delphi调用阿里云的函数计算服务FC

阿里云函数计算：https://www.aliyun.com/product/fc?spm=5176.7933691.765261.210.ijPFRC

delphi版本：Embarcadero® Delphi 10.2 Version 25.0.26309.314 

阿里云最开始有PaaS层的“云引擎ACE”，像百度的“应用引擎BAE”一样，但是在2016时，阿里把它关闭了。

目前，阿里的“函数计算FC”有点类似这个，但感觉比之前ACE限制太多，要访问数据啥的第三方模组，需要使用docker等。

FC的调用SDK没有Delphi的版本，参照javascript的版本，修改了一个，可以运作：

unit wxhAliYun_FC;

interface
uses
REST.Client,system.JSON,system.SysUtils;

function invokeAliFC(req:TRESTRequest;funName:string;body:string):TJSONValue;

implementation

uses
REST.Types,DateUtils,EncdDecd,cHash,System.Classes;

function DateTimeToGMT(const ADate:TDateTime):string;
const
WEEK:array[1..7] of PChar = ('Sun','Mon','Tue','Wed','Thu','Fri','Sat');
MonthDig:array[1..12] of PChar =
('Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec');
var
wWeek,wYear,wMonth,wDay,wHour,wMin,wSec,wMilliSec:Word;
sWeek,sMonth:string;
begin
DecodeDateTime(ADate,wYear,wMonth,wDay,wHour,wMin,wSec,wMilliSec);
wWeek := DayOfWeek(ADate);
sWeek := WEEK[wWeek];
sMonth := MonthDig[wMonth];
Result := Format('%s, %.2d %s %d %.2d:%.2d:%.2d GMT',[sWeek,wDay,sMonth,wYear,wHour,wMin,wSec]);
end;

//加密算法来自http://fundementals.sourceforge.net
function signString(source, secret:AnsiString):string;
var d:T256BitDigest;
begin
d:=CalcHMAC_SHA256(secret,source);
Result:=EncodeBase64(@d.Bytes,length(d.Bytes));
end;

function composeStringToSign(method, contentMD5,contentType,date,signHeaders,path:string):string;
begin
Result:= method+#10+contentMD5+#10+contentType+#10+date+#10+signHeaders+#10+path;
end;

function invokeAliFC(req:TRESTRequest;funName:string;body:string):TJSONValue;
var
vItem:TRESTRequestParameter;
stringToSign,signature,sDate:string;
accountID,path,host,sContentType,contentMD5:string;
contentType:TRESTContentType;
d:T128BitDigest;
s:ansistring;
b0,b:TBytes;
begin
accountID:='你的账号ID';
path:='/2016-08-15/services/flowers/functions/'+funName+'/invocations';
host:=accountID+'.fc.cn-shanghai.aliyuncs.com';
contentType:=TRESTContentType.ctAPPLICATION_OCTET_STREAM;
sContentType:='application/octet-stream';//'application/json';
//sDate:='Sat, 02 Sep 2017 03:08:12 GMT';
sDate:=DateTimeToGMT(TTimeZone.Local.ToUniversalTime(now()));

req.ClearBody();
req.Params.Clear();

req.Client.BaseURL:='http://localhost:8080'+path;
//req.Client.BaseURL:='http://'+host+path;

d:=CalcMD5(body);
SetLength(s, Length(d.Bytes)*2);
{$IFDEF NEXTGEN}
SetLength(b,Length(d.Bytes)*2);
b0:=BytesOf(@d.Bytes,length(d.Bytes));
BinToHex(b0,0, b, 0,Length(b));
s:=StringOf(b);
{$ELSE}
BinToHex(@d.Bytes[0], PAnsiChar(s), Length(d.Bytes));
{$ENDIF}

s:=LowerCase(s);
contentMD5:=EncodeBase64(PAnsiChar(s),Length(s));
stringToSign := composeStringToSign(
'POST',
contentMD5,
sContentType,
sDate,
'x-fc-account-id:'+accountID,
path);
signature := signString(stringToSign,'你的密钥');

vItem:=req.Params.AddItem;
vItem.Kind:=TRESTRequestParameterKind.pkHTTPHEADER;
vItem.ContentType:=contentType;
vItem.Options:=[TRESTRequestParameterOption.poDoNotEncode];
vItem.Name:='authorization';
vItem.Value:='FC 你的访问ID:'+signature;

vItem:=req.Params.AddItem;
vItem.Kind:=TRESTRequestParameterKind.pkHTTPHEADER;
vItem.ContentType:=contentType;
vItem.Options:=[TRESTRequestParameterOption.poDoNotEncode];
vItem.Name:='host';
vItem.Value:=host;

vItem:=req.Params.AddItem;
vItem.Kind:=TRESTRequestParameterKind.pkHTTPHEADER;
vItem.ContentType:=contentType;
vItem.Options:=[TRESTRequestParameterOption.poDoNotEncode];
vItem.Name:='x-fc-account-id';
vItem.Value:=accountID;

vItem:=req.Params.AddItem;
vItem.Kind:=TRESTRequestParameterKind.pkHTTPHEADER;
vItem.ContentType:=contentType;
vItem.Options:=[TRESTRequestParameterOption.poDoNotEncode];
vItem.Name:='date';
vItem.Value:=sDate;

vItem:=req.Params.AddItem;
vItem.Kind:=TRESTRequestParameterKind.pkHTTPHEADER;
vItem.ContentType:=contentType;
vItem.Options:=[TRESTRequestParameterOption.poDoNotEncode];
vItem.Name:='content-md5';
vItem.Value:=contentMD5;

req.Accept:=sContentType;
req.Client.ContentType:=sContentType;

req.AddBody(body);
req.Method:=TRESTRequestMethod.rmPOST;

req.Execute;
Result:=req.Response.JSONValue;
end;

end.注意：

MD5，HMAC-SHA256加密算法来自http://fundementals.sourceforge.net，delphi自带的IdHMACSHA256执行有错。
其中的fc.cn-shanghai.aliyuncs.com，根据你实际注册FC的服务区域修改。