Disable bazel build for gcc 4.8, upgrade versions for grpc and bazel, document bazel support

.bazelrc

@@ -22,3 +22,4 @@ common:tsan --cc_output_directory_tag=tsan
 # This is needed to address false positive problem with abseil.The same setting as gRPC
 # https://github.com/google/sanitizers/issues/953
 common:tsan --test_env=TSAN_OPTIONS=report_atomic_races=0
+

.bazelversion

@@ -1 +1 @@
-3.7.2
+4.2.0

.github/workflows/ci.yml

@@ -128,30 +128,6 @@ jobs:
     - name: run tests
       run: ./ci/do_ci.sh cmake.test_example_plugin
 
-  bazel_gcc_48_test:
-    name: Bazel gcc 4.8
-    runs-on: ubuntu-18.04
-    steps:
-    - uses: actions/checkout@v2
-      with:
-        submodules: 'recursive'
-    - name: Mount Bazel Cache
-      uses: actions/cache@v2
-      env:
-        cache-name: bazel_cache
-      with:
-        path: /home/runner/.cache/bazel
-        key: bazel_gcc_48_test
-    - name: setup
-      run: |
-        sudo ./ci/setup_ci_environment.sh
-        sudo ./ci/install_bazelisk.sh
-        sudo ./ci/install_gcc48.sh
-    - name: run tests
-      run: ./ci/do_ci.sh bazel.legacy.test
-      env:
-        CC: /usr/bin/gcc-4.8
-
   bazel_test:
     name: Bazel
     runs-on: ubuntu-latest
@@ -272,7 +248,7 @@ jobs:
         path: /Users/runner/.cache/bazel
         key: bazel_osx
     - name: run tests
-      run: ./ci/do_ci.sh bazel.test
+      run: ./ci/do_ci.sh bazel.macos.test
 
   benchmark:
     name: Benchmark

INSTALL.md

@@ -133,6 +133,8 @@ target_link_libraries(foo PRIVATE ${OPENTELEMETRY_CPP_LIBRARIES})
 
 ## Build instructions using Bazel
 
+NOTE: Experimental, and not supported for all the components.
+
 ### Prerequisites for Bazel
 
 - A supported platform (e.g. Windows, macOS or Linux).

README.md

@@ -47,11 +47,16 @@ of the current project.
 
  Our CI pipeline builds and tests on following `x86-64` platforms:
 
-* ubuntu-18.04 (Default GCC Compiler - 7.5.0)
-* ubuntu-18.04 (GCC 4.8 with -std=c++11 flag)
-* ubuntu-20.04 (Default GCC Compiler - 9.3.0 with -std=c++20 flags)
-* macOS 10.15 (Xcode 12.2)
-* Windows Server 2019 (Visual Studio Enterprise 2019)
+| Platform                                                            |   Build type  |
+|---------------------------------------------------------------------|---------------|
+| ubuntu-18.04 (Default GCC Compiler - 7.5.0)                         | CMake, Bazel  |
+| ubuntu-18.04 (GCC 4.8 with -std=c++11 flag)                         | CMake [1]     |
+| ubuntu-20.04 (Default GCC Compiler - 9.3.0 with -std=c++20 flags)   | CMake, Bazel  |
+| macOS 10.15 (Xcode 12.2)                                            | Bazel         |
+| Windows Server 2019 (Visual Studio Enterprise 2019)                 | CMake, Bazel  |
+
+[1]: Bazel build is disabled for GCC 4.8, as GRPC library ( required by OTLP expoter)
+  doesn't build with this compiler. CMake build won't build OTLP exporter with GCC 4.8.
 
 In general, the code shipped from this repository should build on all platforms
 having C++ compiler with [supported C++ standards](#supported-c-versions).

bazel/repository.bzl

@@ -32,20 +32,20 @@ def opentelemetry_cpp_deps():
     maybe(
         http_archive,
         name = "com_github_grpc_grpc_legacy",
-        sha256 = "2060769f2d4b0d3535ba594b2ab614d7f68a492f786ab94b4318788d45e3278a",
-        strip_prefix = "grpc-1.33.2",
+        sha256 = "024118069912358e60722a2b7e507e9c3b51eeaeee06e2dd9d95d9c16f6639ec",
+        strip_prefix = "grpc-1.39.1",
         urls = [
-            "https://github.com/grpc/grpc/archive/v1.33.2.tar.gz",
+            "https://github.com/grpc/grpc/archive/v1.39.1.tar.gz",
         ],
     )
 
     maybe(
         http_archive,
         name = "com_github_grpc_grpc",
-        sha256 = "2060769f2d4b0d3535ba594b2ab614d7f68a492f786ab94b4318788d45e3278a",
-        strip_prefix = "grpc-1.33.2",
+        sha256 = "024118069912358e60722a2b7e507e9c3b51eeaeee06e2dd9d95d9c16f6639ec",
+        strip_prefix = "grpc-1.39.1",
         urls = [
-            "https://github.com/grpc/grpc/archive/v1.33.2.tar.gz",
+            "https://github.com/grpc/grpc/archive/v1.39.1.tar.gz",
         ],
     )
 

ci/do_ci.sh

@@ -25,6 +25,11 @@ mkdir -p "${PLUGIN_DIR}"
 
 BAZEL_OPTIONS="--copt=-DENABLE_METRICS_PREVIEW --copt=-DENABLE_LOGS_PREVIEW"
 BAZEL_TEST_OPTIONS="$BAZEL_OPTIONS --test_output=errors"
+
+# https://github.com/bazelbuild/bazel/issues/4341
+BAZEL_MACOS_OPTIONS="$BAZEL_OPRIONS --features=-supports_dynamic_linker"
+BAZEL_MACOS_TEST_OPTIONS="$BAZEL_MACOS_OPTIONS --test_output=errors"
+
 BAZEL_STARTUP_OPTIONS="--output_user_root=$HOME/.cache/bazel"
 
 export CTEST_OUTPUT_ON_FAILURE=1
@@ -158,6 +163,10 @@ elif [[ "$1" == "bazel.test" ]]; then
   bazel $BAZEL_STARTUP_OPTIONS build $BAZEL_OPTIONS //...
   bazel $BAZEL_STARTUP_OPTIONS test $BAZEL_TEST_OPTIONS //...
   exit 0
+elif [[ "$1" == "bazel.macos.test" ]]; then
+  bazel $BAZEL_STARTUP_OPTIONS build $BAZEL_MACOS_OPTIONS //...
+  bazel $BAZEL_STARTUP_OPTIONS test $BAZEL_MACOS_TEST_OPTIONS //...
+  exit 0
 elif [[ "$1" == "bazel.legacy.test" ]]; then
   # we uses C++ future and async() function to test the Prometheus Exporter functionality,
   # that make this test always fail. ignore Prometheus exporter here.

ci/install_bazelisk.sh

@@ -5,7 +5,7 @@
 
 set -e
 
-BAZELISK_VERSION=v1.7.4
+BAZELISK_VERSION=v1.10.1
 
 wget -O /usr/local/bin/bazel https://github.com/bazelbuild/bazelisk/releases/download/$BAZELISK_VERSION/bazelisk-linux-amd64
 chmod +x /usr/local/bin/bazel

ci/setup_grpc.sh

@@ -6,7 +6,7 @@
 set -e
 export DEBIAN_FRONTEND=noninteractive
 old_grpc_version='v1.33.2'
-new_grpc_version='v1.39.0'
+new_grpc_version='v1.39.1'
 gcc_version_for_new_grpc='5.1'
 install_grpc_version=${new_grpc_version}
 grpc_version='v1.39.0'