* For reproducibility, Portage and Profiles are frozen with the help of version control system (git in our case). This is only done on the [[Mirror Server]].
* When building packages in a chroot environment, the portage and overlay versions need to set.
== Portage Snapshotting ==
To be able to reliably rebuild packages, we are working with a snapshotted/versioned portage tree.
=== Updating the snapshot to latest ===
We are using <code>emerge-webrsync</code> since it features an already determined version, checksum- and gpg-validation.
{{Cmd
|git clone "${PORTAGE_GIT_REPO}" portage
|cd portage
|PORTAGE_RSYNC_EXTRA_OPTS{{=}}"--exclude{{=}}/.git --exclude{{=}}/.gitignore" PORTDIR{{=}}"${PWD}" emerge-webrsync
|output=<pre>
Fetching most recent snapshot ...
Trying to retrieve 20140821 snapshot from http://mirror.switch.ch/mirror/gentoo ...
Fetching file portage-20140821.tar.xz.md5sum ...
Fetching file portage-20140821.tar.xz.gpgsig ...
Fetching file portage-20140821.tar.xz ...
Checking digest ...
Getting snapshot timestamp ...
Syncing local tree ...
</pre>}}
{{Warning|If you get the following instead then there is no newer snapshot available}}
{{Cmd
|PORTAGE_RSYNC_EXTRA_OPTS{{=}}"--exclude{{=}}/.git --exclude{{=}}/.gitignore" PORTDIR{{=}}"${PWD}" emerge-webrsync
|output=<pre>
Fetching most recent snapshot ...
* Latest snapshot date: 20140821
*
* Approximate snapshot timestamp: 1408668300
* Current local timestamp: 1408667701
*
* The current local timestamp is possibly identical to the
* timestamp of the latest snapshot. In order to force sync, use
* the --revert option or remove the timestamp file located at
* '/run/user/1000/portage/metadata/timestamp.x'.
</pre>}}
Set the tag and push if there was an update:
{{Cmd
|cd portage/
|git add -A
|snapshot_date{{=}}$(date --date{{=}}@$(( $(cut -f 1 -d " " metadata/timestamp.x) - 86400 )) +%Y-%m-%d)
|git commit -m "Update portage tree to ${snapshot_date}"
|git tag -a -m "Tagging ${snapshot_date}" ${snapshot_date}
|git push && git push --tags
|echo "snapshot date: ${snapshot_date}"
}}
The subtraction of 86400 (1 day in seconds) above is to account for the fact that the snapshot for a given day is taken at 00:45 UTC on the following day and the timestamp contained in the tarball therefore is one day ahead (see {{Path|/usr/bin/emerge-webrsync}}).
The meaning of the tag is therefore: contains at least all changes from that day (and possibly a bit more).
== Chroot Setup ==
=== Setup ===
* Create a staging root directory and extract a stage3 or stage4 tarball:* Mount proc, sys and dev (required for portage to control the tty, determine available storage space, etc.)* Copy {{Path|/etc/resolv.conf}}* Checkout the versioned portage tree (since you probably won't have git yet in the tree)* Enter the chroot
{{RootCmd
|mkdir -p stagingRoot{{=}}/var/staging/staging-base|mkdir -p "${stagingRoot}"|tar -xjpf /var/tmp/your-stage4.tbz2 -C "${stagingRoot}"|mount -t proc none "${stagingRoot}/varproc"|mount --rbind /stagingdev/staging"${stagingRoot}/dev/"|mount -base-rbind /sys/ "${stagingRoot}/sys/"|cp -af /etc/resolv.conf "${stagingRoot}/etc/"|git clone "${PORTAGE_GIT_REPO}" "${stagingRoot}/usr/portage"|chmod -R a+rX "${stagingRoot}/usr/portage"|chroot "${stagingRoot}" /usr/bin/env -i HOME{{=}}"/root" TERM{{=}}"${TERM}" /bin/bash --login|}} {{Note|We are deliberately using a special command for entering the chroot to avoid leaking environment variables}} * Install {{Package|app-portage/layman}} and probably {{Package|dev-vcs/git}} to install overlays* You may want to add a mirror configuration if you have local mirrors:{{File|/etc/portage/make.conf||<source lang='bash'>GENTOO_MIRRORS="https://mirror.example.com/public/gentoo"</source>}} * If needed, put the mirror for fetch restricted ebuilds in a local mirror definition:{{File|/etc/portage/mirrors||<pre>local https://mirror.example.com/restricted/gentoo</pre>}} * Add the following to generate binary packages during installation:{{File|/etc/portage/make.conf||<source lang='bash'>FEATURES="${FEATURES} buildpkg cgroup ipc-sandbox network-sandbox parallel-fetch"</source>}} * Make sure that the repository configuration points to your git mirror as well:{{File|/etc/portage/repos.conf/gentoo.conf||<source lang='ini'>[DEFAULT]main-repo = gentoo [gentoo]location = /usr/portagesync-type = gitsync-uri = https://mirror.example.com/versioned/portage.git</source>}} * Rebuild everything:{{RootCmd|emerge -e world}}
[[Category:Infrastructure]]