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g1t/crates/runner/src/main.rs

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1//! Runs a coding agent on one pull request and reports back to g1t.
2//!
3//! This is the program a hosted sandbox starts. It clones the pull
4//! request's fork, runs the agent harness headless, streams what the agent
5//! does into the pull request's session as it happens, pushes the result
6//! and marks the pull request ready for review. It talks to g1t only through the public API and git, exactly
7//! as an agent on someone's own machine would.
8//!
9//! `MODE` selects another job instead: `checks` runs acceptance checks,
10//! `update` brings a pull request up to date with its target branch,
11//! `review` has an agent review one, and `revise` sends the author back to
12//! address what the checks or a review found, `plan` turns an outcome
13//! into issues, `queue` builds and checks a state of the merge queue,
14//! `mergecheck` finds out whether a pull request merges cleanly,
15//! `actions` runs one job of a GitHub Actions workflow, `backup` cuts a
16//! repository's nightly backup bundle, and `bump` makes a
17//! security update: one package raised in its lockfiles, pushed as g1t.
18//! See the modules of those names.
19//!
20//! Configuration comes from the environment:
21//!
22//! - `G1T_API`, `G1T_TOKEN`, `G1T_USER`: where and who to report as.
23//! - `G1T_REPO`, `PULL_NUMBER`, `GIT_REMOTE`: the pull request and its fork.
24//! - `PROMPT`: what the agent is asked to do.
25//! - `COMMIT_MESSAGE`: used if the agent leaves changes uncommitted.
26//! - `ANTHROPIC_API_KEY`: read by the harness itself.
27//!
28//! Every mode runs with the mining watch in `abuse`: a sandbox that looks
29//! like it is mining stops itself and exits with `abuse::EXIT_CODE`.
30//!
31//! Given a command instead (`register`, `run`, `service`, `remove`,
32//! `update`, `version`), it is a self-hosted runner on someone's own
33//! machine, which runs work in these modes: see `selfhosted`.
34
35mod abuse;
36mod actions;
37mod backup;
38mod bump;
39mod checks;
40mod clone;
41mod confidence;
42mod deploy;
43mod docker;
44mod guard;
45mod harness;
46mod learned;
47mod mergecheck;
48mod plan;
49mod progress;
50mod queue;
51mod reply;
52mod report;
53mod review;
54mod revise;
55mod selfhosted;
56mod steer;
57mod update;
58
59use std::path::Path;
60use std::process::Command;
61
62use anyhow::{Context, Result, bail};
63use base64::Engine;
64use base64::engine::general_purpose::STANDARD;
65
66use report::{Entry, Reporter};
67
68pub(crate) const WORKDIR: &str = "/work/repo";
69/// The name and address on every commit g1t makes here, whether its agent
70/// or g1t itself: `g1t_contracts::system::{USERNAME, EMAIL}`.
71pub(crate) const AUTHOR_NAME: &str = "g1t";
72pub(crate) const AUTHOR_EMAIL: &str = "g1t@users.noreply.g1t.sh";
73
74pub(crate) fn env(name: &str) -> Result<String> {
75 std::env::var(name).with_context(|| format!("{name} is not set"))
76}
77
78/// Runs git and returns its trimmed output, failing on a non-zero exit.
79pub(crate) fn git(dir: &Path, args: &[&str]) -> Result<String> {
80 let output = Command::new("git")
81 .current_dir(dir)
82 .args(args)
83 .output()
84 .context("could not run git")?;
85 if !output.status.success() {
86 bail!(
87 "git {} failed: {}",
88 args.first().unwrap_or(&""),
89 String::from_utf8_lossy(&output.stderr).trim()
90 );
91 }
92 Ok(String::from_utf8_lossy(&output.stdout).trim().to_owned())
93}
94
95/// A git option that authenticates one command. The credential is passed
96/// per command and never written to the clone's config or its remote URL,
97/// where the agent would find it.
98pub(crate) fn auth_option(user: &str, token: &str) -> String {
99 let credentials = STANDARD.encode(format!("{user}:{token}"));
100 format!("http.extraHeader=Authorization: Basic {credentials}")
101}
102
103/// Clones the fork, runs the agent on `PROMPT`, commits and pushes what it
104/// did, and returns its closing summary.
105pub(crate) fn run(reporter: &mut Reporter) -> Result<String> {
106 let mut prompt = env("PROMPT")?;
107 let remote = env("GIT_REMOTE")?;
108 let auth = auth_option(&env("G1T_USER")?, &env("G1T_TOKEN")?);
109 let workdir = Path::new(WORKDIR);
110
111 // Which model, and why: the router's one line names both.
112 let reason = std::env::var("AGENT_MODEL_REASON").unwrap_or_default();
113 if !reason.trim().is_empty() {
114 reporter.record(Entry::new("note", reason.trim()));
115 } else if let Ok(model) = std::env::var("AGENT_MODEL_NAME") {
116 reporter.record(Entry::new("note", &format!("Running on {model}.")));
117 }
118 reporter.record(Entry::new("prompt", &prompt));
119 reporter.flush();
120
121 std::fs::create_dir_all("/work")?;
122 clone::clone(Path::new("/work"), &auth, &[], &remote, WORKDIR).context("could not clone the pull request's fork")?;
123 git(workdir, &["config", "user.name", crate::AUTHOR_NAME])?;
124 git(workdir, &["config", "user.email", crate::AUTHOR_EMAIL])?;
125 let branch = git(workdir, &["rev-parse", "--abbrev-ref", "HEAD"])?;
126 let start = git(workdir, &["rev-parse", "HEAD"]).unwrap_or_default();
127
128 // Sent back to work that is already open: start from where the branch it
129 // will land on is now, so what passes here passes there too.
130 if let (Ok(upstream), Ok(upstream_branch)) = (env("UPSTREAM_REMOTE"), env("UPSTREAM_BRANCH")) {
131 clone::fetch(workdir, &auth, &upstream, &upstream_branch).context("could not fetch the branch this will land on")?;
132 // Shallow: deep enough to tell whether it is behind, and to merge.
133 clone::share_history(workdir, &auth, &[("origin", branch.as_str()), (upstream.as_str(), upstream_branch.as_str())], "HEAD", "FETCH_HEAD")?;
134 let behind = Command::new("git")
135 .current_dir(workdir)
136 .args(["merge-base", "--is-ancestor", "FETCH_HEAD", "HEAD"])
137 .status()
138 .is_ok_and(|status| !status.success());
139 if behind {
140 let message = format!("Catch up with {upstream_branch}");
141 let merged = Command::new("git")
142 .current_dir(workdir)
143 .args(["merge", "--quiet", "--no-edit", "-m", &message, "FETCH_HEAD"])
144 .status()
145 .is_ok_and(|status| status.success());
146 if merged {
147 reporter.record(Entry::new(
148 "note",
149 &format!("Merged in the latest {upstream_branch} before starting."),
150 ));
151 } else {
152 let files = git(workdir, &["diff", "--name-only", "--diff-filter=U"])?;
153 let files: Vec<&str> = files.lines().collect();
154 reporter.record(Entry::new(
155 "note",
156 &format!(
157 "Merged in the latest {upstream_branch} before starting; {} conflict.",
158 files.join(", ")
159 ),
160 ));
161 prompt.push_str(&format!(
162 "\n\nBefore you started, the latest {upstream_branch} was merged into this branch, and these files conflict: {}. Resolve the conflicts first, keeping what both sides meant, then address the points above. Leave no conflict markers.",
163 files.join(", ")
164 ));
165 }
166 reporter.flush();
167 }
168 }
169
170 // The agent is asked what it learned, which goes to memory, and how sure
171 // it is of its change, which g1t weighs with what it observes. Neither
172 // stays in the summary.
173 let asked = confidence::ask(&learned::ask(&prompt));
174 let summary = confidence::finish(learned::finish(harness::run_claude(workdir, &asked, reporter)?));
175
176 // Commit whatever the agent left in the working tree.
177 if !git(workdir, &["status", "--porcelain"])?.is_empty() {
178 let message = std::env::var("COMMIT_MESSAGE").unwrap_or_else(|_| "Agent changes".into());
179 git(workdir, &["add", "--all"])?;
180 git(workdir, &["commit", "--quiet", "--message", &message])?;
181 }
182 let head = git(workdir, &["rev-parse", "HEAD"])?;
183 if head == start {
184 // An agent woken to answer usually only answers.
185 if std::env::var("MODE").as_deref() == Ok("answer") {
186 return Ok(summary);
187 }
188 bail!("the agent finished without changing anything");
189 }
190 git(
191 workdir,
192 &[
193 "-c",
194 &auth,
195 "push",
196 "--quiet",
197 "origin",
198 &format!("HEAD:{branch}"),
199 ],
200 )
201 .context("could not push the pull request's commits")?;
202 reporter.record(Entry::new(
203 "note",
204 &format!("Pushed {}.", &head[..head.len().min(12)]),
205 ));
206 Ok(summary)
207}
208
209fn main() {
210 // The runc the job's Docker Engine starts containers with (docker/oci.rs).
211 if docker::oci::invoked_as_runc() {
212 docker::oci::main();
213 }
214 // A self-hosted runner's commands; the modes below are what it, and
215 // g1t's sandboxes, run work with.
216 let args: Vec<String> = std::env::args().skip(1).collect();
217 if selfhosted::is_command(&args) {
218 std::process::exit(selfhosted::main(args));
219 }
220 // A guarded sandbox's HTTPS is re-signed on its way out: trust that
221 // before anything is fetched. The guard hook runs before every tool
222 // call, so it skips this.
223 if std::env::var("MODE").as_deref() == Ok("guard") {
224 std::process::exit(guard::hook_main());
225 }
226 guard::trust_egress_ca();
227 // Watches for mining for as long as the sandbox runs (abuse.rs). Not in
228 // the hooks the harness runs after every tool call.
229 if std::env::var("MODE").as_deref() != Ok("steer") {
230 abuse::watch();
231 }
232 // The same image does the other jobs a sandbox is started for.
233 match std::env::var("MODE").as_deref() {
234 Ok("actions") => std::process::exit(actions::main()),
235 Ok("backup") => std::process::exit(backup::main()),
236 Ok("bump") => std::process::exit(bump::main()),
237 Ok("checks") => std::process::exit(checks::main()),
238 Ok("deploy") => std::process::exit(deploy::main()),
239 Ok("update") => std::process::exit(update::main()),
240 Ok("review") => std::process::exit(review::main()),
241 Ok("revise") => std::process::exit(revise::main()),
242 Ok("answer") => std::process::exit(revise::answer()),
243 Ok("plan") => std::process::exit(plan::main()),
244 Ok("reply") => std::process::exit(reply::main()),
245 Ok("queue") => std::process::exit(queue::main()),
246 Ok("mergecheck") => std::process::exit(mergecheck::main()),
247 Ok("steer") => std::process::exit(steer::main()),
248 _ => {}
249 }
250 let mut reporter = match Reporter::from_env() {
251 Ok(reporter) => reporter,
252 Err(error) => {
253 eprintln!("g1t-runner: {error:#}");
254 std::process::exit(2);
255 }
256 };
257 match run(&mut reporter) {
258 Ok(summary) => {
259 reporter.flush();
260 if let Err(error) = reporter.ready(&summary) {
261 eprintln!("g1t-runner: could not mark the pull request ready: {error:#}");
262 std::process::exit(1);
263 }
264 }
265 Err(error) => {
266 eprintln!("g1t-runner: {error:#}");
267 // Stopped at a cap: like a person's stop, the pull request is
268 // left open for a person, not closed.
269 if guard::is_halt(&error) {
270 reporter.record(Entry::new("note", &format!("g1t stopped the agent: {error:#}.")));
271 reporter.flush();
272 std::process::exit(1);
273 }
274 reporter.record(Entry::new("note", &format!("The run failed: {error:#}")));
275 reporter.flush();
276 let _ = reporter.close();
277 std::process::exit(1);
278 }
279 }
280}