add support for azure arc

dnsapi/dns_azure.sh

@@ -83,7 +83,7 @@ dns_azure_add() {
     _saveaccountconf_mutable AZUREDNS_CLIENTSECRET "$AZUREDNS_CLIENTSECRET"
   fi
 
-  accesstoken=$(_azure_getaccess_token "$AZUREDNS_MANAGEDIDENTITY" "$AZUREDNS_TENANTID" "$AZUREDNS_APPID" "$AZUREDNS_CLIENTSECRET")
+	  accesstoken=$(_azure_getaccess_token "$AZUREDNS_MANAGEDIDENTITY" "$AZUREDNS_TENANTID" "$AZUREDNS_APPID" "$AZUREDNS_CLIENTSECRET" "$AZUREDNS_ARC")
 
   if ! _get_root "$fulldomain" "$AZUREDNS_SUBSCRIPTIONID" "$accesstoken"; then
     _err "invalid domain"
@@ -186,7 +186,7 @@ dns_azure_rm() {
     fi
   fi
 
-  accesstoken=$(_azure_getaccess_token "$AZUREDNS_MANAGEDIDENTITY" "$AZUREDNS_TENANTID" "$AZUREDNS_APPID" "$AZUREDNS_CLIENTSECRET")
+  accesstoken=$(_azure_getaccess_token "$AZUREDNS_MANAGEDIDENTITY" "$AZUREDNS_TENANTID" "$AZUREDNS_APPID" "$AZUREDNS_CLIENTSECRET", "$AZUREDNS_ARC")
 
   if ! _get_root "$fulldomain" "$AZUREDNS_SUBSCRIPTIONID" "$accesstoken"; then
     _err "invalid domain"
@@ -292,6 +292,7 @@ _azure_getaccess_token() {
   tenantID=$2
   clientID=$3
   clientSecret=$4
+  arc=$5
 
   accesstoken="${AZUREDNS_BEARERTOKEN:-$(_readaccountconf_mutable AZUREDNS_BEARERTOKEN)}"
   expires_on="${AZUREDNS_TOKENVALIDTO:-$(_readaccountconf_mutable AZUREDNS_TOKENVALIDTO)}"
@@ -312,7 +313,16 @@ _azure_getaccess_token() {
   if [ "$managedIdentity" = true ]; then
     # https://docs.microsoft.com/en-us/azure/active-directory/managed-identities-azure-resources/how-to-use-vm-token#get-a-token-using-http
     export _H1="Metadata: true"
-    response="$(_get http://169.254.169.254/metadata/identity/oauth2/token\?api-version=2018-02-01\&resource=https://management.azure.com/)"
+
+    if [ "$arc" = true ]; then 
+    	response="$(_get http://localhost:40342/metadata/identity/oauth2/token\?api-version=2019-08-15\&resource=https://management.azure.com/)"
+    	T=$(cat $HTTP_HEADER | grep Www | sed 's/Www-Authenticate: Basic realm=//g' | sed 's/[^a-zA-Z0-9\/\.\-]//g')
+    	export _H2="Authorization: Basic $(cat $T)"
+    	response="$(_get http://localhost:40342/metadata/identity/oauth2/token\?api-version=2019-08-15\&resource=https://management.azure.com/)"
+    else
+	response="$(_get http://169.254.169.254/metadata/identity/oauth2/token\?api-version=2018-02-01\&resource=https://management.azure.com/)"
+    fi
+
     response="$(echo "$response" | _normalizeJson)"
     accesstoken=$(echo "$response" | _egrep_o "\"access_token\":\"[^\"]*\"" | _head_n 1 | cut -d : -f 2 | tr -d \")
     expires_on=$(echo "$response" | _egrep_o "\"expires_on\":\"[^\"]*\"" | _head_n 1 | cut -d : -f 2 | tr -d \")