add manual publications of ports

README.rst

@@ -40,12 +40,23 @@ your test suite as it runs, as ordinary environment variables::
 Host and Port Mapping
 ---------------------
 
-tox-docker runs docker with the "publish all ports" option. Any port the
-container exposes will be made available to your test suite via environment
-variables of the form ``<image-basename>_<exposed-port>_<protocol>_PORT``.
-For instance, for the PostgreSQL container, there will be an environment
-variable ``POSTGRES_5432_TCP_PORT`` whose value is the ephemeral port number
-that docker has bound the container's port 5432 to.
+By default, tox-docker runs the container with the "publish all ports" option.
+You may also specify port publishing in ``tox.ini``, in a new section like::
+
+    [docker:redis:5.0-alpine]
+    ports = 5432:5432/tcp
+
+The image name -- everything after the ``docker:`` in the section header --
+must *exactly* match the image name used in your testenv's ``docker`` setting.
+Published ports are separated by a newline and are in the format
+``<HOST>:<CONTAINER>/<PROTOCOL>``.
+
+Any port the container exposes will be made available to your test suite via
+environment variables of the form
+``<image-basename>_<exposed-port>_<protocol>_PORT``.  For instance, for the
+PostgreSQL container, there will be an environment variable
+``POSTGRES_5432_TCP_PORT`` whose value is the ephemeral port number that docker
+has bound the container's port 5432 to.
 
 Likewise, exposed UDP ports will have environment variables like
 ``TELEGRAF_8092_UDP_PORT`` Since it's not possible to check whether UDP port

test_ports.py

@@ -0,0 +1,18 @@
+import unittest
+
+import docker
+
+
+class ToxDockerPortTest(unittest.TestCase):
+
+    def test_it_exposes_only_specified_port(self):
+        client = docker.from_env(version="auto")
+        mysql_container = None
+        for container in client.containers.list()
+          if "mysql" in containers.attrs["Config"]["Image"]:
+              mysql_container = container
+              break
+
+        self.assertIsNotNone(mysql_container, "could not find mysql container")
+        self.assertIsNotNone(mysql_container.attrs["NetworkSettings"]["Ports"].get("3306/tcp"))
+        self.assertIsNone(mysql_container.attrs["NetworkSettings"]["Ports"].get("33060/tcp"))

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = integration,registry,healthcheck-builtin,healthcheck-custom
+envlist = integration,registry,healthcheck-builtin,healthcheck-custom,ports
 
 [testenv]
 # commands_pre/_post only work in tox 3.4+, but at least in some
@@ -46,3 +46,11 @@ healthcheck_interval = 1
 healthcheck_timeout = 1
 healthcheck_retries = 30
 healthcheck_start_period = 0.5
+
+[testenv:ports]
+docker = mysql:5.7
+deps = pytest
+commands = py.test [] test_ports.py
+
+[docker:mysql:5.7]
+ports = 3306:3306/tcp

tox_docker.py

@@ -100,11 +100,25 @@ def getint(reader, key):
             "healthcheck_timeout": gettime(reader, "healthcheck_timeout"),
             "healthcheck_retries": getint(reader, "healthcheck_retries"),
             "healthcheck_start_period": gettime(reader, "healthcheck_start_period"),
+            "ports": reader.getlist("ports"),
         }
 
     config._docker_image_configs = image_configs
 
 
+def _validate_port(port_line):
+    host_port, _, container_port_proto = port_line.partition(":")
+    host_port = int(host_port)
+
+    container_port, _, protocol = container_port_proto.partition("/")
+    container_port = int(container_port)
+
+    if protocol.lower() not in ("tcp", "udp"):
+        raise ValueError("protocol is not tcp or udp")
+
+    return (host_port, container_port_proto)
+
+
 @hookimpl
 def tox_runtest_pre(venv):
     envconfig = venv.envconfig
@@ -163,12 +177,20 @@ def tox_runtest_pre(venv):
         else:
             healthcheck = None
 
+        ports = {}
+        for port_mapping in image_config.get("ports", []):
+            host_port, container_port_proto = _validate_port(port_mapping)
+            existing_ports = set(ports.get(container_port_proto, []))
+            existing_ports.add(host_port)
+            ports[container_port_proto] = list(existing_ports)
+
         action.setactivity("docker", "run {!r}".format(image))
         with action:
             container = docker.containers.run(
                 image,
                 detach=True,
-                publish_all_ports=True,
+                publish_all_ports=len(ports) == 0,
+                ports=ports,
                 environment=environment,
                 healthcheck=healthcheck,
             )
@@ -195,6 +217,10 @@ def tox_runtest_pre(venv):
         name, _, tag = image.partition(":")
         gateway_ip = _get_gateway_ip(container)
         for containerport, hostports in container.attrs["NetworkSettings"]["Ports"].items():
+            if hostports is None:
+                # The port is exposed by the container, but not published.
+                continue
+
             for spec in hostports:
                 if spec["HostIp"] == "0.0.0.0":
                     hostport = spec["HostPort"]