Commit graph

309 commits

Author SHA1 Message Date
Eelco Dolstra 2f8ee4578f
Merge remote-tracking branch 'origin/master' into flakes 2020-05-06 12:01:40 +02:00
Guillaume Bouchard 2e5be2a749 StringSink pre allocate
When used with `readFile`, we have a pretty good heuristic of the file
size, so `reserve` this in the `string`. This will save some allocation
/ copy when the string is growing.
2020-04-29 18:44:01 +02:00
Guillaume Bouchard 7afcb5af98 Remove the drain argument from readFile
Now it is always `drain` (see previous commit).
2020-04-29 18:43:45 +02:00
Guillaume Bouchard 5a34a473dd builtins.readFile: do not truncate content
This closes #3026 by allowing `builtins.readFile` to read a file with a
wrongly reported file size, for example, files in `/proc` may report a
file size of 0. Reading file in `/proc` is not a good enough motivation,
however I do think it just makes nix more robust by allowing more file
to be read.  Especially, I do considerer the previous behavior to be
dangerous because nix was previously reading truncated files. Examples
of file system which incorrectly report file size may be network file
system or dynamic file system (for performance reason, a dynamic file
system such as FUSE may generate the content of the file on demand).

```
nix-repl> builtins.readFile "/proc/version"
""
```

With this commit:

```
nix-repl> builtins.readFile "/proc/version"
"Linux version 5.6.7 (nixbld@localhost) (gcc version 9.3.0 (GCC)) #1-NixOS SMP Thu Apr 23 08:38:27 UTC 2020\n"
```

Here is a summary of the behavior changes:

- If the reported size is smaller, previous implementation
was silently returning a truncated file content. The new implementation
is returning the correct file content.

- If a file had a bigger reported file size, previous implementation was
failing with an exception, but the new implementation is returning the
correct file content. This change of behavior is coherent with this pull
request.

Open questions

- The behavior is unchanged for correctly reported file size, however
performances may vary because it uses the more complex sink interface.
Considering that sink is used a lot, I don't think this impacts the
performance a lot.
- `builtins.readFile` on an infinite file, such as `/dev/random` may
fill the memory.
- it does not support adding file to store, such as `${/proc/version}`.
2020-04-29 14:50:52 +02:00
Eelco Dolstra 5ada0831cf Merge remote-tracking branch 'origin/master' into flakes 2020-04-29 13:32:27 +02:00
Alyssa Ross c05e20daa1
Fix long paths permanently breaking GC
Suppose I have a path /nix/store/[hash]-[name]/a/a/a/a/a/[...]/a,
long enough that everything after "/nix/store/" is longer than 4096
(MAX_PATH) bytes.

Nix will happily allow such a path to be inserted into the store,
because it doesn't look at all the nested structure.  It just cares
about the /nix/store/[hash]-[name] part.  But, when the path is deleted,
we encounter a problem.  Nix will move the path to /nix/store/trash, but
then when it's trying to recursively delete the trash directory, it will
at some point try to unlink
/nix/store/trash/[hash]-[name]/a/a/a/a/a/[...]/a.  This will fail,
because the path is too long.  After this has failed, any store deletion
operation will never work again, because Nix needs to delete the trash
directory before recreating it to move new things to it.  (I assume this
is because otherwise a path being deleted could already exist in the
trash, and then moving it would fail.)

This means that if I can trick somebody into just fetching a tarball
containing a path of the right length, they won't be able to delete
store paths or garbage collect ever again, until the offending path is
manually removed from /nix/store/trash.  (And even fixing this manually
is quite difficult if you don't understand the issue, because the
absolute path that Nix says it failed to remove is also too long for
rm(1).)

This patch fixes the issue by making Nix's recursive delete operation
use unlinkat(2).  This function takes a relative path and a directory
file descriptor.  We ensure that the relative path is always just the
name of the directory entry, and therefore its length will never exceed
255 bytes.  This means that it will never even come close to AX_PATH,
and Nix will therefore be able to handle removing arbitrarily deep
directory hierachies.

Since the directory file descriptor is used for recursion after being
used in readDirectory, I made a variant of readDirectory that takes an
already open directory stream, to avoid the directory being opened
multiple times.  As we have seen from this issue, the less we have to
interact with paths, the better, and so it's good to reuse file
descriptors where possible.

I left _deletePath as succeeding even if the parent directory doesn't
exist, even though that feels wrong to me, because without that early
return, the linux-sandbox test failed.

Reported-by: Alyssa Ross <hi@alyssa.is>
Thanks-to: Puck Meerburg <puck@puckipedia.com>
Tested-by: Puck Meerburg <puck@puckipedia.com>
Reviewed-by: Puck Meerburg <puck@puckipedia.com>
2020-04-27 20:50:17 +00:00
Eelco Dolstra e1a94ad852 Backport 'nix dev-shell' from the flakes branch
This also adds a '--profile' option to 'nix build' (replacing 'nix-env
--set').
2020-03-30 19:16:45 +02:00
Eelco Dolstra 4260a22a55 absPath(): Use std::optional
(cherry picked from commit 1bf9eb21b7)
2020-03-24 14:25:28 +01:00
Eelco Dolstra edc34cc1a2 Add function for quoting strings
(cherry picked from commit 7dcf5b011a)
2020-03-24 13:44:04 +01:00
Eelco Dolstra 9f4d8c6170 Pluggable fetchers
Flakes are now fetched using an extensible mechanism. Also lots of
other flake cleanups.
2020-01-21 22:56:04 +01:00
Eelco Dolstra 1bf9eb21b7 absPath(): Use std::optional 2020-01-21 22:39:43 +01:00
Eelco Dolstra 87873d0d65 Merge remote-tracking branch 'origin/master' into flakes 2019-12-18 14:25:25 +01:00
Eelco Dolstra 54bf5ba422 nix-store -r: Handle symlinks to store paths
Fixes #3270.
2019-12-16 19:11:47 +01:00
Eelco Dolstra ecb3a1afa2 Merge remote-tracking branch 'origin/master' into flakes 2019-12-11 14:53:30 +01:00
Eelco Dolstra bbe97dff8b Make the Store API more type-safe
Most functions now take a StorePath argument rather than a Path (which
is just an alias for std::string). The StorePath constructor ensures
that the path is syntactically correct (i.e. it looks like
<store-dir>/<base32-hash>-<name>). Similarly, functions like
buildPaths() now take a StorePathWithOutputs, rather than abusing Path
by adding a '!<outputs>' suffix.

Note that the StorePath type is implemented in Rust. This involves
some hackery to allow Rust values to be used directly in C++, via a
helper type whose destructor calls the Rust type's drop()
function. The main issue is the dynamic nature of C++ move semantics:
after we have moved a Rust value, we should not call the drop function
on the original value. So when we move a value, we set the original
value to bitwise zero, and the destructor only calls drop() if the
value is not bitwise zero. This should be sufficient for most types.

Also lots of minor cleanups to the C++ API to make it more modern
(e.g. using std::optional and std::string_view in some places).
2019-12-10 22:06:05 +01:00
Eelco Dolstra c3c23a52ee Merge remote-tracking branch 'origin/master' into flakes 2019-12-04 00:31:09 +01:00
Eelco Dolstra ba87b08f85
getEnv(): Return std::optional
This allows distinguishing between an empty value and no value.
2019-11-22 16:18:13 +01:00
Eelco Dolstra f730841db4
Merge remote-tracking branch 'origin/master' into flakes 2019-11-07 11:44:02 +01:00
Eelco Dolstra 39a2e166dd
Cleanup 2019-11-06 16:53:02 +01:00
Eelco Dolstra 88c452d160
Merge remote-tracking branch 'origin/master' into flakes 2019-11-06 10:56:33 +01:00
Eelco Dolstra 1b600ecd14
Don't use SOCK_CLOEXEC on macOS
https://hydra.nixos.org/build/105428308
2019-11-05 10:25:09 +01:00
Eelco Dolstra b81d9d26f5
Merge remote-tracking branch 'origin/master' into flakes 2019-11-04 22:29:31 +01:00
Harald van Dijk c935ad3f02
Fix progress bar when nix-prefetch-url is piped.
The intent of the code was that if the window size cannot be determined,
it would be treated as having the maximum possible size. Because of a
missing assignment, it was actually treated as having a width of 0.

The reason the width could not be determined was because it was obtained
from stdout, not stderr, even though the printing was done to stderr.

This commit addresses both issues.
2019-11-03 21:46:59 +00:00
Eelco Dolstra 63b99af85a
Move Unix domain socket creation to libutil
Also drop multithread-unfriendly hacks like doing a temporary
chmod/umask.
2019-10-29 13:30:51 +01:00
Eelco Dolstra 9a18f544ac Merge remote-tracking branch 'origin/master' into flakes 2019-10-21 18:48:21 +02:00
Eelco Dolstra 0abb3ad537 Allow content-addressable paths to have references
This adds a command 'nix make-content-addressable' that rewrites the
specified store paths into content-addressable paths. The advantage of
such paths is that 1) they can be imported without signatures; 2) they
can enable deduplication in cases where derivation changes do not
cause output changes (apart from store path hashes).

For example,

  $ nix make-content-addressable -r nixpkgs.cowsay
  rewrote '/nix/store/g1g31ah55xdia1jdqabv1imf6mcw0nb1-glibc-2.25-49' to '/nix/store/48jfj7bg78a8n4f2nhg269rgw1936vj4-glibc-2.25-49'
  ...
  rewrote '/nix/store/qbi6rzpk0bxjw8lw6azn2mc7ynnn455q-cowsay-3.03+dfsg1-16' to '/nix/store/iq6g2x4q62xp7y7493bibx0qn5w7xz67-cowsay-3.03+dfsg1-16'

We can then copy the resulting closure to another store without
signatures:

  $ nix copy --trusted-public-keys '' ---to ~/my-nix /nix/store/iq6g2x4q62xp7y7493bibx0qn5w7xz67-cowsay-3.03+dfsg1-16

In order to support self-references in content-addressable paths,
these paths are hashed "modulo" self-references, meaning that
self-references are zeroed out during hashing. Somewhat annoyingly,
this means that the NAR hash stored in the Nix database is no longer
necessarily equal to the output of "nix hash-path"; for
content-addressable paths, you need to pass the --modulo flag:

  $ nix path-info --json /nix/store/iq6g2x4q62xp7y7493bibx0qn5w7xz67-cowsay-3.03+dfsg1-16  | jq -r .[].narHash
  sha256:0ri611gdilz2c9rsibqhsipbfs9vwcqvs811a52i2bnkhv7w9mgw

  $ nix hash-path --type sha256 --base32 /nix/store/iq6g2x4q62xp7y7493bibx0qn5w7xz67-cowsay-3.03+dfsg1-16
  1ggznh07khq0hz6id09pqws3a8q9pn03ya3c03nwck1kwq8rclzs

  $ nix hash-path --type sha256 --base32 /nix/store/iq6g2x4q62xp7y7493bibx0qn5w7xz67-cowsay-3.03+dfsg1-16 --modulo iq6g2x4q62xp7y7493bibx0qn5w7xz67
  0ri611gdilz2c9rsibqhsipbfs9vwcqvs811a52i2bnkhv7w9mgw
2019-10-21 17:47:24 +02:00
Eelco Dolstra e99bb91217
Merge remote-tracking branch 'origin/master' into flakes 2019-10-10 12:54:37 +02:00
Eelco Dolstra 9348f9291e
nix-env: Create ~/.nix-profile automatically 2019-10-09 23:35:01 +02:00
Eelco Dolstra a323b7826c
Merge remote-tracking branch 'origin/master' into flakes 2019-10-04 17:26:32 +02:00
Eelco Dolstra 93b1ce1ac5
Revert "std::uncaught_exception() -> std::uncaught_exceptions()"
This reverts commit 6b83174fff because
it doesn't work on macOS yet.

https://hydra.nixos.org/build/102617587
2019-10-04 16:34:59 +02:00
Eelco Dolstra 092ee24627
Merge remote-tracking branch 'origin/master' into flakes 2019-09-18 12:02:50 +02:00
Eelco Dolstra 6b83174fff std::uncaught_exception() -> std::uncaught_exceptions()
The former is deprecated in C++17. Fixes a clang warning.
2019-09-13 20:05:44 +02:00
Eelco Dolstra ebc4dae517 Merge remote-tracking branch 'origin/master' into flakes 2019-08-29 16:11:38 +02:00
Eelco Dolstra a2c4fcd5e9 Don't rely on st_blocks
It doesn't seem very reliable on ZFS.
2019-08-29 14:49:58 +02:00
Eelco Dolstra 1d750e0587
Merge remote-tracking branch 'origin/master' into flakes 2019-08-08 15:49:13 +02:00
regnat 7c5596734f
Add a post-build-hook
Passing `--post-build-hook /foo/bar` to a nix-* command will cause
`/foo/bar` to be executed after each build with the following
environment variables set:

    DRV_PATH=/nix/store/drv-that-has-been-built.drv
    OUT_PATHS=/nix/store/...build /nix/store/...build-bin /nix/store/...build-dev

This can be useful in particular to upload all the builded artifacts to
the cache (including the ones that don't appear in the runtime closure
of the final derivation or are built because of IFD).

This new feature prints the stderr/stdout output to the `nix-build`
and `nix build` client, and the output is printed in a Nix 2
compatible format:

    [nix]$ ./inst/bin/nix-build ./test.nix
    these derivations will be built:
      /nix/store/ishzj9ni17xq4hgrjvlyjkfvm00b0ch9-my-example-derivation.drv
    building '/nix/store/ishzj9ni17xq4hgrjvlyjkfvm00b0ch9-my-example-derivation.drv'...
    hello!
    bye!
    running post-build-hook '/home/grahamc/projects/github.com/NixOS/nix/post-hook.sh'...
    post-build-hook: + sleep 1
    post-build-hook: + echo 'Signing paths' /nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation
    post-build-hook: Signing paths /nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation
    post-build-hook: + sleep 1
    post-build-hook: + echo 'Uploading paths' /nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation
    post-build-hook: Uploading paths /nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation
    post-build-hook: + sleep 1
    post-build-hook: + printf 'very important stuff'
    /nix/store/qr213vjmibrqwnyp5fw678y7whbkqyny-my-example-derivation

    [nix-shell:~/projects/github.com/NixOS/nix]$ ./inst/bin/nix build -L -f ./test.nix
    my-example-derivation> hello!
    my-example-derivation> bye!
    my-example-derivation (post)> + sleep 1
    my-example-derivation (post)> + echo 'Signing paths' /nix/store/c263gzj2kb2609mz8wrbmh53l14wzmfs-my-example-derivation
    my-example-derivation (post)> Signing paths /nix/store/c263gzj2kb2609mz8wrbmh53l14wzmfs-my-example-derivation
    my-example-derivation (post)> + sleep 1
    my-example-derivation (post)> + echo 'Uploading paths' /nix/store/c263gzj2kb2609mz8wrbmh53l14wzmfs-my-example-derivation
    my-example-derivation (post)> Uploading paths /nix/store/c263gzj2kb2609mz8wrbmh53l14wzmfs-my-example-derivation
    my-example-derivation (post)> + sleep 1
    my-example-derivation (post)> + printf 'very important stuff'
    [1 built, 0.0 MiB DL]

Co-authored-by: Graham Christensen <graham@grahamc.com>
Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
2019-08-02 10:48:15 -04:00
Eelco Dolstra ae7b56cd9a
Get last commit time of github flakes 2019-05-29 10:10:40 +02:00
Eelco Dolstra 0f5032c5a4 Merge remote-tracking branch 'origin/master' into flakes 2019-05-15 20:51:29 +02:00
Graham Christensen f1b8e9efe7
runProgram: Uncomment chdir support 2019-05-12 17:03:01 -04:00
Graham Christensen b4a05edbfe
runProgram: support gid, uid, chdir 2019-05-12 13:17:27 -04:00
Graham Christensen 6df61db060
diff hook: execute as the build user, and pass the temp dir 2019-05-12 13:17:26 -04:00
Eelco Dolstra 2bc55aba1e
Merge remote-tracking branch 'origin/master' into flakes 2019-05-08 14:30:27 +02:00
Eelco Dolstra f9a2ea4486
Fix "Bad system call" running i686-linux binaries on x86_64-linux
To determine which seccomp filters to install, we were incorrectly
using settings.thisSystem, which doesn't denote the actual system when
--system is used.

Fixes #2791.
2019-05-03 10:48:33 +02:00
Eelco Dolstra 8ec77614f6 Move createTempFile to libutil 2019-05-02 21:28:41 +02:00
Eelco Dolstra 7dcf5b011a Add function for quoting strings 2019-05-02 21:09:52 +02:00
Nick Van den Broeck b42ba08fc8 Add command flake clone 2019-04-17 13:31:09 +02:00
Nick Van den Broeck d4ee8afd59 Implemented --flake flag for nix build
Also fixed Eelco's PR comments
2019-03-22 11:16:20 +01:00
Eelco Dolstra ef52ccf035
experimental/optional -> optional 2019-03-14 14:10:52 +01:00
Eelco Dolstra c8a0b9d5cb
experimental/optional -> optional 2019-02-12 13:43:32 +01:00
Eelco Dolstra 01d07b1e92
Revert "Restore parent mount namespace before executing a child process"
This reverts commit a0ef21262f. This
doesn't work in 'nix run' and nix-shell because setns() fails in
multithreaded programs, and Boehm GC mark threads are uncancellable.

Fixes #2646.
2019-02-05 10:49:19 +01:00