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Environment Variable replacement for appsettings.json on AppVeyor deployment
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| <# | |
| AppVeyor Deployment Script | |
| This script is run after deployment to the web server. | |
| It substitutes environment variables in the appsettings.json file with values from the environment. | |
| All environment variables that start with the prefix are loaded and substituted into the appsettings.json file | |
| e.g. if the prefix is "APP_" then the environment variable "APP_ConnectionStrings.umbracoDbDSN" will set | |
| the value of "ConnectionStrings.umbracoDbDSN" in the appsettings.json file. | |
| #> | |
| Write-Host "Environment Variable Substitution" -ForegroundColor Cyan | |
| # Environment variables to be added to appsettings.json should be prefixed with this string. | |
| # This avoids leaking unwanted variables into the app. | |
| if ($null -eq $env:APPLICATION_PREFIX) { | |
| Write-Warning "APPLICATION_PREFIX environment variable not set." | |
| Return | |
| } | |
| # supplyng the path as an environment variable lets us target different appsettings files | |
| # in different environments. e.g. appsettings.Staging.json, appsettings.Production.json | |
| if ($null -eq $env:APPSETTINGS_PATH) { | |
| Write-Warning "APPSETTINGS_PATH environment variable not set." | |
| Return | |
| } | |
| $prefix = ${env:APPLICATION_PREFIX} + "*" | |
| $appSettingsPath = $env:APPSETTINGS_PATH | |
| # Get all environment variables that start with the prefix as a list of name/value pairs | |
| $props = Get-ChildItem env:$prefix | Select-Object -Property Name, Value | |
| Write-Host "Loading config file from $appSettingsPath" | |
| $appSettings = Get-Content -Raw $appSettingsPath | ConvertFrom-Json | |
| foreach ($variable in $props) { | |
| $matchString = $variable.Name.replace(${env:APPLICATION_PREFIX}, "") | |
| $propertyPathSegments = $matchString.Split(".") | |
| $obj = $appSettings; | |
| for ($i = 0; $i -lt $propertyPathSegments.Length; $i++) { | |
| $propName = $propertyPathSegments[$i] | |
| # if we're not at the last property, check if the property exists and create it if it doesn't | |
| if ($i -lt ($propertyPathSegments.Length - 1)) { | |
| if ($null -eq $obj.$propName) { | |
| Write-Host "Creating '$propName'" -ForegroundColor Gray | |
| $newObj = New-Object -TypeName PSObject | |
| $obj | Add-Member -MemberType NoteProperty -Name $propName -Value $newObj | |
| } | |
| # recurse | |
| $obj = $obj.$propName | |
| Continue | |
| } | |
| # if we're at the last property, check if it exists | |
| if ($null -eq $obj.$propName) { | |
| Write-Host "Creating & setting '$propName'" -ForegroundColor White | |
| # create it if it doesn't (with the value) | |
| $obj | Add-Member -MemberType NoteProperty -Name $propName -Value $variable.Value | |
| } | |
| else { | |
| # just set the value | |
| Write-Host "Setting '$matchString'" -ForegroundColor White | |
| $obj.$propName = $variable.Value | |
| } | |
| } | |
| } | |
| Write-Host "Saving config file to $appSettingsPath" -ForegroundColor Gray | |
| $appSettings | ConvertTo-Json -depth 100 | Out-File $appSettingsPath | |
| Write-Host "Variable substitution complete" -ForegroundColor Green |
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