Fix bazel-contrib#220: Add exposed_ports to oci_image

e2e/crane_as_registry/BUILD.bazel

@@ -15,6 +15,11 @@ oci_image(
     env = {
         "ENV": "/test",
     },
+    exposed_ports = [
+        "1234/tcp",
+        "5678/udp",
+        "5000",
+    ],
     os = "linux",
 )
 

oci/defs.bzl

@@ -22,7 +22,7 @@ oci_image_rule = _oci_image
 oci_image_index = _oci_image_index
 oci_push_rule = _oci_push
 
-def oci_image(name, labels = None, annotations = None, env = None, cmd = None, entrypoint = None, **kwargs):
+def oci_image(name, labels = None, annotations = None, env = None, cmd = None, entrypoint = None, exposed_ports = None, **kwargs):
     """Macro wrapper around [oci_image_rule](#oci_image_rule).
 
     Allows labels and annotations to be provided as a dictionary, in addition to a text file.
@@ -43,6 +43,7 @@ def oci_image(name, labels = None, annotations = None, env = None, cmd = None, e
         env: Environment variables provisioned by default to the running container. See documentation above.
         cmd: Command & argument configured by default in the running container. See documentation above.
         entrypoint: Entrypoint configured by default in the running container. See documentation above.
+        exposed_ports: Exposed ports in the running container. See documentation above.
         **kwargs: other named arguments to [oci_image_rule](#oci_image_rule) and
             [common rule attributes](https://bazel.build/reference/be/common-definitions#common-attributes).
     """
@@ -108,13 +109,24 @@ def oci_image(name, labels = None, annotations = None, env = None, cmd = None, e
         )
         entrypoint = entrypoint_label
 
+    if types.is_list(exposed_ports):
+        exposed_ports_label = "_{}_write_exposed_ports".format(name)
+        write_file(
+            name = exposed_ports_label,
+            out = "_{}.exposed_ports.txt".format(name),
+            content = [",".join(exposed_ports)],
+            **forwarded_kwargs,
+        )
+        exposed_ports = exposed_ports_label
+
     oci_image_rule(
         name = name,
         annotations = annotations,
         labels = labels,
         env = env,
         cmd = cmd,
         entrypoint = entrypoint,
+        exposed_ports = exposed_ports,
         **kwargs
     )
 

oci/private/image.bzl

@@ -72,6 +72,7 @@ For Linux based systems, all of the following are valid: `user`, `uid`, `user:gr
 If `group/gid` is not specified, the default group and supplementary groups of the given `user/uid` in `/etc/passwd` from the container are applied.
 """),
     "workdir": attr.string(doc = "Sets the current working directory of the `entrypoint` process in the container. This value acts as a default and may be replaced by a working directory specified when creating a container."),
+    "exposed_ports": attr.label(doc = "A file containing a comma separated list of exposed ports. (e.g. 2000/tcp, 3000/udp or 4000. No protocol defaults to tcp).", allow_single_file = True),
     "os": attr.string(doc = "The name of the operating system which the image is built to run on. eg: `linux`, `windows`. See $GOOS documentation for possible values: https://go.dev/doc/install/source#environment"),
     "architecture": attr.string(doc = "The CPU architecture which the binaries in this image are built to run on. eg: `arm64`, `arm`, `amd64`, `s390x`. See $GOARCH documentation for possible values: https://go.dev/doc/install/source#environment"),
     "variant": attr.string(doc = "The variant of the specified CPU architecture. eg: `v6`, `v7`, `v8`. See: https://github.com/opencontainers/image-spec/blob/main/image-index.md#platform-variants for more."),
@@ -149,6 +150,10 @@ def _oci_image_impl(ctx):
         args.add(ctx.file.entrypoint.path, format = "--entrypoint-file=%s")
         inputs_depsets.append(depset([ctx.file.entrypoint]))
 
+    if ctx.attr.exposed_ports:
+        args.add(ctx.file.exposed_ports.path, format = "--exposed-ports-file=%s")
+        inputs_depsets.append(depset([ctx.file.exposed_ports]))
+
     if ctx.attr.cmd:
         args.add(ctx.file.cmd.path, format = "--cmd-file=%s")
         inputs_depsets.append(depset([ctx.file.cmd]))

oci/private/image.sh.tpl

@@ -131,6 +131,11 @@ for ARG in "$@"; do
             FIXED_ARGS+=("--entrypoint=$in")
           done <"${ARG#--entrypoint-file=}"
           ;;
+	(--exposed-ports-file=*)
+	  while IFS= read -r in || [ -n "$in" ]; do
+            FIXED_ARGS+=("--exposed-ports=$in")
+          done <"${ARG#--exposed-ports-file=}"
+          ;;
         (*) FIXED_ARGS+=( "${ARG}" )
     esac
 done