Azure Function App PowerShell script to backup Blob storage to an Azure File share

run.ps1

# Input bindings are passed in via param block.
param($Timer)

# Define variables
$SrcStgAccURI = "https://sourceblobstg.blob.core.windows.net/"
$SrcBlobContainer = "myblobs"
$SrcSASToken = SAS_TOKEN_SOURCE
$SrcFullPath = "$($SrcStgAccURI)$($SrcBlobContainer)?$($SrcSASToken)"

$DstStgAccURI = "https://destinationfilestg.file.core.windows.net/"
$DstFileShare = "backupstaging"
$DstSASToken = SAS_TOKEN_DESTINATION
$DstFullPath = "$($DstStgAccURI)$($DstFileShare)?$($DstSASToken)"

# Get the current universal time in the default string format
$currentUTCtime = (Get-Date).ToUniversalTime()

# The 'IsPastDue' property is 'true' when the current function invocation is later than scheduled.
if ($Timer.IsPastDue) {
    Write-Host "PowerShell timer is running late!"
}

# Write an information log with the current time.
Write-Host "PowerShell timer trigger function ran! TIME: $currentUTCtime"

# uncomment to delete azcopy and force download again
# del azcopy.exe

# Test if AzCopy.exe exists in current folder
$WantFile = "azcopy.exe"
$AzCopyExists = Test-Path $WantFile
Write-Host "AzCopy exists:" $AzCopyExists

# Download AzCopy if it doesn't exist
If ($AzCopyExists -eq $False)
{
    Write-Host "AzCopy not found. Downloading..."
    
    #Download AzCopy
    Invoke-WebRequest -Uri "https://aka.ms/downloadazcopy-v10-windows" -OutFile AzCopy.zip -UseBasicParsing
 
    #Expand Archive
    write-host "Expanding archive..."
    Expand-Archive ./AzCopy.zip ./AzCopy -Force

    # Copy AzCopy to current dir
    Get-ChildItem ./AzCopy/*/azcopy.exe | Copy-Item -Destination "./AzCopy.exe"
}
else
{
    Write-Host "AzCopy found, skipping download."
}

# Set env values for AzCopy
$env:AZCOPY_LOG_LOCATION = $env:temp+'\.azcopy'
$env:AZCOPY_JOB_PLAN_LOCATION = $env:temp+'\.azcopy'

# Run AzCopy from source blob to destination file share

Write-Host "Backing up storage account..."
./azcopy.exe copy $SrcFullPath $DstFullPath --recursive --overwrite=ifsourcenewer

@andrew-kelleher I'm trying to do something similar to what you have above. I've already gotten it loaded and unzipped, and then set the log and plan paths based on what you have above, and am now getting a "panic: invalid state, azcopyAppPathFolder should be initialized by root" error when I try to login in AzCopy.

It seems to be an access issue, so I've tried several locations for the executable and log/plan paths ("$($env:temp).azcopy", "D:\home\site\wwwroot\AzCopy", and others), with hopes of getting past the permissions, but still no luck. Any ideas?

I'm on a Function App on a Standard S1 service plan, runtime version 4, PowerShell 7.2.

Thanks!

Hi @kevsor2,
Did you ever get to the bottom of this, I'm experiencing the exact same problem?
Any help would be appreciated.
Thanks

Hi @stevenjpbrown,
No, I ended up having to drop attempting this method all together because the security team doesn't want to allow using SAS tokens. AzCopy unfortunately requires using a SAS token on at least one end of the copy, so I can't use it at all.
Sorry, wish I was more help. :(

@stevenjpbrown it's been a while since I last looked at this. I suspect something's changed in one of Function App's updated runtimes or libraries, causing this to fail, unfortunately.

Depending on your requirements, there's now a native Azure operational backup capability which I covered here. HTH.

Hi @stevenjpbrown, No, I ended up having to drop attempting this method all together because the security team doesn't want to allow using SAS tokens. AzCopy unfortunately requires using a SAS token on at least one end of the copy, so I can't use it at all. Sorry, wish I was more help. :(

:-( thanks for the reply, kind of stuck at the same point myself

@stevenjpbrown it's been a while since I last looked at this. I suspect something's changed in one of Function App's updated runtimes or libraries, causing this to fail, unfortunately.

Depending on your requirements, there's now a native Azure operational backup capability which I covered here. HTH.

Hi Andrew, thanks for the update but this isn't really what I'm after. I need to trigger a copy to another storage account once it uploads to one storage account. It is a file share with single deep root folders I need to copy only.

hey @stevenjpbrown, i've integrated azcopy.exe in my package folder along run.ps1 and run & "./name of your function/azcopy.exe". It would have been better to directly downloaded it from internet but unfortunalty i run into the same error as you

thanks for the update @GuetarniTarik I take it you didn’t get any further with it? I raised a ticket with MS but didn’t get any further myself.

at the end it worked for me by adding azcopy.exe directly in the package. I suggest you to do the same

I did do that but couldn’t get it working. It didn’t like the path to the log files. It was changing the slash on a windows function app to / rather than . Did you use Linux or windows?

@GuetarniTarik - whats the way to integrate azcopy.exe with the package folder?

Hello Andrew,

I tried to execute this script, but it is not working for me, can you pass on any documentation if it is handy with you.

Thanks!