Re: [isar-cip-core]RFC v2 6/9] Create systemd mount units for a etc overlay


Christian Storm
 

From: Quirin Gylstorff <quirin.gylstorff@...>

As /etc is read-only and needs to be accessed by the initrd
move the user defined settings to a overlay in /var/local/etc.

Signed-off-by: Quirin Gylstorff <quirin.gylstorff@...>
---
.../etc-overlay-fs/etc-overlay-fs_0.1.bb | 16 ++++++++++++++++
.../etc-overlay-fs/files/etc-hostname.service | 14 ++++++++++++++
.../etc-overlay-fs/files/etc-sysusers.service | 14 ++++++++++++++
recipes-core/etc-overlay-fs/files/etc.mount | 13 +++++++++++++
.../files/overlay-parse-etc.service | 12 ++++++++++++
recipes-core/etc-overlay-fs/files/postinst | 6 ++++++
recipes-core/images/cip-core-image-read-only.bb | 1 +
7 files changed, 76 insertions(+)
create mode 100644 recipes-core/etc-overlay-fs/etc-overlay-fs_0.1.bb
create mode 100644 recipes-core/etc-overlay-fs/files/etc-hostname.service
create mode 100644 recipes-core/etc-overlay-fs/files/etc-sysusers.service
create mode 100644 recipes-core/etc-overlay-fs/files/etc.mount
create mode 100644 recipes-core/etc-overlay-fs/files/overlay-parse-etc.service
create mode 100755 recipes-core/etc-overlay-fs/files/postinst

diff --git a/recipes-core/etc-overlay-fs/etc-overlay-fs_0.1.bb b/recipes-core/etc-overlay-fs/etc-overlay-fs_0.1.bb
new file mode 100644
index 0000000..f1c8349
--- /dev/null
+++ b/recipes-core/etc-overlay-fs/etc-overlay-fs_0.1.bb
@@ -0,0 +1,16 @@
+inherit dpkg-raw
+
+SRC_URI = "file://postinst \
+ file://etc.mount \
+ file://overlay-parse-etc.service \
+ file://etc-hostname.service \
+ file://etc-sysusers.service"
+
+do_install[cleandirs]+="${D}/lib/systemd/system ${D}/var/local/etc ${D}/var/local/.atomic"
+do_install() {
+ TARGET=${D}/lib/systemd/system
+ install -m 0644 ${WORKDIR}/etc.mount ${TARGET}/etc.mount
+ install -m 0644 ${WORKDIR}/overlay-parse-etc.service ${TARGET}/overlay-parse-etc.service
+ install -m 0644 ${WORKDIR}/etc-hostname.service ${TARGET}/etc-hostname.service
+ install -m 0644 ${WORKDIR}/etc-sysusers.service ${TARGET}/etc-sysusers.service
+}
diff --git a/recipes-core/etc-overlay-fs/files/etc-hostname.service b/recipes-core/etc-overlay-fs/files/etc-hostname.service
new file mode 100644
index 0000000..2306b9f
--- /dev/null
+++ b/recipes-core/etc-overlay-fs/files/etc-hostname.service
@@ -0,0 +1,14 @@
+[Unit]
+Description=set hostname /etc overlay-aware
+Before=network-pre.target
+Wants=network-pre.target
+Requires=etc.mount
+After=etc.mount
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=/bin/hostname --boot --file /etc/hostname
+
+[Install]
+WantedBy=basic.target
diff --git a/recipes-core/etc-overlay-fs/files/etc-sysusers.service b/recipes-core/etc-overlay-fs/files/etc-sysusers.service
new file mode 100644
index 0000000..6caf6b0
--- /dev/null
+++ b/recipes-core/etc-overlay-fs/files/etc-sysusers.service
@@ -0,0 +1,14 @@
+[Unit]
+Description=make systemd-sysusers /etc overlay aware
+Before=network-pre.target
+Wants=network-pre.target
+Requires=etc.mount
+After=etc.mount
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=/usr/bin/systemd-sysusers
+
+[Install]
+WantedBy=basic.target
Hm, why do you replace/create those services instead of augmenting the
current default ones via conf.d'lets?
Why is this one here dependent on network?
Why does this differ that much from upstream service files, see, e.g.,
https://github.com/systemd/systemd/blob/main/units/systemd-sysusers.service


diff --git a/recipes-core/etc-overlay-fs/files/etc.mount b/recipes-core/etc-overlay-fs/files/etc.mount
new file mode 100644
index 0000000..f0ae3c5
--- /dev/null
+++ b/recipes-core/etc-overlay-fs/files/etc.mount
@@ -0,0 +1,13 @@
+[Unit]
+Description=Overlay-mount /etc
+Requires=var.mount
+After=var.mount
+
+[Mount]
+What=overlay
+Where=/etc
+Type=overlay
+Options=noauto,x-systemd.automount,lowerdir=/etc,upperdir=/var/local/etc,workdir=/var/local/.atomic
+
+[Install]
+WantedBy=local-fs.target
diff --git a/recipes-core/etc-overlay-fs/files/overlay-parse-etc.service b/recipes-core/etc-overlay-fs/files/overlay-parse-etc.service
new file mode 100644
index 0000000..062bb40
--- /dev/null
+++ b/recipes-core/etc-overlay-fs/files/overlay-parse-etc.service
@@ -0,0 +1,12 @@
+[Unit]
+Description=Reload Configuration from the etc overlay
+Requires=etc.mount
+After=etc.mount
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStartPre=!/bin/systemctl daemon-reload
+ExecStart=!/bin/systemctl --no-block isolate multi-user.target
Wow, this is a big cannon, why do you need this? Isn't there another way?


+[Install]
+WantedBy=local-fs.target
diff --git a/recipes-core/etc-overlay-fs/files/postinst b/recipes-core/etc-overlay-fs/files/postinst
new file mode 100755
index 0000000..35641af
--- /dev/null
+++ b/recipes-core/etc-overlay-fs/files/postinst
@@ -0,0 +1,6 @@
+#!/bin/sh
+
+deb-systemd-helper enable etc.mount || true
+deb-systemd-helper enable overlay-parse-etc.service || true
+deb-systemd-helper enable etc-hostname.service || true
+deb-systemd-helper enable etc-sysusers.service || true
diff --git a/recipes-core/images/cip-core-image-read-only.bb b/recipes-core/images/cip-core-image-read-only.bb
index 7ef2dc2..ceb6ac4 100644
--- a/recipes-core/images/cip-core-image-read-only.bb
+++ b/recipes-core/images/cip-core-image-read-only.bb
@@ -2,6 +2,7 @@ require cip-core-image.bb

SQUASHFS_EXCLUDE_DIRS += "home var"

+IMAGE_INSTALL += "etc-overlay-fs"
IMAGE_INSTALL += "tmp-fs"
IMAGE_INSTALL_remove += "initramfs-abrootfs-secureboot"

--
2.30.2


Kind regards,
Christian

--
Dr. Christian Storm
Siemens AG, Technology, T RDA IOT SES-DE
Otto-Hahn-Ring 6, 81739 M√ľnchen, Germany

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