---
title: C言語で書かれたWebアプリをCloud Foundryにデプロイする
tags: ["Cloud Foundry", "Docker", "C"]
categories: ["Dev", "PaaS", "CloudFoundry"]
date: 2017-01-25T13:49:17Z
updated: 2017-01-25T13:56:14Z
---

訳あってC言語で書かれたWebアプリをCloud FoundryにデプロイしたいときのTips。

次の簡易HTTPサーバー(`~/work/httpserver/httpserver.c`)をデプロイしてみる。

``` c
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

int main()
{
  int sock0;
  struct sockaddr_in addr;
  struct sockaddr_in client;
  unsigned len;
  int sock;
  int yes = 1;

  char buf[2048];
  char inbuf[2048];

  sock0 = socket(AF_INET, SOCK_STREAM, 0);
  if (sock0 < 0) {
    perror("socket");
    return 1;
  }

  addr.sin_family = AF_INET;
  addr.sin_port = htons(8080);
  addr.sin_addr.s_addr = INADDR_ANY;

  setsockopt(sock0, SOL_SOCKET, SO_REUSEADDR, (const char *)&yes, sizeof(yes));
  if (bind(sock0, (struct sockaddr *)&addr, sizeof(addr)) != 0) {
    perror("bind");
    return 1;
  }
  if (listen(sock0, 5) != 0) {
    perror("listen");
    return 1;
  }

  memset(buf, 0, sizeof(buf));
  snprintf(buf, sizeof(buf),
	   "HTTP/1.1 200 OK¥r¥n"
	   "Content-Length: 14¥r¥n"
	   "Content-Type: text/html¥r¥n"
	   "¥r¥n"
	   "Hello World!¥r¥n");
  
  while (1) {
    len = sizeof(client);
    sock = accept(sock0, (struct sockaddr *)&client, &len);
    if (sock < 0) {
      perror("accept");
      break;
    }
    memset(inbuf, 0, sizeof(inbuf));
    recv(sock, inbuf, sizeof(inbuf), 0);
    // printf("%s", inbuf); // for debug
    send(sock, buf, (int)strlen(buf), 0);
    close(sock);
  }

  close(sock0);

  return 0;
}
```

HTTPサーバーは[Geekなぺーじの例](http://www.geekpage.jp/programming/linux-network/http-server.php)を使用した。

Cloud Foundryのrootfsであるcflinux2でこのコードをコンパイルする。[cflinux2のDockerイメージ](https://hub.docker.com/r/cloudfoundry/cflinuxfs2/)を使用する。

``` console
$ docker run -v ~/work/httpserver:/tmp cloudfoundry/cflinuxfs2 gcc /tmp/httpserver.c -o /tmp/httpserver
```

手元に`httpserver`ができている。

``` console
$ ls -lh ~/work/httpserver
total 32
-rwxr-xr-x  1 makit  wheel   8.9K Jan 25 22:28 httpserver
-rw-r--r--  1 makit  wheel   1.3K Jan 25 22:27 httpserver.c
```

これを[Binay Buildpack](http://docs.cloudfoundry.org/buildpacks/binary/index.html)を使ってデプロイする。メモリは少量でOK。

``` console
$ cf push http-server -c './httpserver' -b binary_buildpack -m 8m
...
App started


OK

App http-server was started using this command `./httpserver`

Showing health and status for app http-server in org foo / space staging as xxxxx@gmail.com...
OK

requested state: started
instances: 1/1
usage: 8M x 1 instances
urls: http-server.cfapps.io
last uploaded: Wed Jan 25 13:29:23 UTC 2017
stack: cflinuxfs2
buildpack: binary_buildpack

     state     since                    cpu    memory       disk         details
#0   running   2017-01-25 10:29:47 PM   0.0%   2.5M of 8M   1.3M of 1G
```

普通に動く。

![image](https://qiita-image-store.s3.amazonaws.com/0/1852/e87e4902-2e0f-effd-1e96-36d7009c93a6.png)


`manifest.yml`を使う場合は次のような内容にする。

``` yaml
---
applications:
- name: http-server
  buildpack: binary_buildpack
  memory: 8m
  command: ./httpserver
```

あとは

``` console
$ cf push
```