Simplify Docker test infrastructure.

This change adds a layer of abstraction around the internal Docker APIs,
and eliminates all direct dependencies on Dockerfiles in the infrastructure.

A subsequent change will automated the generation of local images (with
efficient caching). Note that this change drops the use of bazel container
rules, as that experiment does not seem to be viable.

PiperOrigin-RevId: 308095430

2 files changed, 15 insertions, 11 deletions

diff --git a/test/packetimpact/testbench/dut.go b/test/packetimpact/testbench/dut.go
index 9335909c0..3f340c6bc 100644
--- a/test/packetimpact/testbench/dut.go
+++ b/test/packetimpact/testbench/dut.go
@@ -132,7 +132,7 @@ func (dut *DUT) CreateBoundSocket(typ, proto int32, addr net.IP) (int32, uint16)
 		copy(sa.Addr[:], addr.To16())
 		dut.Bind(fd, &sa)
 	} else {
-		dut.t.Fatal("unknown ip addr type for remoteIP")
+		dut.t.Fatalf("unknown ip addr type for remoteIP")
 	}
 	sa := dut.GetSockName(fd)
 	var port int
diff --git a/test/packetimpact/tests/test_runner.sh b/test/packetimpact/tests/test_runner.sh
index 2be3c17c3..46d63d5e5 100755
--- a/test/packetimpact/tests/test_runner.sh
+++ b/test/packetimpact/tests/test_runner.sh
@@ -107,21 +107,24 @@ if [[ ! -f "${TESTBENCH_BINARY-}" ]]; then
   exit 2
 fi
 
+function new_net_prefix() {
+  # Class C, 192.0.0.0 to 223.255.255.255, transitionally has mask 24.
+  echo "$(shuf -i 192-223 -n 1).$(shuf -i 0-255 -n 1).$(shuf -i 0-255 -n 1)"
+}
+
 # Variables specific to the control network and interface start with CTRL_.
 # Variables specific to the test network and interface start with TEST_.
 # Variables specific to the DUT start with DUT_.
 # Variables specific to the test bench start with TESTBENCH_.
 # Use random numbers so that test networks don't collide.
-declare -r CTRL_NET="ctrl_net-${RANDOM}${RANDOM}"
-declare -r TEST_NET="test_net-${RANDOM}${RANDOM}"
+declare CTRL_NET="ctrl_net-${RANDOM}${RANDOM}"
+declare CTRL_NET_PREFIX=$(new_net_prefix)
+declare TEST_NET="test_net-${RANDOM}${RANDOM}"
+declare TEST_NET_PREFIX=$(new_net_prefix)
 # On both DUT and test bench, testing packets are on the eth2 interface.
 declare -r TEST_DEVICE="eth2"
 # Number of bits in the *_NET_PREFIX variables.
 declare -r NET_MASK="24"
-function new_net_prefix() {
-  # Class C, 192.0.0.0 to 223.255.255.255, transitionally has mask 24.
-  echo "$(shuf -i 192-223 -n 1).$(shuf -i 0-255 -n 1).$(shuf -i 0-255 -n 1)"
-}
 # Last bits of the DUT's IP address.
 declare -r DUT_NET_SUFFIX=".10"
 # Control port.
@@ -130,6 +133,7 @@ declare -r CTRL_PORT="40000"
 declare -r TESTBENCH_NET_SUFFIX=".20"
 declare -r TIMEOUT="60"
 declare -r IMAGE_TAG="gcr.io/gvisor-presubmit/packetimpact"
+
 # Make sure that docker is installed.
 docker --version
 
@@ -169,19 +173,19 @@ function finish {
 trap finish EXIT
 
 # Subnet for control packets between test bench and DUT.
-declare CTRL_NET_PREFIX=$(new_net_prefix)
 while ! docker network create \
   "--subnet=${CTRL_NET_PREFIX}.0/${NET_MASK}" "${CTRL_NET}"; do
   sleep 0.1
-  declare CTRL_NET_PREFIX=$(new_net_prefix)
+  CTRL_NET_PREFIX=$(new_net_prefix)
+  CTRL_NET="ctrl_net-${RANDOM}${RANDOM}"
 done
 
 # Subnet for the packets that are part of the test.
-declare TEST_NET_PREFIX=$(new_net_prefix)
 while ! docker network create \
   "--subnet=${TEST_NET_PREFIX}.0/${NET_MASK}" "${TEST_NET}"; do
   sleep 0.1
-  declare TEST_NET_PREFIX=$(new_net_prefix)
+  TEST_NET_PREFIX=$(new_net_prefix)
+  TEST_NET="test_net-${RANDOM}${RANDOM}"
 done
 
 docker pull "${IMAGE_TAG}"