GCP disks.list在PowerShell脚本中执行时偶发报错的解决需求

问题 #

在本地Windows机器的PowerShell中使用gcloud CLI操作，单独执行以下命令能得到预期输出：

gcloud compute disks list `
    --project=prj-d-jenkins-poc `
    --filter="-users:*" `
    --format="csv(name,sizeGb,zone,status,type,lastAttachTimestamp,lastDetachTimestamp)"

但整合到以下脚本执行时偶发报错：

#Initiated OUTPUT variable as ArrayList to collect results
$OUTPUT =  New-Object -TypeName "System.Collections.ArrayList"
$OUTPUT.Add("name,sizeGb,zone,status,type,lastAttachTimestamp,lastDetachTimestamp")

#Get list of accessible projects to PROJECTS
$PROJECTS = gcloud projects list --format="value(projectId)"

#Iterate through projects list 
foreach ($i in $PROJECTS)
{
    #Get list of unattached disks 
    $list = gcloud compute disks list `
    --project=$i `
    --filter="-users:*" `
    --format="csv(name,sizeGb,zone,status,type,lastAttachTimestamp,lastDetachTimestamp)"
    
    #If list is not empty, add it to OUTPUT
    if ($list.count -gt 0){
        $list = [System.Collections.ArrayList]$list #Convert a to ArrayList
        $list.RemoveAt($list.0) #Remove first entry for a
    
        $OUTPUT += $list #append a to OUTPUT
    
        Write-Host "Unattached disks in $i wrote to OUTPUT variable."
    }
    else{ #If list is empty, skip
        Write-Host "No unattached disks found in $i."
    }

}

$OUTPUT

报错信息如下：

python.exe : WARNING: The following filter keys were not present in any resource : users
At C:\Users\minh.tran\AppData\Local\Google\Cloud SDK\google-cloud-sdk\bin\gcloud.ps1:117 char:3
+   & "$cloudsdk_python" $run_args_array
+   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (WARNING: The fo...esource : users:String) [], RemoteException
    + FullyQualifiedErrorId : NativeCommandError

推测原因是遍历到无任何磁盘（包括已挂载和未挂载）的项目时，users字段不存在，触发该警告，需要修改代码忽略这类项目。

解决方法 #

1. 提前检查项目是否存在磁盘资源 #

在执行带过滤条件的disks.list命令前，先快速判断当前项目是否有磁盘，避免在无磁盘项目上执行含users字段的过滤命令：

$hasDisks = gcloud compute disks list --project=$i --format="value(name)" --limit=1
if (-not $hasDisks) {
    Write-Host "No disks found in project $i, skipping."
    continue
}

2. 直接抑制警告输出 #

如果不想提前检查，可将gcloud命令的警告/错误流重定向到空，避免控制台报错：

$list = gcloud compute disks list `
    --project=$i `
    --filter="-users:*" `
    --format="csv(name,sizeGb,zone,status,type,lastAttachTimestamp,lastDetachTimestamp)" `
    2>$null

2>$null会将PowerShell中的标准错误流（包含gcloud的警告信息）重定向，不在控制台显示。

3. 优化后的完整脚本 #

结合以上两种方式，优化脚本逻辑并提升效率：

# Initialize OUTPUT variable as ArrayList to collect results
$OUTPUT = New-Object -TypeName "System.Collections.ArrayList"
$null = $OUTPUT.Add("name,sizeGb,zone,status,type,lastAttachTimestamp,lastDetachTimestamp")

# Get list of accessible projects
$PROJECTS = gcloud projects list --format="value(projectId)"

# Iterate through projects list 
foreach ($i in $PROJECTS) {
    # Check if project has any disks first
    $hasDisks = gcloud compute disks list --project=$i --format="value(name)" --limit=1
    if (-not $hasDisks) {
        Write-Host "No disks found in project $i, skipping."
        continue
    }

    # Get list of unattached disks, suppress warnings
    $list = gcloud compute disks list `
        --project=$i `
        --filter="-users:*" `
        --format="csv(name,sizeGb,zone,status,type,lastAttachTimestamp,lastDetachTimestamp)" `
        2>$null
    
    # If list is not empty, add it to OUTPUT
    if ($list.Count -gt 0) {
        $list = [System.Collections.ArrayList]$list
        $list.RemoveAt(0) # Remove header row
        $OUTPUT.AddRange($list) # Use AddRange for more efficient appending
        
        Write-Host "Unattached disks in $i added to OUTPUT variable."
    }
    else {
        Write-Host "No unattached disks found in $i."
    }
}

$OUTPUT

注：

• 使用$null = $OUTPUT.Add(...)避免输出Add方法的返回值
• 用AddRange替代+=提升ArrayList的追加效率
• 提前检查磁盘存在性，减少不必要的过滤命令执行

内容的提问来源于stack exchange，提问作者Minh Tran