[meta-virtualization][PATCH 3/3] podman: Add support for rootless mode

[Andrei Gherzan <andrei@gherzan.com>]

From: Andrei Gherzan <andrei.gherzan@huawei.com>

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>
---
 docs/00-INDEX                                     |  3 +++
 docs/podman.txt                                   | 15 +++++++++++++++
 docs/podman.txt.license                           |  3 +++
 .../podman/podman/00-podman-rootless.conf         |  6 ++++++
 recipes-containers/podman/podman_git.bb           | 15 ++++++++++++++-
 5 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100644 docs/podman.txt
 create mode 100644 docs/podman.txt.license
 create mode 100644 recipes-containers/podman/podman/00-podman-rootless.conf

diff --git a/docs/00-INDEX b/docs/00-INDEX
index 5aa1b3c..6659fbe 100644
--- a/docs/00-INDEX
+++ b/docs/00-INDEX
@@ -11,5 +11,8 @@ alphabetical order as well.
 openvswitch.txt
 	- example on how to setup openvswitch with qemu/kvm.
 
+podman.txt
+	- documentation on podman container engine integration.
+
 xvisor.txt
 	- example on how to setup Xvisor for RISC-V QEMU.
diff --git a/docs/podman.txt b/docs/podman.txt
new file mode 100644
index 0000000..9f35501
--- /dev/null
+++ b/docs/podman.txt
@@ -0,0 +1,15 @@
+Podman
+======
+
+Rootless mode
+-------------
+
+Podman is a daemonless container engine that has as one of its features the
+ability to run in rootless mode. This requires a set of configurations and
+additional components. The OE/Yocto integration configures podman with this
+support enabled by default. This can be changed via configuration files
+(distro, local.conf, etc.) or bbaappends using the `PODMAN_ROOTLESS` variable.
+
+To disable rootless support set the variable to '0':
+
+PODMAN_ROOTLESS = "0"
diff --git a/docs/podman.txt.license b/docs/podman.txt.license
new file mode 100644
index 0000000..940435e
--- /dev/null
+++ b/docs/podman.txt.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: Huawei Inc.
+
+SPDX-License-Identifier: Apache-2.0
diff --git a/recipes-containers/podman/podman/00-podman-rootless.conf b/recipes-containers/podman/podman/00-podman-rootless.conf
new file mode 100644
index 0000000..2aca663
--- /dev/null
+++ b/recipes-containers/podman/podman/00-podman-rootless.conf
@@ -0,0 +1,6 @@
+# SPDX-FileCopyrightText: Huawei Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+# User namespaces are required for rootless containers.
+user.max_user_namespaces	= 15000
diff --git a/recipes-containers/podman/podman_git.bb b/recipes-containers/podman/podman_git.bb
index 961cd18..2680f40 100644
--- a/recipes-containers/podman/podman_git.bb
+++ b/recipes-containers/podman/podman_git.bb
@@ -6,6 +6,10 @@ DESCRIPTION = "Podman is a daemonless container engine for developing, \
     `alias docker=podman`. \
     "
 
+# podman can run in rootless mode with the help of additional components:
+# https://github.com/containers/podman/blob/main/docs/tutorials/rootless_tutorial.md
+PODMAN_ROOTLESS ?= "1"
+
 inherit features_check
 REQUIRED_DISTRO_FEATURES ?= "seccomp ipv6"
 
@@ -21,6 +25,7 @@ SRCREV = "cedbbfa543651a13055a1fe093a4d0a2a28ccdfd"
 SRC_URI = " \
     git://github.com/containers/libpod.git;branch=v4.1;protocol=https \
     file://0001-Rename-BUILDFLAGS-to-GOBUILDFLAGS.patch;patchdir=src/import \
+    ${@bb.utils.contains('PODMAN_ROOTLESS', '1', 'file://00-podman-rootless.conf', '', d)} \
 "
 
 LICENSE = "Apache-2.0"
@@ -97,6 +102,11 @@ do_install() {
 	# Silence docker emulation warnings.
 	mkdir -p ${D}/etc/containers
 	touch ${D}/etc/containers/nodocker
+
+	if [ "${PODMAN_ROOTLESS}" = "1" ]; then
+		install -d "${D}${sysconfdir}/sysctl.d"
+		install -m 0644 "${WORKDIR}/00-podman-rootless.conf" "${D}${sysconfdir}/sysctl.d"
+	fi
 }
 
 FILES:${PN} += " \
@@ -112,6 +122,9 @@ SYSTEMD_SERVICE:${PN} = "podman.service podman.socket"
 # that busybox is configured with nsenter
 VIRTUAL-RUNTIME_base-utils-nsenter ?= "util-linux-nsenter"
 
-RDEPENDS:${PN} += "conmon virtual-runc iptables cni skopeo ${VIRTUAL-RUNTIME_base-utils-nsenter}"
+RDEPENDS:${PN} += "\
+	conmon virtual-runc iptables cni skopeo ${VIRTUAL-RUNTIME_base-utils-nsenter} \
+	${@bb.utils.contains('PODMAN_ROOTLESS', '1', 'fuse-overlayfs slirp4netns', '', d)} \
+"
 RRECOMMENDS:${PN} += "slirp4netns kernel-module-xt-masquerade kernel-module-xt-comment"
 RCONFLICTS:${PN} = "${@bb.utils.contains('PACKAGECONFIG', 'docker', 'docker', '', d)}"
-- 
2.25.1