snapd without systemd (rough draft - looks like the script is missing things)

[s243a]

I was doing some research on how on might be able to use snap packages on puppy. I found the following script to simulate (somewhat) the systemd function:
/usr/bin/systemctl

Code: Select all

#!/bin/bash

# First parameter should be start or stop
# Second parameter will be the name of a unit file

if [ $# -lt 2 ]
then 
  echo "usage: $0 start unit-file"
  exit 0
fi

if [ $1 == "start" ]
then
  what=$(grep What /etc/systemd/system/"$2" | cut -f 2 -d '=')
  where=$(grep Where /etc/systemd/system/"$2" | cut -f 2 -d '=')
  mkdir -p "$where"
  mount $what $where
  exit 0
fi

if [ $1 == "stop" ]
then
  where=$(grep Where /etc/systemd/system/"$2" | cut -f 2 -d '=')
  umount $where
  exit 0
fi

https://forum.mxlinux.org/viewtopic.php ... pd#p435179

according to the thread on the Mx linux form it should work. I'll give it a try. Anyway the basic steps are first to install "snapd" form the package manager.
https://snapcraft.io/docs/installing-snapd

Enable the socket for snapd (assume the above script is installed in lieu of systmd):

Code: Select all

systemctl enable --now snapd.socket

https://snapcraft.io/docs/installing-snap-on-arch-linux

Then start this with the following command:

Code: Select all

systemctl start snapd

Then

Code: Select all

snap install core

and optionally

Code: Select all

snap install snap-store

https://snapcraft.io/docs/installing-snap-store-app

[s243a]

Before trying it, I see some issues:
The script replacement for The drop in replacement for systemctl doesn't define "What" and "Where"

Here is what is in snapd.service

Code: Select all

[Unit]
Description=Snappy daemon
Requires=snapd.socket
OnFailure=snapd.failure.service
# This is handled by snapd
# X-Snapd-Snap: do-not-start

[Service]
# Disabled because it breaks lxd
# (https://bugs.launchpad.net/snapd/+bug/1709536)
#Nice=-5
OOMScoreAdjust=-900
ExecStart=/usr/lib/snapd/snapd
EnvironmentFile=-/etc/environment
Restart=always
WatchdogSec=5m
Type=notify
SuccessExitStatus=42
RestartPreventExitStatus=42
KillMode=process

[Install]
WantedBy=multi-user.target

I see now "What" or "Where" in this file so maybe nothing needs to be mounted for this service. Still though we should start the service and we want to start it with the command:

/usr/lib/snapd/snapd

but first we have to create the socket (i.e. the require part). If the stocket isn't created then if you try to run the snap command you get an error like:

Code: Select all

error: cannot communicate with server: Post http://localhost/v2/snaps/core: dial unix /run/snapd.socket: connect: no such file or directory

I'm guessing it is an http servicer because of the "Post" command shown above in the error. Maybe we can start the server using busybox's httpd.

[s243a]

but first we have to create the socket (i.e. the require part). If the stocket isn't created then if you try to run the snap command you get an error like:

Code: Select all

error: cannot communicate with server: Post http://localhost/v2/snaps/core: dial unix /run/snapd.socket: connect: no such file or directory

I'm guessing it is an http servicer because of the "Post" command shown above in the error. Maybe we can start the server using busybox's httpd.

I realized this is a strange error. The "snaps" folder suggests the "snaps" directory:
https://snapcraft.io/docs/system-snap-directory

which usually is:

Code: Select all

/var/lib/snapd/snaps/

This is weird though because it is almost like the server expects a directory for a package to exist before the package is installed. However, this likely isn't the case since the server likely uses dynamic paths.

As I side note, I'm wondering if I can use ncat here:

Code: Select all

ncat --listen --keep-open -U /run/snapd.socket --exec /usr/lib/snapd/snapd http://localhost/v2 0666

https://man7.org/linux/man-pages/man1/ncat.1.html
https://nmap.org/ncat/guide/index.html

Note that I chose the url path as "http://localhost/v2" because of the following output:

Code: Select all

snap services
error: cannot communicate with server: Get http://localhost/v2/apps?select=service: dial unix /run/snapd.socket: connect: no such file or directory

[s243a]

As I side note, I'm wondering if I can use ncat here:

Code: Select all

ncat --listen --keep-open -U /run/snapd.socket --exec /usr/lib/snapd/snapd http://localhost/v2 0666

https://man7.org/linux/man-pages/man1/ncat.1.html
https://nmap.org/ncat/guide/index.html

Note that I chose the url path as "http://localhost/v2" because of the following output:

Code: Select all

snap services
error: cannot communicate with server: Get http://localhost/v2/apps?select=service: dial unix /run/snapd.socket: connect: no such file or directory

Two problems with my above netcat command. First you just specify a host name (e.g. localhost) rather than the whole uri (i.e. http://localhost/v2/). The other issue is that you can't specify both a local host and a unix domain socket. I tried to get around this as follows. First the command:

Code: Select all

ncat -U /run/snapd.socket  -v --listen --keep-open --exec /usr/lib/snapd/snapd 0666

then in another window I try to connect the unix domain socket with a tcp socket using socat:

Code: Select all

socat TCP-LISTEN:0666,reuseaddr UNIX-CLIENT:/run/snapd.socket

https://serverfault.com/questions/51790 ... y-over-tcp
https://linux.die.net/man/1/socat

At first everything looks good and the output of my ncat command is:

Code: Select all

Ncat: Version 7.70 ( https://nmap.org/ncat )
Ncat: Listening on /run/snapd.socket

However, when I try to run a snap command, I get an error saying the socket is already in use:

Code: Select all

Ncat: Connection from a client on Unix domain socket.
Ncat: Connection from .
Ncat: error: when trying to listen on /run/snapd.socket: socket "/run/snapd.socket" already in use
Connection from a client on Unix domain socket.
Ncat: Connection from .

However, if I don't do the socat command then it will tell me that the socket doesn't exist.

[s243a]

I found something that might be helpful (to research later):

Package: init-system-helpers (1.58) [essential]

helper tools for all init systems

This package contains helper tools that are necessary for switching between the various init systems that Debian contains (e. g. sysvinit or systemd). An example is deb-systemd-helper, a script that enables systemd unit files without depending on a running systemd.

It also includes the "service", "invoke-rc.d", and "update-rc.d" scripts which provide an abstraction for enabling, disabling, starting, and stopping services for all supported Debian init systems as specified by the policy.

While this package is maintained by pkg-systemd-maintainers, it is NOT specific to systemd at all. Maintainers of other init systems are welcome to include their helpers in this package.

https://packages.debian.org/sid/init-system-helpers

I found this by searching for "deputy init" which was mentioned here:
https://forum.snapcraft.io/t/installing ... emd/3949/5
https://lists.ubuntu.com/archives/trust ... 23179.html