EC2上でFTPコンテナ作成

# 1.はじめに
EC2上でFTPコンテナ作ってみたので手順をまとめました

# 2.環境
Amazon Linux2
Docker version 20.10.25

# 3.作ってみる

```php:Dockerfile
FROM amazonlinux:2

RUN yum install -y vsftpd
RUN yum install -y shadow-utils
EXPOSE 21
EXPOSE 60001
EXPOSE 60002
EXPOSE 60003
EXPOSE 60004
COPY vsftpd.conf /etc/vsftpd/
COPY myapp.sh  /usr/local/bin/
RUN useradd ftp-user
RUN echo "ftp-user:ftp-user"|chpasswd
RUN chmod 755 /usr/local/bin/myapp.sh
RUN chmod 777 /var/ftp/pub
RUN chown ftp-user /var/ftp/pub
ENTRYPOINT ["/usr/local/bin/myapp.sh"]
```

```php:vsftpd.conf
# Example config file /etc/vsftpd/vsftpd.conf
#
# The default compiled in settings are fairly paranoid. This sample file
# loosens things up a bit, to make the ftp daemon more usable.
# Please see vsftpd.conf.5 for all compiled in defaults.
#
# READ THIS: This example file is NOT an exhaustive list of vsftpd options.
# Please read the vsftpd.conf.5 manual page to get a full idea of vsftpd's
# capabilities.
#
# Allow anonymous FTP? (Beware - allowed by default if you comment this out).
anonymous_enable=YES
#
# Uncomment this to allow local users to log in.
# When SELinux is enforcing check for SE bool ftp_home_dir
local_enable=YES
#
# Uncomment this to enable any form of FTP write command.
write_enable=YES
#
# Default umask for local users is 077. You may wish to change this to 022,
# if your users expect that (022 is used by most other ftpd's)
local_umask=022
#
# Uncomment this to allow the anonymous FTP user to upload files. This only
# has an effect if the above global write enable is activated. Also, you will
# obviously need to create a directory writable by the FTP user.
# When SELinux is enforcing check for SE bool allow_ftpd_anon_write, allow_ftpd_full_access
anon_upload_enable=YES
#
# Uncomment this if you want the anonymous FTP user to be able to create
# new directories.
#anon_mkdir_write_enable=YES
#
# Activate directory messages - messages given to remote users when they
# go into a certain directory.
dirmessage_enable=YES
#
# Activate logging of uploads/downloads.
xferlog_enable=YES
#
# Make sure PORT transfer connections originate from port 20 (ftp-data).
connect_from_port_20=YES
#
# If you want, you can arrange for uploaded anonymous files to be owned by
# a different user. Note! Using "root" for uploaded files is not
# recommended!
#chown_uploads=YES
#chown_username=whoever
#
# You may override where the log file goes if you like. The default is shown
# below.
#xferlog_file=/var/log/vsftpd.log
#
# If you want, you can have your log file in standard ftpd xferlog format.
# Note that the default log file location is /var/log/xferlog in this case.
xferlog_std_format=YES
#
# You may change the default value for timing out an idle session.
#idle_session_timeout=600
#
# You may change the default value for timing out a data connection.
#data_connection_timeout=120
#
# It is recommended that you define on your system a unique user which the
# ftp server can use as a totally isolated and unprivileged user.
#nopriv_user=ftpsecure
#
# Enable this and the server will recognise asynchronous ABOR requests. Not
# recommended for security (the code is non-trivial). Not enabling it,
# however, may confuse older FTP clients.
#async_abor_enable=YES
#
# By default the server will pretend to allow ASCII mode but in fact ignore
# the request. Turn on the below options to have the server actually do ASCII
# mangling on files when in ASCII mode.
# Beware that on some FTP servers, ASCII support allows a denial of service
# attack (DoS) via the command "SIZE /big/file" in ASCII mode. vsftpd
# predicted this attack and has always been safe, reporting the size of the
# raw file.
# ASCII mangling is a horrible feature of the protocol.
#ascii_upload_enable=YES
#ascii_download_enable=YES
#
# You may fully customise the login banner string:
#ftpd_banner=Welcome to blah FTP service.
#
# You may specify a file of disallowed anonymous e-mail addresses. Apparently
# useful for combatting certain DoS attacks.
#deny_email_enable=YES
# (default follows)
#banned_email_file=/etc/vsftpd/banned_emails
#
# You may specify an explicit list of local users to chroot() to their home
# directory. If chroot_local_user is YES, then this list becomes a list of
# users to NOT chroot().
# (Warning! chroot'ing can be very dangerous. If using chroot, make sure that
# the user does not have write access to the top level directory within the
# chroot)
#chroot_local_user=YES
#chroot_list_enable=YES
# (default follows)
#chroot_list_file=/etc/vsftpd/chroot_list
#
# You may activate the "-R" option to the builtin ls. This is disabled by
# default to avoid remote users being able to cause excessive I/O on large
# sites. However, some broken FTP clients such as "ncftp" and "mirror" assume
# the presence of the "-R" option, so there is a strong case for enabling it.
#ls_recurse_enable=YES
#
# When "listen" directive is enabled, vsftpd runs in standalone mode and
# listens on IPv4 sockets. This directive cannot be used in conjunction
# with the listen_ipv6 directive.
listen=NO
#
# This directive enables listening on IPv6 sockets. By default, listening
# on the IPv6 "any" address (::) will accept connections from both IPv6
# and IPv4 clients. It is not necessary to listen on *both* IPv4 and IPv6
# sockets. If you want that (perhaps because you want to listen on specific
# addresses) then you must run two copies of vsftpd with two configuration
# files.
# Make sure, that one of the listen options is commented !!
listen_ipv6=YES

pam_service_name=vsftpd
userlist_enable=YES
tcp_wrappers=YES

pasv_enable=YES
pasv_min_port=60001
pasv_max_port=60004
```

```php:myapp.sh
#!/usr/bin/bash
/usr/sbin/vsftpd /etc/vsftpd/vsftpd.conf
tail -f /dev/null
```
<br>

適当なディレクトリに上記3ファイルを作成
```
$ pwd
/home/ec2-user/FTP
$ ll
total 16
-rw-r--r--. 1 ec2-user ec2-user  396 Oct 23 19:45 Dockerfile
-rw-r--r--. 1 ec2-user ec2-user   75 Oct 23 19:48 myapp.sh
-rw-r--r--. 1 ec2-user ec2-user 5089 Oct 23 19:47 vsftpd.conf
```

準備は以上で早速コンテナ作ってみましょう
```
$docker build -t ftptest .
(省略)
$docker images
REPOSITORY    TAG       IMAGE ID       CREATED         SIZE
ftptest       latest    4905ecc401e4   5 seconds ago   848MB
amazonlinux   2         86be26c0d660   10 days ago     165MB
$docker run --privileged -p 21:21 -p 60001-60004:60001-60004 -it -d 4905ecc401e4
7a71c5e1786964caf0389197cb25fd13f31f1a36b06dc5ddeabb510f71300011
$docker ps
CONTAINER ID   IMAGE          COMMAND                  CREATED         STATUS         PORTS                                                                                                      NAMES
7a71c5e17869   4905ecc401e4   "/usr/local/bin/myap…"   5 seconds ago   Up 4 seconds   0.0.0.0:21->21/tcp, :::21->21/tcp, 0.0.0.0:60001-60004->60001-60004/tcp, :::60001-60004->60001-60004/tcp   serene_dubinsky
```
「docker build -t ftptest .」の-tはタグ付けなのでお好きな名前を。
コンテナ作成できました。

# 4.接続してみる
同じサブネットにもう一つEC2建ててFTP接続してみる。
※EC2に付与するセキュリティグループにFTPポートを許可するのを忘れずに
```
$ ftp ｛プライベートIPアドレス｝
220 (vsFTPd 3.0.2)
Name (:ec2-user): ftp-user
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp>
```
↑ IPアドレスが記載されているところは消してます。
無事FTP接続することができました。

# 5.おわりに
今回は同じサブネット内のEC2同士でFTP接続するシンプルな構成でしたが、
NLBを使用したりECS上でやったりもしているのでそちらも今後書けたらいいなと思います。

# 6.参考にさせていただきました
https://qiita.com/sukkyxp/items/adea19f9dd676c0ea2c2