feat: implement home (#10)

distroless/BUILD.bazel

@@ -20,6 +20,7 @@ bzl_library(
     deps = [
         "//distroless/private:cacerts",
         "//distroless/private:group",
+        "//distroless/private:home",
         "//distroless/private:java_keystore",
         "//distroless/private:locale",
         "//distroless/private:os_release",

distroless/defs.bzl

@@ -2,6 +2,7 @@
 
 load("//distroless/private:cacerts.bzl", _cacerts = "cacerts")
 load("//distroless/private:group.bzl", _group = "group")
+load("//distroless/private:home.bzl", _home = "home")
 load("//distroless/private:java_keystore.bzl", _java_keystore = "java_keystore")
 load("//distroless/private:locale.bzl", _locale = "locale")
 load("//distroless/private:os_release.bzl", _os_release = "os_release")
@@ -13,3 +14,4 @@ os_release = _os_release
 group = _group
 passwd = _passwd
 java_keystore = _java_keystore
+home = _home

distroless/private/BUILD.bazel

@@ -71,6 +71,16 @@ bzl_library(
     deps = [":tar"],
 )
 
+bzl_library(
+    name = "home",
+    srcs = ["home.bzl"],
+    visibility = ["//distroless:__subpackages__"],
+    deps = [
+        ":tar",
+        "@aspect_bazel_lib//lib:tar",
+    ],
+)
+
 bzl_library(
     name = "tar",
     srcs = ["tar.bzl"],

distroless/private/home.bzl

@@ -0,0 +1,27 @@
+"home"
+
+load("@aspect_bazel_lib//lib:tar.bzl", "tar")
+load(":tar.bzl", "tar_lib")
+
+def home(name, dirs, **kwargs):
+    """
+    Create home directories with specific uid and gids.
+
+    Args:
+        name: name of the target
+        dirs: array of home directory dicts.
+        **kwargs: other named arguments to that is passed to tar. see [common rule attributes](https://bazel.build/reference/be/common-definitions#common-attributes).
+    """
+    mtree = []
+
+    for home in dirs:
+        mtree.extend(
+            tar_lib.add_directory_with_parents(home["home"], uid = str(home["uid"]), gid = str(home["gid"])),
+        )
+
+    tar(
+        name = name,
+        srcs = [],
+        mtree = mtree,
+        **kwargs
+    )

distroless/private/passwd.bzl

@@ -50,7 +50,7 @@ def passwd(name, passwds, **kwargs):
         stamp = 0,
         template = [
             "#mtree",
-            "etc/passwd uid=0 gid=0 mode=0700 time=0 type=file content={content}",
+            "./etc/passwd uid=0 gid=0 mode=0700 time=0 type=file content={content}",
             "",
         ],
         substitutions = {

distroless/private/tar.bzl

@@ -2,9 +2,15 @@
 
 BSDTAR_TOOLCHAIN = "@aspect_bazel_lib//lib:tar_toolchain_type"
 
-def _mtree_line(file, type, content = None, uid = "0", gid = "0", time = "1672560000", mode = "0755"):
+def _mtree_line(dest, type, content = None, uid = "0", gid = "0", time = "1672560000", mode = "0755"):
+    # mtree expects paths to start with ./ so normalize paths that starts with
+    # `/` or relative path (without / and ./)
+    if not dest.startswith("."):
+        if not dest.startswith("/"):
+            dest = "/" + dest
+        dest = "." + dest
     spec = [
-        file,
+        dest,
         "uid=" + uid,
         "gid=" + gid,
         "time=" + time,
@@ -15,19 +21,27 @@ def _mtree_line(file, type, content = None, uid = "0", gid = "0", time = "167256
         spec.append("content=" + content)
     return " ".join(spec)
 
-def _add_parents(path):
+def _add_parents(path, uid = "0", gid = "0", time = "1672560000", mode = "0755"):
     lines = []
     segments = path.split("/")
-    for i in range(1, len(segments)):
-        parent = "/".join(segments[:i])
-        if parent == "":
+    segments.pop()
+    for i in range(0, len(segments)):
+        parent = "/".join(segments[:i + 1])
+        if not parent:
             continue
-        lines.append(_mtree_line(parent.lstrip("/"), "dir"))
+        lines.append(
+            _mtree_line(parent, "dir", uid = uid, gid = gid, time = time, mode = mode),
+        )
     return lines
 
 def _add_file_with_parents(path, file):
     lines = _add_parents(path)
-    lines.append(_mtree_line(path.lstrip("/"), "file", content = file.path))
+    lines.append(_mtree_line(path, "file", content = file.path))
+    return lines
+
+def _add_directory_with_parents(path, **kwargs):
+    lines = _add_parents(path)
+    lines.append(_mtree_line(path, "dir", **kwargs))
     return lines
 
 def _build_tar(ctx, mtree, output, inputs = [], compression = "gzip", mnemonic = "Tar"):
@@ -71,7 +85,7 @@ def _create_mtree(ctx):
 tar_lib = struct(
     create_mtree = _create_mtree,
     line = _mtree_line,
-    add_directory_with_parents = _add_file_with_parents,
+    add_directory_with_parents = _add_directory_with_parents,
     add_file_with_parents = _add_file_with_parents,
     TOOLCHAIN_TYPE = BSDTAR_TOOLCHAIN,
 )

examples/cacerts/BUILD.bazel

@@ -15,7 +15,7 @@ assert_tar_listing(
 ./etc/ssl time=1672560000.0 mode=755 gid=0 uid=0 type=dir
 ./etc/ssl/certs time=1672560000.0 mode=755 gid=0 uid=0 type=dir
 ./etc/ssl/certs/ca-certificates.crt nlink=0 time=1672560000.0 mode=755 gid=0 uid=0 type=file size=200313 cksum=3175436394 sha1digest=01b4ff230afaeeda5cddaf9a002cec9bc9a6d1b4
-./etc/usr time=1672560000.0 mode=755 gid=0 uid=0 type=dir
+./usr time=1672560000.0 mode=755 gid=0 uid=0 type=dir
 ./usr/share time=1672560000.0 mode=755 gid=0 uid=0 type=dir
 ./usr/share/doc time=1672560000.0 mode=755 gid=0 uid=0 type=dir
 ./usr/share/doc/ca-certificates time=1672560000.0 mode=755 gid=0 uid=0 type=dir

examples/home/BUILD.bazel

@@ -0,0 +1,29 @@
+load("//distroless:defs.bzl", "home")
+load("//distroless/tests:asserts.bzl", "assert_tar_listing")
+
+home(
+    name = "home",
+    dirs = [
+        {
+            "home": "/root",
+            "uid": 0,
+            "gid": 0,
+        },
+        {
+            "home": "/home/nonroot",
+            "uid": 666,
+            "gid": 666,
+        },
+    ],
+)
+
+assert_tar_listing(
+    name = "test_home",
+    actual = "home",
+    expected = """\
+#mtree
+./home time=1672560000.0 mode=755 gid=0 uid=0 type=dir
+./home/nonroot time=1672560000.0 mode=755 gid=666 uid=666 type=dir
+./root time=1672560000.0 mode=755 gid=0 uid=0 type=dir
+""",
+)