Stop using undecorated python scripts from bash.

scion.sh was still using togen.py, topodot.py and set_ipv6_addr.py
directly; with the consequence that any significant deviation between the
python environment in the build tree and that of the global environment could
cause these tools to fail.

Instead, we now produce py_binaries for these three tools, install them in
bin/, and use them from there.

To make them work when not invoked from bazel, we have to package them as self
contained executables, which is achieved by adding the --build_python_zip
command line flag. Suprisingly, this is the only method available. There isn't
even an equivalent parameter to the py_binary rule. All other workarounds turn
out to do crazy things (e.g. pkg_tar with the "include_run_files" option
produces non-sense). The tools are requested as part of make all.

Another case of calling python scripts outside bazel was
router_benchmark/benchmark.py. For that one, I arranged so it can be invoked
through bazel (like its twin brother test.py) instead of only from the command
line.

.bazelrc

@@ -18,6 +18,7 @@ build --incompatible_default_to_explicit_init_py
 # Enable resolution of cc toolchain by go toolchain
 build --incompatible_enable_cc_toolchain_resolution
 build --flag_alias=file_name_version=//:file_name_version
+build --build_python_zip
 
 # include one of "--define gotags=sqlite_mattn" or "--define gotags=sqlite_modernc"
 # cannot be in common, because query chokes on it.

BUILD.bazel

@@ -213,10 +213,11 @@ pkg_tar(
 pkg_tar(
     name = "scion-topo",
     srcs = [
-        "//scion-pki/cmd/scion-pki",
+        "//tools:set_ipv6_addr",
+        "//tools:topodot",
+        "//tools:topogen",
     ],
     mode = "0755",
-    package_dir = "",
 )
 
 # Nogo - Go code analysis tool

Makefile

@@ -2,9 +2,10 @@
 
 build-dev:
 	rm -f bin/*
-	bazel build //:scion //:scion-ci
+	bazel build //:scion //:scion-ci //:scion-topo
 	tar -kxf bazel-bin/scion.tar -C bin
 	tar -kxf bazel-bin/scion-ci.tar -C bin
+	tar -kxf bazel-bin/scion-topo.tar -C bin
 
 build:
 	rm -f bin/*
@@ -75,10 +76,6 @@ docker-images:
 	@echo "Load images"
 	@bazel cquery '//docker:prod union //docker:test' --output=files 2>/dev/null | xargs -I{} docker load --input {}
 
-scion-topo:
-	bazel build //:scion-topo
-	tar --overwrite -xf bazel-bin/scion-topo.tar -C bin
-
 protobuf:
 	rm -rf bazel-bin/pkg/proto/*/go_default_library_/github.com/scionproto/scion/pkg/proto/*
 	bazel build --output_groups=go_generated_srcs //pkg/proto/...

acceptance/router_benchmark/BUILD.bazel

@@ -53,6 +53,13 @@ py_library(
 py_binary(
     name = "benchmark",
     srcs = ["benchmark.py"],
+    args = [
+        "--brload",
+        "$(location //acceptance/router_benchmark/brload:brload)",
+    ],
+    data = [
+        "//acceptance/router_benchmark/brload",
+    ],
     visibility = ["//visibility:public"],
     deps = [
         "benchmarklib",

acceptance/router_benchmark/benchmark.py

@@ -86,19 +86,22 @@ class RouterBMTool(cli.Application, RouterBM):
     log_level = cli.SwitchAttr(["l", "loglevel"], str, default='warning', help="Logging level")
 
     doit = cli.Flag(["r", "run"],
-                    help="Run the benchmark, as opposed to seeing the instructions.")
+                    help="Run the benchmark, as opposed to seeing the instructions")
     json = cli.Flag(["j", "json"],
-                    help="Output the report in json format.")
+                    help="Output the report in json format")
 
     # Used by the RouterBM mixin:
     coremark = cli.SwitchAttr(["c", "coremark"], int, default=0,
-                              help="The coremark score of the subject machine.")
+                              help="The coremark score of the subject machine")
     mmbm = cli.SwitchAttr(["m", "mmbm"], int, default=0,
-                          help="The mmbm score of the subject machine.")
+                          help="The mmbm score of the subject machine")
     packet_size = cli.SwitchAttr(["s", "size"], int, default=172,
-                                 help="Test packet size (includes all headers - floored at 154).")
+                                 help="Test packet size (includes all headers - floored at 154)")
+    brload_path = cli.SwitchAttr(["b", "brload"], str, default="bin/brload",
+                                 help="Relative path to the brload tool")
+
     intf_map: dict[str, Intf] = {}
-    brload: LocalCommand = local["./bin/brload"]
+    brload: LocalCommand = None
     brload_cpus: list[int] = []
     artifacts = f"{os.getcwd()}/acceptance/router_benchmark"
     prom_address: str = "localhost:9090"
@@ -332,6 +335,9 @@ def instructions(self):
 """)
 
     def main(self, *interfaces: str):
+        # brload cannot be set statically. It need the cli arguments to be
+        # processed.
+        self.brload = local[self.brload_path]
         status = 1
         try:
             logging.basicConfig(level=self.log_level.upper())

scion.sh

@@ -23,11 +23,11 @@ cmd_topology() {
     cmd_topo-clean
 
     echo "Create topology, configuration, and execution files."
-    tools/topogen.py "$@"
+    ./bin/topogen "$@"
 }
 
 cmd_topodot() {
-    ./tools/topodot.py "$@"
+    ./bin/topodot "$@"
 }
 
 start_scion() {

tools/BUILD.bazel

@@ -45,3 +45,34 @@ py_binary(
         requirement("pyyaml"),
     ],
 )
+
+py_binary(
+    name = "topodot",
+    srcs = ["topodot.py"],
+    data = [
+    ],
+    main = "topodot.py",
+    python_version = "PY3",
+    srcs_version = "PY3",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//tools/topology:py_default_library",
+        "@bazel_tools//tools/python/runfiles",
+        requirement("plumbum"),
+    ],
+)
+
+py_binary(
+    name = "set_ipv6_addr",
+    srcs = ["set_ipv6_addr.py"],
+    data = [
+    ],
+    main = "set_ipv6_addr.py",
+    python_version = "PY3",
+    srcs_version = "PY3",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//tools/topology:py_default_library",
+        "@bazel_tools//tools/python/runfiles",
+    ],
+)