Custom sources for python distribution binaries

[brendan-morin]

Many companies have policies around sourcing artifacts from internal sources only. I'm seeing in the docs that uv uses pre-built third-party distributions from the python-build-standalone project. Is it possible to configure uv to point to an alternate private index for python version distributions?

I imagine as long as there's a well-defined API for how uv queries and returns binaries, the actual source from which these are downloaded should probably not matter much?

Apologies if this is a duplicate, I searched around but didn't spot an existing issue.

[Crypto-Spartan]

Timing is wild, I was just about to submit an issue with this same request. I would love support for changing the URL that uv uses for it's request to the python-build-standalone project as well. (also due to a corporate environment)

[zanieb]

Yep! UV_PYTHON_INSTALL_MIRROR

[zanieb]

Described at https://docs.astral.sh/uv/configuration/environment/

[Crypto-Spartan]

Thank you for the quick response!

Additionally, is there support for providing uv a filepath instead of a URL to the .tar.gz that's downloaded from the python-build-standalone project (cpython-3.X.X+<date>-<target>-install_only_stripped.tar.gz)?

[zanieb]

You can use file:// in the install mirror.

[Crypto-Spartan]

so I'm currently trying to install https://github.com/indygreg/python-build-standalone/releases/download/20241008/cpython-3.12.7+20241008-x86_64_v3-unknown-linux-gnu-pgo+lto-full.tar.zst with uv.

I have it downloaded in $HOME/downloads/python_standalone/20241008/cpython-3.12.7+20241008-x86_64_v3-unknown-linux-gnu-pgo+lto-full.tar.zst

I set UV_PYTHON_INSTALL_MIRROR='file:///home/<user>/downloads/python_standalone'

When I attempt to run uv python install 3.12.7, it fails with

Searching for Python versions matching: Python 3.12.7
error: No download found for request: cpython-3.12.7-linux-x86_64-gnu

> echo $UV_PYTHON_INSTALL_MIRROR
file:///home/<user>/downloads/python_standalone

Could you provide help/guidance as to how I should proceed? Thanks for your help

I also tried with UV_PYTHON_INSTALL_MIRROR='file://home/<user>/downloads/python_standalone' just incase I had too many slashes after the file:, still didn't work

I'm on Ubuntu 22.04 LTS (jammy) if that matters

[zanieb]

Can you share verbose logs? i.e. RUST_LOG=uv=trace uv python install -v 3.12.7

Your uv version needs to support that managed download, so you might just be on a uv version that only has metadata for 3.12.6 and not 3.12.7 yet?

[Crypto-Spartan]

> RUST_LOG=uv-trace uv python install -v 3.12.7
DEBUG uv 0.4.18
TRACE Checking lock for `/home/<user>/.local/share/uv/python` at `/home/<user>/.local/share/uv/python/.lock`
DEBUG Acquired lock for `/home/<user>/.local/share/uv/python`
Searching for Python versions matching: Python 3.12.7
TRACE ld path: /lib64/ld-linux-x86-64.so.2
TRACE stdout output from `ld`: ""
TRACE stderr output from `ld`: "/lib64/ld-linux-x86-64.so.2: missing program name\nTry '/lib64/ld-linux-x86-64.so.2 --help for more information.\n"
TRACE stdout ouput from `ldd --version`: ld.so (Ubuntu GLIBC 2.35-0ubuntu3.8) stable release version 2.35.\nCopyright ...
TRACE Found manylinux 2.35 in stdout of `ldd --version`
DEBUG Released lock at `/home/<user>/.local/share/uv/python/.lock`
error: No download found for request: cpython-3.12.7-linux-x86_64-gnu

uv 0.4.18 is the latest version of uv I'm able to grab off of the pypi mirror in my corporate environment

[zanieb]

3.12.7 was added in https://github.com/astral-sh/uv/pull/7880 which is in uv 0.4.19

[Crypto-Spartan]

Tried again with https://github.com/indygreg/python-build-standalone/releases/download/20240909/cpython-3.12.6+20240909-x86_64-unknown-linux-gnu-pgo+lto-full.tar.zst instead this time.

> uv python install 3.12.6
Searching for Python versions matching: Python 3.12.6
cpython-3.12.6-linux-x86_64-gnu
error: Failed to install cpython-3.12.6-linux-x86_64-gnu
  Caused by: Failed to extract archive: cpython-3.12.6+20240909-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz
  Caused by: Invalid gzip header
cpython-3.12.6-linux-x86_64-gnu

[Crypto-Spartan]

does uv only install the x86_64-unknown-linux-gnu-install_only_stripped.tar.gz? Why can't I install the x86_64-unknown-linux-gnu-pgo+lto-full.tar.zst?

[zanieb]

Sorry this isn't well documented — yes, we only support the target defined in our download metadata.

We could probably support more in the future, it's just more complicated.

[zanieb]

Basically the reason you can't, is that we generate JSON metadata from GitHub release

https://github.com/astral-sh/uv/blob/f6fd849f2c63e3b319ab03c936beab866dc303ba/crates/uv-python/download-metadata.json#L398-L409

then encode it as static Rust code for performance

https://github.com/astral-sh/uv/blob/f6fd849f2c63e3b319ab03c936beab866dc303ba/crates/uv-python/src/downloads.inc#L471-L484

then when you ask for a custom mirror we transform the static URL

https://github.com/astral-sh/uv/blob/891c91dd3a0141f05adea20674f3ea7f4477c510/crates/uv-python/src/downloads.rs#L577-L585

This is quite a naive implementation, but it's intended to unblock core functionality not be fully feature complete.

[Crypto-Spartan]

Is there any specific reason why the generated json only includes the install_only_stripped.tar.gz and none of the other python standalone builds? I'm willing to work on a PR to support the other builds if you're open to accepting it.

[zanieb]

I think we just adopted the "choose a single build" behavior from Rye's code. I'd love to support other builds (see #8019), though it's probably non-trivial. If you want to work on it, I'd appreciate it. Otherwise I'll probably work on #8019 in the near future.

[Crypto-Spartan]

something weird is happening still, it looks like uv is attempting to download from github directly still which won't be possible in my environment.

cpython-3.12.6+20240909-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz is currently in /home/<user>/downloads/python_standalone

> echo $UV_PYTHON_INSTALL_MIRROR
file:///home/<user>/downloads/python_standalone

> RUST_LOG=uv-trace uv python install -v 3.12.6
DEBUG uv 0.4.18
TRACE Checking lock for `/home/<user>/.local/share/uv/python` at `/home/<user>/.local/share/uv/python/.lock`
DEBUG Acquired lock for `/home/<user>/.local/share/uv/python`
Searching for Python versions matching: Python 3.12.6
TRACE ld path: /lib64/ld-linux-x86-64.so.2
TRACE stdout output from `ld`: ""
TRACE stderr output from `ld`: "/lib64/ld-linux-x86-64.so.2: missing program name\nTry '/lib64/ld-linux-x86-64.so.2 --help for more information.\n"
TRACE Tried to find musl version by running `"/lib64/ld-linux-x86-64.so.2"`, but failed: Could not find musl version in output of: `/lib64/ld-linux-x86-64.so.2`
TRACE Tried to find libc version from possible symlink at "/lib64/ld-linux-x86-64.so.2", but failed: Failed to find glibc version in the filename of linker: `/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2`
TRACE stdout ouput from `ldd --version`: ld.so (Ubuntu GLIBC 2.35-0ubuntu3.8) stable release version 2.35.\nCopyright ...
TRACE Found manylinux 2.35 in stdout of `ldd --version`
DEBUG Using request timeout of 30s
TRACE Handling request for https://github.com/indygreg/python-build-standalone/releases/download/20240909/cpython-3.12.6+20240909-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz
TRACE Request for https://github.com/indygreg/python-build-standalone/releases/download/20240909/cpython-3.12.6+20240909-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz is unauthenticated, checking cache
TRACE No credentials in cache for URL https://github.com/indygreg/python-build-standalone/releases/download/20240909/cpython-3.12.6+20240909-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz
TRACE Attempting unauthenticated request for https://github.com/indygreg/python-build-standalone/releases/download/20240909/cpython-3.12.6+20240909-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz
DEBUG Downloading https://github.com/indygreg/python-build-standalone/releases/download/20240909/cpython-3.12.6+20240909-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz to temporary location: /home/<user>/.local/share/uv/python/.cache/.tmpYs2Aii
DEBUG Extracting cpython-3.12.6%2B20240909-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz
error: Failed to install cpython-3.12.6-linux-x86_64-gnu
  Caused by: Failed to extract archive: cpython-3.12.6+20240909-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz
  Caused by: Invalid gzip header
DEBUG Released lock at `/home/<user>/.local/share/uv/python/.lock`

[zanieb]

On my machine, I get something like this if I specify an arbitrary directory:

❯ UV_PYTHON_INSTALL_MIRROR="file:///Users/zb/test" RUST_LOG=uv=trace uv python install -v 3.12.6
DEBUG uv 0.4.18
TRACE Checking lock for `/Users/zb/.local/share/uv/python` at `/Users/zb/.local/share/uv/python/.lock`
DEBUG Acquired lock for `/Users/zb/.local/share/uv/python`
Searching for Python versions matching: Python 3.12.6
DEBUG Using request timeout of 30s
error: Failed to install cpython-3.12.6-macos-aarch64-none
  Caused by: failed to query metadata of file `/Users/zb/test/20240909/cpython-3.12.6+20240909-aarch64-apple-darwin-install_only_stripped.tar.gz`
  Caused by: No such file or directory (os error 2)
DEBUG Released lock at `/Users/zb/.local/share/uv/python/.lock`

[zanieb]

Similarly:

❯ wget https://github.com/indygreg/python-build-standalone/releases/download/20240909/cpython-3.12.6%2B20240909-aarch64-apple-darwin-install_only_stripped.tar.gz
❯ mkdir 20240909
❯ mv cpython-3.12.6+20240909-aarch64-apple-darwin-install_only_stripped.tar.gz 20240909
❯ UV_PYTHON_INSTALL_MIRROR="file:///Users/zb/workspace/uv" RUST_LOG=uv=trace uv python install -v 3.12.6
DEBUG uv 0.4.18
TRACE Checking lock for `/Users/zb/.local/share/uv/python` at `/Users/zb/.local/share/uv/python/.lock`
DEBUG Acquired lock for `/Users/zb/.local/share/uv/python`
Searching for Python versions matching: Python 3.12.6
DEBUG Using request timeout of 30s
DEBUG Downloading file:///Users/zb/workspace/uv/20240909/cpython-3.12.6%2B20240909-aarch64-apple-darwin-install_only_stripped.tar.gz to temporary location: /Users/zb/.local/share/uv/python/.cache/.tmpvg3LcW
DEBUG Extracting cpython-3.12.6%2B20240909-aarch64-apple-darwin-install_only_stripped.tar.gz
DEBUG Moving /Users/zb/.local/share/uv/python/.cache/.tmpvg3LcW/python to /Users/zb/.local/share/uv/python/cpython-3.12.6-macos-aarch64-none
Installed Python 3.12.6 in 380ms
 + cpython-3.12.6-macos-aarch64-none
DEBUG Released lock at `/Users/zb/.local/share/uv/python/.lock`

[Crypto-Spartan]

Figured it out

my filename was urlencoded so was actually cpython-3.12.6%2B20240909-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz instead of cpython-3.12.6+20240909-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz (%2B vs +)

Thanks for all of your help

[zanieb]

That makes sense. We can add more documentation around this.

[guillemc23]

I'm a bit confused. We're currently migrating to uv and we need to install python packages from private sources.

Currently, I'm just adding the following to my pyproject.toml:

[tool.uv]
index-url = "https://<user>:<password>@<host>"

Which is working properly.

I have been unable to find a way to configure this authentication in order to avoid just hardcoding the credentials for obvious reasons. Is this somehow related to this issue? Also, is this the way I should be doing this?

EDIT: I believe what I'm referring to is this PR https://github.com/astral-sh/uv/pull/7741

[chrisrodrigue]

Just took a look at #7741 and I am wondering why the environment variables can't be specified in the pyproject.toml for the index URLs.

[zanieb]

@guillemc23 sorry this issue is about downloading Python distributions — not index URLs for packages. Could you open a new issue for your question instead?

[MeitarR]

Figured it out

my filename was urlencoded so was actually cpython-3.12.6%2B20240909-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz instead of cpython-3.12.6+20240909-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz (%2B vs +)

Thanks for all of your help

Opened PR with a create mirror script to make it easier https://github.com/astral-sh/uv/pull/8548

[MeitarR]

maybe relevant #10203

[leifwalsh]

I'd be interested in something slightly different: rather than just hosting indygreg's tarballs internally, I'd like to use my own builds of python, but I'm content to host those builds with whatever URL pattern uv wants, and to provide a config file (say, https://not-indygregs-trustworthy-snakes.example.com/download-metadata.json) I'd construct myself, with checksums of my preferred tarballs. (Then, presumably, set python-install-mirror = "https://not-indygregs-trustworthy-snakes.example.com", or maybe more likely set something to the path to download-metadata.json in /etc/uv/uv.toml)

Would something like that be in scope for this issue, or should I file a separate one?

[leifwalsh]

@zanieb I can probably work on this or find someone who can, if you all can bounce some design ideas with us. If you'd rather we just pitch something that works too, I just want to make sure you're open to the idea first.

[zanieb]

I'm a little hesitant since we don't have a well-defined or stable format for the python-build-standalone distributions and we're pretty tightly integrated with them.

We also store all the metadata statically via templated Rust right now so it's a bit of a larger change to be able to read that from a file.

I'm sort of into adding support for reading that metadata dynamically, e.g., it's also useful for updating Python without updating uv — but we'll need to have some sort of versioning scheme and I think if you're rolling your own distributions there's no guarantee they'll work well.

[leifwalsh]

Yeah, I've been looking at how that gets included statically. I can patch uv with my own json and get it to use our builds, but reading from a file and getting that configured from settings or environment variables is a bit more plumbing.

What's been changing about the format for distributions? Is that something we could help define/standardize? I also noticed there's no room in the schema for extra version numbers after patch, which we do use (build numbers, in case we rebuild a version), but could probably get by without if that's weird to add.

[zanieb]

What's been changing about the format for distributions? Is that something we could help define/standardize?

The most recent example I can think of is https://github.com/astral-sh/python-build-standalone/pull/373

It's less that they're changing a lot, and more that I'm hesitant to promise they won't :) the python-build-standalone project is pretty young still and we're investing increasing resources into it. I expect things to change more in the future.

Another concern is that we need to apply patches to the distribution at install time. These may or may not be relevant for custom distributions?

I think the best place to start is experimental support for dynamic metadata in uv without stability promises. Then we can iterate on standardization or versioning of the format?

I also noticed there's no room in the schema for extra version numbers after patch, which we do use (build numbers, in case we rebuild a version), but could probably get by without if that's weird to add.

Like, you want to be able to have multiple builds of versions side-by-side in your metadata? I'm not particularly opposed, but it may complicate our Python request logic?