Tag: OpenHAB

Sorting Grep Results When Log File Names Are Incremented Integers

While rotated log files can have a timestamp like YYYYMMDDHHmmss appended, a lot of log files are rotated with incremented integers (i.e. file.3 is removed, file.2 becomes file.3, file.1 becomes file.2, file becomes file.1, and file is a new file for current log ‘stuff’). We had some … challenges changing the log4j settings to use the timestamp format. When you grep all of the log files, the results are organized by alpha-sorted file names. Problem is that alpha sorted file names are 1, 10, 11, 12, …, 19, 2, 20, 21 … which doesn’t produce results in ascending or descending date order. You get:

zwave.log.1:2018-07-01 22:51:21.450 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 58: Node not awake!
zwave.log.1:2018-07-01 22:51:21.450 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 55: Node not awake!
zwave.log.11:2018-07-02 00:47:05.375 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 70: Node not awake!
zwave.log.11:2018-07-02 00:47:05.376 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 46: Node not awake!
zwave.log.12:2018-07-02 01:01:12.850 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 82: Node not awake!
zwave.log.13:2018-07-02 01:11:22.465 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 48: Node not awake!
zwave.log.13:2018-07-02 01:11:22.478 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 82: Node not awake!
zwave.log.13:2018-07-02 01:11:22.478 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 49: Node not awake!
zwave.log.14:2018-07-02 01:25:22.632 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 112: Node not awake!
zwave.log.14:2018-07-02 01:25:22.632 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 212: Node not awake!
zwave.log.15:2018-07-02 01:40:29.053 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 58: Node not awake!
zwave.log.15:2018-07-02 01:40:29.053 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 70: Node not awake!
zwave.log.16:2018-07-02 01:55:01.702 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 50: Node not awake!
zwave.log.16:2018-07-02 01:55:01.702 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 122: Node not awake!
zwave.log.17:2018-07-02 02:08:48.818 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 67: Node not awake!
zwave.log.17:2018-07-02 02:08:48.818 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 212: Node not awake!
zwave.log.18:2018-07-02 02:23:53.281 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 55: Node not awake!
zwave.log.18:2018-07-02 02:23:53.281 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 46: Node not awake!
zwave.log.19:2018-07-02 02:44:23.567 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 48: Node not awake!
zwave.log.19:2018-07-02 02:44:23.567 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 86: Node not awake!
zwave.log.19:2018-07-02 02:44:23.567 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 50: Node not awake!
zwave.log.2:2018-07-01 23:03:36.704 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 57: Node not awake!
zwave.log.2:2018-07-01 23:03:36.704 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 64: Node not awake!
zwave.log.2:2018-07-01 23:03:36.704 [DEBUG] [ng.zwave.internal.protocol.ZWaveTransactionManager] – NODE 68: Node not awake!

So I put together a quick sequence of commands that will produce results sorted by date. This process strips off the file names (I could create a more complex command set to shuffle the file name off to the end, but I didn’t need the file name. I just needed to scroll through the times at which an event occurred).

grep “Node not awake” zwave.log* | sed -r ‘s/^zwave.log.*:2018/2018/’ | sort

The grep results are piped to sed to have the file name prefix removed. The subsequent results are then piped to sort to be, well, sorted.

Controlling Printer Outlet

We normally keep our printer turned off. Residential printer standby can have a decent draw. It’s something you have to research specific to your printer — some have low single-digit standby draw and waste ink when powered on and off. Others, like ours, has a non-trivial standby draw that isn’t offset by ink savings. The problem is that you’ve got to turn the printer on, print your stuff, and then remember to turn it off. The tiny person remote power controller (i.e. Anya) works for this, but it’s not an elegant automated solution.

Scott set up a smart outlet for the printer – you can tell the Echo to turn the printer outlet on and off now. But you still have to remember to turn it off 🙂

So I set up a print queue on the server & all print jobs are submitted to the server-based queue. A scheduled task on the server checks the print queue for jobs and turns the printer on when jobs are found. When the printer is on but no jobs are in the queue, it waits ten minutes and checks again (otherwise you could turn the printer on & have the batch immediately turn it off. Or worse the job could be out of the queue but still printing!), then turns the printer off if there are still no jobs in the queue. Voila, now the printer turns itself on when you want to print something and it remembers to turn itself off later.

The tricky bit was figuring out how to post ‘ON’ and ‘OFF’ to the OpenHAB2 REST API. -Body with just the command:

Invoke-WebRequest -URI ‘http://openhabserver.domain.gTLD:8080/rest/items/Outlet1’ -ContentType “text/plain” -Method POST -Body ‘OFF’


# Get number of jobs in print queue
$iItemsInQueue = get-printjob -PrinterName "WF-7520 Series(Network)" | measure

# Get current state of outlet
$strOutletState = Invoke-WebRequest -URI 'http://openhabserver.domain.gTLD:8080/rest/items/Outlet1/state' -ContentType "text/plain" -Method GET
Write-Host "Status Code:" $_.Exception.Response.StatusCode.value__
Write-Host "Status Description:" $_.Exception.Response.StatusDescription
Write-Host "Status Message:" $_.Exception.Message
Write-Host "Status Response:" $_.Exception.Response
Write-Host "Status Status:" $_.Exception.Status

if($iItemsInQueue.Count -eq 0 -And $strOutletState.Content-eq "ON"){ # No items are in print queue, but outlet is on. Turn it off after a ten minute pause
Start-Sleep 600
$iItemsInQueue2 = get-printjob -PrinterName "WF-7520 Series(Network)" | measure # Check queue again to ensure we are not turning outlet off while someone is submitting print job
if($iItemsInQueue2 -eq 0){
Invoke-WebRequest -URI 'http://openhabserver.domain.gTLD:8080/rest/items/Outlet1' -ContentType "text/plain" -Method POST -Body 'OFF'
Write-Host "Status Code:" $_.Exception.Response.StatusCode.value__
Write-Host "Status Description:" $_.Exception.Response.StatusDescription
Write-Host "Status Message:" $_.Exception.Message
Write-Host "Status Response:" $_.Exception.Response
Write-Host "Status Status:" $_.Exception.Status
elseif ($iItemsInQueue.Count -gt 0 -And $strOutletState.Content-eq "OFF"){ # Items are in print queue and outlet is not presently on
Invoke-WebRequest -URI 'http://openhabserver.domain.gTLD:8080/rest/items/Outlet1' -ContentType "text/plain" -Method POST -Body 'ON'
Write-Host "Status Code:" $_.Exception.Response.StatusCode.value__
Write-Host "Status Description:" $_.Exception.Response.StatusDescription
Write-Host "Status Message:" $_.Exception.Message
Write-Host "Status Response:" $_.Exception.Response
Write-Host "Status Status:" $_.Exception.Status
Write-Host $iItemsInQueue.Count " items in the print queue. The outlet is currently " $strOutletState.Content


Creating An OpenHAB 2.3.0 Snapshot Docker Container

We found quick instructions for creating a Docker container for the OpenHAB 2.3.0 snapshot. These instructions evidently presuppose some basic knowledge of building Docker containers, so I thought I’d write the “I don’t know what I am doing” version of the instructions. Beyond the obvious download & install Docker, then make sure it’s functional (service starts).

The linked Dockerfile is not the only thing you need. Go up a level — you need both the Dockerfile and entrypoint.sh files. Create a directory somewhere and grab these two files. Then build the container using

docker build -t oh2imagename .

I used a short, alpha-numeric only name for my image. When I used slashes as in the example, the container would not start. Then make the folders you want to map into OpenHAB2:

mkdir /some/path/to/openhab/addons
mkdir /some/path/to/openhab/conf
mkdir /some/path/to/openhab/userdata

The instructions conflate local users/groups with in-container users/groups. You do not need to create a local user. You do need to indicate the uidNumber and gidNumber for the openhab user and group. Even if you do create the local user and group, then change the /some/path/to/openhab permissions to provide full access to the user … you may well not be able to access the files. That is SELinux, not a file permission issue. The quick/dirty solution is to start the container with the privileged flag:


Alternately, consult the Universal Archive of All IT Knowledge and figure out how to allow the docker service to write files where you want them. And how to access USB devices if you are trying to use something like a ZWave dongle. We went with the privileged route 🙂 The –name option is just the container name. The –net uses the host network for container communications instead of the bridge network. Saves mapping ports, although you could easily use the bridge network and map out the handful of OpenHab specific ports. The -d runs the container in detached mode. The -e sets some environment flags (used by the user/group creation script that runs upon container startup). The –tty (or -t) attaches a console. Not really used here.

docker run --privileged --name oh2containername --net=host --tty -d -e USER_ID=5555 \
 -e GROUP_ID=5555 oh2imagename

Ideally, your OpenHAB2 instance will be running. Use “docker ps” to list out the running containers. If you don’t see a container with the name supplied above … then something went wrong. You can use “docker history oh2containername” to view a quick history, but “docker logs oh2containername” will probably provide more useful information. We encountered file permission issues (as noted above, due to SELinux) which prevented the initial container setup from running. Once that was sorted, the container showed up in the running container list.

You’re ready to use it — you can access the web console using your computer’s IP address (assuming you set this container up in the host network and not the bridge — if you used the bridge, you can use “docker inspect oh2containername” and look for IPAddress under NetworkSettings) on the default port. You can ssh into the Karaf console with the default user/password on the default port. Or you can shell into the container.

docker exec -it oh2containername /bin/bash

This is a bash shell running on the OH2 container — you’ll find a lot of ‘stuff’ hasn’t been installed, and your normal command aliases won’t be present. But it’s a shell on the server and can be used to start/stop OH2.

Scraping OpenHAB Karaf Console Data

Realized an easier way of scraping the Karaf console output – no need to SSH into the console (which, evidently, can timeout for inactivity … something I sort on my OpenSSH server with a config parameter whenever I’m looking to use tee and scrape output).

You can just pipe the startup script to tee. Have to push stderr into stdout to get the *errors* logged.

./start.sh 2>&1 | tee -a /tmp/logfile.txt

The output gets a little funky – maybe because of the color flags on some of the text? Dunno, but it’s grabbing the text and something like tail displays it without funky odd stuff

ESC[31m ESC[0m __ _____ ____ ESC[0m
ESC[31m ____ ____ ___ ____ ESC[0m/ / / / | / __ ) ESC[0m
ESC[31m / __ \/ __ \/ _ \/ __ \ESC[0m/ /_/ / /| | / __ | ESC[0m
ESC[31m/ /_/ / /_/ / __/ / / / ESC[0m__ / ___ |/ /_/ / ESC[0m
ESC[31m\____/ .___/\___/_/ /_/ESC[0m_/ /_/_/ |_/_____/ ESC[0m
ESC[31m /_/ ESC[0m 2.2.0-SNAPSHOTESC[0m
ESC[31m ESC[0m Build #1114 ESC[0m

Hit 'ESC[1m<tab>ESC[0m' for a list of available commands
and 'ESC[1m[cmd] --helpESC[0m' for help on a specific command.
Hit 'ESC[1m<ctrl-d>ESC[0m' or type 'ESC[1msystem:shutdownESC[0m' or 'ESC[1mlogoutESC[0m' to shutdown openHAB.


But you get the java exceptions too:

      Exception in thread "pool-45-thread-5" java.lang.NullPointerException
              at java.util.AbstractCollection.addAll(AbstractCollection.java:343)
              at com.zsmartsystems.zigbee.ZigBeeNode.setNeighbors(ZigBeeNode.java:510)
              at com.zsmartsystems.zigbee.ZigBeeNetworkMeshMonitor$2.run(ZigBeeNetworkMeshMonitor.java:232)
              at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
              at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
              at java.lang.Thread.run(Thread.java:748)


Logging OpenHAB’s Karaf Console To A File

With OpenHAB2, there is a console where information is displayed. You can copy/paste from the console to save information, but if you are reproducing an issue and expect something to be logged, you can also dump the information from the console into a text file. This is done by ssh’ing into the Karaf console and using tee to write output to a file. Since the SSH server is bound to, you will need to use localhost or This cannot be done remotely without some sort of firewall port redirection or OpenHAB change

     ssh UserName@localhost -p 8101 | tee -a /tmp/test.txt

So what’s the username? Karaf uses karaf as the username and password. OpenHAB uses the users.properties file (./openhab2/userdata/etc) to store users. Our file has the user openhab. You can google the default password or put your own crypt string in there and know the password.

Now everything that comes across the Karaf console (system output and stuff you type) will be in the /tmp/test.txt file.

[root@fedora01 ~]# tail -f /tmp/test.txt

                          __  _____    ____
  ____  ____  ___  ____  / / / /   |  / __ )
 / __ \/ __ \/ _ \/ __ \/ /_/ / /| | / __  |
/ /_/ / /_/ /  __/ / / / __  / ___ |/ /_/ /
\____/ .___/\___/_/ /_/_/ /_/_/  |_/_____/
    /_/                        2.2.0-SNAPSHOT
                               Build #1114

Hit '' for a list of available commands
and '[cmd] --help' for help on a specific command.
Hit '' or type 'system:shutdown' or 'logout' to shutdown openHAB.

openhab> bundle:list
START LEVEL 100 , List Threshold: 50
 ID │ State    │ Lvl │ Version                │ Name
 15 │ Active   │  80 │     │ ZWave Binding
 16 │ Active   │  80 │     │ ZigBee Binding
 17 │ Active   │  80 │     │ OSGi JAX-RS Connector
 18 │ Active   │  80 │ 2.4.5                  │ Jackson-annotations
 19 │ Active   │  80 │ 2.4.5                  │ Jackson-core
 20 │ Active   │  80 │ 2.4.5                  │ jackson-databind
 21 │ Active   │  80 │ 2.4.5                  │ Jackson-dataformat-XML
 22 │ Active   │  80 │ 2.4.5                  │ Jackson-dataformat-YAML
 23 │ Active   │  80 │ 2.4.5                  │ Jackson-module-JAXB-annotations
 24 │ Active   │  80 │ 2.7.0                  │ Gson
 25 │ Active   │  80 │ 18.0.0                 │ Guava: Google Core Libraries for Java
 26 │ Active   │  80 │ 3.0.0.v201312141243    │ Google Guice (No AOP)
 27 │ Active   │  80 │ 3.12.0.OH              │ nrjavaserial
 28 │ Active   │  80 │ 1.5.8                  │ swagger-annotations
 29 │ Active   │  80 │ 3.19.0.GA              │ Javassist
 31 │ Active   │  80 │ 3.5.2                  │ JmDNS
 34 │ Active   │  80 │ 1.1.0.Final            │ Bean Validation API
 36 │ Active   │  80 │ 2.0.1                  │ javax.ws.rs-api

OpenHAB Cloud Installation Prerequisites

We started setting up the OpenHAB cloud server locally, and the instructions we had found omitted a few important steps. They say ‘install redis’ and ‘install mongodb’ without providing any sort of post-install configuration.

# This is optional – if you don’t set a password, you’ll just get a warning on launch that a password was supplied but none is required. While the service is, by default, bound to localhost … I still put a password on everything just to be safe

vi /etc/redis.conf # Your path may vary, this is Fedora. I've seen /etc/redis/redis.conf too

# Find the requirepass line and make one with your password

480 # requirepass foobared
requirepass Y0|_|RP@s5w0rdG03s|-|3re

# Restart redis

service redis restart

# Install mongo (dnf install mongo mongo-server)
# start mongodb

service mongod start

# launch mongo client


# Create user in admin database

db.createUser({user: "yourDBUser", pwd: "yourDBUserPassword", roles: [{role: userAdminAnyDatabase", db: "admin"}]});

# Modify mongodb server config to use security

vi /etc/mongod.conf

# remove remarkes before ‘security: ‘ and ‘authorization’ – set authorization to enabled:

99 # secutiry Options - Authorization and other security settings
100 security:
101 # Private key for cluster authentication
102 #keyFile: <string>
104 # Run with/without security (enabled|disabled, disabled by default)
105 authorization: enabled

# restart mongo

service mongod restart

#Launch mongo client supplying username and connecting to the admin database

mongo -uyourDBUser -p admin

# it will connect and prompt for password – you can use db.getUser to verify the account (but you just logged into it, so that’s a bit redundant)

MongoDB shell version: 3.2.12
Enter password:
connecting to: admin
> > db.getUser("yourDBUser");
        "_id" : "admin.yourDBUser",
        "user" : "yourDBUser",
        "db" : "admin",
        "roles" : [
                        "role" : "userAdminAnyDatabase",
                        "db" : "admin"

# Create the openhab database — mongo is a bit odd in that “use dbname” will switch context to that database if it exists *and* create the databse if it doesn’t exist. Bad for typo-prone types!

use yourDBName;

# Create the user in the openhab database

db.createUser({user: "yourDBUser", pwd: "yourDBUserPassword", roles: [{role: readWrite", db: "yourDBName"}]});

# You can use get user to verify it works


# Now you can launch the mongo client connecting to the openhab database:

mongo -uyourDBUser -p yourDBName

# It will prompt for password and connect. At this point, you can use “node app.js” to launch the openhab cloud connector. Provided yourDBUser, yourDBUserPassword, and yourDBName match what you’ve used in the config file … it’ll connect and create a bunch of stuff


Exchange 2013 Calendar Events In OpenHAB (CalDAV)

We’ve wanted to get our Exchange calendar events into OpenHAB — instead of trying to create a rule to determine preschool is in session, the repeating calendar event will dictate if it is a break or school day. Move the gymnastics session to a new day, and the audio reminder moves itself. Problem is, Microsoft stopped supporting CalDAV.

Scott found DAVMail — essentially a proxy that can translate between CalDAV clients and the EWS WSDL. Installation was straight-forward (click ‘next’ a few times). Configuration — for Exchange 2013, you need to select the “EWS” Exchange protocol and use your server’s EWS WSDL URL. https://yourhost.domain.cTLD/ews/exchange.asmx … then enable a local CalDAV port.

On the ‘network’ tab, check the box to allow remote connections. You *can* put the thumbprint of the IIS web site server certificate for your Exchange server into the “server certificate hash” field or you can leave it blank. On the first connection through DAVMail, there will be a pop-up asking you to verify and accept the certificate.

On the ‘encryption’ tab, you can configure a private keystore to allow the client to communicate over SSL. I used a PKCS12 store (Windows type), but a java keystore should work too (you may need to add the key signing key {a.k.a. CA public key} to the ca truststore for your java instance).

On the advanced tab, I did not enable Kerberos because the OpenHAB CalDAV binding passes credentials. I did enable KeepAlive – not sure if it is used, the CalDAV binding seems to poll. Save changes and open up the DAVMail log viewer to verify traffic is coming through.

Then comes Scott’s part — enable the bindings in OpenHAB (there are two of them – a CalDAVIO and CalDAVCmd). In the caldavio.cfg, the config lines need to be prefixed with ‘caldavio’ even though that’s not how it works in OpenHAB2.


Then in the caldavCommand.cfg file, you just need to tell it to load that calendar identifier:


We have needed stop openhab, delete the config file from ./config/org/openhab/ related to this calendar and binding before config changes are ingested.

Last step is making a calendar item that can do stuff. In the big text box that’s where a message body is located (no idea what that’s called on a calendar entry):


The subject can be whatever you want. The start time and end time are the times for the begin and end events. Voila!

Cleaning Up Old OpenHAB Persistence Tables

So my husband asked for a program that would go out to the OpenHAB persistence database and identify all of the item tables that are no longer associated with active items. If you rename or delete an item from OpenHAB, the associated data is retained in the persistence database. Might be a good thing – maybe you wanted that data. But if it’s useless fluff … well, no need to keep the state changes from a door sensor that’s no longer around.

Wrote the code, and asked him how many days old he wanted the last update to be before the item table got dropped … and he told me this was a useless way to do it and maybe something really hadn’t updated in six months or three years and age of last update is no way to be identifying tables to be removed. Which, yeah, then why ask for it!? Then I needed to write something that takes a list of items from OpenHAB and identifies everything in the items table that does not appear in the OpenHAB list so those tables can be deleted. But I figured I’d post the original code too in case anyone else could use it. Both in perl, and neither in particularly well written perl. I trust the data and don’t want to protect against insertion attacks.

Drop tables for items that no longer appear in OpenHAB:

use strict;
use DBI;

my %strItemsFromOpenHAB = ();
        my $strCurrentItem = $_;
close INPUT;

my $dbh = DBI->connect('DBI:mysql:openhabdb;host=DBHOST', 'DBUID', 'DBPassword', { RaiseError => 1 } );

my $sth = $dbh->prepare("SELECT * FROM items");
while (my @row = $sth->fetchrow_array) {
        my $strItemID = $row[0];
        my $strItemName = $row[1];
        if(! $strItemsFromOpenHAB{$strItemName} ){              # If the current item name is not in the list of items from OpenHAB
#               print "DELETE FROM items where ItemID = $strItemID\n";
                print "DROP TABLE Item$strItemID;  # $strItemName \n";

close OUTPUT;


Identify tables that have not been updated in iTooOldInDays days:

use strict;
use DBI;
use Date::Parse;
use Time::Local;

my $iTooOldInDays = 365;

my $iCurrentEpochTime = time();

my @strItems = ();
my $iItems = 0;

my $dbh = DBI->connect('DBI:mysql:openhabdb;host=DBHOST', 'DBUID', 'DBPassword', { RaiseError => 1 } );

my $sth = $dbh->prepare("SELECT * FROM Items");
while (my @row = $sth->fetchrow_array) {
        $strItems[$iItems++] = $row[0];

for(my $i = 0; $i < $iItems; $i++){ my $strTableName = 'Item' . $strItems[$i]; my $sth = $dbh->prepare("SELECT * FROM $strTableName ORDER BY Time DESC LIMIT 1");
        while (my @row = $sth->fetchrow_array) {
                my $strUpdateTime = $row[0];
                my @strDateTimeBreakout = split(/ /,$strUpdateTime);
                my $strDate = $strDateTimeBreakout[0];
                my $strTime = $strDateTimeBreakout[1];

                my @strDateBreakout = split(/-/,$strDate);
                my @strTimeBreakout = split(/:/,$strTime);

                my $iUpdateEpochTime = timelocal($strTimeBreakout[2],$strTimeBreakout[1],$strTimeBreakout[0], $strDateBreakout[2],$strDateBreakout[1]-1,$strDateBreakout[0]);
                my $iTableAge = $iCurrentEpochTime - $iUpdateEpochTime;

                if($iTableAge > ($iTooOldInDays * 86400) ){
                        print "$strTableName last updated $strUpdateTime - $iUpdateEpochTime\n";

close OUTPUT;

Persisting Port Names For OpenHAB

If you only have one device connected to your Linux box, your controller may well always be assigned the same port when the system is rebooted. In the real world, multiple connected devices make this unlikely. We use udev rules to create symlinks used within the OpenHAB configuration. The udev rule essentially uses attributes of the device to identify the real port and creates a statically named symlink to that port on boot. So the first thing you need to identify is something unique about the device. We have several video capture cards and a Z-Wave/ZigBee combo controller attached to our server. If you do not have udevinfo, you can use lsusb to find details about the device. First list the devices, then identify the proper one and use the -d switch with the ????:???? formatted ID number. The -v switch outputs verbose information. Find a unique attribute or set of attributes that create a unique identifier. In this case, the interface name is unique and we can stop there.

[lisa@server ~]#  lsusb
Bus 001 Device 004: ID 0bda:0111 Realtek Semiconductor Corp. RTS5111 Card Reader Controller
Bus 001 Device 003: ID 1058:1230 Western Digital Technologies, Inc. My Book (WDBFJK0030HBK)
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 002: ID 10c4:8a2a Cygnal Integrated Products, Inc.
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
[lisa@server ~]# lsusb -d 10c4:8a2a -v
Bus 002 Device 002: ID 10c4:8a2a Cygnal Integrated Products, Inc.
Device Descriptor:
 bLength 18
 bDescriptorType 1
 bcdUSB 2.00
 bDeviceClass 0
 bDeviceSubClass 0
 bDeviceProtocol 0
 bMaxPacketSize0 64
 idVendor 0x10c4 Cygnal Integrated Products, Inc.
 idProduct 0x8a2a
 bcdDevice 1.00
 iManufacturer 1 Silicon Labs
 iProduct 2 HubZ Smart Home Controller
 iSerial 5 90F0016B
 bNumConfigurations 1
 Configuration Descriptor:
 bLength 9
 bDescriptorType 2
 wTotalLength 55
 bNumInterfaces 2
 bConfigurationValue 1
 iConfiguration 0
 bmAttributes 0x80
 (Bus Powered)
 MaxPower 100mA
 Interface Descriptor:
 bLength 9
 bDescriptorType 4
 bInterfaceNumber 0
 bAlternateSetting 0
 bNumEndpoints 2
 bInterfaceClass 255 Vendor Specific Class
 bInterfaceSubClass 0
 bInterfaceProtocol 0
 iInterface 3 HubZ Z-Wave Com Port
 Endpoint Descriptor:
 bLength 7
 bDescriptorType 5
 bEndpointAddress 0x81 EP 1 IN
 bmAttributes 2
 Transfer Type Bulk
 Synch Type None
 Usage Type Data
 wMaxPacketSize 0x0040 1x 64 bytes
 bInterval 0
 Endpoint Descriptor:
 bLength 7
 bDescriptorType 5
 bEndpointAddress 0x01 EP 1 OUT
 bmAttributes 2
 Transfer Type Bulk
 Synch Type None
 Usage Type Data
 wMaxPacketSize 0x0040 1x 64 bytes
 bInterval 0
 Interface Descriptor:
 bLength 9
 bDescriptorType 4
 bInterfaceNumber 1
 bAlternateSetting 0
 bNumEndpoints 2
 bInterfaceClass 255 Vendor Specific Class
 bInterfaceSubClass 0
 bInterfaceProtocol 0
 iInterface 4 HubZ ZigBee Com Port
 Endpoint Descriptor:
 bLength 7
 bDescriptorType 5
 bEndpointAddress 0x82 EP 2 IN
 bmAttributes 2
 Transfer Type Bulk
 Synch Type None
 Usage Type Data
 wMaxPacketSize 0x0020 1x 32 bytes
 bInterval 0
 Endpoint Descriptor:
 bLength 7
 bDescriptorType 5
 bEndpointAddress 0x02 EP 2 OUT
 bmAttributes 2
 Transfer Type Bulk
 Synch Type None
 Usage Type Data
 wMaxPacketSize 0x0020 1x 32 bytes
 bInterval 0

We then need to create a file under /etc/udev/rules.d. The file name begins with a number that is used for a load order – I generally number my custom files 99 to avoid interfering with system operations. The bit in “ATTRS” is the attribute name and value to match. The KERNEL section contains the search domain (i.e. look at all of the ttyUSB### devices and find ones where the interface is this). The symlink bit is the name you want to use (more on this later). Set the group and mode to ensure OpenHAB is able to use the symlink.

[root@fedora01 rules.d]# cat 99-server.rules
KERNEL=="ttyUSB[0-9]*", ATTRS{interface}=="HubZ Z-Wave Com Port", SYMLINK+="ttyUSB-5", GROUP="dialout", MODE="0666"
KERNEL=="ttyUSB[0-9]*", ATTRS{interface}=="HubZ ZigBee Com Port", SYMLINK+="ttyUSB-55", GROUP="dialout", MODE="0666"

The symlink name can be anything – when I created udev rules for our video capture cards, I named them something immediately obvious: video-hauppauge250 is the Hauppauge 250 card. Tried to do the same thing here, naming the ports controller-zigbee; while the symlink appeared and had the expected ownership and permissions … OpenHAB couldn’t use it.

Turns out there’s a nuance to Java RxTx where non-standard port names need to be accommodated in the java options. So I could have added -Dgnu.io.rxtxSerialPorts=/dev/controller-zigbee and -Dgnu.io.rxtxSerialPorts=/dev/controller-zwave to the OpenHAB startup and been OK (in theory), it was far easier to name the symlinks using the Linux standard conventions. Hence I have symlinks named ttyUSBsomethingsomethingsomething. 

Smart Home (In)Security

I’ve seen a lot of articles recently about hacked IoT devices (and now one about a malicious company disrupting the customer’s service in retaliation for poor reviews (and possibly abusive calls to technical support). I certainly don’t think *everything* needs to be connected to the Internet. If you want to write messages on toast remotely, whatever … but beyond gimmicks, there are certainly products where the Internet offers no real advantage. But a lot of articles disparage the idea of a smart home based on goofy products.

There are devices that are more convenient than their ‘dumb’ counterparts. Locks that unlock when you are nearby. Garage lights that come on when the door is unlocked or opened. And if that was the extent of home automation, I guess you could still call it a silly fad.

But there are a LOT of connected devices that save resources: Exterior lighting that illuminates as you near your house. With motion detectors controlling light switches and bulbs, you (or the kids) cannot forget to turn out the lights. An outlet that turn OFF to eliminate draw when appliances are in ‘standby’ mode saved us about 50$/year just on the television/receiver. Use moisture sensors to control a sprinkler system so the grass is only watered when there is actual need. Water flow sensors that can alert you to unusual usage (e.g. when the water filter system gasket goes and it starts dumping water through the thing 24×7).

And some that prevent real damages to your home or person. If your house uses combustion for heat, configure the carbon monoxide sensor to shut off the HVAC system when CO levels are too high. Leak sensors shut off the water mains when a leak is detected (and turn off appliances in the wet area if there’s potential for shorting).

The major security problem with any IoT device, smart home systems included, is that you’ve connect private resources to the Internet. With all the hackers, punks, and downright malicious people out there. And from a privacy standpoint, you are providing information that can be mined to enhance marketing profiles — very carefully read the privacy policies of any company whose platform you will be using. Maybe a ‘smart’ coffee machine sounds good to you — but are they collecting (and potentially selling to third parties) information about how many cups of coffee you brew and the times of day you brew them? If you care is a personal decision, but it’s something that should be considered just the same.

When each individual device has its own platform, the privacy and security risks grow. A great number of these devices don’t need to be connected to the INTERNET directly but rather a relay point (hub). From a business perspective, this is a boon … since you have a Trane furnace (big money, not apt to be replaced yearly), you should also buy these other products that we sell and pay the monthly recurring to use our Nexia platform for all of your other smart devices. Or since you have a Samsung TV with a built-in hub … you should not only buy these other Samsung products, but hook all of your other smart ‘things’ up to SmartThings. And in a year or two when you’re shopping for a new TV … wait, you need one with a SmartThings hub or you’re going to have to port your existing configuration to a new vendor. Instant customer loyalty.

For an individual, the single relay point reduce risk (it’s not one of a dozen companies that need to be compromised to affect me, just this one) and confusion (I only have to keep track of one company’s privacy policy). *But* it also gives one company a lot more information. The device type is often indicative, but most people name the devices according to location (i.e. bedroom light, garage light, front door). Using SmartThings, Samsung knew when we went to bed and woke up, that we ate breakfast before brushing teeth (motion in hallway, motion in kitchen, water usage, power draw on appliances, motion in hallway, motion in bathroom, water usage) or showering (power draw on hot water tank, increased water usage). Which rooms we frequented (motion), when we watched TV (not what we watched, but when), when we left the house (no motion, presence change). How often we wash laundry (power draw on washer, water usage) and dishes (power draw in dishwasher, water usage). Temperature in the house (as reported from multi-sensor devices or from a smart thermostat), if we change settings for day/night. How often we drive a car (garage door open/closed with presence change, or speed of location change on presence), how much time we spend away from home. How often we have overnight guests (motion in guest bedroom at night).

And, yeah, the profile they glean is a guess. I might open the garage door when mowing grass. Or I might have rooms with no motion sensors for which they cannot account. But they have a LOT of data on which to base their guesses and no one selling targeted advertising profiles claims to be 100% accurate. Facebook’s algorithm, for quite some time, had me listed as a right-leaning Trump supporter. I finally tired of seeing campaign ads on their site and manually updated my advertising profile. Point is, one company has a lot of data from which they build fairly good targeted profiles. How much of our house is actually used (a lot of bedrooms that rarely get motion, get a ‘downsizing specialist’ real estate flyer. All rooms constantly with motion, get a flyer specific to finding a larger home to give you all some space). If the HVAC system is connected, they could create a target group “people who could use additional insulation or sealing in their house” (outdoor temp for location v/s indoor temp for location v/s energy draw).

In some ways, it’s cool that a company might be able to look at my life and determine a need of which I am not even aware. Didn’t realize how much of our energy bill was HVAC – wow, tightening the house and insulation will save how much?! But it’s also potentially offensive: yeah, we could use a bigger house for all of these people. We could also use a bigger pay cheque, what of it? Yeah, the kids moved out … but this is our house and why would you tell me I should be leaving? And generally invasive — information that doesn’t really cause harm but they’ve got no reason to know either.

What articles highlighting the insecurity of IoT devices seem to miss is that the relay point can reside on your local network with no Internet access. We personally use OpenHAB – which enables our home automation to function completely inside our local network. You trust the developers (or don’t, ours is open source … you can read the whole thing if you don’t want to trust developers), but you own the data and what is done with it.

You don’t need an expensive dedicated server to host your own home automation controller – a Raspberry PI will do. What you do need is technical knowledge and a good bit of time (or hire someone to do it for you, in which case you need money and someone else’s time). But the end result is the same — physical presence is required to compromise the system. Since physical presence will also let you bump locks, smash windows, cut power, flick light switches, open doors … you’re not worse off than before.