Merge pull request moby#3476 from crazy-max/azblob-acct-name

azblob cache: account_name attribute

Author: crazy-max

README.md

@@ -536,6 +536,11 @@ There are 2 options supported for Azure Blob Storage authentication:
 * Any system using environment variables supported by the [Azure SDK for Go](https://docs.microsoft.com/en-us/azure/developer/go/azure-sdk-authentication). The configuration must be available for the buildkit daemon, not for the client.
 * Secret Access Key, using the `secret_access_key` attribute to specify the primary or secondary account key for your Azure Blob Storage account. [Azure Blob Storage account keys](https://docs.microsoft.com/en-us/azure/storage/common/storage-account-keys-manage)
 
+> **Note**
+>
+> Account name can also be specified with `account_name` attribute (or `$BUILDKIT_AZURE_STORAGE_ACCOUNT_NAME`)
+> if it is not part of the account URL host.
+
 `--export-cache` options:
 * `type=azblob`
 * `mode=<min|max>`: specify cache layers to export (default: `min`)

cache/remotecache/azblob/utils.go

@@ -15,6 +15,7 @@ import (
 
 const (
 	attrSecretAccessKey = "secret_access_key"
+	attrAccountName     = "account_name"
 	attrAccountURL      = "account_url"
 	attrPrefix          = "prefix"
 	attrManifestsPrefix = "manifests_prefix"
@@ -50,7 +51,16 @@ func getConfig(attrs map[string]string) (*Config, error) {
 		return &Config{}, errors.Wrap(err, "azure storage account url provided is not a valid url")
 	}
 
-	accountName := strings.Split(accountURL.Hostname(), ".")[0]
+	accountName, ok := attrs[attrAccountName]
+	if !ok {
+		accountName, ok = os.LookupEnv("BUILDKIT_AZURE_STORAGE_ACCOUNT_NAME")
+		if !ok {
+			accountName = strings.Split(accountURL.Hostname(), ".")[0]
+		}
+	}
+	if accountName == "" {
+		return &Config{}, errors.New("unable to retrieve account name from account url or ${BUILDKIT_AZURE_STORAGE_ACCOUNT_NAME} or account_name attribute for azblob cache")
+	}
 
 	container, ok := attrs[attrContainer]
 	if !ok {