CHANGE(server): Remove gRPC implementation

The gRPC implementation never left the experimental state and never
reached a properly stable state to the point where we would feel good
about enabling it by default. In addition to that, there has been no
further attempts at finding and fixing the encountered issues in the
implementation (except #3947 but that was discontinued).

As such we had an essentially unmaintained piece of code in our server
implementation that was known to be buggy and that nobody wanted to fix.
In addition to that the implementation itself could not be considered
very clean or elegant and therefore only represented a few smelly
corners in our code base.

For this reason, we decided to remove the gRPC support entirely from
Mumble (for now).

What we hope to gain by that is:
- Prevent people from building unstable server versions and then coming
to us complaining that it crashed/misbehaved
- Removing (essentially) dead code
- Reduce the RPC implementation complexity

That last piece is crucial: By removing gRPC support we reduce the
amount of supported RPC frameworks to only one (ignoring DBus for now).
Our future plans include a refactoring of how RPC is being handled and
implemented and only having to worry about maintaining compatibility
with one RPC system is much easier than having to worry about two (with
(slightly) different APIs).
Once the RPC implementation has been rewritten, more RPC backends may be
reintroduced and in that process we might investigate adding a proper
gRPC implementation to the code (that then hopefully is more stable than
the current one).

Fixes #4567
Fixes #4197
Fixes #3496
Fixes #3429
Fixes #3265

4 files changed, 0 insertions, 10 deletions

diff --git a/docs/dev/TheMumbleSourceCode.md b/docs/dev/TheMumbleSourceCode.md
index 204c88442..23389c9f2 100644
--- a/docs/dev/TheMumbleSourceCode.md
+++ b/docs/dev/TheMumbleSourceCode.md
@@ -43,7 +43,6 @@ When cloning the repo, the source tree should look something like this:
 │   ├── mumble
 │   ├── mumble_exe
 │   ├── murmur
-│   ├── murmur_grpcwrapper_protoc_plugin
 │   └── tests
 └── themes
     └── Default
diff --git a/docs/dev/build-instructions/build_linux.md b/docs/dev/build-instructions/build_linux.md
index 11c2c4914..dd57fad02 100644
--- a/docs/dev/build-instructions/build_linux.md
+++ b/docs/dev/build-instructions/build_linux.md
@@ -36,9 +36,6 @@ sudo apt install \
   g++-multilib
 ```
 
-If you intend to include grpc-support for the Mumble server (murmur), you also have to install the following packages: `libgrpc++-dev` and
-`protobuf-compiler-grpc`
-
 The dependence on `g++-multilib` only applies if you are on a 64bit system and want to cross-compile overlay support for 32bit applications as well
 (which is enabled by default). If you don't do this (`-Doverlay-xcompile=OFF` when invoking cmake), you also don't have to install `g++-multilib`.
 
diff --git a/docs/dev/build-instructions/build_static.md b/docs/dev/build-instructions/build_static.md
index ccc262156..d551cde95 100644
--- a/docs/dev/build-instructions/build_static.md
+++ b/docs/dev/build-instructions/build_static.md
@@ -46,7 +46,6 @@ qt5-base
 qt5-svg
 qt5-tools
 qt5-translations
-grpc
 boost-accumulators
 opus
 poco
diff --git a/docs/dev/build-instructions/cmake_options.md b/docs/dev/build-instructions/cmake_options.md
index b39525106..9c4c45c82 100644
--- a/docs/dev/build-instructions/cmake_options.md
+++ b/docs/dev/build-instructions/cmake_options.md
@@ -99,11 +99,6 @@ Build the g15helper executable in emulator mode. This will cause an emulated G15
 Build support for Logitech G-Keys. Note: This feature does not require any build-time dependencies, and requires Logitech Gaming Software to be installed to have any effect at runtime.
 (Default: ON)
 
-### grpc
-
-Build support for gRPC.
-(Default: OFF)
-
 ### ice
 
 Build support for Ice RPC.