Add 'nix upgrade-nix' command

This command upgrades Nix to the latest stable version by installing a
store path obtained from

  https://github.com/NixOS/nixpkgs/raw/master/nixos/modules/installer/tools/nix-fallback-paths.nix

which is the same store path that the installer at
https://nixos.org/nix/install.sh uses.

The upgrade fails if Nix is not installed in a profile (e.g. on NixOS,
or when installed outside of the Nix store).
This commit is contained in:
Eelco Dolstra 2018-01-31 16:14:47 +01:00
parent 8af911be5c
commit 6fa690291a
No known key found for this signature in database
GPG key ID: 8170B4726D7198DE
4 changed files with 142 additions and 1 deletions

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@ -79,6 +79,11 @@
<listitem><para><command>nix add-to-store</command> (970366266b8df712f5f9cedb45af183ef5a8357f).</para></listitem> <listitem><para><command>nix add-to-store</command> (970366266b8df712f5f9cedb45af183ef5a8357f).</para></listitem>
<listitem><para><command>nix upgrade-nix</command> upgrades Nix
to the latest stable version. This requires that Nix is
installed in a profile. (Thus it wont work on NixOS, or if its
installed outside of the Nix store.)</para></listitem>
<listitem><para>Progress indicator.</para></listitem> <listitem><para>Progress indicator.</para></listitem>
<listitem><para>All options are available as flags now <listitem><para>All options are available as flags now

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@ -5,6 +5,8 @@
namespace nix { namespace nix {
extern std::string programPath;
struct Value; struct Value;
class Bindings; class Bindings;
class EvalState; class EvalState;

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@ -16,6 +16,8 @@ void chrootHelper(int argc, char * * argv);
namespace nix { namespace nix {
std::string programPath;
struct NixArgs : virtual MultiCommand, virtual MixCommonArgs struct NixArgs : virtual MultiCommand, virtual MixCommonArgs
{ {
NixArgs() : MultiCommand(*RegisterCommand::commands), MixCommonArgs("nix") NixArgs() : MultiCommand(*RegisterCommand::commands), MixCommonArgs("nix")
@ -78,7 +80,8 @@ void mainWrapped(int argc, char * * argv)
initNix(); initNix();
initGC(); initGC();
string programName = baseNameOf(argv[0]); programPath = argv[0];
string programName = baseNameOf(programPath);
{ {
auto legacy = (*RegisterLegacyCommand::commands)[programName]; auto legacy = (*RegisterLegacyCommand::commands)[programName];

131
src/nix/upgrade-nix.cc Normal file
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@ -0,0 +1,131 @@
#include "command.hh"
#include "store-api.hh"
#include "download.hh"
#include "eval.hh"
#include "attr-path.hh"
using namespace nix;
struct CmdUpgradeNix : StoreCommand
{
Path profileDir;
CmdUpgradeNix()
{
mkFlag()
.longName("profile")
.shortName('p')
.labels({"profile-dir"})
.description("the Nix profile to upgrade")
.dest(&profileDir);
}
std::string name() override
{
return "upgrade-nix";
}
std::string description() override
{
return "upgrade Nix to the latest stable version";
}
Examples examples() override
{
return {
Example{
"To upgrade Nix to the latest stable version:",
"nix upgrade-nix"
},
Example{
"To upgrade Nix in a specific profile:",
"nix upgrade-nix -p /nix/var/nix/profiles/per-user/alice/profile"
},
};
}
void run(ref<Store> store) override
{
settings.pureEval = true;
if (profileDir == "")
profileDir = getProfileDir(store);
printInfo("upgrading Nix in profile '%s'", profileDir);
Path storePath;
{
Activity act(*logger, lvlInfo, actUnknown, "querying latest Nix version");
storePath = getLatestNix(store);
}
{
Activity act(*logger, lvlInfo, actUnknown, fmt("downloading '%s'...", storePath));
store->ensurePath(storePath);
}
{
Activity act(*logger, lvlInfo, actUnknown, fmt("verifying that '%s' works...", storePath));
auto program = storePath + "/bin/nix-env";
auto s = runProgram(program, false, {"--version"});
if (s.find("Nix") == std::string::npos)
throw Error("could not verify that '%s' works", program);
}
{
Activity act(*logger, lvlInfo, actUnknown, fmt("installing '%s' into profile '%s'...", storePath, profileDir));
runProgram(settings.nixBinDir + "/nix-env", false,
{"--profile", profileDir, "-i", storePath, "--no-sandbox"});
}
}
/* Return the profile in which Nix is installed. */
Path getProfileDir(ref<Store> store)
{
Path where;
for (auto & dir : tokenizeString<Strings>(getEnv("PATH"), ":"))
if (pathExists(dir + "/nix-env")) {
where = dir;
break;
}
if (where == "")
throw Error("couldn't figure out how Nix is installed, so I can't upgrade it");
printInfo("found Nix in '%s'", where);
if (hasPrefix(where, "/run/current-system"))
throw Error("Nix on NixOS must be upgraded via 'nixos-rebuild'");
Path profileDir;
Path userEnv;
if (baseNameOf(where) != "bin" ||
!hasSuffix(userEnv = canonPath(profileDir = dirOf(where), true), "user-environment"))
throw Error("directory '%s' does not appear to be part of a Nix profile", where);
if (!store->isValidPath(userEnv))
throw Error("directory '%s' is not in the Nix store", userEnv);
return profileDir;
}
/* Return the store path of the latest stable Nix. */
Path getLatestNix(ref<Store> store)
{
// FIXME: use nixos.org?
auto req = DownloadRequest("https://github.com/NixOS/nixpkgs/raw/master/nixos/modules/installer/tools/nix-fallback-paths.nix");
auto res = getDownloader()->download(req);
EvalState state(Strings(), store);
auto v = state.allocValue();
state.eval(state.parseExprFromString(*res.data, "/no-such-path"), *v);
Bindings & bindings(*state.allocBindings(0));
auto v2 = findAlongAttrPath(state, settings.thisSystem, bindings, *v);
return state.forceString(*v2);
}
};
static RegisterCommand r1(make_ref<CmdUpgradeNix>());