Tag: linux

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Downgrade docker by installing an older version on linux

Sometimes the latest version of software may include bugs that have not been fixed.This is the case for docker on Ubuntu 22.04. The buildkit version prints on stderr instead of stdout and this causes some issues on teamcity. As a solution I wanted to downgrade docker on a previous version. First you will need to delete the existing docker installation. You can do this with the below commands:

sudo apt-get purge -y docker-engine docker docker.io docker-ce docker-ce-cli docker-compose-plugin
sudo apt-get autoremove -y --purge docker-engine docker docker.io docker-ce docker-compose-plugin

sudo rm -rf /var/lib/docker /etc/docker
sudo rm /etc/apparmor.d/docker
sudo groupdel docker
sudo rm -rf /var/run/docker.sock

Based on your OS version you can go under docker downloads and find a specific version. Some older docker version exist for older OS versions but you can install them on later versions also.

Index of linux/ubuntu/dists/ (docker.com)

There could be a case when you have jammy (22.04) but you want to install binaries that were available on bionic version (18.04). In order to install an older version of docker you will need to download the old binaries by navigating inside the specific version then selecting pool and finally stable. Inside the last folder you can find all the architectures that are supported and you should select the appropriate one. For x64 you can select amd64 and then you can find a specific version of the binary.

In order to install specific version you will need to download all the packages that you need (some of them are dependencies of docker-ce) with wget and then install them.

Download:

wget https://download.docker.com/linux/ubuntu/dists/bionic/pool/stable/amd64/docker-scan-plugin_0.17.0~ubuntu-bionic_amd64.deb

Install:

dpkg -i docker-scan-plugin_0.17.0~ubuntu-bionic_amd64.deb
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Query servers disk size – Azure Log Analytics

Log Analytics can be a powerful monitoring tool for your infrastructure as you can query various metrics that are important for your servers availability like disk space.

The below query can be used to get free space for your Linux VM disks. 

 InsightsMetrics
| where Origin == "vm.azm.ms"
    and Namespace == "LogicalDisk"  
    and Name == "FreeSpaceMB"
| extend Disk=tostring(todynamic(Tags)["vm.azm.ms/mountId"]),
    Disk_Size_GB=(todynamic(Tags)["vm.azm.ms/diskSizeMB"]) / (1024)
| summarize Disk_Free_Space_GB = avg(Val) / (1024)
    by Computer,
    Disk, Disk_Size_GB, _ResourceId
| where Disk in ('sda1', 'sdb1', 'sdc1', 'sdd1','/')
| project Computer, Disk, Disk_Size_GB, Disk_Free_Space_GB

You can also select the scope of the query in order to get results for specific resources/resource groups.

The result will bring all disks size and free space that their name is included in the list 

('sda1', 'sdb1', 'sdc1', 'sdd1','/')

The same query with a small change can be applied also for windows vms in order to get the available space for your C: drive.

 InsightsMetrics
| where Origin == "vm.azm.ms"
    and Namespace == "LogicalDisk"  
    and Name == "FreeSpaceMB"
| extend Disk=tostring(todynamic(Tags)["vm.azm.ms/mountId"]),
    Disk_Size_GB=(todynamic(Tags)["vm.azm.ms/diskSizeMB"]) / (1024)
| summarize Disk_Free_Space_GB = avg(Val) / (1024)
    by Computer,
    Disk, Disk_Size_GB, _ResourceId
| where Disk in ('C:')
| project Computer, Disk, Disk_Size_GB, Disk_Free_Space_GB

Finally you can pin this result inside an Azure dashboard by clicking pin and select the specific dashboard.

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Install linux azure devops agent on docker container

As we previously examined how we can create a containerized azure devops agent running on a windows machine, we will now go through the same procedure but with linux OS.

You can read the windows container azure devops agent article using the below link:

Install windows azure devops agent on docker container

The first thing that you will need is a virtual machine that runs docker. When this requirement is fulfilled you can jump on the image building. In order to build your image you will need your Dockerfile and the instructions for the agent.

You can read the rest of the article on Medium using the link below:

View at Medium.com

A detailed deployment video can be found on my Udemy course:

https://www.udemy.com/course/mastering-azure-devops-cicd-pipelines-with-yaml/

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Creating Windows/Linux Web App terraform: (Site Name “” / Resource Group “”): web.AppsClient#CreateOrUpdate: Failure sending request: StatusCode=0 — Original Error: autorest/azure: Service returned an error. Status=

I was struggling to create an app service using Terraform with the error shown below. I could not find a way to resolve this as the error message was difficult to interpret. 

Creating Windows/Linux Web App: (Site Name "" / Resource Group ""): web.AppsClient#CreateOrUpdate: Failure sending request: StatusCode=0 -- Original Error: autorest/azure: Service returned an error. Status=<nil> <nil>

The code for the service plan was simple enough and I was so confused about this behavior.

resource "azurerm_resource_group" "rg" {
  name     = var.resource_group_name
  location = var.resource_group_location
}

resource "azurerm_service_plan" "app_service_plan" {
  name                = var.app_service_plan_name
  location            = azurerm_resource_group.rg.location
  resource_group_name = azurerm_resource_group.rg.name
  os_type             = "Windows"
  sku_name            = "F1"

}

resource "azurerm_windows_web_app" "app_service" {
  name                = var.app_service_name
  location            = azurerm_resource_group.rg.location
  resource_group_name = azurerm_resource_group.rg.name
  service_plan_id = azurerm_service_plan.app_service_plan.id

  site_config {
    use_32_bit_worker = true
  }
}

In order to resolve I enabled detailed debugging on terraform. As I was using Windows I used on powershell

$Env:TF_LOG = "TRACE"

and then I tried to run terraform apply again.

Terraform will provide detailed information about the running commands, so that I was able to determine the error.

Voila!

AlwaysOn should be disabled as there is a conflict.

In the documentation of azure web app one can find that always on is disabled by default however it does not seem to be correct.

https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/windows_web_app#site_config

In order to resolve you should add the always_one variable to false.

  site_config {
    use_32_bit_worker = true
    always_on = false
  }

Then you can run terraform apply again, and the resource will be created.

Enable debugging on terraform for your OS:

https://support.hashicorp.com/hc/en-us/articles/360001113727-Enabling-debug-and-trace-run-logs-in-Terraform-CLI-Cloud-or-Enterprise

Update

I perfomed a PR in order to correct the wrong documentation and it has been merged. As a result the documentation will be correct counting from the next deploy.

[Docs fix]Correct docs for resource azurerm_windows_web_app by geralexgr · Pull Request #17051 · hashicorp/terraform-provider-azurerm (github.com)