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| -rw-r--r-- | doc/guix.texi | 132 |
1 files changed, 98 insertions, 34 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index 4f8453ebf0..2b3ffc9a8a 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -23,7 +23,7 @@ Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@* Copyright @copyright{} 2015, 2016, 2017 Leo Famulari@* Copyright @copyright{} 2015, 2016, 2017 Ricardo Wurmus@* Copyright @copyright{} 2016 Ben Woodcroft@* -Copyright @copyright{} 2016 Chris Marusich@* +Copyright @copyright{} 2016, 2017 Chris Marusich@* Copyright @copyright{} 2016, 2017 Efraim Flashner@* Copyright @copyright{} 2016 John Darrington@* Copyright @copyright{} 2016 ng0@* @@ -40,7 +40,8 @@ Copyright @copyright{} 2017 Christopher Allan Webber@* Copyright @copyright{} 2017 Marius Bakke@* Copyright @copyright{} 2017 Hartmut Goebel@* Copyright @copyright{} 2017 Maxim Cournoyer@* -Copyright @copyright{} 2017 Tobias Geerinckx-Rice +Copyright @copyright{} 2017 Tobias Geerinckx-Rice@* +Copyright @copyright{} 2017 George Clemmer Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or @@ -130,6 +131,15 @@ Package Management * Invoking guix pack:: Creating software bundles. * Invoking guix archive:: Exporting and importing store files. +Substitutes + +* Official Substitute Server:: One particular source of substitutes. +* Substitute Server Authorization:: How to enable or disable substitutes. +* Substitute Authentication:: How Guix verifies substitutes. +* Proxy Settings:: How to get substitutes via proxy. +* Substitution Failure:: What happens when substitution fails. +* On Trusting Binaries:: How can you trust that binary blob? + Programming Interface * Defining Packages:: Defining new packages. @@ -1108,10 +1118,6 @@ Do not use substitutes for build products. That is, always build things locally instead of allowing downloads of pre-built binaries (@pxref{Substitutes}). -By default substitutes are used, unless the client---such as the -@command{guix package} command---is explicitly invoked with -@code{--no-substitutes}. - When the daemon runs with @code{--no-substitutes}, clients can still explicitly enable substitution @i{via} the @code{set-build-options} remote procedure call (@pxref{The Store}). @@ -2111,7 +2117,6 @@ preserve transformations across upgrades, you should define your own package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH} (@pxref{Defining Packages}). - @node Substitutes @section Substitutes @@ -2119,8 +2124,8 @@ package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH} @cindex pre-built binaries Guix supports transparent source/binary deployment, which means that it can either build things locally, or download pre-built items from a -server. We call these pre-built items @dfn{substitutes}---they are -substitutes for local build results. In many cases, downloading a +server, or both. We call these pre-built items @dfn{substitutes}---they +are substitutes for local build results. In many cases, downloading a substitute is much faster than building things locally. Substitutes can be anything resulting from a derivation build @@ -2128,8 +2133,22 @@ Substitutes can be anything resulting from a derivation build pre-built package binaries, but source tarballs, for instance, which also result from derivation builds, can be available as substitutes. -The @code{hydra.gnu.org} server is a front-end to a build farm that -builds packages from the GNU distribution continuously for some +@menu +* Official Substitute Server:: One particular source of substitutes. +* Substitute Server Authorization:: How to enable or disable substitutes. +* Substitute Authentication:: How Guix verifies substitutes. +* Proxy Settings:: How to get substitutes via proxy. +* Substitution Failure:: What happens when substitution fails. +* On Trusting Binaries:: How can you trust that binary blob? +@end menu + +@node Official Substitute Server +@subsection Official Substitute Server + +@cindex hydra +@cindex build farm +The @code{hydra.gnu.org} server is a front-end to an official build farm +that builds packages from the GNU distribution continuously for some architectures, and makes them available as substitutes. This is the default source of substitutes; it can be overridden by passing the @option{--substitute-urls} option either to @command{guix-daemon} @@ -2144,8 +2163,19 @@ using HTTP makes all communications visible to an eavesdropper, who could use the information gathered to determine, for instance, whether your system has unpatched security vulnerabilities. +Substitutes from the official build farm are enabled by default when +using the Guix System Distribution (@pxref{GNU Distribution}). However, +they are disabled by default when using Guix on a foreign distribution, +unless you have explicitly enabled them via one of the recommended +installation steps (@pxref{Installation}). The following paragraphs +describe how to enable or disable substitutes for the official build +farm; the same procedure can also be used to enable substitutes for any +other substitute server. + +@node Substitute Server Authorization +@subsection Substitute Server Authorization + @cindex security -@cindex digital signatures @cindex substitutes, authorization thereof @cindex access control list (ACL), for substitutes @cindex ACL (access control list), for substitutes @@ -2156,7 +2186,7 @@ imports, using the @command{guix archive} command (@pxref{Invoking guix archive}). Doing so implies that you trust @code{hydra.gnu.org} to not be compromised and to serve genuine substitutes. -This public key is installed along with Guix, in +The public key for @code{hydra.gnu.org} is installed along with Guix, in @code{@var{prefix}/share/guix/hydra.gnu.org.pub}, where @var{prefix} is the installation prefix of Guix. If you installed Guix from source, make sure you checked the GPG signature of @@ -2197,6 +2227,17 @@ The following files would be downloaded: This indicates that substitutes from @code{hydra.gnu.org} are usable and will be downloaded, when possible, for future builds. +@cindex substitutes, how to disable +The substitute mechanism can be disabled globally by running +@code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking +guix-daemon}). It can also be disabled temporarily by passing the +@code{--no-substitutes} option to @command{guix package}, @command{guix +build}, and other command-line tools. + +@node Substitute Authentication +@subsection Substitute Authentication + +@cindex digital signatures Guix detects and raises an error when attempting to use a substitute that has been tampered with. Likewise, it ignores substitutes that are not signed, or that are not signed by one of the keys listed in the ACL. @@ -2221,15 +2262,6 @@ comes first in the list and can be considered a mirror of produce the same binaries, thanks to bit-reproducible builds (see below). -@vindex http_proxy -Substitutes are downloaded over HTTP or HTTPS. -The @code{http_proxy} environment -variable can be set in the environment of @command{guix-daemon} and is -honored for downloads of substitutes. Note that the value of -@code{http_proxy} in the environment where @command{guix build}, -@command{guix package}, and other client commands are run has -@emph{absolutely no effect}. - When using HTTPS, the server's X.509 certificate is @emph{not} validated (in other words, the server is not authenticated), contrary to what HTTPS clients such as Web browsers usually do. This is because Guix @@ -2237,18 +2269,50 @@ authenticates substitute information itself, as explained above, which is what we care about (whereas X.509 certificates are about authenticating bindings between domain names and public keys.) -You can get statistics on the substitutes provided by a server using the -@command{guix weather} command (@pxref{Invoking guix weather}). - -The substitute mechanism can be disabled globally by running -@code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking -guix-daemon}). It can also be disabled temporarily by passing the -@code{--no-substitutes} option to @command{guix package}, @command{guix -build}, and other command-line tools. - +@node Proxy Settings +@subsection Proxy Settings -@unnumberedsubsec On Trusting Binaries +@vindex http_proxy +Substitutes are downloaded over HTTP or HTTPS. +The @code{http_proxy} environment +variable can be set in the environment of @command{guix-daemon} and is +honored for downloads of substitutes. Note that the value of +@code{http_proxy} in the environment where @command{guix build}, +@command{guix package}, and other client commands are run has +@emph{absolutely no effect}. +@node Substitution Failure +@subsection Substitution Failure + +Even when a substitute for a derivation is available, sometimes the +substitution attempt will fail. This can happen for a variety of +reasons: the substitute server might be offline, the substitute may +recently have been deleted, the connection might have been interrupted, +etc. + +When substitutes are enabled and a substitute for a derivation is +available, but the substitution attempt fails, Guix will attempt to +build the derivation locally depending on whether or not +@code{--fallback} was given (@pxref{fallback-option,, common build +option @code{--fallback}}). Specifically, if @code{--fallback} was +omitted, then no local build will be performed, and the derivation is +considered to have failed. However, if @code{--fallback} was given, +then Guix will attempt to build the derivation locally, and the success +or failure of the derivation depends on the success or failure of the +local build. Note that when substitutes are disabled or no substitute +is available for the derivation in question, a local build will +@emph{always} be performed, regardless of whether or not +@code{--fallback} was given. + +To get an idea of how many substitutes are available right now, you can +try running the @command{guix weather} command (@pxref{Invoking guix +weather}). This command provides statistics on the substitutes provided +by a server. + +@node On Trusting Binaries +@subsection On Trusting Binaries + +@cindex trust, of pre-built binaries Today, each individual's control over their own computing is at the mercy of institutions, corporations, and groups with enough power and determination to subvert the computing infrastructure and exploit its @@ -2275,7 +2339,6 @@ In the future, we want Guix to have support to publish and retrieve binaries to/from other users, in a peer-to-peer fashion. If you would like to discuss this project, join us on @email{guix-devel@@gnu.org}. - @node Packages with Multiple Outputs @section Packages with Multiple Outputs @@ -5198,9 +5261,10 @@ derivations has failed. @itemx -n Do not build the derivations. +@anchor{fallback-option} @item --fallback When substituting a pre-built binary fails, fall back to building -packages locally. +packages locally (@pxref{Substitution Failure}). @item --substitute-urls=@var{urls} @anchor{client-substitute-urls} |