fluidattacks_core_git/clone/

mod.rs

pub mod codecommit;
pub mod https;
pub mod ssh;

pub(crate) mod reason;

pub use https::build_https_config_args;
pub use https::embed_credentials_in_url;
pub use https::format_https_url;
pub use ssh::normalize_ssh_url;
pub use ssh::setup_ssh_env;
pub use ssh::url_has_port;

use anyhow::{bail, Context, Result};
use serde_json::json;
use std::fs;
use std::path::{Path, PathBuf};
use tokio::process::Command;
use tracing::{info, warn};

use crate::types::{CredentialKind, Credentials, GitRoot};

/// Which refs a clone takes, and what it leaves on disk.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum CloneShape {
    /// The named branch and only it, with a working tree.
    SingleBranch,
    /// Every ref the remote advertises, as a bare mirror.
    Mirror,
    /// Every branch head — `refs/heads/*` plus `HEAD` — as a bare repo:
    /// no tags, no hidden refs, no mirror config remnants.
    BareHeads,
}

pub struct CloneOpts {
    pub group_name: String,
    pub nickname: String,
    pub repo_url: String,
    pub branch: String,
    pub credentials: Option<Credentials>,
    pub follow_redirects: bool,
    pub skip_existing: bool,
    pub shape: CloneShape,
}

impl CloneOpts {
    #[must_use]
    pub fn from_root(
        group: &str,
        root: &GitRoot,
        credentials: Option<Credentials>,
        skip_existing: bool,
        shape: CloneShape,
    ) -> Self {
        Self {
            group_name: group.to_owned(),
            nickname: root.nickname.clone(),
            repo_url: root.url.clone(),
            branch: root.branch.clone(),
            credentials,
            follow_redirects: root.follow_redirects(),
            skip_existing,
            shape,
        }
    }
}

async fn dispatch_clone(opts: &CloneOpts, dest: &Path) -> Result<()> {
    match &opts.credentials {
        Some(Credentials {
            kind: CredentialKind::Ssh { .. },
        }) => ssh::clone_ssh(opts, dest).await,
        Some(Credentials {
            kind: CredentialKind::Https { .. },
        }) => https::clone_https(opts, dest).await,
        Some(Credentials {
            kind: CredentialKind::Token { .. },
        }) => https::clone_https_token(opts, dest).await,
        Some(Credentials {
            kind: CredentialKind::AwsRole { .. },
        }) => codecommit::clone_codecommit(opts, dest).await,
        None if opts.repo_url.starts_with("http") => https::clone_https_public(opts, dest).await,
        _ => bail!("no suitable credentials found for root {:?}", opts.nickname),
    }
}

pub async fn clone_root(opts: &CloneOpts) -> Result<()> {
    let repo_dir = PathBuf::from("groups")
        .join(&opts.group_name)
        .join(&opts.nickname);

    if opts.skip_existing {
        if let Ok(entries) = fs::read_dir(&repo_dir) {
            if entries.count() > 0 {
                info!(nickname = opts.nickname, "skipping existing repo");
                return Ok(());
            }
        }
    }

    // Use tempdir_in targeting repo_dir's parent to avoid cross-filesystem rename (EXDEV)
    let tmp_parent = repo_dir.parent().unwrap_or_else(|| Path::new("."));
    fs::create_dir_all(tmp_parent)
        .with_context(|| format!("creating parent dir {}", tmp_parent.display()))?;
    let tmp_dir = tempfile::tempdir_in(tmp_parent).context("creating temp dir")?;
    let clone_dest = tmp_dir.path().join(&opts.nickname);

    dispatch_clone(opts, &clone_dest)
        .await
        .with_context(|| format!("cloning {:?}", opts.nickname))?;

    if opts.shape == CloneShape::Mirror {
        convert_bare_to_worktree(&clone_dest)
            .await
            .with_context(|| format!("converting mirror to worktree for {:?}", opts.nickname))?;
    }

    if repo_dir.exists() {
        fs::remove_dir_all(&repo_dir)
            .with_context(|| format!("removing old repo dir {}", repo_dir.display()))?;
    }
    fs::rename(&clone_dest, &repo_dir)
        .with_context(|| format!("moving cloned repo to {}", repo_dir.display()))?;

    log_clone_result(&repo_dir, opts).await;

    if opts.shape == CloneShape::Mirror {
        if let Err(e) = write_mirror_info(&repo_dir, opts) {
            warn!(error = %e, "failed to write .info.json");
        }
    }

    Ok(())
}

async fn convert_bare_to_worktree(clone_dest: &Path) -> Result<()> {
    let bare_tmp = clone_dest.with_extension("bare");
    fs::rename(clone_dest, &bare_tmp)
        .with_context(|| format!("renaming bare repo to {}", bare_tmp.display()))?;
    fs::create_dir_all(clone_dest)
        .with_context(|| format!("creating worktree dir {}", clone_dest.display()))?;
    let git_dir = clone_dest.join(".git");
    fs::rename(&bare_tmp, &git_dir)
        .with_context(|| format!("moving bare contents to {}", git_dir.display()))?;

    let dest_str = clone_dest.to_string_lossy().to_string();

    let config_out = Command::new("git")
        .args(["-C", &dest_str, "config", "core.bare", "false"])
        .output()
        .await
        .context("running git config core.bare false")?;
    if !config_out.status.success() {
        bail!(
            "git config core.bare false failed: {}",
            String::from_utf8_lossy(&config_out.stderr)
        );
    }

    let reset_out = Command::new("git")
        .args(["-C", &dest_str, "reset", "--hard", "HEAD"])
        .output()
        .await
        .context("running git reset --hard HEAD")?;
    if !reset_out.status.success() {
        bail!(
            "git reset --hard HEAD failed: {}",
            String::from_utf8_lossy(&reset_out.stderr)
        );
    }

    Ok(())
}

async fn log_clone_result(repo_dir: &Path, opts: &CloneOpts) {
    let label = match opts.shape {
        CloneShape::Mirror => "cloned (mirror)",
        CloneShape::BareHeads => "cloned (bare heads)",
        CloneShape::SingleBranch => "cloned",
    };
    let repo_dir_str = repo_dir.to_string_lossy().to_string();
    match Command::new("git")
        .args(["-C", &repo_dir_str, "log", "-1", "--format=%H %ai"])
        .output()
        .await
    {
        Ok(output) if output.status.success() => {
            let head = String::from_utf8_lossy(&output.stdout).trim().to_owned();
            info!(nickname = opts.nickname, head = head, label);
        }
        _ => {
            info!(nickname = opts.nickname, dir = %repo_dir.display(), label);
        }
    }
}

fn write_mirror_info(repo_dir: &Path, opts: &CloneOpts) -> Result<()> {
    let info = json!({
        "fluid_branch": opts.branch,
        "repo": opts.repo_url,
    });
    let data = serde_json::to_string_pretty(&info)?;
    fs::write(repo_dir.join(".info.json"), data)?;
    Ok(())
}

/// Clones a repo directly into `temp_dir/{uuid}` and returns
/// `(Some(path), None)` on success or `(None, Some(error))` on failure.
#[allow(clippy::too_many_arguments)]
pub async fn clone_to_temp(
    repo_url: &str,
    repo_branch: &str,
    temp_dir: &str,
    credentials: Option<Credentials>,
    follow_redirects: bool,
    mirror: bool,
) -> (Option<String>, Option<String>) {
    let nickname = uuid::Uuid::new_v4().to_string();
    let dest = PathBuf::from(temp_dir).join(&nickname);

    if let Err(e) = fs::create_dir_all(temp_dir) {
        return (None, Some(e.to_string()));
    }

    let opts = CloneOpts {
        group_name: String::new(),
        nickname: nickname.clone(),
        repo_url: repo_url.to_owned(),
        branch: repo_branch.to_owned(),
        credentials,
        follow_redirects,
        skip_existing: false,
        shape: if mirror {
            CloneShape::Mirror
        } else {
            CloneShape::SingleBranch
        },
    };

    let result = dispatch_clone(&opts, &dest).await;

    match result {
        Ok(()) => {
            log_clone_result(&dest, &opts).await;
            if opts.shape == CloneShape::Mirror {
                if let Err(e) = write_mirror_info(&dest, &opts) {
                    warn!(error = %e, "failed to write .info.json");
                }
            }
            (Some(dest.to_string_lossy().to_string()), None)
        }
        Err(e) => {
            let _ = fs::remove_dir_all(&dest);
            (None, Some(e.to_string()))
        }
    }
}

/// Builds the common clone arguments: config flags, clone subcommand, shape, URL, dest.
#[must_use]
pub fn build_clone_args(
    opts: &CloneOpts,
    repo_url: &str,
    dest: &Path,
    extra_config: &[String],
) -> Vec<String> {
    let mut args = vec![
        "-c".to_owned(),
        "core.symlinks=false".to_owned(),
        "-c".to_owned(),
        format!("http.followRedirects={}", opts.follow_redirects),
    ];

    args.extend(extra_config.iter().cloned());

    args.push("clone".to_owned());

    match opts.shape {
        CloneShape::Mirror => args.push("--mirror".to_owned()),
        // Every branch head and nothing else: unlike --mirror this skips
        // refs/pull, refs/merge-requests and keep-around refs, and writes no
        // mirror refspec into the clone's config.
        CloneShape::BareHeads => args.extend(["--bare".to_owned(), "--no-tags".to_owned()]),
        CloneShape::SingleBranch => {
            if !opts.branch.is_empty() {
                args.extend([
                    "--branch".to_owned(),
                    opts.branch.clone(),
                    "--single-branch".to_owned(),
                ]);
            }
        }
    }

    args.extend([
        "--".to_owned(),
        repo_url.to_owned(),
        dest.to_string_lossy().to_string(),
    ]);

    args
}

#[cfg(test)]
mod tests {
    use std::path::Path;
    use std::process::Command;

    use super::{build_clone_args, CloneOpts, CloneShape};

    fn opts(shape: CloneShape) -> CloneOpts {
        CloneOpts {
            group_name: "a-group".to_owned(),
            nickname: "a_root".to_owned(),
            repo_url: "https://gitlab.com/org/repo".to_owned(),
            branch: "trunk".to_owned(),
            credentials: None,
            follow_redirects: false,
            skip_existing: false,
            shape,
        }
    }

    fn args_of(follow_redirects: bool) -> Vec<String> {
        let opts = CloneOpts {
            follow_redirects,
            ..opts(CloneShape::SingleBranch)
        };

        build_clone_args(&opts, &opts.repo_url, Path::new("/tmp/a_root"), &[])
    }

    fn shape_args(shape: CloneShape) -> Vec<String> {
        let opts = opts(shape);

        // Between "clone" and "--" sits exactly the shape.
        build_clone_args(&opts, &opts.repo_url, Path::new("/tmp/a_root"), &[])
            .iter()
            .skip_while(|arg| *arg != "clone")
            .skip(1)
            .take_while(|arg| *arg != "--")
            .cloned()
            .collect()
    }

    fn run_git(dir: &Path, args: &[&str]) -> String {
        let output = Command::new("git")
            .arg("-C")
            .arg(dir)
            .args([
                "-c",
                "user.email=test@example.com",
                "-c",
                "user.name=Test",
                "-c",
                "commit.gpgsign=false",
                "-c",
                "tag.gpgsign=false",
            ])
            .args(args)
            .output()
            .expect("git runs");
        assert!(
            output.status.success(),
            "git {args:?} failed: {}",
            String::from_utf8_lossy(&output.stderr)
        );
        String::from_utf8_lossy(&output.stdout).trim().to_owned()
    }

    #[test]
    fn a_clone_never_writes_a_symbolic_link() {
        assert!(args_of(false).contains(&"core.symlinks=false".to_owned()));
        assert!(args_of(true).contains(&"core.symlinks=false".to_owned()));
    }

    #[test]
    fn a_root_that_takes_no_redirect_says_so_instead_of_leaving_it_to_git() {
        assert!(args_of(false).contains(&"http.followRedirects=false".to_owned()));
    }

    #[test]
    fn a_root_that_needs_a_redirect_keeps_asking_for_one() {
        assert!(args_of(true).contains(&"http.followRedirects=true".to_owned()));
    }

    #[test]
    fn a_branch_clone_is_single_branch() {
        assert_eq!(
            shape_args(CloneShape::SingleBranch),
            ["--branch", "trunk", "--single-branch"]
        );
    }

    #[test]
    fn a_mirror_clone_takes_every_ref() {
        assert_eq!(shape_args(CloneShape::Mirror), ["--mirror"]);
    }

    #[test]
    fn a_bare_heads_clone_takes_heads_without_tags() {
        assert_eq!(shape_args(CloneShape::BareHeads), ["--bare", "--no-tags"]);
    }

    #[test]
    fn a_bare_heads_clone_holds_exactly_the_branch_heads() {
        let tmp = tempfile::tempdir().expect("tempdir");
        let source = tmp.path().join("source");
        std::fs::create_dir(&source).expect("mkdir");
        run_git(&source, &["init", "--initial-branch=main"]);
        std::fs::write(source.join("file.txt"), "content\n").expect("write");
        run_git(&source, &["add", "file.txt"]);
        run_git(&source, &["commit", "-m", "first"]);
        run_git(&source, &["branch", "feature"]);
        run_git(&source, &["tag", "v1"]);
        // The kind of hidden ref --mirror would drag in.
        run_git(&source, &["update-ref", "refs/pull/1/head", "HEAD"]);

        let dest = tmp.path().join("dest");
        let opts = opts(CloneShape::BareHeads);
        let args = build_clone_args(&opts, &source.to_string_lossy(), &dest, &[]);
        let clone = Command::new("git").args(&args).output().expect("git runs");
        assert!(
            clone.status.success(),
            "clone failed: {}",
            String::from_utf8_lossy(&clone.stderr)
        );

        let refs = run_git(&dest, &["for-each-ref", "--format=%(refname)"]);
        let mut held: Vec<&str> = refs.lines().collect();
        held.sort_unstable();
        assert_eq!(held, ["refs/heads/feature", "refs/heads/main"]);
        assert_eq!(run_git(&dest, &["symbolic-ref", "HEAD"]), "refs/heads/main");
        assert_eq!(run_git(&dest, &["config", "core.bare"]), "true");
        // No mirror remnants: neither the flag nor a fetch refspec.
        for key in ["remote.origin.mirror", "remote.origin.fetch"] {
            let lookup = Command::new("git")
                .args(["-C", &dest.to_string_lossy(), "config", "--get", key])
                .output()
                .expect("git runs");
            assert!(!lookup.status.success(), "{key} is set");
        }
    }
}