Public/Ssh/Wait-VmSshReady.ps1
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# --------------------------------------------------------------------------- # Wait-VmSshReady # Polls a remote SSH port until it accepts a TCP connection or a deadline # expires. Returns $true on success, $false on timeout. Never throws on # the network path - callers decide what to do with a $false result. # # Use this after booting (or rebooting) a VM to wait for cloud-init or # sshd startup to finish. A successful return is a stronger signal than # ICMP ping: it means sshd has bound the port and is accepting TCP # connections, which is the precondition the next SSH call needs. # # For a single non-blocking probe, call Test-VmSshPort directly instead - # this function is the loop on top of that primitive. # --------------------------------------------------------------------------- function Wait-VmSshReady { [CmdletBinding()] [OutputType([bool])] param( [Parameter(Mandatory)] [string] $IpAddress, [int] $Port = 22, # 120 s covers a typical Ubuntu cloud-init first-boot with slack. # Cold-boot waits (10 min) should override this. [int] $TimeoutSeconds = 120, [int] $PollIntervalSeconds = 2, [int] $ConnectTimeoutMilliseconds = 2000 ) $deadline = (Get-Date).AddSeconds($TimeoutSeconds) while ((Get-Date) -lt $deadline) { if (Test-VmSshPort -IpAddress $IpAddress ` -Port $Port ` -TimeoutMilliseconds $ConnectTimeoutMilliseconds) { return $true } Start-Sleep -Seconds $PollIntervalSeconds } return $false } |