build: Provide a proper home dir to python tests that run "docker com…

…pose".

This is due to a bug in some version of docker-compose v2 that causes
an unused .cache directory to be created in $HOME. Due to a bug in
Bazel, tests don't have a HOME variable (it should be set to $TEST_TMPDIR
but isn't set at all). So we must provide one ourselves.

My previous work around of using /tmp had the potential of
creating collisions in the future. This method is cleaner. It uses
an output location internal to the test. This is the simplest I could
manage. Tools are supposed to be enablers, but Bazel prefers to be
a disabler it seems.

BUILD.bazel

@@ -245,6 +245,7 @@ updatesrc_update_all(
 write_source_files(
     name = "write_all_source_files",
     additional_update_targets = [
+        "//doc/_build/_static/command:write_files",
         "//doc/command:write_files",
     ],
 )

acceptance/common/raw.bzl

@@ -1,13 +1,19 @@
 load("//tools/lint:py.bzl", "py_binary", "py_library", "py_test")
 load("@com_github_scionproto_scion_python_deps//:requirements.bzl", "requirement")
 
+# Bug in bazel: HOME isn't set to TEST_TMPDIR.
+# Bug in docker-compose v2.21 a writable HOME is required (eventhough not used).
+# Poor design in Bazel, there's no sane way to obtain the path to some
+# location that's not a litteral dependency.
+# So, HOME must be provided by the invoker.
 def raw_test(
         name,
         src,
         args = [],
         deps = [],
         data = [],
         tags = [],
+        homedir = "",
         local = False):
     py_library(
         name = "%s_lib" % name,
@@ -63,6 +69,6 @@ def raw_test(
             "PYTHONUNBUFFERED": "1",
             # Ensure that unicode output can be printed to the log/console
             "PYTHONIOENCODING": "utf-8",
-            "HOME": "/tmp",
+            "HOME": homedir,
         },
     )

acceptance/common/topogen.bzl

@@ -1,6 +1,11 @@
 load("//tools/lint:py.bzl", "py_binary", "py_library", "py_test")
 load("@com_github_scionproto_scion_python_deps//:requirements.bzl", "requirement")
 
+# Bug in bazel: HOME isn't set to TEST_TMPDIR.
+# Bug in docker-compose v2.21 a writable HOME is required (eventhough not used).
+# Poor design in Bazel, there's no sane way to obtain the path to some
+# location that's not a litteral dependency.
+# So, HOME must be provided by the invoker.
 def topogen_test(
         name,
         src,
@@ -10,6 +15,7 @@ def topogen_test(
         args = [],
         deps = [],
         data = [],
+        homedir = "",
         tester = "//docker:tester"):
     """Creates a test based on a topology file.
 
@@ -105,7 +111,7 @@ def topogen_test(
             "PYTHONUNBUFFERED": "1",
             # Ensure that unicode output can be printed to the log/console
             "PYTHONIOENCODING": "utf-8",
-            "HOME": "/tmp",
+            "HOME": homedir,
         },
     )
 

acceptance/router_multi/BUILD.bazel

@@ -30,6 +30,7 @@ raw_test(
         "--bfd",
     ],
     data = data,
+    homedir = "$(rootpath :router)",
     # This test uses sudo and accesses /var/run/netns.
     local = True,
 )
@@ -39,6 +40,7 @@ raw_test(
     src = "test.py",
     args = args,
     data = data,
+    homedir = "$(rootpath :router)",
     # This test uses sudo and accesses /var/run/netns.
     local = True,
 )

acceptance/trc_update/BUILD.bazel

@@ -7,5 +7,6 @@ topogen_test(
         "--executable=end2end_integration:$(location //tools/end2end_integration)",
     ],
     data = ["//tools/end2end_integration"],
+    homedir = "$(rootpath //tools/end2end_integration)",
     topo = "//topology:tiny4.topo",
 )