[runtime tests] Add documentation.

Added a README describing what these tests are, how they work and how to run
them locally. Also reorganized the exclude files into a directory.

PiperOrigin-RevId: 332079697

test/runtimes/BUILD

@@ -5,7 +5,7 @@ package(licenses = ["notice"])
 
 runtime_test(
     name = "go1.12",
-    exclude_file = "exclude_go1.12.csv",
+    exclude_file = "exclude/go1.12.csv",
     lang = "go",
     shard_count = 8,
 )
@@ -13,28 +13,28 @@ runtime_test(
 runtime_test(
     name = "java11",
     batch = 100,
-    exclude_file = "exclude_java11.csv",
+    exclude_file = "exclude/java11.csv",
     lang = "java",
     shard_count = 16,
 )
 
 runtime_test(
     name = "nodejs12.4.0",
-    exclude_file = "exclude_nodejs12.4.0.csv",
+    exclude_file = "exclude/nodejs12.4.0.csv",
     lang = "nodejs",
     shard_count = 8,
 )
 
 runtime_test(
     name = "php7.3.6",
-    exclude_file = "exclude_php7.3.6.csv",
+    exclude_file = "exclude/php7.3.6.csv",
     lang = "php",
     shard_count = 8,
 )
 
 runtime_test(
     name = "python3.7.3",
-    exclude_file = "exclude_python3.7.3.csv",
+    exclude_file = "exclude/python3.7.3.csv",
     lang = "python",
     shard_count = 8,
 )

test/runtimes/README.md

@@ -0,0 +1,62 @@
+# gVisor Runtime Tests
+
+App Engine uses gvisor to sandbox application containers. The runtime tests aim
+to test `runsc` compatibility with these
+[standard runtimes](https://cloud.google.com/appengine/docs/standard/runtimes).
+The test itself runs the language-defined tests inside the sandboxed standard
+runtime container.
+
+Note: [Ruby runtime](https://cloud.google.com/appengine/docs/standard/ruby) is
+currently in beta mode and so we do not run tests for it yet.
+
+### Testing Locally
+
+To run runtime tests individually from a given runtime, use the following table.
+
+Language | Version | Download Image                              | Run Test(s)
+-------- | ------- | ------------------------------------------- | -----------
+Go       | 1.12    | `make -C images load-runtimes_go1.12`       | If the test name ends with `.go`, it is an on-disk test: <br> `docker run --runtime=runsc -it gvisor.dev/images/runtimes/go1.12 ( cd /usr/local/go/test ; go run run.go -v -- <TEST_NAME>... )` <br> Otherwise it is a tool test: <br> `docker run --runtime=runsc -it gvisor.dev/images/runtimes/go1.12 go tool dist test -v -no-rebuild ^TEST1$\|^TEST2$...`
+Java     | 11      | `make -C images load-runtimes_java11`       | `docker run --runtime=runsc -it gvisor.dev/images/runtimes/java11 jtreg -agentvm -dir:/root/test/jdk -noreport -timeoutFactor:20 -verbose:summary <TEST_NAME>...`
+NodeJS   | 12.4.0  | `make -C images load-runtimes_nodejs12.4.0` | `docker run --runtime=runsc -it gvisor.dev/images/runtimes/nodejs12.4.0 python tools/test.py --timeout=180 <TEST_NAME>...`
+Php      | 7.3.6   | `make -C images load-runtimes_php7.3.6`     | `docker run --runtime=runsc -it gvisor.dev/images/runtimes/php7.3.6 make test "TESTS=<TEST_NAME>..."`
+Python   | 3.7.3   | `make -C images load-runtimes_python3.7.3`  | `docker run --runtime=runsc -it gvisor.dev/images/runtimes/python3.7.3 ./python -m test <TEST_NAME>...`
+
+To run an entire runtime test locally, use the following table.
+
+Note: java runtime test take 1+ hours with 16 cores.
+
+Language | Version | Running the test suite
+-------- | ------- | ----------------------------------------
+Go       | 1.12    | `make go1.12-runtime-tests{_vfs2}`
+Java     | 11      | `make java11-runtime-tests{_vfs2}`
+NodeJS   | 12.4.0  | `make nodejs12.4.0-runtime-tests{_vfs2}`
+Php      | 7.3.6   | `make php7.3.6-runtime-tests{_vfs2}`
+Python   | 3.7.3   | `make python3.7.3-runtime-tests{_vfs2}`
+
+#### Clean Up
+
+Sometimes when runtime tests fail or when the testing container itself crashes
+unexpectedly, the containers are not removed or sometimes do not even exit. This
+can cause some docker commands like `docker system prune` to hang forever.
+
+Here are some helpful commands (should be executed in order):
+
+```bash
+docker ps -a  # Lists all docker processes; useful when investigating hanging containers.
+docker kill $(docker ps -a -q)  # Kills all running containers.
+docker rm $(docker ps -a -q)  # Removes all exited containers.
+docker system prune  # Remove unused data.
+```
+
+### Testing Infrastructure
+
+There are 3 components to this tests infrastructure:
+
+-   [`runner`](runner) - This is the test entrypoint. This is the binary is
+    invoked by `bazel test`. The runner spawns the target runtime container
+    using `runsc` and then copies over the `proctor` binary into the container.
+-   [`proctor`](proctor) - This binary acts as our agent inside the container
+    which communicates with the runner and actually executes tests.
+-   [`exclude`](exclude) - Holds a CSV file for each language runtime containing
+    the full path of tests that should be excluded from running along with a
+    reason for exclusion.