For a long time I've been a happy user of both up2date and later yum
without having any deeper understanding of how it works.
Inspired by a couple of comments on my posting Sweetxml:
Updating Skype with yum - updated repository location I decided to have
a closer look at it. The yum repository that I wrote about was for Skype
with the baseurl http://download.skype.com/linux/repos/fedora/updates/i586/.
Making a visit to that URL gives an 403:
$ wget -S http://download.skype.com/linux/repos/fedora/updates/i586/ --23:30:03-- http://download.skype.com/linux/repos/fedora/updates/i586/ Resolving download.skype.com... 194.192.199.202, 194.192.199.201 Connecting to download.skype.com|194.192.199.202|:80... connected. HTTP request sent, awaiting response... HTTP/1.1 403 Forbidden Server: nginx/0.5.20 Date: Tue, 18 Mar 2008 23:01:25 GMT Content-Type: text/html Content-Length: 1292 Connection: keep-alive 23:30:03 ERROR 403: Forbidden.
Which could be interpreted as there was something wrong with the
repository, but that would be a mis-conclusion. The 403 contains a /html/head/meta[@http-equiv="refresh"]
that sendes the browser to http://www.skype.com/go/download
<meta http-equiv="refresh" content="0;url=http://www.skype.com/go/download" />
which will send you through further a couple of 302's
:
$ wget -S http://www.skype.com/go/download --23:36:57-- http://www.skype.com/go/download Resolving www.skype.com... 204.9.163.136 Connecting to www.skype.com|204.9.163.136|:80... connected. HTTP request sent, awaiting response... HTTP/1.1 302 Found Date: Tue, 18 Mar 2008 22:36:57 GMT Server: Apache Location: http://www.skype.com/download/redirect Vary: Accept-Encoding,User-Agent Content-Length: 0 Keep-Alive: timeout=5, max=1200 Connection: Keep-Alive Content-Type: text/html; charset=utf-8 Content-Language: en Location: http://www.skype.com/download/redirect [following] --23:36:57-- http://www.skype.com/download/redirect Reusing existing connection to www.skype.com:80. HTTP request sent, awaiting response... HTTP/1.1 302 Found Date: Tue, 18 Mar 2008 22:36:57 GMT Server: Apache Location: http://www.skype.com/intl/da/download/skype/windows/ Pragma: no-cache Cache-Control: no-store, no-cache, must-revalidate Cache-Control: post-check=0, pre-check=0 Vary: Accept-Encoding,User-Agent Content-Length: 780 Keep-Alive: timeout=5, max=1199 Connection: Keep-Alive Content-Type: text/html; charset=utf-8 Content-Language: en Location: http://www.skype.com/intl/da/download/skype/windows/ [following] --23:36:58-- http://www.skype.com/intl/da/download/skype/windows/ Reusing existing connection to www.skype.com:80. HTTP request sent, awaiting response... HTTP/1.1 200 OK Date: Tue, 18 Mar 2008 22:36:58 GMT Server: Apache Accept-Ranges: bytes Vary: Accept-Encoding,User-Agent Connection: close Content-Type: text/html; charset=utf-8 Content-Language: en Length: unspecified [text/html]
Here ending up on the windows download page (probaly the default, since wget doesn't give enogh OS information).
Looking for some in depth information about yum repositories I had to do more seaching that I had expected, but I finally ended at Duke University Yellow dog Updater, Modified (yum) project and especially createrepo that has a short description of the anatomy of a yum repository in the Explanations section.
The metadata file (for the metadata files) for the repository is
located relatively in repodata/repomd.xml which for this
repository becomes: http://download.skype.com/linux/repos/fedora/updates/i586/repodata/repomd.xml:
1 <?xml version="1.0" encoding="UTF-8"?> 2 <repomd xmlns="http://linux.duke.edu/metadata/repo"> 3 <data type="other"> 4 <location href="repodata/other.xml.gz" /> 5 <checksum type="sha">289da3573161f83988b15dc74db0a1efa8ef9781</checksum> 6 <timestamp>1191408972</timestamp> 7 <open-checksum type="sha">c709dc7b0f3f7c0f38c767ebda5d33979eb2a943</open-checksum> 8 </data> 9 <data type="filelists"> 10 <location href="repodata/filelists.xml.gz" /> 11 <checksum type="sha">5c9fa749066ef5799f2ea9159a2963502644ecaa</checksum> 12 <timestamp>1191408972</timestamp> 13 <open-checksum type="sha">6eb325e10d4e8fcb091e292c27dd09176cd3aa4d</open-checksum> 14 </data> 15 <data type="primary"> 16 <location href="repodata/primary.xml.gz" /> 17 <checksum type="sha">68df664b42a6f6b97baa9f0022a5d2e89f5b95e1</checksum> 18 <timestamp>1191408972</timestamp> 19 <open-checksum type="sha">97ef94dac5f6f6a6b610eca8ed48f806d4eaac2d</open-checksum> 20 </data> 21 </repomd>
So from this it's clear that this is an active repository, though direct browsing the baseurl could give you the idea that it wasn't.
Taking it in reverse order the primary metadata is in the file repodata/primary.xml.gz, as described on the Duke website:
this file stores the primary metadata information. This includes information such as:
- name, epoch, version, release, architecture
- file size, file location, description, summary, format, checksums header byte-ranges, etc.
- dependencies, provides, conflicts, obsoletes, suggests, recommends
- file lists for the package for CERTAIN files - specifically files matching: /etc*, *bin/*, /usr/lib/sendmail
- it also includes a 'format' element which allows for format specific information to be stored. The formats known about right now are deb and rpm
This file (when gunzip'ed) looks like:
1 <?xml version="1.0" encoding="UTF-8"?> 2 <metadata 3 xmlns="http://linux.duke.edu/metadata/common" 4 xmlns:rpm="http://linux.duke.edu/metadata/rpm" 5 packages="1"> 6 <package type="rpm"> 7 <name>skype</name> 8 <arch>i586</arch> 9 <version 10 epoch="0" 11 ver="1.4.0.118" 12 rel="fc5" /> 13 <checksum 14 type="sha" 15 pkgid="YES"> 16 35d0bb0ed0738c4392827b2cd3d6ad5b1f098506 17 </checksum> 18 <summary>Skype is free Internet telephony that just works</summary> 19 <description> 20 Skype - Take a deep breath 21 22 Skype is a little piece of software that lets you make free calls to anyone else 23 on Skype, anywhere in the world. And even though the calls are free, they are really 24 excellent quality. 25 26 * Make free Skype-to-Skype calls to anyone else, anywhere in the world. 27 * Call ordinary phones and mobiles at pretty cheap rates per minute. 28 * Group chat with up to 100 people or conference call with up to nine others. 29 * Free to download. 30 </description> 31 <packager /> 32 <url>http://www.skype.com/products/skype/linux/</url> 33 <time 34 file="1191408970" 35 build="1190911586" /> 36 <size 37 package="13410121" 38 installed="16209093" 39 archive="16225988" /> 40 <location href="skype-1.4.0.118-fc.i586.rpm" /> 41 <format> 42 <rpm:license>Commercial</rpm:license> 43 <rpm:vendor /> 44 <rpm:group>Applications/Internet</rpm:group> 45 <rpm:buildhost>linux-build.skype.net</rpm:buildhost> 46 <rpm:sourcerpm>skype-1.4.0.118-fc5.src.rpm</rpm:sourcerpm> 47 <rpm:header-range 48 start="440" 49 end="25645" /> 50 <rpm:provides> 51 <rpm:entry 52 name="config(skype)" 53 flags="EQ" 54 epoch="0" 55 ver="1.4.0.118" 56 rel="fc5" /> 57 <rpm:entry 58 name="skype" 59 flags="EQ" 60 epoch="0" 61 ver="1.4.0.118" 62 rel="fc5" /> 63 </rpm:provides> 64 <rpm:requires> 65 <rpm:entry name="libstdc++.so.6(CXXABI_1.3)" /> 66 <rpm:entry name="libc.so.6(GLIBC_2.1.3)" /> 67 <rpm:entry name="libasound.so.2(ALSA_0.9)" /> 68 <rpm:entry 69 name="config(skype)" 70 flags="EQ" 71 epoch="0" 72 ver="1.4.0.118" 73 rel="fc5" /> 74 <rpm:entry name="libgcc_s.so.1(GCC_3.0)" /> 75 <rpm:entry name="libX11.so.6" /> 76 <rpm:entry name="libc.so.6(GLIBC_2.3)" /> 77 <rpm:entry name="libpthread.so.0(GLIBC_2.3.2)" /> 78 <rpm:entry name="libc.so.6(GLIBC_2.1)" /> 79 <rpm:entry 80 name="rpmlib(PayloadFilesHavePrefix)" 81 flags="LE" 82 epoch="0" 83 ver="4.0" 84 rel="1" 85 pre="1" /> 86 <rpm:entry 87 name="rpmlib(CompressedFileNames)" 88 flags="LE" 89 epoch="0" 90 ver="3.0.4" 91 rel="1" 92 pre="1" /> 93 <rpm:entry name="libpthread.so.0" /> 94 <rpm:entry name="libpthread.so.0(GLIBC_2.0)" /> 95 <rpm:entry name="libstdc++.so.6(CXXABI_1.3.1)" /> 96 <rpm:entry name="libstdc++.so.6(GLIBCXX_3.4)" /> 97 <rpm:entry name="libpthread.so.0(GLIBC_2.1)" /> 98 <rpm:entry name="libQtDBus.so.4" /> 99 <rpm:entry name="libgcc_s.so.1" /> 100 <rpm:entry name="libm.so.6" /> 101 <rpm:entry name="libm.so.6(GLIBC_2.0)" /> 102 <rpm:entry name="libasound.so.2(ALSA_0.9.0rc4)" /> 103 <rpm:entry name="libQtNetwork.so.4" /> 104 <rpm:entry name="libstdc++.so.6(GLIBCXX_3.4.4)" /> 105 <rpm:entry name="libasound.so.2" /> 106 <rpm:entry name="libstdc++.so.6" /> 107 <rpm:entry name="libgcc_s.so.1(GLIBC_2.0)" /> 108 <rpm:entry name="libc.so.6(GLIBC_2.0)" /> 109 <rpm:entry name="libc.so.6(GLIBC_2.4)" /> 110 <rpm:entry name="librt.so.1" /> 111 <rpm:entry name="libQtGui.so.4" /> 112 <rpm:entry name="libc.so.6(GLIBC_2.3.4)" /> 113 <rpm:entry 114 name="/bin/sh" 115 pre="1" /> 116 <rpm:entry 117 name="qt4-x11" 118 flags="GE" 119 epoch="0" 120 ver="4.2" /> 121 <rpm:entry name="libQtCore.so.4" /> 122 <rpm:entry name="libpthread.so.0(GLIBC_2.2)" /> 123 <rpm:entry name="libc.so.6" /> 124 <rpm:entry name="libc.so.6(GLIBC_2.2)" /> 125 <rpm:entry name="libsigc-2.0.so.0" /> 126 </rpm:requires> 127 <file>/etc/dbus-1/system.d/skype.conf</file> 128 <file>/usr/bin/skype</file> 129 </format> 130 </package> 131 </metadata>
The format partly defined in the DTD for package and DTD for rpm metadata.
The repodata/filelists.xml.gz, described as this file stores the complete file and directory listings for the packages. The package is identified by: name, epoch, version, release, architecture and package checksum id
contains:
1 <?xml version="1.0" encoding="UTF-8"?> 2 <filelists 3 xmlns="http://linux.duke.edu/metadata/filelists" 4 packages="1"> 5 <package 6 pkgid="97ff8fb3b6eb70289a73545ea39c02fcce4f6b4a" 7 name="skype" 8 arch="i586"> 9 <version 10 epoch="0" 11 ver="2.0.0.63" 12 rel="fc5" /> 13 <file>/etc/dbus-1/system.d/skype.conf</file> 14 <file>/usr/bin/skype</file> 15 <file>/usr/share/applications/skype.desktop</file> 16 <file>/usr/share/doc/skype-2.0.0.63/LICENSE</file> 17 <file>/usr/share/doc/skype-2.0.0.63/README</file> 18 <file>/usr/share/icons/skype.png</file> 19 <file>/usr/share/pixmaps/skype.png</file> 20 <file>/usr/share/skype/lang/skype_bg.qm</file> 21 <file>/usr/share/skype/lang/skype_bg.ts</file> 22 <file>/usr/share/skype/lang/skype_de.qm</file> 23 <file>/usr/share/skype/lang/skype_de.ts</file> 24 <file>/usr/share/skype/lang/skype_en.qm</file> 25 <file>/usr/share/skype/lang/skype_en.ts</file> 26 <file>/usr/share/skype/lang/skype_es.qm</file> 27 <file>/usr/share/skype/lang/skype_es.ts</file> 28 <file>/usr/share/skype/lang/skype_et.qm</file> 29 <file>/usr/share/skype/lang/skype_et.ts</file> 30 <file>/usr/share/skype/lang/skype_fr.qm</file> 31 <file>/usr/share/skype/lang/skype_fr.ts</file> 32 <file>/usr/share/skype/lang/skype_it.qm</file> 33 <file>/usr/share/skype/lang/skype_it.ts</file> 34 <file>/usr/share/skype/lang/skype_ja.qm</file> 35 <file>/usr/share/skype/lang/skype_ja.ts</file> 36 <file>/usr/share/skype/lang/skype_ko.qm</file> 37 <file>/usr/share/skype/lang/skype_ko.ts</file> 38 <file>/usr/share/skype/lang/skype_lt.qm</file> 39 <file>/usr/share/skype/lang/skype_lt.ts</file> 40 <file>/usr/share/skype/lang/skype_lv.qm</file> 41 <file>/usr/share/skype/lang/skype_lv.ts</file> 42 <file>/usr/share/skype/lang/skype_pl.qm</file> 43 <file>/usr/share/skype/lang/skype_pl.ts</file> 44 <file>/usr/share/skype/lang/skype_pt_br.qm</file> 45 <file>/usr/share/skype/lang/skype_pt_br.ts</file> 46 <file>/usr/share/skype/lang/skype_pt_pt.qm</file> 47 <file>/usr/share/skype/lang/skype_pt_pt.ts</file> 48 <file>/usr/share/skype/lang/skype_ro.qm</file> 49 <file>/usr/share/skype/lang/skype_ro.ts</file> 50 <file>/usr/share/skype/lang/skype_ru.qm</file> 51 <file>/usr/share/skype/lang/skype_ru.ts</file> 52 <file>/usr/share/skype/lang/skype_th.qm</file> 53 <file>/usr/share/skype/lang/skype_th.ts</file> 54 <file>/usr/share/skype/lang/skype_tr.qm</file> 55 <file>/usr/share/skype/lang/skype_tr.ts</file> 56 <file>/usr/share/skype/lang/skype_zh_s.qm</file> 57 <file>/usr/share/skype/lang/skype_zh_s.ts</file> 58 <file>/usr/share/skype/lang/skype_zh_t.qm</file> 59 <file>/usr/share/skype/lang/skype_zh_t.ts</file> 60 <file>/usr/share/skype/sounds/CallBusy.wav</file> 61 <file>/usr/share/skype/sounds/CallConnecting.wav</file> 62 <file>/usr/share/skype/sounds/CallFailed.wav</file> 63 <file>/usr/share/skype/sounds/CallHangup.wav</file> 64 <file>/usr/share/skype/sounds/CallHold.wav</file> 65 <file>/usr/share/skype/sounds/CallRemoteHangup.wav</file> 66 <file>/usr/share/skype/sounds/CallResume.wav</file> 67 <file>/usr/share/skype/sounds/CallRingingIn.wav</file> 68 <file>/usr/share/skype/sounds/CallRingingOut.wav</file> 69 <file>/usr/share/skype/sounds/ChatIncoming.wav</file> 70 <file>/usr/share/skype/sounds/ChatIncomingInitial.wav</file> 71 <file>/usr/share/skype/sounds/ChatOutgoing.wav</file> 72 <file>/usr/share/skype/sounds/ContactAdded.wav</file> 73 <file>/usr/share/skype/sounds/ContactAuthRequest.wav</file> 74 <file>/usr/share/skype/sounds/ContactOffline.wav</file> 75 <file>/usr/share/skype/sounds/ContactOnline.wav</file> 76 <file>/usr/share/skype/sounds/SkypeLogin.wav</file> 77 <file>/usr/share/skype/sounds/SkypeLogout.wav</file> 78 <file>/usr/share/skype/sounds/TransferComplete.wav</file> 79 <file>/usr/share/skype/sounds/TransferFailed.wav</file> 80 <file>/usr/share/skype/sounds/TransferRequest.wav</file> 81 <file>/usr/share/skype/sounds/VoicemailReceived.wav</file> 82 <file type="dir">/usr/share/doc/skype-2.0.0.63</file> 83 </package> 84 85 </filelists>
And finally repodata/other.xml.gz, with the description this file currently only stores the changelog data from packages. However, this file could be used for any other additional metadata that could be useful for clients
contains:
1 <?xml version="1.0" encoding="UTF-8"?> 2 <otherdata 3 xmlns="http://linux.duke.edu/metadata/other" 4 packages="1"> 5 <package 6 pkgid="97ff8fb3b6eb70289a73545ea39c02fcce4f6b4a" 7 name="skype" 8 arch="i586"> 9 <version 10 epoch="0" 11 ver="2.0.0.63" 12 rel="fc5" /> 13 <changelog 14 author="Skype Technologies S.A. <info@skype.net> 2.0.0.63-fc5" 15 date="1204704000"> 16 - feature: Add call cost per minute to 1:1 SkypeOut calls. 17 - feature: Add UI detection of Slovakian, Farsi (Persian) and Vietnamese language files. 18 - feature: Added privacy option to disable the sending of the number of contacts you have to your contacts. 19 - feature: Implement HashLinkURL to provide easy links to #12345 references in chats. 20 - feature: Shadows on user avatars on contact card. 21 - feature: Show an indicator when the user is on an embedded device such as a Skype phone. 22 - feature API: BTN_PRESSED/BTN_RELEASED are now implemented. 23 - feature API: SEARCH ACTIVECHATS is now implemented. 24 - bugfix: 1:1 chats should not have Leave Chat button. 25 - bugfix: Add a blinking window effect for some windows which are already open when we get a new chat message. 26 - bugfix: Add a workaround for a KWin issue preventing closed minimized chats from being reopened. 27 - bugfix: Add bubbles from mood message to avatars on contact card. 28 - bugfix: Add right-click context menu to chat window for copying text/links. 29 - bugfix: Avoid status text being truncated on status button in profile editor. 30 - bugfix: BTN_PRESSED YES should activate Call functionality regardless of double-click action. 31 - bugfix: Be sure the chat window doesn't reappear after we leave the chat. 32 - bugfix: Call Ringing sound shouldn't be audible during Do Not Disturb status mode. 33 - bugfix: Can't add a contact to a chat using drag and drop. 34 - bugfix: Change Call Hold/Resume button at the correct times (even when changing hold/resume during fullscreen video) 35 - bugfix: Change file transfer filename to saved filename if different from original filename in transfer window. 36 - bugfix: Compare chats in recent chats/etc menus correctly to check if they are unread. 37 - bugfix: Contacts shouldn't disappear when they're moved between columns when receiving contacts. 38 - bugfix: Copy URLs to both X selection and Clipboard, as users may want to middle-click the copied link into their browser. 39 - bugfix: Crash after 2 minutes of signing in if we are signed out at that time. 40 - bugfix: Crash after signing in with incorrect details after signing out. 41 - bugfix: Display video in full-screen at correct aspect ratio regardless of monitor dimensions. 42 - bugfix: Do not always put new chat windows at top left corner if no previous setting found, let window manager determine position. 43 - bugfix: Do not freeze when opening options dialog 44 - bugfix: Do not initialise /dev/video0 whenever we start a video call (could prevent video from working when video0 fails) 45 - bugfix: Do not instantly close Voicemail events when clicking the play button in new events panel. 46 - bugfix: Do not let Voicemail messages continue to play in the background after closing them. 47 - bugfix: Do not show authorisation options in context menu for events if we already authorised the user. 48 - bugfix: Do not unnecessarily init device twice when starting video (speeds up video init by 50%) 49 - bugfix: Downscaling for Myself View / Oversized Video on X11 (non-accelerated). 50 - bugfix: echo123 should be called Skype Test Call and should not have an 'Request Authorization' option. 51 - bugfix: Ending an incoming conference call should be allowed to redirect to Voicemail also. 52 - bugfix: Escape should close send contacts window before we attempt to send contacts. 53 - bugfix: Fix for chat being stuck in unread state after becoming multichat. 54 - bugfix: Fix for video output when not using XShm extension. 55 - bugfix: Fix locking up the client for up to 30 seconds randomly sometimes for heavy Skype users. 56 - bugfix: If main window is thinner than login window and right-aligned, it would move to the left after restart. 57 - bugfix: Incoming calls should be redirected to Voicemail if configured to do so and another call is active. 58 - bugfix: Make 'Invite selected contacts to conference call' option work in contact list multiple selections menu. 59 - bugfix: Make contact list even more responsive whilst loading historical calls. 60 - bugfix: Make login/startup much faster and cleaner. 61 - bugfix: Make missed event text for birthdays clearer. 62 - bugfix: Many bugfixes to video in call window to handle window updates during paused video calls. 63 - bugfix: Only move main window if we have a previously saved position. 64 - bugfix: Only play chat message sent sound for actual sent messages and emotive actions. 65 - bugfix: Only redirect incoming calls to Voicemail if we actually have Voicemail capability. 66 - bugfix: Properly remember unread chats as unread after a Skype restart. 67 - bugfix: Receive Contacts should close when Escape is pressed. 68 - bugfix: Remember 'Show Myself View' setting during the video call (when switching to fullscreen and back, etc). 69 - bugfix: Remember chat splitter arrangement per user for 1:1 chats. 70 - bugfix: Remember chat window position per user for 1:1 chats. 71 - bugfix: Remember show/hide chat member list setting per user for 1:1 chats. 72 - bugfix: Remove grey contact card background. 73 - bugfix: Reordered Voicemail Options dialog to keep individual Voicemail features independent. 74 - bugfix: Send Contacts should cancel and/or close when Escape is pressed. 75 - bugfix: Shortened SkypeIn and SkypeOut call error messages. 76 - bugfix: Show correct saving filename in child transfer widget when receiving multiple files. 77 - bugfix: Shrink myself view so it scales better on Xv and properly on X11. 78 - bugfix: Starting a conference call with a MySpace contact would result in a single call being made to 'myspace'. 79 - bugfix: Stop window from moving lower and lower on each restart. 80 - bugfix: Update chat window area size correctly after clearing to avoid mystery scrollbar returning. 81 - bugfix: Video call window is out of shape if the contact has a really long name. 82 - bugfix API: SET CHATMESSAGE [id] SEEN should remove now-read chats from events panel. 83 </changelog> 84 </package> 85 </otherdata>
On howtoforge.com there's an article How To Set Up A Local Yum Repository On Fedora 8 which could be a very good idea if I someday had to develop (and maintain) an application for Linux.
