Add tracing support (#1)

Co-authored-by: Thor Anker Kvisgård Lange <[email protected]>

README.md

@@ -16,6 +16,9 @@ The application will listen for requests on three endpoints:
 `/echo/`
   a simple echo server sending any incomming input back to the requestor
 
+`/entropy/`
+  a server emulating having multiple dependencies on other services
+
 Besides this the application exposes the Go [pprof](https://golang.org/pkg/net/http/pprof/) allowing runtime profiling and more. This is served on the default path of `/debug/pprof`.
 
 
@@ -44,7 +47,7 @@ bazel run --platforms=@io_bazel_rules_go//go/toolchain:linux_amd64 //cmd/jytte:d
 Update Bazel dependencies generated from `go.mod`:
 
 ```bash
-bazel run //:gazelle -- update-repos -from_file=go.mod -to_macro=deps.bzl%go_dependencies -build_file_proto_mode=disable_global
+bazel run //:gazelle -- update-repos -from_file=go.mod -to_macro=deps.bzl%go_dependencies
 ```
 
 Update the Bazel build files:

WORKSPACE

@@ -1,4 +1,5 @@
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
 
 http_archive(
     name = "io_bazel_rules_go",
@@ -47,6 +48,34 @@ container_pull(
     digest = "sha256:59b46c319f3b66dfda96faafd0c6959e9b2f409792d0236204f270dfd0235960",
 )
 
+#
+# Protobuf needed by OTEL
+#
+
+http_archive(
+    name = "rules_proto",
+    sha256 = "602e7161d9195e50246177e7c55b2f39950a9cf7366f74ed5f22fd45750cd208",
+    strip_prefix = "rules_proto-97d8af4dc474595af3900dd85cb3a29ad28cc313",
+    urls = [
+        "https://mirror.bazel.build/github.com/bazelbuild/rules_proto/archive/97d8af4dc474595af3900dd85cb3a29ad28cc313.tar.gz",
+        "https://github.com/bazelbuild/rules_proto/archive/97d8af4dc474595af3900dd85cb3a29ad28cc313.tar.gz",
+    ],
+)
+
+load("@rules_proto//proto:repositories.bzl", "rules_proto_dependencies", "rules_proto_toolchains")
+rules_proto_dependencies()
+rules_proto_toolchains()
+
+git_repository(
+    name = "com_google_protobuf",
+    commit = "09745575a923640154bcf307fba8aedff47f240a",
+    remote = "https://github.com/protocolbuffers/protobuf",
+    shallow_since = "1558721209 -0700",
+)
+
+load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
+protobuf_deps()
+
 load("@bazel_gazelle//:deps.bzl", "gazelle_dependencies")
 gazelle_dependencies()