Bits & Bytes

Terraform 101

Posted on Tuesday, May 12, 2020

Files

main.tf - resource definition, main logic
data.tf - data from existing resources
output.tf - data output
terraform.tf - terraform settings
variables.tf - variables definition
terraform.tfvars and *.auto.tfvars - variable initialization

Variables

Official documentation page
Can be defined in files like terraform.tfvars or *.auto.tfvars
You can use any name for tfvars file by using -var-file option of terraform apply
Variables can be passed directly to terraform apply by using -var "varaible=value" (multiple instances of -var can be used to pass multiple variables)
Any environment variable which starts with TF_VAR_ gets treated by Terraform like a variable

Syntax

# String variable with validation
variable "string_variable" {
    type        = string
    description = "String variable is a sequence of Unicode characters"
    validation  {
        condition = length(regexall("^(Expected|Values)", var.variable_name)) == 1
        error_message = "Variable must be set with expected value"
    }
}

# Bool variable
variable "bool_variable" {
    type        = bool
    description = "Bool variable either true or false and values can be used in conditional logic"
    default     = true
}

# Number variable
variable "number_variable" {
    type        = number
    description = "Number variable type can represent both whole and fractional"
}

# Number variable
variable "list_variable" {
    type        = list(<type>)
    description = "List variable accepts any element type as long as every element is the same type"
}

# Map variable
variable "map_variable" {
    type        = map
    description = "Map variable a collection of values where each is identified by a string label"
    default     = {
        key1    = "value"
        key2    = 43
        key3    = ("1","2","3")
        key4    = {
            subkey1 = "sample"
            subkey2 = "value"
        }
    }
}

Local variables

# Local variables
# To use local variable you have to prefix its name with local. instead of var. e.g. local.local_string_variable
locals {
  local_string_variable = "test"
}

Conditionals

# CONDITION ? TRUEVAL : FALSEVAL

# Operators:
#  - Equality: == and !=
#  - Comparison: >, <, >= and <=
#  - Logic: &&, || and unary !

# Set resource option value based on variable value 
resource "sample_resource" "this" {
    option = var.test == "value" ? 1 : 0
}

# Conditional resource creation
resource "another_sample_resource" "this" {
    count = var.create_another_sample_resource ? 1 : 0
}

Useful links

Add KeyVault certificate to VMSS

Posted on Wednesday, February 26, 2020

$KeyVaultName = "KeyVaultName"
$CertificateName = "CertificateName"
$VMSSName = "VMSSName"
$VMSSResourceGroupName = "VMSSResourceGroupName"


$KeyVault = Get-AzKeyVault -VaultName $KeyVaultName
$KeyVaultCertificate = Get-AzKeyVaultCertificate -VaultName $KeyVaultName -Name $CertificateName
$VMSS = Get-AzVmss -VMScaleSetName $VMSSName -ResourceGroupName $VMSSResourceGroupName

$SourceVaultAlreadyExist = $false
$CertificateAlreadyExist = $false

$VMSS.VirtualMachineProfile.OsProfile.Secrets | % {
    if ($_.SourceVault.Id -eq $KeyVault.ResourceId) {
        $SourceVaultAlreadyExist = $true
        $SourceVaultId = $VMSS.VirtualMachineProfile.OsProfile.Secrets.IndexOf($_)

        $_.VaultCertificates | % {
            if ($_.CertificateUrl -eq $KeyVaultCertificate.SecretId) {
                $CertificateAlreadyExist = $true
            }
        }

        if (!$CertificateAlreadyExist) {
            $Certificate = New-Object Microsoft.Azure.Management.Compute.Models.VaultCertificate
            $Certificate.CertificateStore = "My"
            $Certificate.CertificateUrl = $KeyVaultCertificate.SecretId
            $VMSS.VirtualMachineProfile.OsProfile.Secrets[$SourceVaultId].VaultCertificates.Add($Certificate)
        }
    }
}

if (!$SourceVaultAlreadyExist -and !$CertificateAlreadyExist) {
    $Secrets = New-Object System.Collections.Generic.List[Microsoft.Azure.Management.Compute.Models.VaultSecretGroup]
    $Secret = New-Object Microsoft.Azure.Management.Compute.Models.VaultSecretGroup
    $Secret.SourceVault = $KeyVault.ResourceId
    $Certificates = New-Object System.Collections.Generic.List[Microsoft.Azure.Management.Compute.Models.VaultCertificate]
    $Certificate = New-Object Microsoft.Azure.Management.Compute.Models.VaultCertificate
    $Certificate.CertificateStore = "My"
    $Certificate.CertificateUrl = $KeyVaultCertificate.SecretId
    $Certificates.Add($Certificate)
    $Secret.VaultCertificates = $Certificates
    $Secrets.Add($Secret)
    $VMSS.VirtualMachineProfile.OsProfile.Secrets = $Secrets
}

$VMSS.VirtualMachineProfile.OsProfile.Secrets | ConvertTo-Json -Depth 10
$VMSS | Update-AzVmss

Kubernetes 101

Posted on Monday, February 24, 2020

Tools to install kubernetes cluster

Local installation
- minikube
- docker client
Server installation
- kops (recomended for AWS)
- kubeadm (more generic)

Useful links

https://github.com/kelseyhightower/kubernetes-the-hard-way

Kudu zip deployment

Posted on Tuesday, January 28, 2020

$SiteName = "webapp"
$SitePassword = "You can get it from publish profile"
$ApiUrl = "https://$SiteName.scm.azurewebsites.de/api/zipdeploy"
$ArchivePath = "WebApp.zip"

$Base64 = [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(("{0}:{1}" -f "`$$SiteName", $SitePassword)))
$Headers = @{Authorization=("Basic {0}" -f $Base64)}
Invoke-RestMethod -Uri $ApiUrl `
                  -Headers $Headers `
                  -UserAgent "powershell/1.0" `
                  -Method POST -InFile $ArchivePath `
                  -ContentType "multipart/form-data"

Git pull vs fetch

Posted on Monday, January 20, 2020

git pull = git fetch + git merge

Find Azure resource across all subscriptions

Posted on Friday, January 10, 2020

Get-AzSubscription | % {
  Select-AzSubscription $_
  Get-AzResource | Where-Object {$_.Name -match "<resource name>"} | Select-Object *
}

Load Azure PowersShell on the fly

Posted on Friday, November 8, 2019

Sometimes installing modules on the system is not an option. E.g. build servers or any kind of machines where you want to run non-standard cmdlet but you don't want to (or not allowed to) install anything.

In order to do it you need three files.

load.ps1 - does the heavy lifting. Just look at the script. Everything works pretty straight forward.

$modulesPath = ".\modules"

# Cleanup
Remove-Module Az*
Remove-Item -Path $modulesPath -Force -Recurse

# Download nuget.exe in case you don't have it
Invoke-WebRequest -Uri "https://dist.nuget.org/win-x86-commandline/latest/nuget.exe" -OutFile "nuget.exe"

# Restore packages from PowerShell Gallery
& ".\nuget.exe" "restore" "packages.config" "-packagesdirectory" $modulesPath

# Remove version portion from each package folder (otherwise system will not recognize modules)
Get-ChildItem $modulesPath -Directory | % { 
    Rename-Item -Path $_.FullName -NewName $($_.Name -replace "\.\d+\.\d+\.\d+","") 
}

# Add our module folder to the system modules path
$env:PSModulePath += ";$(Resolve-Path -Path $modulesPath)"

# Import Az module
Import-Module Az

nuget.config - defines package source. By default nuget.exe will use nuget.org or any other repository defined on a user/system level. The chances that it already has PowerShell Gallery in it is pretty low (at least in the environments I work with).

<?xml version="1.0" encoding="utf-8"?>
<configuration>
<packageSources>
    <add key="powershellgallery.com" value="https://www.powershellgallery.com/api/v2/" protocolVersion="2" />
</packageSources>
<config>
    <add key="signatureValidationMode" value="Accept" />
</config>
</configuration>

packages.config - holds the list of packages. In our case we're getting Az 2.8.0 but it can be adjusted to download virtually any number/kind of modules (don't forget to add Import-Module statements for any other module(s) you add).

<?xml version="1.0" encoding="utf-8"?>
<packages>
    <package id="Az" version="2.8.0" />
    <package id="Az.Accounts" version="1.6.4" />
    <package id="Az.Advisor" version="1.0.1" />
    <package id="Az.Aks" version="1.0.2" />
    <package id="Az.AnalysisServices" version="1.1.1" />
    <package id="Az.ApiManagement" version="1.3.2" />
    <package id="Az.ApplicationInsights" version="1.0.2" />
    <package id="Az.Automation" version="1.3.4" />
    <package id="Az.Batch" version="1.1.2" />
    <package id="Az.Billing" version="1.0.1" />
    <package id="Az.Cdn" version="1.3.1" />
    <package id="Az.CognitiveServices" version="1.2.1" />
    <package id="Az.Compute" version="2.7.0" />
    <package id="Az.ContainerInstance" version="1.0.1" />
    <package id="Az.ContainerRegistry" version="1.1.0" />
    <package id="Az.DataFactory" version="1.4.0" />
    <package id="Az.DataLakeAnalytics" version="1.0.1" />
    <package id="Az.DataLakeStore" version="1.2.3" />
    <package id="Az.DeploymentManager" version="1.0.1" />
    <package id="Az.DevTestLabs" version="1.0.0" />
    <package id="Az.Dns" version="1.1.1" />
    <package id="Az.EventGrid" version="1.2.2" />
    <package id="Az.EventHub" version="1.4.0" />
    <package id="Az.FrontDoor" version="1.1.1" />
    <package id="Az.HDInsight" version="2.0.2" />
    <package id="Az.HealthcareApis" version="1.0.0" />
    <package id="Az.IotHub" version="1.3.1" />
    <package id="Az.KeyVault" version="1.3.1" />
    <package id="Az.LogicApp" version="1.3.1" />
    <package id="Az.MachineLearning" version="1.1.1" />
    <package id="Az.ManagedServices" version="1.0.1" />
    <package id="Az.MarketplaceOrdering" version="1.0.1" />
    <package id="Az.Media" version="1.1.0" />
    <package id="Az.Monitor" version="1.4.0" />
    <package id="Az.Network" version="1.15.0" />
    <package id="Az.NotificationHubs" version="1.1.0" />
    <package id="Az.OperationalInsights" version="1.3.3" />
    <package id="Az.PolicyInsights" version="1.1.3" />
    <package id="Az.PowerBIEmbedded" version="1.1.0" />
    <package id="Az.RecoveryServices" version="1.4.5" />
    <package id="Az.RedisCache" version="1.1.1" />
    <package id="Az.Relay" version="1.0.2" />
    <package id="Az.Resources" version="1.7.0" />
    <package id="Az.ServiceBus" version="1.4.0" />
    <package id="Az.ServiceFabric" version="1.2.0" />
    <package id="Az.SignalR" version="1.1.0" />
    <package id="Az.Sql" version="1.15.0" />
    <package id="Az.Storage" version="1.8.0" />
    <package id="Az.StorageSync" version="1.2.1" />
    <package id="Az.StreamAnalytics" version="1.0.0" />
    <package id="Az.TrafficManager" version="1.0.2" />
    <package id="Az.Websites" version="1.5.0" />
</packages>

Git cheatsheet

Posted on Tuesday, October 29, 2019

Update existing commit

git commit --amend --no-edit
git push --force

Remove all local changes

git clean -fdx

Mirror repositories

git clone --mirror <source.repository>
cd source.repository.git
git push --mirror <target.repository>

Update submodules

git submodule update --init --recursive --progress

Remove last commit

git reset --soft HEAD~1
git reset --hard HEAD~1

Reset file

git checkout -- <path>

Merge changes as a single commit

git merge --squash <source branch>
git commit --message "merge commit message"

Get remote changes and apply local changes

git stash
git pull --rebase origin <source branch>
git stash pop