[Docker] Fix bug when a putative target address did not exist.

src/python/pants/backend/docker/util_rules/dependencies.py

@@ -3,6 +3,7 @@
 
 from pants.backend.docker.subsystems.dockerfile_parser import DockerfileInfo, DockerfileInfoRequest
 from pants.backend.docker.target_types import DockerDependenciesField
+from pants.base.specs import AddressSpecs, MaybeEmptySiblingAddresses
 from pants.core.goals.package import PackageFieldSet
 from pants.engine.addresses import Addresses, UnparsedAddressInputs
 from pants.engine.rules import Get, collect_rules, rule
@@ -22,18 +23,28 @@ class InjectDockerDependencies(InjectDependenciesRequest):
 
 @rule
 async def inject_docker_dependencies(request: InjectDockerDependencies) -> InjectedDependencies:
-    """Inspects COPY instructions in the Dockerfile for references to known targets."""
+    """Inspects COPY instructions in the Dockerfile for references to known packagable targets."""
     dockerfile_info = await Get(
         DockerfileInfo, DockerfileInfoRequest(request.dependencies_field.address)
     )
 
-    targets = await Get(
-        Targets,
+    # Parse all putative target addresses.
+    putative_addresses = await Get(
+        Addresses,
         UnparsedAddressInputs(
             dockerfile_info.putative_target_addresses,
             owning_address=dockerfile_info.address,
         ),
     )
+
+    # Get the target for those addresses that are known.
+    directories = {address.spec_path for address in putative_addresses}
+    all_addresses = await Get(Addresses, AddressSpecs(map(MaybeEmptySiblingAddresses, directories)))
+    targets = await Get(
+        Targets, Addresses((address for address in putative_addresses if address in all_addresses))
+    )
+
+    # Only keep those targets that we can "package".
     package = await Get(FieldSetsPerTarget, FieldSetsPerTargetRequest(PackageFieldSet, targets))
     referenced_targets = (
         field_sets[0].address for field_sets in package.collection if len(field_sets) > 0

src/python/pants/backend/docker/util_rules/docker_build_context_test.py

@@ -286,7 +286,7 @@ def test_packaged_pex_path(rule_runner: RuleRunner) -> None:
     rule_runner.write_files(
         {
             "src/docker/BUILD": """docker_image(dependencies=["src/python/proj/cli:bin"])""",
-            "src/docker/Dockerfile": """FROM python""",
+            "src/docker/Dockerfile": """FROM python:3.8""",
             "src/python/proj/cli/BUILD": """pex_binary(name="bin", entry_point="main.py")""",
             "src/python/proj/cli/main.py": """print("cli main")""",
         }
@@ -593,3 +593,38 @@ def test_create_docker_build_context() -> None:
     assert dict(context.build_env.environment) == {"ENVNAME": "value2"}
     assert context.dockerfile == "test/Dockerfile"
     assert context.stages == ("base", "dev", "prod")
+
+
+def test_pex_custom_output_path_issue14031(rule_runner: RuleRunner) -> None:
+    rule_runner.write_files(
+        {
+            "project/test/BUILD": dedent(
+                """\
+                pex_binary(
+                  name="test",
+                  entry_point="main.py",
+                  output_path="project/test.pex",
+                )
+
+                docker_image(
+                  name="test-image",
+                  dependencies=[":test"],
+                )
+                """
+            ),
+            "project/test/main.py": "print('Hello')",
+            "project/test/Dockerfile": dedent(
+                """\
+                FROM python:3.8
+                COPY project/test.pex .
+                CMD ["./test.pex"]
+                """
+            ),
+        }
+    )
+
+    assert_build_context(
+        rule_runner,
+        Address("project/test", target_name="test-image"),
+        expected_files=["project/test/Dockerfile", "project/test.pex"],
+    )