self_update

self_update provides updaters for updating rust executables in-place from various release distribution backends.

Supported backends: GitHub, GitLab, Gitea, and S3 (Amazon S3, Google GCS, DigitalOcean Spaces, or any S3-compatible endpoint). Each exposes the same Update (configure -> build -> update) and ReleaseList builder API.

Quick start

use self_update::cargo_crate_version;

fn update() -> Result<(), Box<dyn std::error::Error>> {
    let status = self_update::backends::github::Update::configure()
        .repo_owner("jaemk")
        .repo_name("self_update")
        .bin_name("github")
        .show_download_progress(true)
        .current_version(cargo_crate_version!())
        .build()?
        .update()?;
    println!("Update status: `{}`!", status.version());
    Ok(())
}

Upgrading from 0.x? 1.0 makes a focused set of breaking changes to clean up the public API. See the 1.0 migration guide for a step-by-step walkthrough, or the agent-oriented guide for automated migration tooling.

Running unattended (daemon / CI / service)? The defaults are interactive: show_output is true and no_confirm is false, so update() prints a release-status block to stdout and then blocks on an interactive yes/no prompt waiting on stdin. With no terminal attached this stalls (or aborts). For any non-interactive caller set .no_confirm(true) to skip the prompt, and usually .show_output(false) to silence the status block. These are settings only -- the defaults are unchanged. Note the status block is printed before the confirmation prompt, so suppressing one does not suppress the other.

Usage

Features

Exactly one HTTP client and one TLS backend must be selected (they are mutually exclusive -- enabling both, or neither, is a compile error):

• reqwest (default): use the reqwest HTTP client;
• ureq: use the ureq HTTP client instead (set default-features = false);
• default-tls (default): native TLS for the selected client;
• rustls: use a pure rust TLS implementation instead. This feature does not support 32bit macOS.

The following optional cargo features are disabled by default; activate the one(s) your release files need:

• archive-tar: Support for tar archive format;
• archive-zip: Support for zip archive format;
• compression-flate2: Support for gzip compression;
• compression-zip-deflate: Support for zip's deflate compression format;
• compression-zip-bzip2: Support for zip's bzip2 compression format;
• signatures: Use zipsign to verify .zip and .tar.gz artifacts. Artifacts are assumed to have been signed using zipsign;
• checksums: Verify a downloaded artifact against a known SHA-256/SHA-512 checksum (e.g. from a SHA256SUMS file) before installing it;
• s3-auth: Sign S3 requests (AWS SigV4) to update from private buckets via the S3 backend;
• async: Add async (*_async) update methods alongside the unchanged blocking API. tokio-only and reqwest-only (incompatible with ureq); see Async below.

The S3 backend needs no feature -- it is always compiled. Only private-bucket request signing needs an actual feature, s3-auth.

Example

Run the following example to see self_update in action:

cargo run --example github --features "archive-tar archive-zip compression-flate2 compression-zip-deflate".

There are equivalent examples for the other backends (gitlab, gitea, s3), e.g.:

cargo run --example gitlab --features "archive-tar archive-zip compression-flate2 compression-zip-deflate".

Amazon S3, Google GCS, and DigitalOcean Spaces, as well as any S3 compatible server are also supported through the S3 backend to check for new releases. Provided a bucket_name and asset_prefix string, self_update will look up all matching files using the following format as a convention for the filenames: [directory/]<asset name>-<semver>-<platform/target>.<extension>. Leading directories will be stripped from the file name allowing the use of subdirectories in the S3 bucket, and any file not matching the format, or not matching the provided prefix string, will be ignored.

use self_update::cargo_crate_version;

fn update() -> Result<(), Box<dyn ::std::error::Error>> {
    let status = self_update::backends::s3::Update::configure()
        // .end_point(self_update::backends::s3::EndPoint::GCS)
        // .end_point("https://s3.example.com")
        .bucket_name("self_update_releases")
        .asset_prefix("something/self_update")
        .region("eu-west-2")
        .bin_name("self_update_example")
        // To authenticate (requires the `s3-auth` feature), read the credentials at
        // runtime rather than baking them into the binary with `env!`:
        // .access_key((std::env::var("AWS_ACCESS_KEY_ID")?, std::env::var("AWS_SECRET_ACCESS_KEY")?))
        .show_download_progress(true)
        .current_version(cargo_crate_version!())
        .build()?
        .update()?;
    println!("S3 Update status: `{}`!", status.version());
    Ok(())
}

Separate utilities are also exposed (NOTE: the following example extracts a .tar.gz, which requires both the archive-tar and compression-flate2 features -- archive-tar reads the tar archive and compression-flate2 decodes the gzip layer; see the features section above). It downloads, extracts, and replaces the running binary by hand; the staging directory and the in-place replacement use the tempfile and self_replace crates, which you add as your own dependencies (they are no longer re-exported from self_update):

fn update() -> Result<(), Box<dyn std::error::Error>> {
    let releases = self_update::backends::github::ReleaseList::configure()
        .repo_owner("jaemk")
        .repo_name("self_update")
        .build()?
        .fetch()?;
    println!("found releases:");
    println!("{:#?}\n", releases);

    // get the first available release
    let asset = releases[0]
        .asset_for(&self_update::get_target(), None)
        .unwrap();

    let tmp_dir = tempfile::Builder::new()
            .prefix("self_update")
            .tempdir_in(::std::env::current_dir()?)?;
    let tmp_tarball_path = tmp_dir.path().join(&asset.name);
    let tmp_tarball = ::std::fs::File::create(&tmp_tarball_path)?;

    self_update::Download::from_url(&asset.download_url)
        .header(self_update::http::header::ACCEPT, "application/octet-stream")?
        .download_to(&tmp_tarball)?;

    let bin_name = std::path::PathBuf::from("self_update_bin");
    self_update::Extract::from_source(&tmp_tarball_path)
        .archive(self_update::ArchiveKind::Tar(Some(self_update::Compression::Gz)))
        .extract_file(&tmp_dir.path(), &bin_name)?;

    let new_exe = tmp_dir.path().join(bin_name);
    self_replace::self_replace(new_exe)?;

    Ok(())
}

Multi-file / non-executable install

The high-level update() flow replaces a single executable. To update a tool that ships more than one file (a binary plus sidecar libraries/resources), or to install files that aren't the running executable, download and extract the whole archive yourself and then install the files with MoveAll, which applies a set of (source -> dest) moves transactionally: either every move succeeds, or — on the first failure — all already-applied moves are rolled back, so a failed update can't leave a half-installed tool. Because it uses rename (which can't cross filesystems), the source files, every destination, and the temp dir must all be on the same filesystem.

NOTE: this example extracts a .tar.gz, which requires both the archive-tar and compression-flate2 features.

fn update() -> Result<(), Box<dyn std::error::Error>> {
    let tmp_dir = tempfile::TempDir::new()?;
    let tarball_path = tmp_dir.path().join("release.tar.gz");
    // ... download the archive to `tarball_path` (see the example above) ...

    // The extracted files are renamed into place, so the staging dir (the move sources) and the
    // stash dir must be on the same filesystem as the destinations — create both next to them
    // rather than in $TMPDIR. The `/usr/local` paths below are illustrative; use destinations
    // and temp dirs you have write access to (these may require elevated privileges).
    let staging = tempfile::TempDir::new_in("/usr/local")?;
    self_update::Extract::from_source(&tarball_path)
        .archive(self_update::ArchiveKind::Tar(Some(self_update::Compression::Gz)))
        .extract_into(staging.path())?;

    // Install several files atomically (all-or-nothing).
    let stash = tempfile::TempDir::new_in("/usr/local")?;
    self_update::MoveAll::from_temp(stash.path())
        .add(staging.path().join("app"), "/usr/local/bin/app")
        .add(staging.path().join("libapp.so"), "/usr/local/lib/libapp.so")
        .commit()?;
    Ok(())
}

Checksum verification

With the checksums feature, pass a known digest (e.g. one published in a SHA256SUMS file alongside the release) and the crate verifies the downloaded artifact against it before installing — a mismatch aborts the update. The algorithm is chosen by the Checksum variant (Sha256 / Sha512); it complements the signatures feature (zipsign), which verifies authenticity rather than a published digest.

fn update() -> Result<(), Box<dyn std::error::Error>> {
    self_update::backends::github::Update::configure()
        .repo_owner("jaemk")
        .repo_name("self_update")
        .bin_name("github")
        .current_version(self_update::cargo_crate_version!())
        // hex digest, obtained out of band (e.g. parsed from the release's SHA256SUMS)
        .verify_checksum(self_update::Checksum::Sha256("9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08".into()))
        .build()?
        .update()?;
    Ok(())
}

Checking for an update without installing

To check whether a newer release exists without downloading or installing anything, fetch the releases once and query the returned Releases. The updater no longer has an is_update_available() method; instead call get_latest_releases() (the full candidate list) or get_latest_release() (a one-element list with just the newest release), then ask the result: .is_update_available() compares the newest fetched release against the configured current_version, and .latest() / .all() expose the releases themselves. The fetch happens once; every query reads the already-fetched data.

fn check() -> Result<(), Box<dyn std::error::Error>> {
    let releases = self_update::backends::github::Update::configure()
        .repo_owner("jaemk")
        .repo_name("self_update")
        .bin_name("github")
        .current_version(self_update::cargo_crate_version!())
        .build()?
        .get_latest_releases()?;

    if releases.is_update_available()? {
        if let Some(latest) = releases.latest() {
            println!("update available: {}", latest.version);
        }
    } else {
        println!("already up to date");
    }
    Ok(())
}

Listing releases (ReleaseList)

Each built-in backend exposes a ReleaseList builder for fetching the list of available releases without performing an update. There is no single unifying self_update::ReleaseList type: every backend has its own, distinct ReleaseList (the fields and request shape differ per host), so they are reached through their backend modules rather than re-exported at the crate root:

• backends::github::ReleaseList
• backends::gitlab::ReleaseList
• backends::gitea::ReleaseList
• backends::s3::ReleaseList

The custom backend has no ReleaseList by design: listing is performed entirely by your ReleaseSource (or AsyncReleaseSource) implementation, which already returns Release values directly.

Custom backends

To update from a host the built-in backends (github, gitlab, gitea, s3) don't cover — another forge, a private artifact registry, a plain HTTP directory — implement the ReleaseSource trait (three fetch methods that say where releases come from) and drive a full update through the backends::custom backend, which reuses the crate's compare → select-asset → download → verify → extract → install flow. You build Releases with Release::builder and ReleaseAsset::new; the ReleaseUpdate trait stays sealed.

ReleaseSource is synchronous. For a natively-async source, implement AsyncReleaseSource (the same three fetches as async fn) and drive it through backends::custom::AsyncUpdate + build_async(); to reuse a Clone sync source from the async API, wrap it in backends::custom::Blocking.

use self_update::{Release, ReleaseAsset, ReleaseSource, cargo_crate_version};

struct MyHost;
impl ReleaseSource for MyHost {
    fn get_latest_release(&self) -> self_update::Result<Release> {
        Ok(Release::builder()
            .version("1.2.3")
            .asset(ReleaseAsset::new("app-x86_64-unknown-linux-gnu.tar.gz", "https://host/app.tar.gz"))
            .build()?)
    }
    fn get_latest_releases(&self, _current: &str) -> self_update::Result<Vec<Release>> {
        Ok(vec![self.get_latest_release()?])
    }
    fn get_release_version(&self, _ver: &str) -> self_update::Result<Release> {
        self.get_latest_release()
    }
}

fn update() -> Result<(), Box<dyn std::error::Error>> {
    let status = self_update::backends::custom::Update::configure()
        .source(MyHost)
        .bin_name("app")
        .current_version(cargo_crate_version!())
        .build()?
        .update()?;
    println!("custom backend update status: `{}`!", status.version());
    Ok(())
}

Async

With the async feature, every built-in backend's Update builder gains a build_async() that returns a concrete Update with async (*_async) verbs — update_async(), update_extended_async(), get_latest_release_async(), get_latest_releases_async(), and get_release_version_async() — so a tokio application can update without wrapping the blocking calls in spawn_blocking. The blocking API is unchanged; the async path is purely additive. It is tokio-only and reqwest-only (ureq has no async story, so async is incompatible with ureq). Network IO becomes async; the extract/replace step stays synchronous.

async fn update() -> Result<(), Box<dyn std::error::Error>> {
    let status = self_update::backends::github::Update::configure()
        .repo_owner("jaemk")
        .repo_name("self_update")
        .bin_name("github")
        .current_version(self_update::cargo_crate_version!())
        .build_async()?
        .update_async()
        .await?;
    println!("Update status: `{}`!", status.version());
    Ok(())
}

Custom HTTP client

The .timeout() / .request_header() / .retries() builder knobs cover most transport needs, but for full control — custom TLS roots / mTLS, connection pooling, redirect policy, proxy-with-auth, or simply reusing your application's existing client — you can hand the crate a pre-built client. It is used for both the release listing and the download. The setters are client-specific (the client types differ and are mutually exclusive): reqwest_client (a blocking reqwest::blocking::Client, used by the blocking API), reqwest_async_client (an async reqwest::Client, used by the *_async verbs), and ureq_agent (a ureq::Agent). The selected client crate is re-exported (self_update::reqwest / self_update::ureq) so you don't need a separate dependency to name the type.

When you inject a client, .request_header() still applies, and .retries() still applies to the release-listing requests (the download is never retried), and for reqwest the per-request .timeout() is layered on too; but HTTP(S)_PROXY env and the crate's TLS feature are left entirely to your client (and a ureq::Agent owns its own timeout, so .timeout() does not apply to an injected agent — configure it on the agent). reqwest_client feeds the sync verbs and reqwest_async_client the async ones — injecting only one and calling the other half just uses the crate's per-call client for that half.

fn update() -> Result<(), Box<dyn std::error::Error>> {
    let client = self_update::reqwest::blocking::Client::builder()
        // .add_root_certificate(...) / .proxy(...) / .danger_accept_invalid_certs(...) etc.
        .build()?;
    self_update::backends::github::Update::configure()
        .repo_owner("jaemk")
        .repo_name("self_update")
        .bin_name("github")
        .current_version(self_update::cargo_crate_version!())
        .reqwest_client(client)
        .build()?
        .update()?;
    Ok(())
}

Troubleshooting

When using cross compilation tools such as cross if you want to use rustls and not openssl

self_update = { version = "1", features = ["rustls"], default-features = false }

TLS certificate errors on Linux (default-tls / OpenSSL). With the native-TLS backend, OpenSSL finds the system CA bundle on its own on most distributions. In a minimal environment where it can't (some containers, musl static builds, or a non-standard cert layout) a request may fail with a certificate-verification error. Point OpenSSL at the bundle by exporting SSL_CERT_FILE (and, if needed, SSL_CERT_DIR) before running your program — the paths vary by distribution, e.g. on a Debian/Ubuntu base:

export SSL_CERT_FILE=/etc/ssl/certs/ca-certificates.crt
export SSL_CERT_DIR=/etc/ssl/certs

Alternatively build with the rustls feature, which uses a bundled root store and does not depend on the system OpenSSL cert layout.

License: MIT