Create a bazel rule to print Envoy's dependencies

.gitignore

@@ -21,3 +21,4 @@ TAGS
 .vimrc
 .vs
 .vscode
+*.bzlc

api/bazel/BUILD

@@ -0,0 +1 @@
+exports_files(["repository_locations.bzl"])

api/bazel/envoy_http_archive.bzl

@@ -0,0 +1,33 @@
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+load(":repository_locations.bzl", "REPOSITORY_LOCATIONS")
+
+def envoy_http_archive(name, repository_locations = REPOSITORY_LOCATIONS, **kwargs):
+    # `existing_rule_keys` contains the names of repositories that have already
+    # been defined in the Bazel workspace. By skipping repos with existing keys,
+    # users can override dependency versions by using standard Bazel repository
+    # rules in their WORKSPACE files.
+    existing_rule_keys = native.existing_rules().keys()
+    if name in existing_rule_keys:
+        # This repository has already been defined, probably because the user
+        # wants to override the version. Do nothing.
+        return
+
+    loc_key = kwargs.pop("repository_key", name)
+    location = repository_locations[loc_key]
+
+    # Git tags are mutable. We want to depend on commit IDs instead. Give the
+    # user a useful error if they accidentally specify a tag.
+    if "tag" in location:
+        fail(
+            "Refusing to depend on Git tag %r for external dependency %r: use 'commit' instead." %
+            (location["tag"], name),
+        )
+
+    # HTTP tarball at a given URL. Add a BUILD file if requested.
+    http_archive(
+        name = name,
+        urls = location["urls"],
+        sha256 = location["sha256"],
+        strip_prefix = location.get("strip_prefix", ""),
+        **kwargs
+    )

api/bazel/repositories.bzl

@@ -1,43 +1,47 @@
-BAZEL_SKYLIB_RELEASE = "0.5.0"
-BAZEL_SKYLIB_SHA256 = "b5f6abe419da897b7901f90cbab08af958b97a8f3575b0d3dd062ac7ce78541f"
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+load(":envoy_http_archive.bzl", "envoy_http_archive")
 
-GOGOPROTO_RELEASE = "1.1.1"
-GOGOPROTO_SHA256 = "9f8c2ad49849ab063cd9fef67e77d49606640044227ecf7f3617ea2c92ef147c"
+PROMETHEUSMETRICS_BUILD_CONTENT = """
+load("@envoy_api//bazel:api_build_system.bzl", "api_proto_library")
+load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
 
-PGV_RELEASE = "0.0.11"
-PGV_SHA256 = "d92c7f22929f495cf9f7d825c44f9190eda1d8256af321e3e8692570181b28a6"
+api_proto_library(
+    name = "client_model",
+    srcs = [
+        "metrics.proto",
+    ],
+    visibility = ["//visibility:public"],
+)
 
-GOOGLEAPIS_GIT_SHA = "d642131a6e6582fc226caf9893cb7fe7885b3411"  # May 23, 2018
-GOOGLEAPIS_SHA = "16f5b2e8bf1e747a32f9a62e211f8f33c94645492e9bbd72458061d9a9de1f63"
+go_proto_library(
+    name = "client_model_go_proto",
+    importpath = "client_model",
+    proto = ":client_model",
+    visibility = ["//visibility:public"],
+)
+"""
 
-PROMETHEUS_GIT_SHA = "99fa1f4be8e564e8a6b613da7fa6f46c9edafc6c"  # Nov 17, 2017
-PROMETHEUS_SHA = "783bdaf8ee0464b35ec0c8704871e1e72afa0005c3f3587f65d9d6694bf3911b"
+OPENCENSUSTRACE_BUILD_CONTENT = """
+load("@envoy_api//bazel:api_build_system.bzl", "api_proto_library")
+load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
 
-OPENCENSUS_GIT_SHA = "ab82e5fdec8267dc2a726544b10af97675970847"  # May 23, 2018
-OPENCENSUS_SHA = "1950f844d9f338ba731897a9bb526f9074c0487b3f274ce2ec3b4feaf0bef7e2"
+api_proto_library(
+    name = "trace_model",
+    srcs = [
+        "trace.proto",
+    ],
+    visibility = ["//visibility:public"],
+)
 
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+go_proto_library(
+    name = "trace_model_go_proto",
+    importpath = "trace_model",
+    proto = ":trace_model",
+    visibility = ["//visibility:public"],
+)
+"""
 
-def api_dependencies():
-    http_archive(
-        name = "bazel_skylib",
-        sha256 = BAZEL_SKYLIB_SHA256,
-        strip_prefix = "bazel-skylib-" + BAZEL_SKYLIB_RELEASE,
-        url = "https://github.com/bazelbuild/bazel-skylib/archive/" + BAZEL_SKYLIB_RELEASE + ".tar.gz",
-    )
-    http_archive(
-        name = "com_lyft_protoc_gen_validate",
-        sha256 = PGV_SHA256,
-        strip_prefix = "protoc-gen-validate-" + PGV_RELEASE,
-        url = "https://github.com/lyft/protoc-gen-validate/archive/v" + PGV_RELEASE + ".tar.gz",
-    )
-    http_archive(
-        name = "googleapis",
-        strip_prefix = "googleapis-" + GOOGLEAPIS_GIT_SHA,
-        url = "https://github.com/googleapis/googleapis/archive/" + GOOGLEAPIS_GIT_SHA + ".tar.gz",
-        # TODO(dio): Consider writing a Skylark macro for importing Google API proto.
-        sha256 = GOOGLEAPIS_SHA,
-        build_file_content = """
+GOOGLEAPIS_BUILD_CONTENT = """
 load("@com_google_protobuf//:protobuf.bzl", "cc_proto_library", "py_proto_library")
 load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
 
@@ -52,8 +56,8 @@ filegroup(
 proto_library(
     name = "api_httpbody_protos_proto",
     srcs = [":api_httpbody_protos_src"],
-    deps = ["@com_google_protobuf//:descriptor_proto"],
     visibility = ["//visibility:public"],
+    deps = ["@com_google_protobuf//:descriptor_proto"],
 )
 
 cc_proto_library(
@@ -63,8 +67,8 @@ cc_proto_library(
     ],
     default_runtime = "@com_google_protobuf//:protobuf",
     protoc = "@com_google_protobuf//:protoc",
-    deps = ["@com_google_protobuf//:cc_wkt_protos"],
     visibility = ["//visibility:public"],
+    deps = ["@com_google_protobuf//:cc_wkt_protos"],
 )
 
 py_proto_library(
@@ -85,7 +89,7 @@ go_proto_library(
     proto = ":api_httpbody_protos_proto",
     visibility = ["//visibility:public"],
     deps = [
-      ":descriptor_go_proto",
+        ":descriptor_go_proto",
     ],
 )
 
@@ -108,8 +112,8 @@ go_proto_library(
 proto_library(
     name = "http_api_protos_proto",
     srcs = [":http_api_protos_src"],
-    deps = ["@com_google_protobuf//:descriptor_proto"],
     visibility = ["//visibility:public"],
+    deps = ["@com_google_protobuf//:descriptor_proto"],
 )
 
 cc_proto_library(
@@ -120,8 +124,8 @@ cc_proto_library(
     ],
     default_runtime = "@com_google_protobuf//:protobuf",
     protoc = "@com_google_protobuf//:protoc",
-    deps = ["@com_google_protobuf//:cc_wkt_protos"],
     visibility = ["//visibility:public"],
+    deps = ["@com_google_protobuf//:cc_wkt_protos"],
 )
 
 py_proto_library(
@@ -143,34 +147,34 @@ go_proto_library(
     proto = ":http_api_protos_proto",
     visibility = ["//visibility:public"],
     deps = [
-      ":descriptor_go_proto",
+        ":descriptor_go_proto",
     ],
 )
 
 filegroup(
-     name = "rpc_status_protos_src",
-     srcs = [
-         "google/rpc/status.proto",
-     ],
-     visibility = ["//visibility:public"],
+    name = "rpc_status_protos_src",
+    srcs = [
+        "google/rpc/status.proto",
+    ],
+    visibility = ["//visibility:public"],
 )
 
 proto_library(
-     name = "rpc_status_protos_lib",
-     srcs = [":rpc_status_protos_src"],
-     deps = ["@com_google_protobuf//:any_proto"],
-     visibility = ["//visibility:public"],
+    name = "rpc_status_protos_lib",
+    srcs = [":rpc_status_protos_src"],
+    visibility = ["//visibility:public"],
+    deps = ["@com_google_protobuf//:any_proto"],
 )
 
 cc_proto_library(
-     name = "rpc_status_protos",
-     srcs = ["google/rpc/status.proto"],
-     default_runtime = "@com_google_protobuf//:protobuf",
-     protoc = "@com_google_protobuf//:protoc",
-     deps = [
-         "@com_google_protobuf//:cc_wkt_protos"
-     ],
-     visibility = ["//visibility:public"],
+    name = "rpc_status_protos",
+    srcs = ["google/rpc/status.proto"],
+    default_runtime = "@com_google_protobuf//:protobuf",
+    protoc = "@com_google_protobuf//:protoc",
+    visibility = ["//visibility:public"],
+    deps = [
+        "@com_google_protobuf//:cc_wkt_protos",
+    ],
 )
 
 go_proto_library(
@@ -179,30 +183,24 @@ go_proto_library(
     proto = ":rpc_status_protos_lib",
     visibility = ["//visibility:public"],
     deps = [
-      "@com_github_golang_protobuf//ptypes/any:go_default_library",
+        "@com_github_golang_protobuf//ptypes/any:go_default_library",
     ],
 )
 
 py_proto_library(
-     name = "rpc_status_protos_py",
-     srcs = [
-         "google/rpc/status.proto",
-     ],
-     include = ".",
-     default_runtime = "@com_google_protobuf//:protobuf_python",
-     protoc = "@com_google_protobuf//:protoc",
-     visibility = ["//visibility:public"],
-     deps = ["@com_google_protobuf//:protobuf_python"],
+    name = "rpc_status_protos_py",
+    srcs = [
+        "google/rpc/status.proto",
+    ],
+    include = ".",
+    default_runtime = "@com_google_protobuf//:protobuf_python",
+    protoc = "@com_google_protobuf//:protoc",
+    visibility = ["//visibility:public"],
+    deps = ["@com_google_protobuf//:protobuf_python"],
 )
-""",
-    )
+"""
 
-    http_archive(
-        name = "com_github_gogo_protobuf",
-        sha256 = GOGOPROTO_SHA256,
-        strip_prefix = "protobuf-" + GOGOPROTO_RELEASE,
-        url = "https://github.com/gogo/protobuf/archive/v" + GOGOPROTO_RELEASE + ".tar.gz",
-        build_file_content = """
+GOGOPROTO_BUILD_CONTENT = """
 load("@com_google_protobuf//:protobuf.bzl", "cc_proto_library", "py_proto_library")
 load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
 
@@ -211,10 +209,10 @@ proto_library(
     srcs = [
         "gogoproto/gogo.proto",
     ],
+    visibility = ["//visibility:public"],
     deps = [
         "@com_google_protobuf//:descriptor_proto",
     ],
-    visibility = ["//visibility:public"],
 )
 
 go_proto_library(
@@ -231,8 +229,8 @@ cc_proto_library(
     ],
     default_runtime = "@com_google_protobuf//:protobuf",
     protoc = "@com_google_protobuf//:protoc",
-    deps = ["@com_google_protobuf//:cc_wkt_protos"],
     visibility = ["//visibility:public"],
+    deps = ["@com_google_protobuf//:cc_wkt_protos"],
 )
 
 go_proto_library(
@@ -254,58 +252,24 @@ py_proto_library(
     protoc = "@com_google_protobuf//:protoc",
     visibility = ["//visibility:public"],
     deps = ["@com_google_protobuf//:protobuf_python"],
-)
-        """,
-    )
+)"""
 
-    http_archive(
+def api_dependencies():
+    envoy_http_archive("bazel_skylib")
+    envoy_http_archive("com_lyft_protoc_gen_validate")
+    envoy_http_archive(
+        name = "googleapis",
+        build_file_content = GOOGLEAPIS_BUILD_CONTENT,
+    )
+    envoy_http_archive(
+        name = "com_github_gogo_protobuf",
+        build_file_content = GOGOPROTO_BUILD_CONTENT,
+    )
+    envoy_http_archive(
         name = "prometheus_metrics_model",
-        strip_prefix = "client_model-" + PROMETHEUS_GIT_SHA,
-        url = "https://github.com/prometheus/client_model/archive/" + PROMETHEUS_GIT_SHA + ".tar.gz",
-        sha256 = PROMETHEUS_SHA,
-        build_file_content = """
-load("@envoy_api//bazel:api_build_system.bzl", "api_proto_library")
-load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
-
-api_proto_library(
-    name = "client_model",
-    srcs = [
-        "metrics.proto",
-    ],
-    visibility = ["//visibility:public"],
-)
-
-go_proto_library(
-    name = "client_model_go_proto",
-    importpath = "client_model",
-    proto = ":client_model",
-    visibility = ["//visibility:public"],
-)
-        """,
+        build_file_content = PROMETHEUSMETRICS_BUILD_CONTENT,
     )
-
-    http_archive(
+    envoy_http_archive(
         name = "io_opencensus_trace",
-        strip_prefix = "opencensus-proto-" + OPENCENSUS_GIT_SHA + "/opencensus/proto/trace",
-        url = "https://github.com/census-instrumentation/opencensus-proto/archive/" + OPENCENSUS_GIT_SHA + ".tar.gz",
-        sha256 = OPENCENSUS_SHA,
-        build_file_content = """
-load("@envoy_api//bazel:api_build_system.bzl", "api_proto_library")
-load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
-
-api_proto_library(
-    name = "trace_model",
-    srcs = [
-        "trace.proto",
-    ],
-    visibility = ["//visibility:public"],
-)
-
-go_proto_library(
-    name = "trace_model_go_proto",
-    importpath = "trace_model",
-    proto = ":trace_model",
-    visibility = ["//visibility:public"],
-)
-        """,
+        build_file_content = OPENCENSUSTRACE_BUILD_CONTENT,
     )