Build Utils examples in Bazel (#157)

Signed-off-by: Michael Carroll <mjcarroll@intrinsic.ai>

BUILD.bazel

@@ -36,6 +36,7 @@ cc_library(
     srcs = ["src/Environment.cc"],
     hdrs = ["include/gz/utils/Environment.hh"],
     includes = ["include"],
+    visibility = ["//visibility:public"],
     deps = [
         ":Config",
         ":Export",

cli/BUILD.bazel

@@ -1,12 +1,6 @@
-load("@rules_license//rules:license.bzl", "license")
-
 package(
     default_applicable_licenses = ["//:license"],
-)
-
-license(
-    name = "license",
-    package_name = "gz-utils-cli",
+    default_visibility = ["__subpackages__"],
 )
 
 cc_library(
@@ -23,6 +17,7 @@ cc_library(
         "include/gz/utils/cli/GzFormatter.hpp",
     ],
     includes = ["include"],
+    visibility = ["//visibility:public"],
     deps = [
         "//:Export",
     ],

examples/BUILD.bazel

@@ -0,0 +1,21 @@
+package(
+    default_applicable_licenses = ["//:license"],
+    default_visibility = ["//visibility:private"],
+)
+
+cc_binary(
+    name = "log",
+    srcs = ["log/main.cc"],
+    deps = [
+        "//log:Logger",
+    ],
+)
+
+cc_binary(
+    name = "using_cli",
+    srcs = ["using_cli/main.cc"],
+    deps = [
+        "//:Config",
+        "//cli",
+    ],
+)

log/BUILD.bazel

@@ -1,13 +1,8 @@
 load("@rules_gazebo//gazebo:headers.bzl", "gz_export_header")
-load("@rules_license//rules:license.bzl", "license")
 
 package(
     default_applicable_licenses = ["//:license"],
-)
-
-license(
-    name = "license",
-    package_name = "gz-utils-log",
+    default_visibility = ["__subpackages__"],
 )
 
 gz_export_header(
@@ -26,6 +21,7 @@ cc_library(
         "include/gz/utils/log/SplitSink.hh",
     ],
     includes = ["include"],
+    visibility = ["//visibility:public"],
     deps = [
         ":Export",
         "//:Config",
@@ -43,6 +39,7 @@ cc_library(
         "include/gz/utils/log/Logger.hh",
     ],
     includes = ["include"],
+    visibility = ["//visibility:public"],
     deps = [":SplitSink"],
 )
 
@@ -58,6 +55,7 @@ cc_library(
 cc_test(
     name = "SplitSink_TEST",
     srcs = ["src/SplitSink_TEST.cc"],
+    visibility = ["//visibility:public"],
     deps = [
         ":log",
         "@googletest//:gtest_main",