An average guy's IT (mis)adventures

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

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.

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

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.

I am most productive at night, when there is finally silence - apart from background music. The last couple hours of this Wednesday brought some nice additions to the @wpn support MUC:

• chat is not XMPP only anymore, but it got bridged to Matrix, via "matterbridge".
• a bot is now sending "BOFH excuses" to the chat, once a day.

XMPP MUC can be reached from: https://invite.woodpeckersnest.space/#status@chat.woodpeckersnest.space?join

Matrix room can be reached from: https://matrix.to/#/#wpn:matrix.org

Bridged chat means that everything being written in any of those rooms, gets relayed to the other by bots: there are in fact 2 bots connected to the 2 rooms, one is an XMPP bot and the other is a Matrix one, operated by "matterbridge", as I said earlier.

About "BOFH excuses", they are some fortune cookies from the relative Linux package, which are all about "Bastard Operators From Hell" excuses.. They are some short funny sentences about IT which an imaginary Operator (sysop, sysadmin, you name it) could say as excuse to justify issues.

Example?

BOFH excuse #266:
All of the packets are empty.

I have the same script running on gemini, at gemini://woodpeckersnest.space/cgi-bin/bofh

Basically it's some python spaghetti which runs the fortune command, does some formatting to the resulting text and sends it over gemini, or in the case of @wpn chat, over webhook to one other bot, which then posts its content to XMPP. It's more complicated to explain than do it 😀

P.S. @wpn support MUC is not publicly listed, so even if I'm posting links which may be used to join it, it should be treated as limited to @wpn users only.

gemlog

Last evening, at around 22:00 CET, Contabo migrated my VPS from old Hub at Nuremberg to the newly built "Hub Europe".

They rebooted it and everything came back up as usual.. I wasn't at home when it happened, didn't even notice anything until I connected and found no tmux session running. Even my phone which was connected to wireguard, quietly continued working and sending notifications 😎

Meanwhile, my friends and I watched "The Creator" on Disney+

Can't really say I do recommend it, but for some casual evening/entertainment, it wasn't half bad.

gemlog

I've been rethinking about the publication license of these blog posts.

Changes I made:

• Some "public" posts were turned to "CC BY-NC-SA"
• Some "all-rights-reserved" posts were turned to "CC BY-NC-SA"

At the moment there are still other public and all-rights-reserved posts.. Most of the public ones are from me, while some are from friends who told me to publish them with such license.

The all-rights-reserved ones are mostly from content I grabbed over the net and published here, where I wasn't able to contact the original authors (so credits are to themselves) and some others are e.g. posts with pictures I took myself.

So.. From now on, all these types of licenses will co-exist and each post will be tagged with the correct/relative one (hopefully).

Disclaimer: If not specified, you can assume it's "CC BY-NC-SA" by Simone "roughnecks" Canaletti

https://creativecommons.org/licenses/by-nc-sa/4.0/

You can try this script on #fediverso at irc.libera.chat, where me, cage, ndo and other friends hang out

bot: "verne", running on @wpn

SearXNG instance: https://search.woodpeckersnest.space/

Thanks to cage for the script and ndo for creating the channel o/

# © cage released under CC0, public domain
# https://creativecommons.org/publicdomain/zero/1.0/

# Date: 16-08-2024
# Version: 0.1

# Package description: do a web search using your searxng instance
# Public ones won't probably work because of "limiter"

# Authorize your channel from the partyline with:
# .chanset +searxng #your-channel

# Do a search
# .search <query> | .search paris (this query goes to default engine)
# .search +<engine> <query> | .search +wp paris (this query goes to
# wikipedia)
# .search !images paris | this query search only paris' images

# List of engines: https://docs.searxng.org/user/configured_engines.html

# tcllib is required

############## configuration directives ############################

# url of the HTTP(S) server of the search engine

set searxconfig(website_url)    "https://example.com/searxng"

# serach command to trigger the search

set searxconfig(cmd)            ".search"

# default search engine

set searxconfig(default_engine) "ddg"

# maximum number of search results printed

set searxconfig(max_results)    3

# time tracker file
# NB: when this script runs any file with the same name within the path in the
# working  directory  (depending of  what  is  considered the  working
# directory of the script) will be erased and overwritten!

set searxconfig(file_millis)    "searx_millis.tmp"

# Minimum search frequency in milliseconds.
# This is  the minimum  time that must  pass between  two consecutive
# search

set searxconfig(max_freq)       30000

############## configuration ends here #############

# tcllib is required
package require csv

setudef flag searxng

if { !([info exists searxconfig(lastmillis)]) } {
    set searxconfig(lastmillis) 0
}

bind pub - $searxconfig(cmd) search:searxng

proc send_message {message} {
    putserv "PRIVMSG $message"
}

proc slurp_file {path} {
    set fp [open $path r]
    set file_data [read $fp]
    close $fp
    return $file_data
}

proc process_csv {csv channel} {
    global searxconfig
    set rows [split $csv "\n"]
    set count 0
    #remove the header
    set rows [lrange $rows 1 [llength $rows]]
    if {[llength $rows] < 1} {
        send_message "$channel :Something gone wrong."
    } else {
        foreach row $rows {
            if {$count < $searxconfig(max_results)} {
                set row_splitted [csv::split $row]
                set title [lindex $row_splitted 0]
                set url   [lindex $row_splitted 1]
                send_message "$channel :$title $url"
                incr count
            } else {
                break
            }
        }
    }
}

proc encode {query} {
    set query [regsub -all { } $query "%20"]
    set query [regsub -all {&} $query "%26"]
    set query [regsub -all {=} $query "%3D"]
    set query [regsub -all {!} $query "%21"]
}

proc get_query_results {engine query} {
    global searxconfig
    set query [encode $query]
    set engine [encode $engine]
    set url "$searxconfig(website_url)search?q=$query&format=csv&engines=$engine"
    ## decomment the line below for debugging purposes
    # putlog $url
    return [exec curl -sS $url]
}

proc get_last_millis { } {
    global searxconfig
    if {[file exists $searxconfig(file_millis)]} {
        set searxconfig(lastmillis) [slurp_file $searxconfig(file_millis)]
    } else {
        set fp [open $searxconfig(file_millis) w]
        puts $fp 0
        close $fp
        get_last_millis
    }
}

proc set_last_millis { } {
    global searxconfig
    set fp [open $searxconfig(file_millis) w]
    puts $fp [clock milliseconds]
    close $fp
}

proc search:searxng {nick host hand chan text} {
    global searxconfig

    if {!([channel get $chan searxng])} {
        send_message "$chan :This script has not been authorized to run in this channel."
        return 0
    }

    set millis [clock milliseconds]

    get_last_millis

    if { [expr $millis - $searxconfig(lastmillis)] > $searxconfig(max_freq) } {
        ## test antiflood superato

        set_last_millis

        set text_splitted [split $text " {}"]
        set engine [lindex $text_splitted 0]
        set text_length [llength $text_splitted]
        set query [lrange $text_splitted 1 $text_length]


        if {![regexp {^\+} $engine]} {
            set engine $searxconfig(default_engine)
            set query $text_splitted
        } else {
            set engine [string range $engine 1 [string length $engine]]
        }

        if {$query == {}} {
            send_message "$chan :Missing search criteria."
        } else {
            set csv [get_query_results $engine $query]
            process_csv $csv $chan
        }

        return 1;
    }
        send_message "$chan :Try again later."
    return 0
}

putlog "SearXNG Loaded"`

gemlog