An average guy's IT (mis)adventures

Hello!

Last "real" post was about 2 months ago.. I got busy with stuff at home but also made a lot of adjustments here and there at @wpn. Let me list the most important ones:

• Set up shell and email users' homes backup: archives are still stored on the VPS for the time being, till when I'll find another proper backup location.
• Cleaned up /var/www/ and nginx virtualhosts; also removed "Shaarli", since I wasn't really using it anymore.
• Added a new board on the main site for BitTorrent, reachable here: https://woodpeckersnest.space/board/torrents
• Upgraded XMPP Prosody server to 13.0.0 and isolated anon webchat even more, so that those users won't be able to connect to Biboumi IRC gateway.
• Upgraded all #slixmpp powered bots to 1.10, released only yesterday
• Formatted (again) the 2 pdf files regarding @wpn's Term of Use and Privacy Notice (no rules updates though)

I think that's about it.. probably 😀 I'm definitely forgetting something.

Some other news: a few new users joined XMPP and more than a few logged in our Movim COMMutiny pod. Welcome Aboard everyone! Be Nice!!

I'm keeping the pod up-to-date as much as I can (it's running on master branch), but that also mean I have to restart it sometimes; I will try to do that only during weekends from now on.. promise.

And now I'd better get going again.. See you soon!

I'll update this post whenever I see fits, A.K.A. when I have other bits of information which don't require a whole post.

Operations on files and directories

Move files to the current/parent directory in Linux

Current dir

find . -type f -exec mv {} . \;

Parent dir

find . -type f -exec mv {} .. \;

Recursive chmod on files and dirs

To change all the directories to 755 (-rwxr-xr-x):

find /var/www/blog -type d -exec chmod 755 {} \;

To change all the files to 644 (-rw-r--r--):

find /var/www/blog -type f -exec chmod 644 {} \;

Certbot

Certbot cli

/etc/letsencrypt/cli.ini

When renewing, use the same private key as the existing certificate. (default: False):

reuse-key = True

Common commands

Register single domain:

certbot certonly --standalone -d domain.tld --dry-run

• Remove “–dry-run” when ok.

Renew single domain:

certbot renew --cert-name domain.tld --dry-run

• Remove “–dry-run” when ok.

Delete single domain:

certbot delete --cert-name domain.tld

• Cannot use "--dry-run" in this case.

Revoke certificate:

certbot revoke --cert-path /etc/letsencrypt/archive/${YOUR_DOMAIN}/cert1.pem

Check certificate's expiry date:

cat /etc/letsencrypt/live/domain.tld/cert.pem | openssl x509 -noout -enddate

GIT

To reset your git repository to given commit id, do:

git reset --hard <commit-id>
git push origin master --force

Ignoring files that are already tracked

git update-index --assume-unchanged <your file here>

Delta Chat Mail sieve

require ["fileinto"];
# rule:[DeltaChat]
if header :contains "Chat-Version" "1.0"
{
	fileinto "DeltaChat";
	stop;
}

Postfix mail queue

To view postfix mail queue in case of problems and remove a particular message from it, do as follows:

# mailq

-Queue ID-  --Size-- ----Arrival Time---- -Sender/Recipient-------
6DCF32201B*    4824 Thu Oct 19 22:54:44  roughnecks@woodpeckersnest.eu
                                         debian@spacenet.it

-- 4 Kbytes in 1 Request.

# postsuper -d 6DCF32201B

postsuper: 6DCF32201B: removed
postsuper: Deleted: 1 message

To delete all emails in the queue, use this command:

# postsuper -d ALL

Check Preferred Outgoing IP (when multiple are set on <interface>)

curl ifconfig.me

The correct command to add a new Linux user (in this case without a shell)

adduser --shell /usr/sbin/nologin <username>

I always forget which command is the complete one, useradd or adduser

Packages management with apt and aptitude

Finding currently installed "external" packages (not from stable repo)

# aptitude search "?narrow(?installed,?not(?archive(stable)))"

i   containerd.io              - An open and reliable container runtime
i   docker-buildx-plugin       - Docker Buildx cli plugin.
i   docker-ce                  - Docker: the open-source application container engine
i   docker-ce-cli              - Docker CLI: the open-source application container engine
i A docker-ce-rootless-extras  - Rootless support for Docker.
i   docker-compose-plugin      - Docker Compose (V2) plugin for the Docker CLI.

In the above example, "i" means installed and "A" means it was automatically installed, such as a dependency. I'm running upstream docker.

This is another package that I have installed from sid and set on "hold":

# apt-cache policy toot

toot:
  Installed: 0.45.0-1
  Candidate: 0.45.0-1
  Version table:
 *** 0.45.0-1 100
        100 /var/lib/dpkg/status
     0.34.1-1 500
        500 http://deb.debian.org/debian bookworm/main amd64 Packages
        500 http://deb.debian.org/debian bookworm/main i386 Packages

bookworm version of toot is rather old, as you can see.

Busy Days, Exciting Progress 🚀

It’s been a couple working months, busy and sometimes hard but in the best way possible!

For starters, today the "GD" website went officially online, after we completed its migration from ZOPE to Wordpress and I couldn't be happier 😉

Another thrilling update is with COMMutiny, our social network project. The converse.js anonymous chat, originally set up for @wpn’s support room, has now found its own space within COMMutiny. This is a big step forward, and we’re inviting everyone interested in #XMPP, gaming, and social networks to join the conversation, anonymously or not.

On top of that, we’ve launched a brand-new freelance website, powered by Hugo. It’s sleek, fast, and everything we hoped it would be — hooray for #Hugo!

If you’re passionate about decentralized communication, gaming communities, or just want to connect with like-minded folks, we’d love to see you in COMMutiny! See you soon 👋

prosodyctl shell

Launch the shell:

# prosodyctl shell

Delete pubsub node (the ">" sign at the beginning is important and also dangerous, as it lets you do anything!):

>prosody.hosts["pubsub.example.tld"].modules.pubsub.service:delete("blog", true)

Delete ALL pubsub nodes

>local service = prosody.hosts["pubsub.example.tld"].modules.pubsub.service; for node in pairs(select(2, assert(service:get_nodes(true)))) do service:delete(node, true); end

Check subscription by user:

>prosody.hosts["pubsub.example.tld"].modules.pubsub.service.subscriptions["user@example.tld"]

Change affiliation on pubsub nodes (make user owner):

>prosody.hosts["pubsub.example.tld"].modules.pubsub.service:set_affiliation("blog",true,"user@example.tld","owner")

Unsubscribe from node

>prosody.hosts["pubsub.example.tld"].modules.pubsub.service:remove_subscription("blog",true,"user@example.tld")

Subscribe to node

>prosody.hosts["pubsub.example.tld"].modules.pubsub.service:add_subscription("blog",true,"user@example.tld")

prosodyctl commands

Asking for help:

# prosodyctl shell help

# prosodyctl shell 'help SECTION'

Show all listening ports:

# prosodyctl shell port list

Show all http endpoints:

# prosodyctl shell http list

List registered users:

# prosodyctl shell user list example.tld

List existing MUCs:

# prosodyctl shell muc list [component name]

List connected clients:

# prosodyctl shell c2s show

Activate a component:

# prosodyctl shell host activate some.component.example.tld

Generate Invites: create a new invite using an ad-hoc command in an XMPP client connected to your admin account, or use the command line:

# prosodyctl mod_invites generate example.tld

Reset forgot passsword: "doesn't seem to work - see below"

# prosodyctl mod_invites generate example.tld --reset <USERNAME>

Automatic Certificates Import: prosodyctl has the ability to import and activate certificates in one command:

# prosodyctl --root cert import HOSTNAME /path/to/certificates

Certificates and their keys are copied to /etc/prosody/certs (can be changed with the certificates option) and then it signals Prosody to reload itself. –root lets prosodyctl write to paths that may not be writable by the prosody user, as is common with /etc/prosody. Multiple hostnames and paths can be given, as long as the hostnames are given before the paths.

This command can be put in cron or passed as a callback to automated certificate renewal programs such as certbot or other Let's Encrypt clients.

Import All:

# prosodyctl --root cert import /etc/letsencrypt/live

Reset forgot password

# prosodyctl install --server=https://modules.prosody.im/rocks/ mod_password_reset

Reload prosody configuration then use ad-hoc commands to generate a reset link for given JID

It's been a few days now that I'm experiencing downtimes at night, early mornings.

When I wake up, connect to the VPS and attach to tmux, I am welcomed by these messages in console:

        Message from syslogd@pandora at Nov 3 05:37:13 ...
        kernel:[1586232.350737] Dazed and confused, but trying to continue

        Message from syslogd@pandora at Nov 3 05:37:24 ...
        kernel:[1586235.049143] Uhhuh. NMI received for unknown reason
        30 on CPU 1.

        Message from syslogd@pandora at Nov 3 05:37:24 ...
        kernel:[1586235.049145] Dazed and confused, but trying to continue

        Message from syslogd@pandora at Nov 3 05:37:55 ...
        kernel:[1586273.642163] watchdog: BUG: soft lockup - CPU#2 stuck
        for 27s! [dockerd:526408]

        Message from syslogd@pandora at Nov 3 05:38:00 ...
        kernel:[1586278.545172] watchdog: BUG: soft lockup - CPU#1 stuck
        for 24s! [systemd-journal:257]

        Message from syslogd@pandora at Nov 3 05:38:02 ...
        kernel:[1586281.187611] watchdog: BUG: soft lockup - CPU#3 stuck
        for 35s! [lua5.4:1702]

There's no need to say that when this happens, the server is completely frozen and doesn't respond to anything.

I already contacted support, but they didn't investigate at all, I believe. They manually restarted my VPS once and did some pings and connection tests (VNC, SSH) afterwards.. "everything is working fine!"

This last Saturday I was up when it happened, so I did a mtr from my PC to the VPS's IP and logged it, then I sent another email with the output to support.. Still waiting for them to reply, I guess tomorrow (Monday).

Friends like lorenzo and shai are having difficulties too, with the same provider, so I'm not imagining things.

Well, that's all I got to say, will keep you posted if any news.