Public/Slack/Send-SlackNotification.ps1
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function Send-SlackNotification { [CmdletBinding( DefaultParameterSetName = "Default" )] Param( [Parameter( Mandatory = $true, ValueFromPipelineByPropertyName = $true, Position = 1 )] [string] $Message, [Parameter( Mandatory = $true, ValueFromPipelineByPropertyName = $true, Position = 2 )] [string] $Webhook, [Parameter( Mandatory = $false, ValueFromPipelineByPropertyName = $true, Position = 3 )] [string] $Channel, [Parameter( Mandatory = $false, ValueFromPipelineByPropertyName = $true, ParameterSetName = "Attachments" )] [string] [Alias('color')] $Colour, [Parameter( Mandatory = $false, ValueFromPipelineByPropertyName = $true, ParameterSetName = "Attachments" )] [Alias('Push')] [string] $Title, [Parameter( Mandatory = $false, ValueFromPipelineByPropertyName = $true )] [array] $UpperBlocks, [Parameter(Mandatory = $false, ValueFromPipelineByPropertyName = $true, ParameterSetName = "Attachments" )] [array] $SubBlocks, [Parameter(Mandatory = $false, ValueFromPipelineByPropertyName = $true, ParameterSetName = "Attachments" )] [array] $Fields ) if ($Title.Length -gt 75) { throw "Title must be 75 characters or less" } if ($Fields -and $SubBlocks) { throw "You cannot specify both -Fields and SubBlocks" } # Let's initialize an empty hash table that we'll use to build up the JSON payload # By default we set the "text" field to the $message variable so we always have something to send $SlackBody = @{ text = $Message blocks = @() attachments = @( @{ blocks = @( ) } ) } if ($Channel) { $SlackBody.Add('channel', $Channel) } if ($Colour) { if ($Colour -notmatch '#[0-9A-Fa-f]{6}') { throw "Colour must match the hexadecimal colour format. (e.g #FF1234)" } $SlackBody.attachments[0].Add('color', $Colour) } # If we've got any "attachments" then we need to make sure our message is set in the "attachments" section If ($Title -or $Colour) { # Make sure the "text" param is blanked out otherwise it really messes things up :( $SlackBody.text = "" # Add a fallback message to the attachment - this affects things like pop-up's/toasts $SlackBody.attachments[0].Add('fallback', $Title) # If the message is longer than the max length we'll need to send it as raw text to the attachment instead. try { $MessageLength = ($Message | ConvertTo-Json).Length } catch { # Ignore errors } if (!$MessageLength) { Write-Verbose "Failed to determine JSON length of message, falling back to legacy method" $MessageLength = $Message.Length } if ($MessageLength -lt 3000 -and (!$Fields)) { # Build up a message object, but add it later $MessageObject = @{ type = 'section' text = @{ type = 'mrkdwn' text = $Message } } } else { Write-Verbose "Message over 3000 characters or -Fields specified, falling back to legacy method" $SlackBody.attachments[0].Add('text', $Message) # We need to tell Slack that the text is a "mrkdwn" type $SlackBody.attachments[0].Add('mrkdwn_in', @('text')) } } if ($Title) { # If we're using the "attachments" for our main text then we need to add the title to the attachment instead of the blocks if ($SlackBody.attachments[0].text) { $SlackBody.attachments[0].Add('title', $Title) } else { # Build up the "title" object and add it to the body $TitleObject = @{ type = 'header' text = @{ type = 'plain_text' text = $Title emoji = $true } } $SlackBody.attachments[0].blocks += $TitleObject } } # We need to add the message object _after_ the title otherwise things look wrong 😂 if ($MessageObject) { $SlackBody.attachments[0].blocks += $MessageObject } # If we've got any sub-blocks then add them at the end of the message if ($SubBlocks) { if ($SlackBody.attachments[0].text) { Write-Warning "Cannot use SubBlocks due to length of main message, they will be ignored.`nTry using -UpperBlocks or -Fields instead" $SubBlocks = $null } if ($SubBlocks.count -gt 100) { Write-Warning "Cannot use SubBlocks due to too many blocks, they will be ignored. (Maximum 100 blocks)" $SubBlocks = $null } if ($SubBlocks.fields) { if ($SubBlocks.fields.count -gt 10) { Write-Warning "Cannot use SubBlocks with fields that contain more than 10 items, they will be ignored." $SubBlocks = $null } } if ($SubBlocks) { $SubBlocks | ForEach-Object { $SlackBody.attachments[0].blocks += $_ } } } # If we've got any upper-blocks then add them in if ($UpperBlocks) { if ($UpperBlocks.count -gt 100) { Write-Warning "Cannot use SubBlocks due to too many blocks, they will be ignored. (Maximum 100 blocks)" $UpperBlocks = $null } if ($UpperBlocks.fields) { if ($UpperBlocks.fields.count -gt 10) { Write-Warning "Cannot use SubBlocks with fields that contain more than 10 items, they will be ignored." $UpperBlocks = $null } } if ($UpperBlocks) { $UpperBlocks | ForEach-Object { $SlackBody.blocks += $_ } } } # If we've got any fields then add them in if ($Fields) { # 'fields' and 'blocks' cannot be used together, so remove blocks if we've got them $SlackBody.attachments[0].remove('blocks') $SlackBody.attachments[0].Add('fields', @()) if ($Fields.Count -gt 3) { Write-Warning "Cannot use Fields with more than 3 items, they will be ignored." $Fields = $null } if ($Fields) { $Fields | ForEach-Object { $SlackBody.attachments[0].fields += $_ } } } # Convert with a reasonable depth, we have a lot of nested objects! $ConvertedBody = $SlackBody | ConvertTo-Json -Depth 10 Write-Debug $ConvertedBody try { Invoke-RestMethod -Uri $Webhook -Method Post -Body $ConvertedBody -ErrorAction Stop } catch { # We can't control what a user enters in the SubBlocks parameter, so try to warn them if they've got something wrong $AdditionalError = "" if ($SubBlocks) { $AdditionalError += "`nYou are using SubBlocks, it's possible that your SubBlocks are malformed, try removing them and running the command again." } if ($UpperBlocks) { $AdditionalError += "`nYou are using UpperBlocks, it's possible that your UpperBlocks are malformed, try removing them and running the command again." } if ($Fields) { $AdditionalError += "`nYou are using Fields, it's possible that your Fields are malformed, try removing them and running the command again." } Write-Error "Failed to send Slack notification.$AdditionalError.`n$($_.Exception.Message)" } } |