読者です 読者をやめる 読者になる 読者になる

Docker + GNU GLOBALで手軽にソースコードリーディング環境を作る

alpinelinux linux docker

Kia Ora! この記事はプロ生ちゃん Advent Calendar 2016の16日目の記事です。 2015年bash-completionでコマンド補完するときにプロ生ちゃんに何か言ってもらう - φ(・・*)ゞ ウーン カーネルとか弄ったりのメモなんて記事を書きました。2014年はプロ生ちゃん Advent Calenderではないけど、 systemdでshutdown時にプロ生ちゃんに挨拶してもらう - φ(・・*)ゞ ウーン カーネルとか弄ったりのメモなんてネタを書いたりしました。

今年はすぱこー焼きそばソースを頂きました(∩´∀`)∩ワーイ

今年はプロ生ちゃん要素はこれくらいしかありません(´・ω・`)

では、気を取り直してタイトルを回収します。ソースコードリーディングする時にvimとかemacsならctags等を使ってタグジャンプとかしたりすると思います。ブラウザで動作するものだと Linux/ - Linux Cross Reference - Free Electronsで使っているLXR、またはGNU GLOBALなんかが有名かなと思います。今回はGNU GLOBALを使ってコードリーディング環境を作ります。

GNU GLOBALはgtagsとhtagsという2個のコマンドがあり、タギングに関してはgtagsが行います。htagsのほうはgtagsで作ったtagを解析してHTMLとして見れるようにするものです。なのでvim等のエディタで見る場合、gtagsだけも十分だったりします。ブラウザで見れるようにしたいという場合にhtagsの出番になります。 また、htagsで出力したHTMLファイルは関数名等にリンクが付くのでWEBサーバ無しで閲覧可能です。検索機能を使いたい場合はcgiを使うためWEBサーバが必要になります。 Dockerで環境作れるようにするとWEBサーバの設定とか楽だよねってなる感じですね。

今回はGNU Helloのソースを読む環境を作ってみます。ソースコードgitでcloneできます。

ディレクトリ構成はこのようになっています。cgiの実行にWEBサーバ必要なので、今回は手軽にapache2を選択しました。

global/ --- docker-compose.yml
        |-- Dockerfile
        |-- httpd.conf
        |-- hello/

Dockerfileはこうなります。ディストリビューションAlpine Linuxの最新です。選択理由は軽めなディストリビューションというところと、個人的な趣味です。Alpine LinuxはtestingリポジトリGNU GLOBALの最新バージョンがあるため、edge/testingを有効にしています。edge/testing以外のリポジトリにはGNU GLOBALはありません。その他は動作に必要なパッケージをインストールしてます。手軽に済ませたかったので1dockerファイル・1プロジェクト的になってますが、httpd.confの設定次第で複数のプロジェクトのコードを閲覧する環境にしても良いかと思います。 全文検索に使うcgiのファイルはperlとかglobalのパスが/usr/local/binを見ているので、/usr/bin/に直したりしてます。htagsのオプションはlinuxカーネル用に作ったときは「-anfvF」にしました。

FROM alpine:latest

RUN apk add global --update-cache --repository http://dl-3.alpinelinux.org/alpine/edge/testing/ --allow-untrusted && \
apk add py-pip ctags && \
apk add apache2 perl && \
pip install Pygments

RUN mkdir -p /opt/global && \
mkdir -p /run/apache2

COPY httpd.conf /etc/apache2/httpd.conf
COPY ./hello /opt/global/hello

WORKDIR /opt/global/hello

RUN gtags -v && \
htags -aosnfvF

RUN sed -i 's/\/opt\/local\/bin\/perl/\/usr\/bin\/perl/' HTML/cgi-bin/global.cgi
RUN sed -i 's/\/usr\/local\/bin\/global/\/usr\/bin\/global/' HTML/cgi-bin/global.cgi

CMD /usr/sbin/httpd -D FOREGROUND -f /etc/apache2/httpd.conf

docker-compose.ymlは特にこれと言ったことはしてません。

global:
  build: .
  ports:
    - 8080:80

httpd.confはそのまま貼り付けましたが、こんな感じです。

#
# This is the main Apache HTTP server configuration file.  It contains the
# configuration directives that give the server its instructions.
# See <URL:http://httpd.apache.org/docs/2.4/> for detailed information.
# In particular, see
# <URL:http://httpd.apache.org/docs/2.4/mod/directives.html>
# for a discussion of each configuration directive.
#
# Do NOT simply read the instructions in here without understanding
# what they do.  They're here only as hints or reminders.  If you are unsure
# consult the online docs. You have been warned.
#
# Configuration and logfile names: If the filenames you specify for many
# of the server's control files begin with "/" (or "drive:/" for Win32), the
# server will use that explicit path.  If the filenames do *not* begin
# with "/", the value of ServerRoot is prepended -- so "logs/access_log"
# with ServerRoot set to "/usr/local/apache2" will be interpreted by the
# server as "/usr/local/apache2/logs/access_log", whereas "/logs/access_log"
# will be interpreted as '/logs/access_log'.

#
# ServerTokens
# This directive configures what you return as the Server HTTP response
# Header. The default is 'Full' which sends information about the OS-Type
# and compiled in modules.
# Set to one of:  Full | OS | Minor | Minimal | Major | Prod
# where Full conveys the most information, and Prod the least.
#
ServerTokens OS

#
# ServerRoot: The top of the directory tree under which the server's
# configuration, error, and log files are kept.
#
# Do not add a slash at the end of the directory path.  If you point
# ServerRoot at a non-local disk, be sure to specify a local disk on the
# Mutex directive, if file-based mutexes are used.  If you wish to share the
# same ServerRoot for multiple httpd daemons, you will need to change at
# least PidFile.
#
ServerRoot /var/www

#
# Mutex: Allows you to set the mutex mechanism and mutex file directory
# for individual mutexes, or change the global defaults
#
# Uncomment and change the directory if mutexes are file-based and the default
# mutex file directory is not on a local disk or is not appropriate for some
# other reason.
#
# Mutex default:/run/apache2

#
# Listen: Allows you to bind Apache to specific IP addresses and/or
# ports, instead of the default. See also the <VirtualHost>
# directive.
#
# Change this to Listen on specific IP addresses as shown below to
# prevent Apache from glomming onto all bound IP addresses.
#
#Listen 12.34.56.78:80
Listen 80

#
# Dynamic Shared Object (DSO) Support
#
# To be able to use the functionality of a module which was built as a DSO you
# have to place corresponding `LoadModule' lines at this location so the
# directives contained in it are actually available _before_ they are used.
# Statically compiled modules (those listed by `httpd -l') do not need
# to be loaded here.
#
# Example:
# LoadModule foo_module modules/mod_foo.so
#
LoadModule authn_file_module modules/mod_authn_file.so
#LoadModule authn_dbm_module modules/mod_authn_dbm.so
#LoadModule authn_anon_module modules/mod_authn_anon.so
#LoadModule authn_dbd_module modules/mod_authn_dbd.so
#LoadModule authn_socache_module modules/mod_authn_socache.so
LoadModule authn_core_module modules/mod_authn_core.so
LoadModule authz_host_module modules/mod_authz_host.so
LoadModule authz_groupfile_module modules/mod_authz_groupfile.so
LoadModule authz_user_module modules/mod_authz_user.so
#LoadModule authz_dbm_module modules/mod_authz_dbm.so
#LoadModule authz_owner_module modules/mod_authz_owner.so
#LoadModule authz_dbd_module modules/mod_authz_dbd.so
LoadModule authz_core_module modules/mod_authz_core.so
LoadModule access_compat_module modules/mod_access_compat.so
LoadModule auth_basic_module modules/mod_auth_basic.so
#LoadModule auth_form_module modules/mod_auth_form.so
#LoadModule auth_digest_module modules/mod_auth_digest.so
#LoadModule allowmethods_module modules/mod_allowmethods.so
#LoadModule file_cache_module modules/mod_file_cache.so
#LoadModule cache_module modules/mod_cache.so
#LoadModule cache_disk_module modules/mod_cache_disk.so
#LoadModule cache_socache_module modules/mod_cache_socache.so
#LoadModule socache_shmcb_module modules/mod_socache_shmcb.so
#LoadModule socache_dbm_module modules/mod_socache_dbm.so
#LoadModule socache_memcache_module modules/mod_socache_memcache.so
#LoadModule watchdog_module modules/mod_watchdog.so
#LoadModule macro_module modules/mod_macro.so
#LoadModule dbd_module modules/mod_dbd.so
#LoadModule dumpio_module modules/mod_dumpio.so
#LoadModule echo_module modules/mod_echo.so
#LoadModule buffer_module modules/mod_buffer.so
#LoadModule data_module modules/mod_data.so
#LoadModule ratelimit_module modules/mod_ratelimit.so
LoadModule reqtimeout_module modules/mod_reqtimeout.so
#LoadModule ext_filter_module modules/mod_ext_filter.so
#LoadModule request_module modules/mod_request.so
#LoadModule include_module modules/mod_include.so
LoadModule filter_module modules/mod_filter.so
#LoadModule reflector_module modules/mod_reflector.so
#LoadModule substitute_module modules/mod_substitute.so
#LoadModule sed_module modules/mod_sed.so
#LoadModule charset_lite_module modules/mod_charset_lite.so
#LoadModule deflate_module modules/mod_deflate.so
LoadModule mime_module modules/mod_mime.so
LoadModule log_config_module modules/mod_log_config.so
#LoadModule log_debug_module modules/mod_log_debug.so
#LoadModule log_forensic_module modules/mod_log_forensic.so
#LoadModule logio_module modules/mod_logio.so
LoadModule env_module modules/mod_env.so
#LoadModule mime_magic_module modules/mod_mime_magic.so
#LoadModule expires_module modules/mod_expires.so
LoadModule headers_module modules/mod_headers.so
#LoadModule usertrack_module modules/mod_usertrack.so
#LoadModule unique_id_module modules/mod_unique_id.so
LoadModule setenvif_module modules/mod_setenvif.so
LoadModule version_module modules/mod_version.so
#LoadModule remoteip_module modules/mod_remoteip.so
#LoadModule session_module modules/mod_session.so
#LoadModule session_cookie_module modules/mod_session_cookie.so
#LoadModule session_dbd_module modules/mod_session_dbd.so
#LoadModule slotmem_shm_module modules/mod_slotmem_shm.so
#LoadModule slotmem_plain_module modules/mod_slotmem_plain.so
#LoadModule dialup_module modules/mod_dialup.so
#LoadModule mpm_event_module modules/mod_mpm_event.so
LoadModule mpm_prefork_module modules/mod_mpm_prefork.so
#LoadModule mpm_worker_module modules/mod_mpm_worker.so
LoadModule unixd_module modules/mod_unixd.so
#LoadModule heartbeat_module modules/mod_heartbeat.so
#LoadModule heartmonitor_module modules/mod_heartmonitor.so
LoadModule status_module modules/mod_status.so
LoadModule autoindex_module modules/mod_autoindex.so
#LoadModule asis_module modules/mod_asis.so
#LoadModule info_module modules/mod_info.so
#LoadModule suexec_module modules/mod_suexec.so
<IfModule !mpm_prefork_module>
        #LoadModule cgid_module modules/mod_cgid.so
</IfModule>
<IfModule mpm_prefork_module>
        LoadModule cgi_module modules/mod_cgi.so
</IfModule>
#LoadModule vhost_alias_module modules/mod_vhost_alias.so
#LoadModule negotiation_module modules/mod_negotiation.so
LoadModule dir_module modules/mod_dir.so
#LoadModule actions_module modules/mod_actions.so
#LoadModule speling_module modules/mod_speling.so
#LoadModule userdir_module modules/mod_userdir.so
LoadModule alias_module modules/mod_alias.so
#LoadModule rewrite_module modules/mod_rewrite.so

LoadModule negotiation_module modules/mod_negotiation.so

<IfModule unixd_module>
#
# If you wish httpd to run as a different user or group, you must run
# httpd as root initially and it will switch.
#
# User/Group: The name (or #number) of the user/group to run httpd as.
# It is usually good practice to create a dedicated user and group for
# running httpd, as with most system services.
#
User apache
Group apache

</IfModule>

# 'Main' server configuration
#
# The directives in this section set up the values used by the 'main'
# server, which responds to any requests that aren't handled by a
# <VirtualHost> definition.  These values also provide defaults for
# any <VirtualHost> containers you may define later in the file.
#
# All of these directives may appear inside <VirtualHost> containers,
# in which case these default settings will be overridden for the
# virtual host being defined.
#

#
# ServerAdmin: Your address, where problems with the server should be
# e-mailed.  This address appears on some server-generated pages, such
# as error documents.  e.g. admin@your-domain.com
#
ServerAdmin you@example.com

#
# Optionally add a line containing the server version and virtual host
# name to server-generated pages (internal error documents, FTP directory
# listings, mod_status and mod_info output etc., but not CGI generated
# documents or custom error documents).
# Set to "EMail" to also include a mailto: link to the ServerAdmin.
# Set to one of:  On | Off | EMail
#
ServerSignature On

#
# ServerName gives the name and port that the server uses to identify itself.
# This can often be determined automatically, but we recommend you specify
# it explicitly to prevent problems during startup.
#
# If your host doesn't have a registered DNS name, enter its IP address here.
#
#ServerName www.example.com:80
ServerName localhost:80

#
# Deny access to the entirety of your server's filesystem. You must
# explicitly permit access to web content directories in other
# <Directory> blocks below.
#
<Directory />
    AllowOverride none
    Require all denied
</Directory>

#
# Note that from this point forward you must specifically allow
# particular features to be enabled - so if something's not working as
# you might expect, make sure that you have specifically enabled it
# below.
#

#
# DocumentRoot: The directory out of which you will serve your
# documents. By default, all requests are taken from this directory, but
# symbolic links and aliases may be used to point to other locations.
#
DocumentRoot "/opt/global/hello/HTML"
<Directory "/opt/global/hello/HTML">
    #
    # Possible values for the Options directive are "None", "All",
    # or any combination of:
    #   Indexes Includes FollowSymLinks SymLinksifOwnerMatch ExecCGI MultiViews
    #
    # Note that "MultiViews" must be named *explicitly* --- "Options All"
    # doesn't give it to you.
    #
    # The Options directive is both complicated and important.  Please see
    # http://httpd.apache.org/docs/2.4/mod/core.html#options
    # for more information.
    #
    Options Indexes FollowSymLinks

    #
    # AllowOverride controls what directives may be placed in .htaccess files.
    # It can be "All", "None", or any combination of the keywords:
    #   AllowOverride FileInfo AuthConfig Limit
    #
    AllowOverride None

    #
    # Controls who can get stuff from this server.
    #
    Require all granted
</Directory>

#
# DirectoryIndex: sets the file that Apache will serve if a directory
# is requested.
#
<IfModule dir_module>
    DirectoryIndex index.html
</IfModule>

#
# The following lines prevent .htaccess and .htpasswd files from being
# viewed by Web clients.
#
<Files ".ht*">
    Require all denied
</Files>

#
# ErrorLog: The location of the error log file.
# If you do not specify an ErrorLog directive within a <VirtualHost>
# container, error messages relating to that virtual host will be
# logged here.  If you *do* define an error logfile for a <VirtualHost>
# container, that host's errors will be logged there and not here.
#
ErrorLog logs/error.log

#
# LogLevel: Control the number of messages logged to the error_log.
# Possible values include: debug, info, notice, warn, error, crit,
# alert, emerg.
#
LogLevel warn

<IfModule log_config_module>
    #
    # The following directives define some format nicknames for use with
    # a CustomLog directive (see below).
    #
    LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
    LogFormat "%h %l %u %t \"%r\" %>s %b" common

    <IfModule logio_module>
      # You need to enable mod_logio.c to use %I and %O
      LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" %I %O" combinedio
    </IfModule>

    #
    # The location and format of the access logfile (Common Logfile Format).
    # If you do not define any access logfiles within a <VirtualHost>
    # container, they will be logged here.  Contrariwise, if you *do*
    # define per-<VirtualHost> access logfiles, transactions will be
    # logged therein and *not* in this file.
    #
    #CustomLog logs/access.log common

    #
    # If you prefer a logfile with access, agent, and referer information
    # (Combined Logfile Format) you can use the following directive.
    #
    CustomLog logs/access.log combined
</IfModule>

<IfModule alias_module>
    #
    # Redirect: Allows you to tell clients about documents that used to
    # exist in your server's namespace, but do not anymore. The client
    # will make a new request for the document at its new location.
    # Example:
    # Redirect permanent /foo http://www.example.com/bar

    #
    # Alias: Maps web paths into filesystem paths and is used to
    # access content that does not live under the DocumentRoot.
    # Example:
    # Alias /webpath /full/filesystem/path
    #
    # If you include a trailing / on /webpath then the server will
    # require it to be present in the URL.  You will also likely
    # need to provide a <Directory> section to allow access to
    # the filesystem path.

    #
    # ScriptAlias: This controls which directories contain server scripts.
    # ScriptAliases are essentially the same as Aliases, except that
    # documents in the target directory are treated as applications and
    # run by the server when requested rather than as documents sent to the
    # client.  The same rules about trailing "/" apply to ScriptAlias
    # directives as to Alias.
    #
    ScriptAlias /cgi-bin/ "/opt/global/hello/HTML/cgi-bin/"

</IfModule>

<IfModule cgid_module>
    #
    # ScriptSock: On threaded servers, designate the path to the UNIX
    # socket used to communicate with the CGI daemon of mod_cgid.
    #
    #Scriptsock cgisock
</IfModule>

#
# "/var/www/localhost/cgi-bin" should be changed to whatever your ScriptAliased
# CGI directory exists, if you have that configured.
#
<Directory "/opt/global/hello/HTML/cgi-bin">
    AllowOverride None
    Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
    Order allow,deny
    Allow from all
    Require all granted
</Directory>

<IfModule mime_module>
    #
    # TypesConfig points to the file containing the list of mappings from
    # filename extension to MIME-type.
    #
    TypesConfig /etc/apache2/mime.types

    #
    # AddType allows you to add to or override the MIME configuration
    # file specified in TypesConfig for specific file types.
    #
    #AddType application/x-gzip .tgz
    #
    # AddEncoding allows you to have certain browsers uncompress
    # information on the fly. Note: Not all browsers support this.
    #
    #AddEncoding x-compress .Z
    #AddEncoding x-gzip .gz .tgz
    #
    # If the AddEncoding directives above are commented-out, then you
    # probably should define those extensions to indicate media types:
    #
    AddType application/x-compress .Z
    AddType application/x-gzip .gz .tgz

    #
    # AddHandler allows you to map certain file extensions to "handlers":
    # actions unrelated to filetype. These can be either built into the server
    # or added with the Action directive (see below)
    #
    # To use CGI scripts outside of ScriptAliased directories:
    # (You will also need to add "ExecCGI" to the "Options" directive.)
    #
    AddHandler cgi-script .cgi

    # For type maps (negotiated resources):
    #AddHandler type-map var

    #
    # Filters allow you to process content before it is sent to the client.
    #
    # To parse .shtml files for server-side includes (SSI):
    # (You will also need to add "Includes" to the "Options" directive.)
    #
    #AddType text/html .shtml
    #AddOutputFilter INCLUDES .shtml
</IfModule>

#
# The mod_mime_magic module allows the server to use various hints from the
# contents of the file itself to determine its type.  The MIMEMagicFile
# directive tells the module where the hint definitions are located.
#
<IfModule mime_magic_module>
    MIMEMagicFile /etc/apache2/magic
</IfModule>

#
# Customizable error responses come in three flavors:
# 1) plain text 2) local redirects 3) external redirects
#
# Some examples:
#ErrorDocument 500 "The server made a boo boo."
#ErrorDocument 404 /missing.html
#ErrorDocument 404 "/cgi-bin/missing_handler.pl"
#ErrorDocument 402 http://www.example.com/subscription_info.html
#

#
# MaxRanges: Maximum number of Ranges in a request before
# returning the entire resource, or one of the special
# values 'default', 'none' or 'unlimited'.
# Default setting is to accept 200 Ranges.
#MaxRanges unlimited

#
# EnableMMAP and EnableSendfile: On systems that support it,
# memory-mapping or the sendfile syscall may be used to deliver
# files.  This usually improves server performance, but must
# be turned off when serving from networked-mounted
# filesystems or if support for these functions is otherwise
# broken on your system.
# Defaults: EnableMMAP On, EnableSendfile Off
#
#EnableMMAP off
#EnableSendfile on

# Load config files from the config directory "/etc/apache2/conf.d".
#
IncludeOptional /etc/apache2/conf.d/*.conf

あとはdocker-compose up --buildして、ブラウザでhttp://localhost:8080/にアクセスすればこのようにTOP画面が表示されます。

f:id:masami256:20161215004524p:plain

ローカル環境にWebサーバを建てようとはあまり思わないんですが、docker使うと別の場所で動かすこともすぐできるし良いですよねヽ(=´▽`=)ノ

詳解UNIXプログラミング 第3版

詳解UNIXプログラミング 第3版