🥇Microservices ni C++. Àròsọ àbí òtítọ́?

Ninu nkan yii Emi yoo sọrọ nipa bii MO ṣe ṣẹda awoṣe kan (cookiecutter) ati ṣeto agbegbe kan fun kikọ iṣẹ API REST ni C ++ nipa lilo docker / docker-compose ati oluṣakoso package conan.

Lakoko hackathon t’okan, ninu eyiti Mo kopa bi olupilẹṣẹ ẹhin, ibeere naa dide nipa kini lati lo lati kọ microservice atẹle. Ohun gbogbo ti a ti kọ bẹ jina ti a ti kọ nipa emi ati awọn mi ẹlẹgbẹ ni Python, niwon mi ẹlẹgbẹ je ohun iwé ni aaye yi ati agbejoro ni idagbasoke backends, nigba ti mo ti wà gbogbo ifibọ awọn ọna šiše Olùgbéejáde ati ki o kowe ninu awọn nla ati ẹru C ++, ati ki o Mo ti o kan kọ Python ni University.

Nitorinaa, a dojuko pẹlu iṣẹ-ṣiṣe ti kikọ iṣẹ fifuye giga, iṣẹ akọkọ ti eyiti o jẹ lati ṣaju awọn data ti o nbọ si ati kọ si ibi ipamọ data. Ati lẹhin isinmi ẹfin miiran, ọrẹ kan daba pe Emi, gẹgẹbi olupilẹṣẹ C ++, kọ iṣẹ yii ni lilo awọn anfani. Jiyan eyi ni pe yoo yarayara, diẹ sii ni iṣelọpọ, ati ni gbogbogbo, awọn imomopaniyan yoo ni inudidun pẹlu bi a ṣe mọ bi a ṣe le ṣakoso awọn orisun ẹgbẹ. Si eyiti Mo dahun pe Emi ko ṣe iru awọn nkan bẹẹ ni C ++ ati pe MO le ni irọrun ya awọn wakati 20+ to ku si wiwa, ṣajọ ati sisopọ awọn ile-ikawe to dara. Nìkan fi, Mo adie jade. Eyi ni ohun ti a pinnu ati ni idakẹjẹ pari ohun gbogbo ni Python.

Ni bayi, lakoko ipinya ara ẹni ti o fi agbara mu, Mo pinnu lati ro ero bi o ṣe le kọ awọn iṣẹ ni C ++. Ohun akọkọ lati ṣe ni pinnu lori ile-ikawe ti o yẹ. Yiyan mi ṣubu lori POCO, niwọn igba ti a ti kọ ọ ni ara ti o da lori ohun ati pe o tun ṣogo awọn iwe aṣẹ deede. Pẹlupẹlu, ibeere naa dide nipa yiyan eto apejọ kan. Titi di aaye yii Mo ti ṣiṣẹ nikan pẹlu Visual Studio, IAR ati awọn makefiles igboro. Ati pe ko si ọkan ninu awọn eto wọnyi ti o ṣafẹri si mi, niwọn igba ti Mo gbero lati ṣiṣe gbogbo iṣẹ naa ni apoti docker kan. Lẹhinna Mo pinnu lati gbiyanju lati ṣawari cmake ati oluṣakoso package ti o nifẹ kan. Oluṣakoso package gba ọ laaye lati forukọsilẹ gbogbo awọn igbẹkẹle ninu faili kan

conanfile.txt
[nbeere] poco / 1.9.3
libpq / 11.5

[generators] cmake

ati pẹlu aṣẹ ti o rọrun "conan fi sori ẹrọ." fi sori ẹrọ awọn pataki ikawe. Nipa ti, o tun jẹ dandan lati ṣe awọn ayipada si

CMakeLists.txt

include(build/conanbuildinfo.cmake)
conan_basic_setup()
target_link_libraries(<target_name> ${CONAN_LIBS})

Lẹ́yìn ìyẹn, mo bẹ̀rẹ̀ sí wá ibi ìkówèésí kan láti máa bá PostgreSQL ṣiṣẹ́, níwọ̀n bí ó ti jẹ́ èyí tí mo ní ìrírí díẹ̀ tí mo bá ń ṣiṣẹ́, ó sì tún jẹ́ èyí tí àwọn iṣẹ́ Python wa bá. Ati pe o mọ ohun ti Mo kọ? O wa ni POCO! Ṣugbọn conan ko mọ pe o wa ni POCO ati pe ko mọ bi o ṣe le kọ; faili iṣeto ti igba atijọ wa ninu ibi ipamọ (Mo ti kọ tẹlẹ nipa aṣiṣe yii si awọn olupilẹṣẹ POCO). Eyi tumọ si pe iwọ yoo ni lati wa ile-ikawe miiran.

Ati lẹhinna yiyan mi ṣubu lori ile-ikawe olokiki ti ko gbajumọ libpg. Ati pe Mo ni orire iyalẹnu, o ti wa tẹlẹ ninu conan ati pe a ti ṣajọpọ ati pejọ.

Igbesẹ ti o tẹle ni lati kọ awoṣe iṣẹ kan ti o le ṣe ilana awọn ibeere.
A gbọdọ jogun kilasi TemplateServerApp wa lati ọdọ Poco :: Util :: ServerApplication ki o si yi ọna akọkọ pada.

TemplateServerApp

#pragma once

#include <string>
#include <vector>
#include <Poco/Util/ServerApplication.h>

class TemplateServerApp : public Poco::Util::ServerApplication
{
    protected:
        int main(const std::vector<std::string> &);
};

int TemplateServerApp::main(const vector<string> &)
{
    HTTPServerParams* pParams = new HTTPServerParams;

    pParams->setMaxQueued(100);
    pParams->setMaxThreads(16);

    HTTPServer s(new TemplateRequestHandlerFactory, ServerSocket(8000), pParams);

    s.start();
    cerr << "Server started" << endl;

    waitForTerminationRequest();  // wait for CTRL-C or kill

    cerr << "Shutting down..." << endl;
    s.stop();

    return Application::EXIT_OK;
}

Ni akọkọ ọna a gbọdọ ṣeto awọn paramita: ibudo, nọmba ti awọn okun ati isinyi iwọn. Ati pataki julọ, o gbọdọ pato olutọju kan fun awọn ibeere ti nwọle. Eyi ni a ṣe nipasẹ ṣiṣẹda ile-iṣẹ kan

TemplateRequestHandlerFactory

class TemplateRequestHandlerFactory : public HTTPRequestHandlerFactory
{
public:
    virtual HTTPRequestHandler* createRequestHandler(const HTTPServerRequest & request)
    {
        return new TemplateServerAppHandler;
    }
};

Ninu ọran mi, o rọrun ṣẹda olutọju kanna ni gbogbo igba - TemplateServerAppHandler. Eyi ni ibiti a ti le gbe ọgbọn iṣowo wa.

TemplateServerAppHandler

class TemplateServerAppHandler : public HTTPRequestHandler
{
public:
    void handleRequest(HTTPServerRequest &req, HTTPServerResponse &resp)
    {
        URI uri(req.getURI());
        string method = req.getMethod();

        cerr << "URI: " << uri.toString() << endl;
        cerr << "Method: " << req.getMethod() << endl;

        StringTokenizer tokenizer(uri.getPath(), "/", StringTokenizer::TOK_TRIM);
        HTMLForm form(req,req.stream());

        if(!method.compare("POST"))
        {
            cerr << "POST" << endl;
        }
        else if(!method.compare("PUT"))
        {
            cerr << "PUT" << endl;
        }
        else if(!method.compare("DELETE"))
        {
            cerr << "DELETE" << endl;
        }

        resp.setStatus(HTTPResponse::HTTP_OK);
        resp.setContentType("application/json");
        ostream& out = resp.send();

        out << "{"hello":"heh"}" << endl;
        out.flush();
    }
};

Mo tun ṣẹda awoṣe kilasi lati ṣiṣẹ pẹlu PostgreSQL. Lati ṣe SQL ti o rọrun, gẹgẹbi ṣiṣẹda tabili kan, ọna kan wa ExecuteSQL(). Fun awọn ibeere ti o ni eka sii tabi imupadabọ data, iwọ yoo ni lati gba asopọ nipasẹ GetConnection() ati lo API libpg. (Boya nigbamii Emi yoo ṣe atunṣe aiṣododo yii).

database

#pragma once

#include <memory>
#include <mutex>
#include <libpq-fe.h>

class Database
{
public:
    Database();
    std::shared_ptr<PGconn> GetConnection() const;
    bool ExecuteSQL(const std::string& sql);

private:
    void establish_connection();
    void LoadEnvVariables();

    std::string m_dbhost;
    int         m_dbport;
    std::string m_dbname;
    std::string m_dbuser;
    std::string m_dbpass;

    std::shared_ptr<PGconn>  m_connection;
};

Gbogbo awọn paramita fun sisopọ si ibi ipamọ data ni a mu lati agbegbe, nitorinaa o tun nilo lati ṣẹda ati tunto faili .env

.env

DATABASE_NAME=template
DATABASE_USER=user
DATABASE_PASSWORD=password
DATABASE_HOST=postgres
DATABASE_PORT=5432

O le wo gbogbo koodu ni github.

Ati nisisiyi ba wa ni ipele ikẹhin ti kikọ dockerfile ati docker-compose.yml. Lati ṣe otitọ, eyi gba akoko pupọ julọ, kii ṣe nitori pe emi jẹ noob nikan, nitori pe o jẹ dandan lati tun awọn ile-ikawe naa ṣe ni gbogbo igba, ṣugbọn nitori awọn ipalara ti conan. Fun apẹẹrẹ, ni ibere fun conan lati ṣe igbasilẹ, fi sori ẹrọ ati kọ awọn igbẹkẹle pataki, ko to fun lati ṣe igbasilẹ “conan fi sori ẹrọ.”, o tun nilo lati kọja paramita -s compiler.libcxx=libstdc++11, bibẹẹkọ. o ni ewu lati gba opo awọn aṣiṣe ni ipele sisopọ ohun elo rẹ. Mo ti di pẹlu aṣiṣe yii fun awọn wakati pupọ ati pe Mo nireti pe nkan yii yoo ṣe iranlọwọ fun awọn eniyan miiran lati yanju iṣoro yii ni akoko diẹ.

Nigbamii ti, lẹhin kikọ docker-compose.yml, lori imọran ọrẹ mi, Mo ṣafikun atilẹyin kukisita ati ni bayi o le gba ararẹ ni awoṣe kikun fun iṣẹ API REST ni C ++, pẹlu agbegbe ti a ṣe adani, ati PostgreSQL ti fi sori ẹrọ, nirọrun nipa titẹ “kukisi” sinu console. https://github.com/KovalevVasiliy/cpp_rest_api_template.git" Ati lẹhinna “docker-compose up — kọ”.

Mo nireti pe awoṣe yii yoo ṣe iranlọwọ fun awọn olubere lori ọna ti o nira wọn ti idagbasoke awọn ohun elo API REST ni nla ati alagbara, ṣugbọn iru ede ti o ni irọra bii C ++.
Paapaa, Mo ṣeduro gíga kika nibi eyi article. O ṣe alaye ni alaye diẹ sii bi o ṣe le ṣiṣẹ pẹlu POCO ati kọ iṣẹ API REST tirẹ.

orisun: www.habr.com

Microservices ni C ++. Àròsọ àbí òtítọ́?

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