ors/719f891d5db9fd5e73ade25b0c847fd1/external/junit/jar/BUILD.bazel:2:1: output 'external/junit/jar/_ijar/jar/external/junit/jar/junit-4.12-ijar.jar' was not created.
ERROR: /private/var/tmp/_bazel_ors/719f891d5db9fd5e73ade25b0c847fd1/external/junit/jar/BUILD.bazel:2:1: not all outputs were created or valid.
____Building complete.
Target //src/main/java/com/example:my_test failed to build
Use --verbose_failures to see the command lines of failed build steps.
____Elapsed time: 13.614s, Critical Path: 0.21s

Am I doing anything wrong? Do I need to run it differently when running the remote worker on an actual (or virtual) remote machine (vs. just running it locally)?

---

Important to mention: my machine is mac osx sierra. , I believe that docker openjdk:8 is ubuntu based, I'm running locally bazel development version (sha 956810b6ee24289e457a4b8d0a84ff56eb32c264).

Answer 1

Running the remote worker on a different architecture / OS combination than Bazel itself isn't working yet. We still have a couple of places in Bazel where we inspect the local machine - they were added as temporary measures, but haven't been fixed yet.

Edit: It may work in some cases, especially for platform-independent code (e.g., Java or Scala).

If your build is test-heavy, you could try only running tests remotely with --test_strategy=remote; I'm not sure if the default Jvm configuration will work, though.

If you want to run the entire build remotely, then you need to tell Bazel what kind of machines / OS it's executing on. Right now, that'd require setting --host_cpu, and probably --crosstool_top / --host_crosstool_top to configure a C++ compiler for that platform.

Also, some combinations of platforms are more and some less likely to work. In particular, combining MacOS and Linux or different flavors of Linux are much more likely to work than Windows in any combination.