Hi All,
We have been working to allow Mesos modules to be built outside the Mesos
source tree (or without the need to build Mesos) and wanted to get some
community feedback. The issue is tracked here:
https://issues.apache.org/jira/browse/MESOS-2096.
Best,
Kapil
Objective: Build Mesos modules by using just the publicly exposed headers.
This necessarily means that a third party contributor would only need to
install the mesos-dev package in order to build a module.
Out of scope: Ideally, we want to ensure version compatibility of various
third-party components (e.g., protobufs and glog) used by Mesos and
modules. One possibility is to create a utility like mesos-config similar
in spirit to python-config that emits configuration options that were used
to build Mesos. The configure script for a third-party module can then
decide upon the compatibility.
Here are the required changes for our objective:
A) Expose some internal protobufs (by putting them in mesos.proto).
Examples of such protobufs include Modules, and any other protobufs needed
by the files being exposed (see B). Along with exposing said protobufs, we
need to expose the corresponding operators definitions that are not
generated by the protobuf compiler (i.e. definitions in
common/type_utils.hpp).
B) Expose Isolator headers (slave/containerizer/isolator.hpp and
slave/state.hpp). Use mesos::slave for isolator.hpp and mesos::slave::state
for state.hpp. Isolator depends on slave/state.hpp and so we need to
expose both. This also requires us to disentangle these two files from the
rest of the code.
C) Expose authentication headers. This is similar in spirit to B.
Next is a list of RRs that address A, B, and C.
A. Expose internal protobufs:
1. Moved Modules protobuf to mesos namespace by moving it into
mesos.proto
(https://reviews.apache.org/r/29598/)
2. Moved Task and StatusUpdate from messages.proto to mesos.proto.
(These protobufs are used by the Isolator header)
(https://reviews.apache.org/r/29600/)
3. Moved authentication messages to mesos.proto.
(https://reviews.apache.org/r/29605)
4. Moved operators for internal protobufs to messages/messages.hpp.
This allows type_utils.hpp to only have operators corresponding to public
protobufs defined in mesos.proto.
(https://reviews.apache.org/r/2978)
5. Exposed type_utils.hpp as include/mesos/type_utils.hpp.
(https://reviews.apache.org/r/29781)
B. Expose Isolator headers:
6. Move mesos::internal::slave::state to mesos::slave::state.
(https://reviews.apache.org/r/29782)
7. Moved mesos::internal::slave::Isolator to mesos::slave namespace.
(https://reviews.apache.org/r/29602)
8. Exposed slave/containerizer/isolator.hpp and slave/state.hpp.
(https://reviews.apache.org/r/29603)
9. Exposed module/isolator.hpp for out-of-tree module building.
Review: https://reviews.apache.org/r/29604
C. Expose authentication headers
10. Exposed authentication headers.
(https://reviews.apache.org/r/29606)
