linux – Jenkins installation fails on Ubuntu 20.04 with dpkg: error processing package jenkins (–configure)

I was trying to install Jenkins in my server Ubuntu 20.04 with the following commands

wget -q -O - | sudo apt-key add -
sudo sh -c 'echo deb binary/ > /etc/apt/sources.list.d/jenkins.list'
sudo apt update
sudo apt install jenkins

But installation fails with dpkg: error processing package jenkins (--configure):

Job for jenkins.service failed because the control process exited with error code.
See "systemctl status jenkins.service" and "journalctl -xe" for details.
invoke-rc.d: initscript jenkins, action "start" failed.
‚óŹ jenkins.service - LSB: Start Jenkins at boot time
     Loaded: loaded (/etc/init.d/jenkins; generated)
     Active: failed (Result: exit-code) since Sun 2021-01-24 20:09:16 UTC; 13ms ago
       Docs: man:systemd-sysv-generator(8)
    Process: 1620107 ExecStart=/etc/init.d/jenkins start (code=exited, status=1/FAILURE)

Jan 24 20:09:16 ubuntu-s-1vcpu-1gb-nyc3-01 systemd(1): Starting LSB: Start Jenkins at boot time...
Jan 24 20:09:16 ubuntu-s-1vcpu-1gb-nyc3-01 jenkins(1620107): ERROR: No Java executable found in current PATH: /bin:/usr/bin:/sbin:/usr/sbin
Jan 24 20:09:16 ubuntu-s-1vcpu-1gb-nyc3-01 jenkins(1620107): If you actually have java installed on the system make sure the executable is in the aforementioned path and that 'type -p java' returns the java executable path
Jan 24 20:09:16 ubuntu-s-1vcpu-1gb-nyc3-01 systemd(1): jenkins.service: Control process exited, code=exited, status=1/FAILURE
Jan 24 20:09:16 ubuntu-s-1vcpu-1gb-nyc3-01 systemd(1): jenkins.service: Failed with result 'exit-code'.
Jan 24 20:09:16 ubuntu-s-1vcpu-1gb-nyc3-01 systemd(1): Failed to start LSB: Start Jenkins at boot time.
dpkg: error processing package jenkins (--configure):
 installed jenkins package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
E: Sub-process /usr/bin/dpkg returned an error code (1)

I’ve tried this, removing and again installation, changing the content of /etc/securetty here but none of them is working. I’m only facing this problem when I try to install Jenkins in server, while I tried to install my own laptop having Ubuntu 20.04 it works fine.

Ubuntu 20.04.1 – Is there a way to configure capacitive touchscreen sensitivity (for glove / capacitive stylus use)?

I have a laptop with a capacitive Egalax touchscreen. In Windows, the manufacturer (Getac) provides a utility to configure the touchscreen for use with a capacitive stylus or gloves. So far, I have been unable to configure the touchscreen similarly under Ubuntu. Everything works otherwise.

Any insight would be welcome.

security – How do you configure Windows firewall for selective web browsing?

I’m configuring administrative hosts in a management subnet. I’ve installed Chromium to enable our technology staff to be able to browse to our internal web management interfaces for administrative tasks, but I want to block them browsing the internet. I can’t block the hosts themselves from the internet because they have other processes which need to communicate with cloud services, etc., so I planned to just restrict the Chromium executable by destination subnet, ACL-style.

I tried to use the Windows firewall to achieve this:

New-NetFirewallRule -Direction Outbound -DisplayName 'Block Chromium from Internet' `
-Group 'Jumpbox Security' -Enabled True -Profile Any `
-Program 'C:Program FilesChromiumApplicationchrome.exe' -Protocol TCP -Action Block `

New-NetFirewallRule -Direction Outbound -DisplayName 'Allow Chromium to Internal Networks' `
-Group 'Jumpbox Security' -Enabled True -Profile Any `
-Program 'C:Program FilesChromiumApplicationchrome.exe' -Protocol TCP -Action Allow `
-RemoteAddress -OverrideBlockRules Allow

I tried this on both the outbound and inbound rule sets and it does not restrict Chromium at all, presumably because the first rule is being invalidated by another rule match. Before I begin a tedious rule audit and apply additional, more complicated configuration, does anyone know of a cleaner way to achieve the end result?

networking – What DNS records are required to configure web hosting for a subdomain?

I’ve browsed several questions about DNS setup for subdomains and not quite found an answer, so I’m hoping you can assist.

Our domain name ( is registered with one provider (NetRegistry), and our main web site is now hosted by SquareSpace (configured using a CNAME record). We need to set up a separate, simple web hosting service with another provider using a subdomain (

I was originally advised that we could use their nameservers, and so created NS records for the subdomain with our registrar using the zone management tool available through their control panel. This didn’t work, though. Speaking to the hosting provider, I was advised to add an A name record for the subdomain pointing to a specific IP address for the new site, which I’ve also done. But throughout this process the subdomain has not resolved; I get a failure when using nslookup, as though it’s not recognised anywhere.

Currently we have both the A and NS records for the subdomain on our registrar, and I suspect we should only have one or the other; is that the case? I’m rusty with DNS and didn’t think this would be complicated, but if anyone can advise what records should be sufficient to for setting this up, I’d appreciate it.

audio – How do I automatically configure an Adapt Sound profile?

I have configured different audio profiles for each of my Bluetooth devices. How do I automatically configure to set a specific profile for each device?

I didn’t find a option using Bixby Assistant or the Tasker app. The only thing I managed to do was creating a direct shortcut to the setting using the Shotcut Maker app.

Configure the default route that the Azure VPN Gateway provides to P2S clients (to allow for multiple connections)

I have two completely independent Azure environments that I control. One virtual network uses the address space, the other uses the address space. I need my users to be able to connect to both vnets simultaneously via point-to-site (P2S) VPN connections.

I have much of this working. I’m using plain-old, built-in rasphone for this- no special extra VPN client software, I set up the connection directly in rasphone with no downloads or installs. Either one of the connections work perfectly alone, the problem comes when I try to use them together.

Apparently, when I connect to either of them, a route gets added for So when I connect to both of them, two conflicting routes get added. The one with precedence wins, so in practice one connection of the two will work, while the other fails. In case that isn’t clear, here’s the output from route print:

Network Destination        Netmask          Gateway       Interface  Metric     36     36

In the above case a tracert for shows that it’s trying to resolve the IP address via the gateway (the one with precedence), which is the wrong one, so it finds nothing. I need to route traffic through, and through

Now, I could try to modify the route explicitly on every client PC, but that adds a whole extra step to the process of setting up each and every PC. The Azure VPN Gateway is obviously capable of telling the client what routes to add, since the route gets added automatically every time I connect, so I’m hoping there’s a way to configure that default route and limit it to only the IP range I want. And if there isn’t a way to explicitly alter it, is there at least some way I can rearrange my address spaces so that the gateway realizes I don’t want to route all of

networking – netplan: routes and different IP , how to configure it?

I spent the whole morning trying to solve this.

I have two IP addresses available on the same interface (different gateways), let’s say and

My YAML is:

  version: 2
  renderer: networkd
        macaddress: u.u.u.u
      #gateway6: fe80::1
        - to:
          on-link: true
        search: ( invalid )
          - x.x.x.x
          - y.y.y.y

I tought that, to let this server surf the net with, it would be easy as changing the “via” line to:


This doesn’t work. I launch netplan apply and nothing changes, I always surf the web with (as stated by curl and also in ifconfig).

What am I missing?

I have a custom domain for email. Do I need to configure DNS to prevent outgoing text messages with an address from my domain?

I own a custom domain that I use for e-mail. The mail server is configured with a catch-all that redirects messages to any user to my inbox. For the first time this afternoon, I received a benign “auto-reply” to a message (“I’m driving and will get back to you later”) that was “sent by” and sent to some phone number (which seems to be Verizon).

My domain is configured with SPF, which previously seemed effective at preventing spammers from spoofing the use of my domain (based on no longer receiving bounced messages). However, it seems pretty clear that someone managed to send a text message that looked like it came from my domain. Do I need to configure anything else to prevent this? Is this Verizon’s fault for not checking? Or should I conclude that someone was able to send spam from my email provider?

networking – How to configure my router to redirect clients to use AdGuardHome as DNS?

I have setup a local server in my LAN to host a AdGuardHome DNS server that filters Ads etc (a bit like PieHole if you want) on a fixed, e.g. IP

If I configure that DNS server to be used in a client (e.g. Windows 10) instead of “Automatic”, I can see that machine connecting to the DNS server and the filter works fine. The manual setting allows me to set specific filters for that client (e.g. parental controls) that do not apply to others. All other machines use my router (LinkSYS Velop) as DNS on which redirects to whatever my provider has set.

What I would like to achieve is that all clients connect to the DNS at .1.88 instead of the default at 1.1 and that I can see and configure all my clients on the AdGuardHome interface:

I thought I can achieve that by setting the DNS in my router to the .1.88 address:

enter image description here

But all that I get then is that I can now see my router in the AdGuardHome dashboard doing all the requests and there is no way to configure the filters by device:

enter image description here

Should it not be that the router is telling the clients that they should be using 1.88 as a DNS server instead of the router using that address? Or is there another setting I need to apply to have this achieved?


java – Backend service to configure and interact with custom Android app remotely?

I am developing a custom Android application in Java to run on a phone (the target phone). The app controls and collects data from a BLE wearable device connected to the target phone. Ideally, the app running on the target phone can be configured and setup remotely from some backend service/app.

An example scenario: I need the BLE device to perform an action and collect data at a specific time. Currently, I can set this up using the app on my target phone directly by selecting which time of day I want to start the task and then “configure” these commands to the connected device. What I want is for the target phone connected to the BLE device to instead be a middleman between a remote service and the BLE device. I don’t need full access or screen-sharing of the target phone, I just need to be able to send certain functions and configure settings that the phone can then in turn configure with the connected device.

What sort of service/backend will I need in order to connect to the target phone from a remote location?

workflow with target phone as the "middle man"