I am trying to set up Mosquitto using this guide: https://www.digitalocean.com/community/tutorials/how-to-install-and-secure-the-mosquitto-mqtt-messaging-broker-on-ubuntu-18-04 I am using ubuntu 20.04 but I couldn't find any Focal-specific guides. When I first install it, I can start and restart the service without issue. However, adding my cofig file seems to break it, specifically the keyfile lines. I have tried Mosquitto both from the Ubuntu repos and from the PPA. The error appears after I make a conf file, which looks like this:

allow_anonymous false
password_file /etc/mosquitto/pwfile

listener 1883 localhost

listener 8883
certfile /etc/letsencrypt/live/mydomain/cert.pem
cafile /etc/letsencrypt/live/mydomain/chain.pem
keyfile /etc/letsencrypt/live/mydomain/privkey.pem

listener 8083
protocol websockets
certfile /etc/letsencrypt/live/mydomain/cert.pem
cafile /etc/letsencrypt/live/mydomain/chain.pem
keyfile /etc/letsencrypt/live/mydomain/privkey.pem

` and when I restart the service after adding the above conf file, it fails and this is what is in journalctl -xe :

-- A start job for unit mosquitto.service has begun execution.
-- 
-- The job identifier is 4722.
Dec 20 06:45:32 thestash mosquitto: 1608464732: Loading config file /etc/mosquitto/conf.d/default.conf
Dec 20 06:45:32 thestash systemd: mosquitto.service: Main process exited, code=exited, status=1/FAILURE
-- Subject: Unit process exited
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support 
-- 
-- An ExecStart= process belonging to unit mosquitto.service has exited.
-- 
-- The process' exit code is 'exited' and its exit status is 1.
Dec 20 06:45:32 thestash systemd: mosquitto.service: Failed with result 'exit-code'.
-- Subject: Unit failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support 
-- 
-- The unit mosquitto.service has entered the 'failed' state with result 'exit-code'.
Dec 20 06:45:32 thestash systemd: Failed to start Mosquitto MQTT Broker.
-- Subject: A start job for unit mosquitto.service has failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support 
-- 
-- A start job for unit mosquitto.service has finished with a failure.
-- 
-- The job identifier is 4722 and the job result is failed.
Dec 20 06:45:32 thestash systemd: mosquitto.service: Scheduled restart job, restart counter is at 5.
-- Subject: Automatic restarting of a unit has been scheduled
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support 
-- 
-- Automatic restarting of the unit mosquitto.service has been scheduled, as the result for
-- the configured Restart= setting for the unit.
Dec 20 06:45:32 thestash systemd: Stopped Mosquitto MQTT Broker.
-- Subject: A stop job for unit mosquitto.service has finished
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support 
-- 
-- A stop job for unit mosquitto.service has finished.
-- 
-- The job identifier is 4794 and the job result is done.
Dec 20 06:45:32 thestash systemd: mosquitto.service: Start request repeated too quickly.
Dec 20 06:45:32 thestash systemd: mosquitto.service: Failed with result 'exit-code'.
-- Subject: Unit failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support 
-- 
-- The unit mosquitto.service has entered the 'failed' state with result 'exit-code'.
Dec 20 06:45:32 thestash systemd: Failed to start Mosquitto MQTT Broker.
-- Subject: A start job for unit mosquitto.service has failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support 
-- 
-- A start job for unit mosquitto.service has finished with a failure.
-- 
-- The job identifier is 4794 and the job result is failed.
Dec 20 06:45:34 thestash sudo: admin : TTY=pts/0 ; PWD=/home/admin ; USER=root ; COMMAND=/usr/bin/nano /etc/mosquitto/conf.d/default.conf
Dec 20 06:45:34 thestash sudo: pam_unix(sudo:session): session opened for user root by admin(uid=0)
Dec 20 06:45:38 thestash sudo: pam_unix(sudo:session): session closed for user root
Dec 20 06:45:38 thestash kernel: [UFW BLOCK] IN=eth0 OUT= MAC=d6:32:76:db:0a:3b:18:2a:d3:e0:df:f0:08:00 SRC=45.129.33.168 DST=104.236.7.145 LEN=40 TOS=0x00 PREC=0x00 TTL=245 ID=11309 PROTO=TCP SPT=59534 DPT=21661 WINDOW=1024 RES=0x00 SYN URGP=0 
Dec 20 06:45:44 thestash sudo: admin : TTY=pts/0 ; PWD=/home/admin ; USER=root ; COMMAND=/usr/bin/journalctl -xe
Dec 20 06:45:44 thestash sudo: pam_unix(sudo:session): session opened for user root by admin(uid=0)

If I comment out the keyfile lines in my default.conf, the service restarts without error. The keys are there and do not seem to cause problems for anything else on my server. And the mosquitto.log file indicates that it is indeed a problem with reading the certificate. A permissions issue seems like a good guess, but I don't see why that would be a problem only for privkey.pem but not the other two files, which also have the same permissions. Also, nginx can use my certificates without owning them.

1608463912: mosquitto version 2.0.3 starting
1608463912: Config loaded from /etc/mosquitto/mosquitto.conf.
1608463912: Opening ipv4 listen socket on port 1883.
1608463912: Opening ipv4 listen socket on port 8883.
1608463912: Opening ipv6 listen socket on port 8883.
1608463912: Error: Unable to load CA certificates. Check cafile "/etc/letsencrypt/live/mylittlestashbox.com/chain.pem".
1608463912: Error: Unable to load server certificate "/etc/letsencrypt/live/mylittlestashbox.com/cert.pem". Check certfile.
1608463912: OpenSSL Error: error:0200100D:system library:fopen:Permission denied
1608463912: OpenSSL Error: error:20074002:BIO routines:file_ctrl:system lib
1608463912: OpenSSL Error: error:140DC002:SSL routines:use_certificate_chain_file:system lib
1608464267: mosquitto version 2.0.3 starting
1608464267: Config loaded from /etc/mosquitto/mosquitto.conf.
1608464267: Opening ipv4 listen socket on port 1883.
1608464267: Opening ipv4 listen socket on port 8883.
1608464267: Opening ipv6 listen socket on port 8883.
1608464267: Error: Unable to load CA certificates. Check cafile "/etc/letsencrypt/live/mylittlestashbox.com/chain.pem".
/var/log/mosquitto/mosquitto.log

I have written a small bash script (datalogger.sh) to store the mqtt data on to SD card inside a linux machine. The bash script is as below:- #!/bin/bash fileNumber=1 temp=1 // flag to check and create new files fileName="Data" while [ $temp -le 1 ] do if [ -f "/media/card/$fileName$fileNumber.txt" ] then ((fileNumber++)) else touch "/media/card/$fileName$fileNumber.txt" mosquitto_sub -v -t "gateway/+/rx" | tee /media/card/$fileName$fileNumber.txt temp=2 fi done The bash script works totally fine if i run it with the following command ./datalogger.sh As of next step, i used the update-rc.d datalogger.sh defaults so that on boot the bash script automatically runs. However, i only get the empty text files. Could anyone guide me, what mistake i am making? Best Regards,

I'm using zmq to receive data from another pc. I would like to formard this received data to the Internet via namespace. I've created this python script: import subprocess import zmq context = zmq.Context() socket = context.socket(zmq.SUB) socket.connect("tcp://10.1.24.50:4000") socket.subscribe("") while True: print("message rcv") data = socket.recv_string() command = ['sudo', 'ip', 'netns', 'exec', 'ue1', 'ping', '-i', '1', '-c', '1', '-s', str(len(data)), '8.8.8.8'] print(data) subprocess.run(command, input=data, text=True) When I execute the script in a terminal I get this output. message rcv Lat 41.283637867194834, Lon=1.9846894680137672 PING 8.8.8.8 (8.8.8.8) 46(74) bytes of data. 54 bytes from 8.8.8.8: icmp_seq=1 ttl=114 time=184 ms --- 8.8.8.8 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 184.334/184.334/184.334/0.000 ms However, I don't see the transmitted data (using wireshark). What I'm doing wrong?

I have simple secure (I guess) Mosquitto server described in my previous question . Client machine has no any keys or certificate installed except single ca.crt certificate file generated and taken from Mosquitto server. Is it possible that request performed by simple MQTT client below is encrypted and secure? mosquitto_sub -h 192.168.1.8 -t sensor --cafile ca.crt -p 8883 -d This client uses only single certificate file and no keys. Is it somehow possible encrypt traffic by having only certificate and no keys?

I am trying to write fail2ban filter to block bruteforcing IP addresses which are trying to subscribe to username/password protected mosquitto service by guessing username/password combinations. On attempt to subscribe with incorrect details, mosquitto writes two lines to log like: 1544984465: New connection from 123.123.123.123 on port 1883. 1544984465: Socket error on client , disconnecting. I managed to write regex matching this two lines pattern by using https://regex101.com/ set to "python flavor". Regex looks like this: \s(?P\d+)\: New connection from (?P[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}) .+\n(?P=date): Socket error on client \, disconnecting. Unfortunately, fail2ban is unable to find matches in log by using this regex: # fail2ban-regex '/var/log/testlog.log' '\s(?P\d+)\: New connection from (?P[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}) .+\n(?P=date): Socket error on client \, disconnecting.' Running tests ============= Use failregex line : \s(?P\d+)\: New connection from (?P[0-... Use log file : /var/log/testlog.log Use encoding : UTF-8 Results ======= Failregex: 0 total Ignoreregex: 0 total Date template hits: |- [# of hits] date format | Epoch `- Lines: 13 lines, 0 ignored, 0 matched, 13 missed [processed in 0.00 sec] |- Missed line(s): | 1544984465: New connection from 123.123.123.123 on port 1883. | 1544984465: Socket error on client , disconnecting. | 1544984466: New connection from 123.123.123.123 on port 1883. | 1544984466: Socket error on client , disconnecting. | 1544984468: New connection from 123.123.123.123 on port 1883. | 1544984468: Socket error on client , disconnecting. | 1544984469: New connection from 123.123.123.123 on port 1883. | 1544984469: Socket error on client , disconnecting. | 1544984470: New connection from 123.123.123.123 on port 1883. | 1544984470: Socket error on client , disconnecting. | 1544984471: New connection from 123.123.123.123 on port 1883. | 1544984471: Socket error on client , disconnecting. | 1544984473: New connection from 123.123.123.123 on port 1883. `- Fail2ban version is 0.9.6-1.el6.1. Running on Centos 6 server.

I want to have 2 mosquitto brokers running on Debian 11, each with it's own configuration. I have one instance installed and running, but don't know how to start second. I'm a newbie so please answear as simply and clearly as possible

A 'listener' console was setup: mosquitto_sub -h test.mosquitto.org -t "myTopic" -v mosquitto_pub returns an error:

pi@raspberrypi:~ $ mosquitto_pub -h test.mosquitto.org  -t 'myTopic' -m 'hello world'
**Error: The connection was lost.**

What steps, from the command line, can be taken to diagnose if there is a syntax problem? Update: Replacing the MQTT server with iot.eclipse.org does not suffer the error and returns payloads as expected. Listener console setup: mosquitto_sub -h iot.eclipse.org -t "myTopic" -v Send payload: mosquitto_pub -h iot.eclipse.org -t 'myTopic' -m 'hello world' mosquitto_pub returns: pi@raspberrypi:~ $ mosquitto_sub -h iot.eclipse.org -t "myTopic" -v myTopic hello world Publish a payload: pi@raspberrypi:~ $ mosquitto_pub -h test.mosquitto.org -t 'myTopic' -m 'hello world' Changing the MQTT broker demonstrates there is not a syntax error, however, the question remains why there is an error returned in the original testing

I have a Python script which I'd like to run at startup. However when I run it as a systemd service, it seems to be unable to find one of the modules. Here's the status message: ● mqttproc.service - MQTT Post-processor Loaded: loaded (/etc/systemd/system/mqttproc.service; enabled; vendor preset: enabled) Active: failed (Result: exit-code) since Mon 2021-12-06 11:10:45 GMT; 2min 31s ago Process: 2375 ExecStart=/usr/bin/python3 /home/ken/python/mqttproc/mqttproc.py (code=exited, status=1/FAILURE) Main PID: 2375 (code=exited, status=1/FAILURE) Dec 06 11:10:45 MintVM systemd: Started MQTT Post-processor. Dec 06 11:10:45 MintVM python3: Sensor positions [100.0, 80.0, 60.0, 40.0, 20.0, 0.0] (Litres) Dec 06 11:10:45 MintVM python3: Traceback (most recent call last): Dec 06 11:10:45 MintVM python3: File "/home/ken/python/mqttproc/mqttproc.py", line 131, in Dec 06 11:10:45 MintVM python3: import paho.mqtt.client as mqtt Dec 06 11:10:45 MintVM python3: ModuleNotFoundError: No module named 'paho' Dec 06 11:10:45 MintVM systemd: mqttproc.service: Main process exited, code=exited, status=1/FAILURE Dec 06 11:10:45 MintVM systemd: mqttproc.service: Failed with result 'exit-code'. The bizarre thing is this script runs without fail from the commandline. I even have it running as a systemd service on another machine. My .service file is as simple as they come: [Unit] Description=MQTT Post-processor [Service] ExecStart=/usr/bin/python3 /home/ken/python/mqttproc/mqttproc.py WorkingDirectory=/home/ken/python/mqttproc [Install] WantedBy=multi-user.target Can anyone point out the obvious thing I'm missing, please? Thanks in advance.

I am trying to fit the output of the following string (that is a simple number) df -hl | grep '/dev/mapper/4tb' | awk '{;percent+=$5;} END{print percent}' | column -t into the following mqtt message mosquitto_pub -h 192.168.1.1 -p 1883 -u user -P password -t disk_usage/4tb -m *[here sould go the output of the previous command]* I have tried the following script and many many of its variants (different quotes and parentesis, etc.) but I still cannot figure it out. #!/bin/sh var1='{df -hl | grep '/dev/mapper/4tb' | awk '{;percent+=$5;} END{print percent}' | column -t}' echo $var1 mosquitto_pub -h 192.168.1.65 -p 1883 -u mqtt -P mqtt_password -t GC01SRVR/disk_usage -m "{\"Content\": $var1}"

If this is not the right place to post a this question, please say. I’m running zigbee2mqtt (Zigbee broker) on a USB dongle device (CC2531 with antenna, forgot the antenna model) and a Linux machine (KDE neon User Edition 5.19, based on Ubuntu 18.04). Sometimes zigbee2mqtt stops working and I have to change the ownership of the device (with chown) to successfully run it again. So I put it in one script: ~/my_services/zigbee2mqtt_service $ cat z2m.sh sudo chown gal /dev/ttyACM0 cd /opt/zigbee2mqtt npm start and created a service in systemd to run the script: ~/my_services/zigbee2mqtt_service $ systemctl cat zigbee2mqtt.service # /etc/systemd/system/zigbee2mqtt.service [Unit] Description=zigbee2mqtt After=network.target [Service] # ExecStart=/usr/local/bin/npm start # WorkingDirectory=/opt/zigbee2mqtt ExecStart=/home/gal/my_services/zigbee2mqtt_service/z2m.sh StandardOutput=inherit StandardError=inherit Restart=always User=gal [Install] WantedBy=multi-user.target This used to work, but for some reason, now the service won't start. I’m tried enabling it, starting manually, and to reload daemon. If I run the z2m.sh script manually it works well, but I’m working from a remote machine so I have to disconnect, which stops zigbee2mqtt. It’d be great if you can point me to what to fix, or to a different way to recover from the ‘revoked ownership’. Edit: This is what I get when checking the service status: ~ $ systemctl status zigbee2mqtt.service ● zigbee2mqtt.service - zigbee2mqtt Loaded: loaded (/etc/systemd/system/zigbee2mqtt.service; enabled; vendor pres Active: failed (Result: exit-code) since Mon 2020-07-20 11:00:57 IDT; 2 days Process: 4059 ExecStart=/home/gal/my_services/zigbee2mqtt_service/z2m.sh (code Main PID: 4059 (code=exited, status=203/EXEC) Jul 20 11:00:57 phoenix systemd: zigbee2mqtt.service: Service hold-off time o Jul 20 11:00:57 phoenix systemd: zigbee2mqtt.service: Scheduled restart job, Jul 20 11:00:57 phoenix systemd: Stopped zigbee2mqtt. Jul 20 11:00:57 phoenix systemd: zigbee2mqtt.service: Start request repeated Jul 20 11:00:57 phoenix systemd: zigbee2mqtt.service: Failed with result 'exi Jul 20 11:00:57 phoenix systemd: Failed to start zigbee2mqtt. lines 1-12/12 (END)

I have generated client key certificate on self signed secure Mosquitto server. I have copied CA and client certificate with client key into client machine. Client subscription runs fine: mosquitto_sub -h 192.168.1.8 -t sensor --cafile ca.crt --cert client.crt --key client.key -p 8883 -d But what if somebody hack my client machine and will get credentials. How I can disable this certificate in server machine?

I have simple MQTT Mosquitto server that I'm trying to make secure. Mosquitto.conf: log_type all password_file /etc/mosquitto/mosquitto_users.txt pid_file /var/run/mosquitto.pid persistence true persistence_location /var/lib/mosquitto/ port 8883 cafile /etc/mosquitto/ca_certificates/ca.crt keyfile /etc/mosquitto/ca_certificates/server.key certfile /etc/mosquitto/ca_certificates/server.crt tls_version tlsv1 On current server I generated: CA certificate openssl genrsa -des3 -out ca.key 2048 openssl req -new -x509 -days 3650 -key ca.key -out ca.crt Server certificate: openssl genrsa -out server.key 2048 openssl req -new -out server.csr -key server.key Self sign server certificate: openssl x509 -req -in server.csr -CA ca.crt -CAkey ca.key -CAcreateserial -out server.crt -days 720 All required files placed according to msoquitto.conf configuration. I'm using following commands to subscribe and post messages by using ca.crt certificate. mosquitto_sub -h 192.168.1.8 -t sensor --cafile ca.crt -p 8883 -d mosquitto_pub -h 192.168.1.8 -t sensor --cafile ca.crt -m "test" -p 8883 -d Everything works fine. But does it men communication is secured? Should I place server on Internet and nobody will grab information?

A test MQTT broker can be found at: http://test.mosquitto.org/ . The website suggests trying the command: mosquitto_sub -h test.mosquitto.org -t "#" -v I believe that the "#" denote a wildcard for topics, which would show any topic and its payload. A raspberry pi has successfully run the mosquitto command per instructables MQTT example , however **no output is observed with the above command.** It is unclear if there is an entity publishing to the test server that would return a result in the subscribing client. This could be on reason that I am not observing anything. I would think there are other possible obstacles / pitfalls and look forward to enlightening responses. Attempts to publish to a topic failed as described in: https://unix.stackexchange.com/questions/534236/

Context: OSMC distro on Raspberry Pi Zero-W. MQTT Mosquitto package installation failed. Why would an attempt to: sudo apt-get install mosquitto trigger an attempt to remove an OSMC package? The following packages will be REMOVED: ssh-app-osmc Log: osmc@osmczero:~$ sudo apt-get install mosquitto Reading package lists... Done Building dependency tree Reading state information... Done The following additional packages will be installed: libev4 libuv1 libwebsockets8 Suggested packages: apparmor The following packages will be REMOVED: ssh-app-osmc The following NEW packages will be installed: libev4 libuv1 libwebsockets8 mosquitto 0 upgraded, 4 newly installed, 1 to remove and 0 not upgraded. 1 not fully installed or removed. Need to get 0 B/314 kB of archives. After this operation, 673 kB of additional disk space will be used. Do you want to continue? [Y/n] Y (Reading database ... 34694 files and directories currently installed.) Removing ssh-app-osmc (1.2.3) ... Removing 'diversion of /etc/ssh/sshd_config to /etc/ssh/sshd_config.distributed by ssh-app-osmc' dpkg-divert: error: rename involves overwriting '/etc/ssh/sshd_config' with different file '/etc/ssh/sshd_config.distributed', not allowed dpkg: error processing package ssh-app-osmc (--remove): subprocess installed post-removal script returned error exit status 2 Errors were encountered while processing: ssh-app-osmc E: Sub-process /usr/bin/dpkg returned an error code (1) UPDATE === Dependency query: osmc@osmczero:~$ apt-cache show ssh-app-osmc Package: ssh-app-osmc Origin: OSMC Version: 1.2.3 Essential: No Pre-Depends: openssh-server Architecture: all Maintainer: Sam G Nazarko Priority: required Section: metapackages Filename: pool/main/s/ssh-app-osmc/ssh-app-osmc_1.2.3_all.deb Size: 3168 SHA256: 6fe60f2956b2d5105d9da82693f1747195be55ce81a6e4b4085ab5acc0af33fb SHA1: edcb33f8a2f0ed82028e31e53ae6889dc99714f5 MD5sum: 9602092e26c9fe46596dc2165759b78d Description: SSH server for OSMC with prepopulated configuration Description-md5: a4e3a71ca28452ae99a476d87b31377c Installed-Size: 38

What information can be gleaned for corrective action to enable subscription to the example MQTT topic? The goal is to reproduce the test (subscribe & publish), per the instruction's Step 3 : an MQTT server was installed and attempts to subscribe with MQTT Client fails: pi@raspberrypi:~ $ mosquitto_sub –d –t armtronix_mqtt **Error: Unknown option '–d'.** Use 'mosquitto_sub --help' to see usage. Help Page: pi@raspberrypi:~ $ mosquitto_sub --help mosquitto_sub is a simple mqtt client that will subscribe to a single topic and print all messages it receives. mosquitto_sub version 1.4.10 running on libmosquitto 1.4.10. Usage: mosquitto_sub [-c] [-h host] [-k keepalive] [-p port] [-q qos] [-R] -t topic ... [-C msg_count] [-T filter_out] [-A bind_address] [-S] [-i id] [-I id_prefix] [-d] [-N] [--quiet] [-v] [-u username [-P password]] [--will-topic [--will-payload payload] [--will-qos qos] [--will-retain]] [{--cafile file | --capath dir} [--cert file] [--key file] [--ciphers ciphers] [--insecure]] [--psk hex-key --psk-identity identity [--ciphers ciphers]] [--proxy socks-url] mosquitto_sub --help -A : bind the outgoing socket to this host/ip address. Use to control which interface the client communicates over. -c : disable 'clean session' (store subscription and pending messages when client disconnects). -C : disconnect and exit after receiving the 'msg_count' messages. -d : enable debug messages. -h : mqtt host to connect to. Defaults to localhost. -i : id to use for this client. Defaults to mosquitto_sub_ appended with the process id. -I : define the client id as id_prefix appended with the process id. Useful for when the broker is using the clientid_prefixes option. -k : keep alive in seconds for this client. Defaults to 60. -N : do not add an end of line character when printing the payload. -p : network port to connect to. Defaults to 1883. -P : provide a password (requires MQTT 3.1 broker) -q : quality of service level to use for the subscription. Defaults to 0. -R : do not print stale messages (those with retain set). -S : use SRV lookups to determine which host to connect to. -t : mqtt topic to subscribe to. May be repeated multiple times. -T : topic string to filter out of results. May be repeated. -u : provide a username (requires MQTT 3.1 broker) -v : print published messages verbosely. -V : specify the version of the MQTT protocol to use when connecting. Can be mqttv31 or mqttv311. Defaults to mqttv31. --help : display this message. --quiet : don't print error messages. --will-payload : payload for the client Will, which is sent by the broker in case of unexpected disconnection. If not given and will-topic is set, a zero length message will be sent. --will-qos : QoS level for the client Will. --will-retain : if given, make the client Will retained. --will-topic : the topic on which to publish the client Will. --cafile : path to a file containing trusted CA certificates to enable encrypted certificate based communication. --capath : path to a directory containing trusted CA certificates to enable encrypted communication. --cert : client certificate for authentication, if required by server. --key : client private key for authentication, if required by server. --ciphers : openssl compatible list of TLS ciphers to support. --tls-version : TLS protocol version, can be one of tlsv1.2 tlsv1.1 or tlsv1. Defaults to tlsv1.2 if available. --insecure : do not check that the server certificate hostname matches the remote hostname. Using this option means that you cannot be sure that the remote host is the server you wish to connect to and so is insecure. Do not use this option in a production environment. --psk : pre-shared-key in hexadecimal (no leading 0x) to enable TLS-PSK mode. --psk-identity : client identity string for TLS-PSK mode. --proxy : SOCKS5 proxy URL of the form: socks5h://[username[:password]@]hostname[:port] Only "none" and "username" authentication is supported. MQTT Client install log: pi@raspberrypi:~ $ sudo apt-get install mosquitto-clients Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: coinor-libipopt1v5 libmumps-seq-4.10.0 libraw15 Use 'sudo apt autoremove' to remove them. The following additional packages will be installed: libmosquitto1 The following NEW packages will be installed: libmosquitto1 mosquitto-clients 0 upgraded, 2 newly installed, 0 to remove and 1 not upgraded. Need to get 99.5 kB of archives. After this operation, 222 kB of additional disk space will be used. Do you want to continue? [Y/n] y Get:1 http://raspbian.raspberrypi.org/raspbian stretch/main armhf libmosquitto1 armhf 1.4.10-3+deb9u4 [47.2 kB] Get:2 http://raspbian.raspberrypi.org/raspbian stretch/main armhf mosquitto-clients armhf 1.4.10-3+deb9u4 [52.3 kB] Fetched 99.5 kB in 1s (86.7 kB/s) Selecting previously unselected package libmosquitto1:armhf. (Reading database ... 141867 files and directories currently installed.) Preparing to unpack .../libmosquitto1_1.4.10-3+deb9u4_armhf.deb ... Unpacking libmosquitto1:armhf (1.4.10-3+deb9u4) ... Selecting previously unselected package mosquitto-clients. Preparing to unpack .../mosquitto-clients_1.4.10-3+deb9u4_armhf.deb ... Unpacking mosquitto-clients (1.4.10-3+deb9u4) ... Processing triggers for libc-bin (2.24-11+deb9u4) ... Processing triggers for man-db (2.7.6.1-2) ... Setting up libmosquitto1:armhf (1.4.10-3+deb9u4) ... Setting up mosquitto-clients (1.4.10-3+deb9u4) ... Processing triggers for libc-bin (2.24-11+deb9u4) ... .list file install for Raspbian buster: pi@raspberrypi:~ $ cd /etc/apt/sources.list.d/ pi@raspberrypi:/etc/apt/sources.list.d $ sudo wget http://repo.mosquitto.org/debian/mosquitto-buster.list --2019-08-01 00:01:16-- http://repo.mosquitto.org/debian/mosquitto-buster.list Resolving repo.mosquitto.org (repo.mosquitto.org)... 85.119.83.194, 2001:ba8:1f1:f271::2 Connecting to repo.mosquitto.org (repo.mosquitto.org)|85.119.83.194|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 50 [application/octet-stream] Saving to: ‘mosquitto-buster.list’ mosquitto-buster.list 100%[===================================================================>] 50 --.-KB/s in 0s 2019-08-01 00:01:17 (1.14 MB/s) - ‘mosquitto-buster.list’ saved [50/50] pi@raspberrypi:/etc/apt/sources.list.d $ mosquitto_sub –t armtronix_mqtt Error: Unknown option '–t'. Use 'mosquitto_sub --help' to see usage. pi@raspberrypi:/etc/apt/sources.list.d $ sudo apt-get install mosquitto-clients Reading package lists... Done Building dependency tree Reading state information... Done mosquitto-clients is already the newest version (1.4.10-3+deb9u4). The following packages were automatically installed and are no longer required: coinor-libipopt1v5 libmumps-seq-4.10.0 libraw15 Use 'sudo apt autoremove' to remove them. 0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded. pi@raspberrypi:/etc/apt/sources.list.d $ mosquitto_sub –t armtronix_mqtt Error: Unknown option '–t'. Use 'mosquitto_sub --help' to see usage. pi@raspberrypi:/etc/apt/sources.list.d $ mosquitto_sub -d –t armtronix_mqtt Error: Unknown option '–t'. Use 'mosquitto_sub --help' to see usage.

As I understand it, Raspbian (

-04-08-raspbian-stretch-full.img

) features Node-Red out of the box. I have seen the youTube examples that show Node-Red configuring an MQTT server and left to wonder does the Raspbian image already have an MQTT server? If a default broker is installed,how does one 'smoke test' the broker? I would like to understand how to test (from the command line) if an MQTT server is installed, so I can determine if I need to install MQTT on the rPi.

I'm developing a C++ program (for a home IoT Project) on Debian 9 that needs to act as an MQTT client. I found paho.mqtt would be helpful in this regard, but none of the on-line documentations to install it worked so far. Does anyone has any experience on getting paho mqtt c++ client to work on Debian 9? If so, could you help me with the steps I need to do to get it working? (My Backgroud : I'm pretty comfortable around Linux, kind of OK when it comes to writing code in C or C++, but not that familiar with how c++ compiler works or how to get get C++ header files available for my program in this case) Thanks in advance!

My config.mk file has the following settings: # Select your backends from this list BACKEND_CDB ?= no BACKEND_MYSQL ?= no BACKEND_SQLITE ?= no BACKEND_REDIS ?= no BACKEND_POSTGRES ?= yes BACKEND_LDAP ?= no BACKEND_HTTP ?= no BACKEND_JWT ?= no BACKEND_MONGO ?= no BACKEND_FILES ?= yes BACKEND_MEMCACHED ?= no # Specify the path to the Mosquitto sources here MOSQUITTO_SRC = /usr/include # Specify the path the OpenSSL here OPENSSLDIR = /usr/bin/openssl # Specify optional/additional linker/compiler flags here # On macOS, add # CFG_LDFLAGS = -undefined dynamic_lookup # as described in https://github.com/eclipse/mosquitto/issues/244 CFG_LDFLAGS = CFG_CFLAGS = -DRAW_SALT When i am trying to compile it sudo make it throws the following error: Selected backends: PostgreSQL Files Using mosquitto source dir: /usr/include OpenSSL install dir: /usr/bin/openssl If you changed the backend selection, you might need to 'make clean' first CFLAGS: -DRAW_SALT -I/usr/include/src/ -I/usr/include/lib/ -fPIC -Wall -Werror -DBE_POSTGRES -DBE_FILES -I/usr/include/postgresql -I/src -DDEBUG=1 -I/usr/bin/openssl /include LDFLAGS: -L/usr/include/lib/ LDADD: -L/usr/lib/x86_64-linux-gnu -lpq -L/usr/bin/openssl /lib -lcrypto -lmosquitto cc -DRAW_SALT -I/usr/include/src/ -I/usr/include/lib/ -fPIC -Wall -Werror -DBE_POSTGRES -DBE_FILES -Ipg_config --includedir -I/src -DDEBUG=1 -I/usr/bin/openssl /include -c -o auth-plug.o auth-plug.c cc: error: /include: No such file or directory : recipe for target 'auth-plug.o' failed make: *** [auth-plug.o] Error 1 Could you please advice whats wrong and how can i fix the problem?

I want to compile mosquitto-auth-plugin, which requires configuration of config.mk file, where one of the required parameter is to Specify the path to the Mosquitto sources MOSQUITTO_SRC =.Could you please advice which directory i have to indicate if mosquitto was installed using advanced package tool (apt)?

Hi I want to try and convert a message receieved from MQTT into a variable so I can do an "IF script" using messages sent from a certain topic on mqtt. I tried this at top of script but didn't work: Message = mosquitto_sub -d -t "test/test" Thank you