forked from lix-project/lix
c30330df6f
So for instance "nix copy --to ... nixpkgs.hello" will build nixpkgs.hello first. It's debatable whether this is a good idea. It seems desirable for commands like "nix copy" but maybe not for commands like "nix path-info".
105 lines
3.8 KiB
C++
105 lines
3.8 KiB
C++
#include "command.hh"
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#include "common-args.hh"
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#include "shared.hh"
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#include "store-api.hh"
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#include "derivations.hh"
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#include "local-store.hh"
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#include "finally.hh"
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#if __linux__
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#include <sys/mount.h>
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#endif
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using namespace nix;
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struct CmdRun : InstallablesCommand
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{
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CmdRun()
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{
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}
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std::string name() override
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{
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return "run";
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}
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std::string description() override
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{
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return "run a shell in which the specified packages are available";
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}
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void run(ref<Store> store) override
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{
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auto outPaths = buildInstallables(store, false);
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auto store2 = store.dynamic_pointer_cast<LocalStore>();
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if (store2 && store->storeDir != store2->realStoreDir) {
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#if __linux__
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uid_t uid = getuid();
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uid_t gid = getgid();
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if (unshare(CLONE_NEWUSER | CLONE_NEWNS) == -1)
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throw SysError("setting up a private mount namespace");
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/* Bind-mount realStoreDir on /nix/store. If the latter
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mount point doesn't already exists, we have to create a
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chroot environment containing the mount point and bind
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mounts for the children of /. Would be nice if we could
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use overlayfs here, but that doesn't work in a user
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namespace yet (Ubuntu has a patch for this:
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https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1478578). */
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if (!pathExists(store->storeDir)) {
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// FIXME: Use overlayfs?
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Path tmpDir = createTempDir();
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createDirs(tmpDir + store->storeDir);
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if (mount(store2->realStoreDir.c_str(), (tmpDir + store->storeDir).c_str(), "", MS_BIND, 0) == -1)
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throw SysError(format("mounting ‘%s’ on ‘%s’") % store2->realStoreDir % store->storeDir);
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for (auto entry : readDirectory("/")) {
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Path dst = tmpDir + "/" + entry.name;
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if (pathExists(dst)) continue;
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if (mkdir(dst.c_str(), 0700) == -1)
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throw SysError(format("creating directory ‘%s’") % dst);
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if (mount(("/" + entry.name).c_str(), dst.c_str(), "", MS_BIND | MS_REC, 0) == -1)
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throw SysError(format("mounting ‘%s’ on ‘%s’") % ("/" + entry.name) % dst);
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}
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char * cwd = getcwd(0, 0);
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if (!cwd) throw SysError("getting current directory");
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Finally freeCwd([&]() { free(cwd); });
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if (chroot(tmpDir.c_str()) == -1)
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throw SysError(format("chrooting into ‘%s’") % tmpDir);
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if (chdir(cwd) == -1)
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throw SysError(format("chdir to ‘%s’ in chroot") % cwd);
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} else
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if (mount(store2->realStoreDir.c_str(), store->storeDir.c_str(), "", MS_BIND, 0) == -1)
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throw SysError(format("mounting ‘%s’ on ‘%s’") % store2->realStoreDir % store->storeDir);
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writeFile("/proc/self/setgroups", "deny");
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writeFile("/proc/self/uid_map", (format("%d %d %d") % uid % uid % 1).str());
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writeFile("/proc/self/gid_map", (format("%d %d %d") % gid % gid % 1).str());
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#else
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throw Error(format("mounting the Nix store on ‘%s’ is not supported on this platform") % store->storeDir);
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#endif
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}
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auto unixPath = tokenizeString<Strings>(getEnv("PATH"), ":");
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for (auto & path : outPaths)
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if (pathExists(path + "/bin"))
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unixPath.push_front(path + "/bin");
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setenv("PATH", concatStringsSep(":", unixPath).c_str(), 1);
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if (execlp("bash", "bash", nullptr) == -1)
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throw SysError("unable to exec ‘bash’");
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}
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};
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static RegisterCommand r1(make_ref<CmdRun>());
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