Tag Archives: ubuntu

RaspberryPi Camera not detected – Ubuntu 20.04.5 LTS

Hi everyone,

I ran into a bit of an issue with a RaspberryPi 4 running Ubuntu 20.04.5 this morning. Running vcgencmd get_camera should have returned supported=1 detected=1 but instead I was getting supported=0 detected=0.

This was a bit of a hard one to track down with Google but I eventually came across a stackoverflow post suggesting the following:

Run sudo nano /boot/firmware/config.txt
Add start_x=1 at the end
Reboot

Check out this post for more info: https://askubuntu.com/a/1244259/770194.

If you’re using a new camera you may also run into this error:

mmal: Cannot read camera info, keeping the defaults for OV5647
mmal: mmal_vc_component_create: failed to create component 'vc.ril.camera' (1:ENOMEM)
mmal: mmal_component_create_core: could not create component 'vc.ril.camera' (1)
mmal: Failed to create camera component
mmal: main: Failed to create camera component
mmal: Only 76M of gpu_mem is configured. Try running "sudo raspi-config" and ensure that "memory_split" has a value of 128 or greater

The fix for this one is to simply append another line to /boot/firmware/config.txt. All you’ll need is gpu_mem=128.

Another issue you might run into is VHCI initialization failed. Generally, that just means you need to add your current user to the video group.

# Check your current user's groups.
groups

# Add your user to the video group.
sudo usermod -aG video <username>

Once you’ve added the group, rebooting should be enough to get past that error.

libgl error pic id driver null – ros2 turtlesim

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Hi everyone,

I’m currently following the ros2 turtlesim tutorial with Ubuntu on an M1 Mac with Parallels and Ubuntu. Unfortunately, I hit a ‘device not found’ when trying to start the control node.

A bit of Googling revealed that 3D acceleration might not be enabled. To fix this, all you need to do is the following:

Open settings in Parallels (the cog icon)
Click the Hardware tab up the top
Click Graphics on the left hand side
Click Advanced
Tick Enable 3D Acceleration

You’ll need to restart the VM, but once that’s done the libgl error should be resolved!

If this doesn’t work, there are a few other things you can check. First, double check that you’ve installed (or re-installed) Parallels Tools.

I have also found that the 3D Acceleration seems to randomly break or reset itself. If it hasn’t automatically unchecked itself, I’ve occasionally had to do the following to get it working again:

Stop the VM
Disable 3D Acceleration
Start the VM
Stop the VM
Enable 3D Acceleration
Start the VM

Another options mentioned in this thread is to set the following environment variable before starting rviz or gazebo:

export LIBGL_ALWAYS_SOFTWARE=1

The Repository is not Signed – Ubuntu ros2 installation

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Hi everyone,

I’m currently installing ros2 on Ubuntu (with Parallels) and ran into the following error:

Hit:1 http://au.ports.ubuntu.com/ubuntu-ports jammy InRelease
Hit:2 http://ports.ubuntu.com/ubuntu-ports jammy-security InRelease
Get:3 http://packages.ros.org/ros2/ubuntu jammy InRelease [4,673 B]
Hit:4 http://au.ports.ubuntu.com/ubuntu-ports jammy-updates InRelease
Err:3 http://packages.ros.org/ros2/ubuntu jammy InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F42ED6FBAB17C654
Get:5 http://ports.ubuntu.com/ubuntu-ports jammy-proposed InRelease [270 kB]
Hit:6 http://au.ports.ubuntu.com/ubuntu-ports jammy-backports InRelease
Reading package lists… Done
W: GPG error: http://packages.ros.org/ros2/ubuntu jammy InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F42ED6FBAB17C654
E: The repository 'http://packages.ros.org/ros2/ubuntu jammy InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

I was following the official tutorial so I was little surprised to see this crop up. What I hadn’t realised was that I’d missed an error in the output dump while running sudo apt update:

chris@chris-parallels-ubuntu:~$ sudo apt update && sudo apt install curl gnupg lsb-release
sudo curl -sSL https://raw.githubusercontent.com/ros/rosdistro/master/ros.key -o /usr/share/keyrings/ros-archive-keyring.gpg
Hit:1 http://au.ports.ubuntu.com/ubuntu-ports jammy InRelease
Hit:2 http://ports.ubuntu.com/ubuntu-ports jammy-security InRelease
Get:3 http://packages.ros.org/ros2/ubuntu jammy InRelease [4,673 B]
Err:3 http://packages.ros.org/ros2/ubuntu jammy InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F42ED6FBAB17C654
Hit:4 http://au.ports.ubuntu.com/ubuntu-ports jammy-updates InRelease
Hit:5 http://ports.ubuntu.com/ubuntu-ports jammy-proposed InRelease
Hit:6 http://au.ports.ubuntu.com/ubuntu-ports jammy-backports InRelease
Reading package lists… Done
W: GPG error: http://packages.ros.org/ros2/ubuntu jammy InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F42ED6FBAB17C654
E: The repository 'http://packages.ros.org/ros2/ubuntu jammy InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
sudo: curl: command not found

This was a clean install of Ubuntu and I hadn’t yet installed curl. Luckily, this is a simple fix:

sudo apt update
sudo apt install curl

The current operating system is not capable of running this task. That typically means the task was written for Windows only. For example, written for Windows Desktop PowerShell. – AzureFileCopy@4

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Hi everyone,

I am currently setting up an azure pipeline to deploy a ReactApp to a Blob storage container. I was a bit surprised when I hit the following error with an Ubuntu pool:

Task         : Azure file copy
Description  : Copy files to Azure Blob Storage or virtual machines
Version      : 4.184.1
Author       : Microsoft Corporation
Help         : https://docs.microsoft.com/azure/devops/pipelines/tasks/deploy/azure-file-copy
==============================================================================
##[error]The current operating system is not capable of running this task. That typically means the task was written for Windows only. For example, written for Windows Desktop PowerShell.
##[debug]System.InvalidOperationException: The current operating system is not capable of running this task. That typically means the task was written for Windows only. For example, written for Windows Desktop PowerShell.
   at Microsoft.VisualStudio.Services.Agent.Worker.TaskRunner.RunAsync()
   at Microsoft.VisualStudio.Services.Agent.Worker.StepsRunner.RunStepAsync(IStep step, CancellationToken jobCancellationToken)

I did a quick search in the task lists and couldn’t find anything specifically for Linux. A bit of Googling brought up an open Github thread stating that there currently isn’t a built in task to address this issue.

The next best alternative is to use the AzureCli task and invoke it that way:

- task: AzureCLI@1
    displayName: Deploy the UI
    inputs:
      azureSubscription: $(azureSubscription)
      scriptLocation: inlineScript
      inlineScript: |
        az storage blob upload-batch \
          --destination \$web \
          --account-name "$(storageAccountName)" \
          --source "$(Agent.BuildDirectory)/$(outputDir)"

I’ve linked the GitHub issue below. It has a few alternatives to this task as well so worth reading if you’re having issues: https://github.com/microsoft/azure-pipelines-tasks/issues/8920#issuecomment-640596461

Setup MongoDB on an Azure VM

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Hi everyone,

I’m currently using a small linux vm to host a MongoDB instance on Azure. These are the steps I followed:

## MongoDB

### Install
https://docs.mongodb.com/manual/tutorial/install-mongodb-on-ubuntu/

1. Import the public key: `wget -qO - https://www.mongodb.org/static/pgp/server-4.4.asc | sudo apt-key add -`
2. Create a list file:  `echo "deb [ arch=amd64,arm64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/4.4 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-4.4.list`
   - This is for Ubuntu 18.04, check version using `lsb_release -a` 
3. Reload the local package database: `sudo apt-get update`
4. Install MongoDb: `sudo apt-get install -y mongodb-org`
5. Pin the version to prevent automatic upgrades 
```
echo "mongodb-org hold" | sudo dpkg --set-selections
echo "mongodb-org-server hold" | sudo dpkg --set-selections
echo "mongodb-org-shell hold" | sudo dpkg --set-selections
echo "mongodb-org-mongos hold" | sudo dpkg --set-selections
echo "mongodb-org-tools hold" | sudo dpkg --set-selections
```

### Allow remote access
https://www.digitalocean.com/community/tutorials/how-to-configure-remote-access-for-mongodb-on-ubuntu-20-04

1. sudo nano /etc/mongod.conf
2. Find the `network interfaces` section
3. Find the `bindIp` value
4. Append the public ip of your vm to this address list `bindIp: 0.0.0.0`
   - *Note that this is the VM ip not the ip of the machine you plan to connect from.*
5. Restart MongoDB `sudo systemctl restart mongod`

### Add authentication
1. Connect to the instance from an ssh connection: `mongo --port 27017'
2. Create the user:
https://stackoverflow.com/a/38921949/522859
```
db.createUser(
  {
    user: "YOUR_USERNAME",
    pwd: "YOUR_PASSWORD",
    roles: [ { role: "root", db: "admin" } ]
  }
)
```
3. Restart with access control: `mongod --auth --port 27017 --dbpath /data/db1`
4. Authenticate as the user adminstrator: `mongo --port 27017 -u "YOUR_USERNAME" -p "YOUR_PASSWORD"  --authenticationDatabase "admin"`
5. Locate the commented out security heading and uncomment it.
6. Add `authorized: enabled`
```
security:
  authorization: enabled
```
7. Restart with access control: `mongod --auth --port 27017 --dbpath /data/db1`

Simple Staging/Test Environment with Heroku – Ruby on Rails

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Hey everyone,

This is just a quick guide on how to create a test/staging environment with Heroku.

-- Create staging environment
heroku create --remote staging

-- Push to staging app
heroku push staging master

-- Run rake db:migrate on staging app
heroku run rake db:migrate --remote staging

-- Add pgbackups add ons
heroku addons:add pgbackups --remote staging
heroku addons:add pgbackups --remote heroku

-- Create backup of production data
heroku pgbackups:capture --remote heroku

-- Copy to staging environemnt
heroku pgbackups:restore DATABASE `heroku pgbackups:url --remote heroku` --remote staging

-- Create a new config file called staging.rb (/config/environments/staging.rb)

-- Add environment variables
heroku config:add RACK_EVN=staging RAILS_ENV=staging --remote staging

-- Ready to go !

For those of you using git branches etc, the following may come in handy as well:

-- Create local development branch
git branch development

-- Switch to dev branch
git checkout development

-- Make your changes and commit them
git init
git add .
git commit -m "My changes"

-- Push to staging environment (local development branch to staging environment master branch)
git push staging development:master

If you run into any trouble, I found the following links pretty helpful:

http://stackoverflow.com/a/6931462/522859
https://devcenter.heroku.com/articles/pgbackups#transfer
https://devcenter.heroku.com/articles/multiple-environments

Let me know if you’ve got anything to add.

Assets:Precompile (Rake Aborted) – Heroku

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Hey everyone,

I ran into the following error over the weekend while trying to push to heroku:

Running: rake assets:precompile
rake aborted!
could not connect to server: Connection refused
Is the server running on host “127.0.0.1” and accepting
TCP/IP connections on port 5432?

This stackoverflow post helped to solve the issue. All you need to do is add the following line to your application.rb file:

#Applicication.rb
config.assets.initialize_on_precompile = false

Let me know if you have any problems.

Installing SQL Developer on Ubuntu – make-sqldeveloper-package chmod: missing operand after `755′

2 Replies

Hey everyone,

I was following a guide while trying to install SQL Developer on Ubuntu, however I ran into the following error:

make-sqldeveloper-package chmod: missing operand after `755′

To fix it, simply change line number #381 in ‘/usr/bin /make-sqldeveloper-package’ as follows:

Original

${FIND} "${OPTDIR}" ! ( -type d -o -name "*.jar" ) |${XARGS} ${XARGS_OPTS} ${FILE} ${FILE_OPTS} |${GREP} ${GREP_OPTS} "shell script text executable" |${CUT} ${CUT_OPTS_FUNC_CLEAN} |${XARGS} ${XARGS_OPTS} ${CHMOD} ${CHMOD_OPTS}

Modified

${FIND} "${OPTDIR}" ! ( -type d -o -name "*.jar" ) |${XARGS} ${XARGS_OPTS} ${FILE} ${FILE_OPTS} |${GREP} ${GREP_OPTS} "shell script" | ${GREP} ${GREP_OPTS} "text executable" |${CUT} ${CUT_OPTS_FUNC_CLEAN} |${XARGS} ${XARGS_OPTS} ${CHMOD} ${CHMOD_OPTS}

Thanks to this blog post for the solution, just note that it is Polish.

Let me know if you have any issues!

WARN Could not determine content-length of response body – Ruby on Rails

2 Replies

Hey everyone

I was going through my development logs today and noticed that the following line was appearing everywhere:

WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true

While nothing appeared to be wrong, it made the logs a lot harder to read. A stackoverflow post indicates that this is a webrick issue that can be avoided by switching to thin. This is also the recommended option for heroku. In order to use thin, you simply need to add it to your Gemfile:

#Gemfile

#Added gems
gem 'therubyracer' #JavaScript
gem 'thin' #Instead of webrick

Run bundle install

chris@chris-VirtualBox:~/calendar$ bundle install
Fetching gem metadata from https://rubygems.org/...........
Fetching gem metadata from https://rubygems.org/..
Using rake (10.0.2) 
Using i18n (0.6.1) 
Using multi_json (1.4.0) 
Using activesupport (3.2.9) 
Using builder (3.0.4) 
Using activemodel (3.2.9) 
Using erubis (2.7.0) 
Using journey (1.0.4) 
Using rack (1.4.1) 
Using rack-cache (1.2) 
Using rack-test (0.6.2) 
Using hike (1.2.1) 
Using tilt (1.3.3) 
Using sprockets (2.2.2) 
Using actionpack (3.2.9) 
Using mime-types (1.19) 
Using polyglot (0.3.3) 
Using treetop (1.4.12) 
Using mail (2.4.4) 
Using actionmailer (3.2.9) 
Using arel (3.0.2) 
Using tzinfo (0.3.35) 
Using activerecord (3.2.9) 
Using activeresource (3.2.9) 
Using bcrypt-ruby (3.0.1) 
Using bundler (1.2.3) 
Using coffee-script-source (1.4.0) 
Using execjs (1.4.0) 
Using coffee-script (2.2.0) 
Using rack-ssl (1.3.2) 
Using json (1.7.5) 
Using rdoc (3.12) 
Using thor (0.16.0) 
Using railties (3.2.9) 
Using coffee-rails (3.2.2) 
Installing daemons (1.1.9) 
Installing eventmachine (1.0.0) with native extensions 
Using jquery-rails (2.1.4) 
Using libv8 (3.3.10.4) 
Using pg (0.14.1) 
Using rails (3.2.9) 
Using sass (3.2.3) 
Using sass-rails (3.2.5) 
Using therubyracer (0.10.2) 
Installing thin (1.5.0) with native extensions 
Using uglifier (1.3.0) 
Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is installed.

And finally start thin:

chris@chris-VirtualBox:~/calendar$ rails s thin
=> Booting Thin
=> Rails 3.2.9 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
>> Thin web server (v1.5.0 codename Knife)
>> Maximum connections set to 1024
>> Listening on 0.0.0.0:3000, CTRL+C to stop

If you’d prefer to keep using Webrick, the following patch is said to resolve the issue:
https://bugs.ruby-lang.org/attachments/2300/204_304_keep_alive.patch

Link

Hey everyone,

I’ve just done a fresh install of RVM using the guide below. There were a few dependencies missing, but other than that it all went pretty smoothly.

Link: http://stjhimy.com/posts/10-five-quick-steps-to-set-up-rvm-with-rails-2-and-rails3

Next time I do an install I’ll try to document the whole thing, but for now that link is probably one of the better/simpler guides I’ve come across. If you have any problems please leave a comment below and I’ll try to get back to you.

UPDATE:

Just another guide I’ve come across that seems to work well, this one is a complete “start to finish” one:
http://rails.vandenabeele.com/blog/2011/11/26/installing-ruby-and-rails-with-rvm-on-ubuntu-11-dot-10/

What I Broke – Programming and Web Development

Let's take a look at what I've broken today

Tag Archives: ubuntu

RaspberryPi Camera not detected – Ubuntu 20.04.5 LTS

libgl error pic id driver null – ros2 turtlesim

The Repository is not Signed – Ubuntu ros2 installation

The current operating system is not capable of running this task. That typically means the task was written for Windows only. For example, written for Windows Desktop PowerShell. – AzureFileCopy@4

Setup MongoDB on an Azure VM

Simple Staging/Test Environment with Heroku – Ruby on Rails

Assets:Precompile (Rake Aborted) – Heroku

Installing SQL Developer on Ubuntu – make-sqldeveloper-package chmod: missing operand after `755′

Original

Modified

WARN Could not determine content-length of response body – Ruby on Rails