feat: add support for settings volumes

Fixes #406.

docs/compare_dockerfile.md

@@ -27,7 +27,7 @@ Let's compare them to their rules_oci counterparts:
 - `SHELL`       -> Use `oci_image#entrypoint` instead.
 - `STOPSIGNAL`  -> Not supported
 - `USER`        -> Not supported. Use the tar rule's mechanism for setting gid/uid
-- `VOLUME`      -> See: https://github.com/bazel-contrib/rules_oci/issues/406
+- `VOLUME`      -> Use `oci_image#volumes`
 - `WORKDIR`     -> Use `oci_image#workdir`
 
 

examples/assert.bzl

@@ -24,6 +24,7 @@ def assert_oci_config(
         cmd_eq = None,
         env_eq = None,
         exposed_ports_eq = None,
+        volumes_eq = None,
         user_eq = None,
         workdir_eq = None,
         architecture_eq = None,
@@ -46,6 +47,8 @@ def assert_oci_config(
         config["WorkingDir"] = workdir_eq
     if exposed_ports_eq:
         config["ExposedPorts"] = {port: {} for port in exposed_ports_eq}
+    if volumes_eq:
+        config["Volumes"] = {volume: {} for volume in volumes_eq}
     if user_eq:
         config["User"] = user_eq
     if labels_eq:

examples/assertion/BUILD.bazel

@@ -187,6 +187,7 @@ oci_image(
         "5678/udp",
         "5000",
     ],
+    volumes = ["/srv/data"],
     # user & workdir
     user = "root",
     workdir = "/root",
@@ -230,6 +231,9 @@ assert_oci_config(
         "5678/udp",
         "5000",
     ],
+    volumes_eq = [
+        "/srv/data",
+    ],
     image = ":case8",
     labels_eq = {
         "org.opencontainers.image.version": "0.0.0",

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, exposed_ports = None, **kwargs):
+def oci_image(name, labels = None, annotations = None, env = None, cmd = None, entrypoint = None, exposed_ports = None, volumes = 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.
@@ -44,6 +44,7 @@ def oci_image(name, labels = None, annotations = None, env = None, cmd = None, e
         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.
+        volumes: Volumes for the 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).
     """
@@ -109,6 +110,16 @@ def oci_image(name, labels = None, annotations = None, env = None, cmd = None, e
         )
         exposed_ports = exposed_ports_label
 
+    if types.is_list(volumes):
+        volumes_label = "_{}_write_volumes".format(name)
+        write_file(
+            name = volumes_label,
+            out = "_{}.volumes.txt".format(name),
+            content = [",".join(volumes)],
+            **forwarded_kwargs
+        )
+        volumes = volumes_label
+
     oci_image_rule(
         name = name,
         annotations = annotations,
@@ -117,6 +128,7 @@ def oci_image(name, labels = None, annotations = None, env = None, cmd = None, e
         cmd = cmd,
         entrypoint = entrypoint,
         exposed_ports = exposed_ports,
+        volumes = volumes,
         **kwargs
     )
 

oci/private/image.bzl

@@ -82,6 +82,7 @@ If `group/gid` is not specified, the default group and supplementary groups of t
 """),
     "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),
+    "volumes": attr.label(doc = "A file containing a comma separated list of volumes. (e.g. /srv/data,/srv/other-data)", 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."),
@@ -195,6 +196,10 @@ def _oci_image_impl(ctx):
         args.add(ctx.file.exposed_ports.path, format = "--exposed-ports=%s")
         inputs.append(ctx.file.exposed_ports)
 
+    if ctx.attr.volumes:
+        args.add(ctx.file.volumes.path, format = "--volumes=%s")
+        inputs.append(ctx.file.volumes)
+
     if ctx.attr.cmd:
         args.add(ctx.file.cmd.path, format = "--cmd=%s")
         inputs.append(ctx.file.cmd)

oci/private/image.sh

@@ -154,6 +154,9 @@ for ARG in "$@"; do
   --exposed-ports=*)
     CONFIG=$(jq --rawfile ep "${ARG#--exposed-ports=}" '.config.ExposedPorts = ($ep | split(",") | map({key: ., value: {}}) | from_entries)' <<<"$CONFIG")
     ;;
+  --volumes=*)
+    CONFIG=$(jq --rawfile volumes "${ARG#--volumes=}" '.config.Volumes = ($volumes | split(",") | map({key: ., value: {}}) | from_entries)' <<<"$CONFIG")
+    ;;
   --user=*)
     CONFIG=$(jq --arg user "${ARG#--user=}" '.config.User = $user' <<<"$CONFIG")
     ;;