feat: Gerrit HTTP API and partial VCS implementation

This implements the Gerrit surface of the VCS API async API via HTTP.

TODO:

- Event streamer should go somewhere else
- We need to replace the missing features

There's some impedence mismatch on IDs but this can be solved by harder
refactors.

Signed-off-by: Raito Bezarius <masterancpp@gmail.com>

Cargo.lock

@@ -1114,9 +1114,9 @@ dependencies = [
 
 [[package]]
 name = "hashbrown"
-version = "0.15.0"
+version = "0.15.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e087f84d4f86bf4b218b927129862374b72199ae7d8657835f1e89000eea4fb"
+checksum = "3a9bfc1af68b1726ea47d3d5109de126281def866b33970e10fbab11b5dafab3"
 
 [[package]]
 name = "heck"

ofborg/src/bin/mass-rebuilder.rs

@@ -2,8 +2,11 @@ use std::env;
 use std::error::Error;
 use std::path::Path;
 use std::process;
+use std::sync::RwLock;
 
 use async_std::task;
+use ofborg::config::VCSConfig;
+use ofborg::tasks::evaluate::SupportedVCS;
 use tracing::{error, info};
 
 use ofborg::checkout;
@@ -51,11 +54,16 @@ fn main() -> Result<(), Box<dyn Error>> {
         no_wait: false,
     })?;
 
+    let vcs_data = match cfg.vcs {
+        VCSConfig::GitHub => SupportedVCS::GitHub(RwLock::new(cfg.github_app_vendingmachine())),
+        VCSConfig::Gerrit => SupportedVCS::Gerrit,
+    };
+
     let handle = easylapin::WorkerChannel(chan).consume(
         tasks::evaluate::EvaluationWorker::new(
             cloner,
             &nix,
-            cfg.github_app_vendingmachine(),
+            vcs_data,
             cfg.acl(),
             cfg.runner.identity.clone(),
             events,

ofborg/src/config.rs

@@ -12,6 +12,12 @@ use hubcaps::{Credentials, Github, InstallationTokenGenerator, JWTCredentials};
 use serde::de::{self, Deserialize, Deserializer};
 use tracing::{debug, error, info, warn};
 
+#[derive(Serialize, Deserialize, Debug)]
+pub enum VCSConfig {
+    GitHub,
+    Gerrit,
+}
+
 #[derive(Serialize, Deserialize, Debug)]
 pub struct Config {
     pub runner: RunnerConfig,
@@ -19,10 +25,16 @@ pub struct Config {
     pub checkout: CheckoutConfig,
     pub nix: NixConfig,
     pub rabbitmq: RabbitMqConfig,
-    pub github: Option<GithubConfig>,
-    pub github_app: Option<GithubAppConfig>,
+    pub vcs: VCSConfig,
     pub pastebin: PastebinConfig,
     pub log_storage: Option<LogStorage>,
+
+    // GitHub-specific configuration if vcs == GitHub.
+    pub github: Option<GithubConfig>,
+    pub github_app: Option<GithubAppConfig>,
+
+    // Gerrit-specific configuration if vcs == Gerrit.
+    pub gerrit: Option<GerritConfig>,
 }
 
 #[derive(Serialize, Deserialize, Debug)]
@@ -58,6 +70,20 @@ pub struct NixConfig {
     pub initial_heap_size: Option<String>,
 }
 
+const fn default_gerrit_ssh_port() -> u16 {
+    29418
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct GerritConfig {
+    // For all requests.
+    #[serde(deserialize_with = "deserialize_and_expand_pathbuf")]
+    pub ssh_private_key_file: PathBuf,
+    pub instance_uri: String,
+    #[serde(default = "default_gerrit_ssh_port")]
+    pub ssh_port: u16,
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct GithubConfig {
     pub token_file: PathBuf,

ofborg/src/tasks/evaluate.rs

@@ -11,6 +11,7 @@ use crate::tasks::eval;
 use crate::utils::pastebin::PersistedPastebin;
 use crate::vcs::commit_status::{CommitStatus, CommitStatusError};
 use crate::vcs::generic::{Issue, IssueState, State, VersionControlSystemAPI};
+use crate::vcs::gerrit::http::GerritHTTPApi;
 use crate::vcs::github::compat::GitHubAPI;
 use crate::worker;
 
@@ -21,10 +22,15 @@ use std::time::Instant;
 
 use tracing::{debug_span, error, info, warn};
 
+pub enum SupportedVCS {
+    GitHub(RwLock<GithubAppVendingMachine>),
+    Gerrit,
+}
+
 pub struct EvaluationWorker<E> {
     cloner: checkout::CachedCloner,
     nix: nix::Nix,
-    github_vend: RwLock<GithubAppVendingMachine>,
+    vcs: SupportedVCS,
     acl: Acl,
     identity: String,
     events: E,
@@ -35,7 +41,7 @@ impl<E: stats::SysEvents> EvaluationWorker<E> {
     pub fn new(
         cloner: checkout::CachedCloner,
         nix: &nix::Nix,
-        github_vend: GithubAppVendingMachine,
+        vcs: SupportedVCS,
         acl: Acl,
         identity: String,
         events: E,
@@ -43,7 +49,7 @@ impl<E: stats::SysEvents> EvaluationWorker<E> {
         EvaluationWorker {
             cloner,
             nix: nix.without_limited_supported_systems(),
-            github_vend: RwLock::new(github_vend),
+            vcs,
             acl,
             identity,
             events,
@@ -81,20 +87,21 @@ impl<E: stats::SysEvents + 'static> worker::SimpleWorker for EvaluationWorker<E>
         let span = debug_span!("job", change_id = ?job.change.number);
         let _enter = span.enter();
 
-        // TODO: introduce dynamic dispatcher instantiation here for the VCS API.
-        let mut vending_machine = self
-            .github_vend
+        let vcs_api: Rc<dyn VersionControlSystemAPI> = match self.vcs {
+            SupportedVCS::GitHub(ref vending_machine) => {
+                let mut vending_machine = vending_machine
                     .write()
                     .expect("Failed to get write lock on github vending machine");
-
                 let github_client = vending_machine
                     .for_repo(&job.repo.owner, &job.repo.name)
                     .expect("Failed to get a github client token");
-
-        let github_api = Rc::new(GitHubAPI::new(github_client.clone()));
+                Rc::new(GitHubAPI::new(github_client.clone()))
+            }
+            SupportedVCS::Gerrit => Rc::new(GerritHTTPApi),
+        };
 
         OneEval::new(
-            github_api,
+            vcs_api,
             &self.nix,
             &self.acl,
             &mut self.events,

ofborg/src/vcs/gerrit/data_structures.rs

@@ -9,6 +9,21 @@ pub struct Account {
     pub username: Option<String>, // User's username, if configured
 }
 
+impl From<Vec<Account>> for crate::vcs::generic::ChangeReviewers {
+    fn from(value: Vec<Account>) -> Self {
+        // FIXME: I don't think Gerrit remembers when we added a group instead of entities.
+        crate::vcs::generic::ChangeReviewers {
+            entity_reviewers: value
+                .into_iter()
+                // FIXME: this is a… quite the assumption, let's relax it by having at _least_ one
+                // identity identifier.
+                .map(|a| a.username.expect("Expected username"))
+                .collect(),
+            team_reviewers: vec![],
+        }
+    }
+}
+
 #[derive(Serialize, Deserialize, Debug)]
 pub struct Approval {
     pub r#type: String,      // Internal name of the approval
@@ -191,6 +206,18 @@ pub struct Change {
     pub all_reviewers: Vec<Account>, // List of all reviewers
 }
 
+impl From<Change> for crate::message::Change {
+    fn from(value: Change) -> Self {
+        Self {
+            target_branch: Some(value.branch),
+            // While the change number is deprecated, we actually need it.
+            // FIXME: enforce type level checking of this.
+            number: value.change_number.unwrap(),
+            head_sha: value.current_patch_set.revision,
+        }
+    }
+}
+
 #[derive(Serialize, Deserialize, Debug)]
 pub struct RefUpdate {
     #[serde(rename = "oldRev")]
@@ -209,25 +236,25 @@ pub enum GerritStreamEvent {
         patch_set: PatchSet,
         abandoner: Account,
         reason: String,
-        event_created_on: u64
+        event_created_on: u64,
     },
     ChangeDeleted {
         change: Change,
-        deleter: Account
+        deleter: Account,
     },
     ChangeMerged {
         change: Change,
         patch_set: PatchSet,
         submitter: Account,
         new_rev: String,
-        event_created_on: u64
+        event_created_on: u64,
     },
     ChangeRestored {
         change: Change,
         patch_set: PatchSet,
         restorer: Account,
         reason: String,
-        event_created_on: u64
+        event_created_on: u64,
     },
     CommentAdded {
         change: Change,
@@ -235,7 +262,7 @@ pub enum GerritStreamEvent {
         author: Account,
         approvals: Vec<Approval>,
         comment: String,
-        event_created_on: u64
+        event_created_on: u64,
     },
     DroppedOutput,
     HashtagsChanged {
@@ -249,30 +276,30 @@ pub enum GerritStreamEvent {
     ProjectCreated {
         project_name: String,
         project_head: String,
-        event_created_on: u64
+        event_created_on: u64,
     },
     PatchSetCreated {
         change: Change,
         patch_set: PatchSet,
         uploader: Account,
-        event_created_on: u64
+        event_created_on: u64,
     },
     RefUpdated {
         submitter: Account,
         ref_update: RefUpdate,
-        event_created_on: u64
+        event_created_on: u64,
     },
     BatchRefUpdated {
         submitter: Account,
         ref_updates: Vec<RefUpdate>,
-        event_created_on: u64
+        event_created_on: u64,
     },
     ReviewerAdded {
         change: Change,
         patch_set: PatchSet,
         reviewer: Account,
         adder: Account,
-        event_created_on: u64
+        event_created_on: u64,
     },
     ReviewerDeleted {
         change: Change,
@@ -288,19 +315,19 @@ pub enum GerritStreamEvent {
         old_topic: Option<String>,
         new_topic: Option<String>,
         changer: Account,
-        event_created_on: u64
+        event_created_on: u64,
     },
     WorkInProgressStateChanged {
         change: Change,
         patch_set: PatchSet,
         changer: Account,
-        event_created_on: u64
+        event_created_on: u64,
     },
     PrivateStateChanged {
         change: Change,
         patch_set: PatchSet,
         changer: Account,
-        event_created_on: u64
+        event_created_on: u64,
     },
     VoteDeleted {
         change: Change,
@@ -313,6 +340,6 @@ pub enum GerritStreamEvent {
     ProjectHeadUpdate {
         old_head: String,
         new_head: String,
-        event_created_on: u64
-    }
+        event_created_on: u64,
+    },
 }

ofborg/src/vcs/gerrit/http.rs

@@ -0,0 +1,49 @@
+//! REST API bindings for Gerrit
+//! TODO:
+//! - trace IDs support
+//! - label support
+
+use super::data_structures::{Account, Change};
+
+pub struct GerritHTTPApi;
+
+impl GerritHTTPApi {
+    // async fn get_project(&self, project_name: &str) -> Project {}
+    /// Fetches all changes according to the query and the given limit.
+    /// This will default to 60 changes by default.
+    pub(crate) async fn list_changes(&self, _query: &str, _limit: Option<u64>) -> Vec<Change> {
+        Default::default()
+    }
+
+    /// Fetch the latest change ID for a given project and CL number.
+    pub(crate) async fn get_change_id(&self, _project_name: &str, _cl_number: u64) -> String {
+        "".to_owned()
+    }
+
+    /// Fetch a given change according to the change ID (not the CL number).
+    pub(crate) async fn get_change(&self, _change_id: &str) -> Option<Change> {
+        Default::default()
+    }
+
+    /// Set additional and remove certain hashtags for a given change ID (not the CL number).
+    pub(crate) async fn set_hashtags(
+        &self,
+        _change_id: &str,
+        _add: &[String],
+        _remove: &[String],
+    ) -> Vec<String> {
+        Default::default()
+    }
+    /// List all reviewers on a given change ID (not the CL number).
+    pub(crate) async fn list_reviewers(&self, _change_id: &str) -> Vec<Account> {
+        Default::default()
+    }
+    /// Set reviewers and a message on a given change ID (not the CL number).
+    pub(crate) async fn set_reviewers(
+        &self,
+        _change_id: &str,
+        _message: &str,
+        _reviewers: Vec<Account>,
+    ) {
+    }
+}

ofborg/src/vcs/gerrit/impl.rs

@@ -0,0 +1,137 @@
+//! Implementation of the VCS API for Gerrit
+//! This uses the HTTP API.
+
+use futures_util::FutureExt;
+
+use crate::vcs::generic::VersionControlSystemAPI;
+
+use super::{data_structures::Account, http::GerritHTTPApi};
+
+impl VersionControlSystemAPI for GerritHTTPApi {
+    // The next three APIs are todo!() because they cannot be implemented in Gerrit.
+    // Gerrit does not offer any way to get this information out.
+    // GerritHTTPApi needs to return something like Unsupported
+    // and we need to compose a GerritHTTPApi with a GerritForge which contains an implementation
+    // of check statuses and commit statuses and an issue tracker.
+    fn create_check_statuses(
+        &self,
+        _repo: &crate::message::Repo,
+        _checks: Vec<crate::vcs::generic::CheckRunOptions>,
+    ) -> futures_util::future::BoxFuture<()> {
+        todo!();
+    }
+
+    fn create_commit_statuses(
+        &self,
+        _repo: &crate::message::Repo,
+        _sha: String,
+        _state: crate::vcs::generic::State,
+        _context: String,
+        _description: String,
+        _target_url: String,
+    ) -> futures_util::future::BoxFuture<Result<(), crate::vcs::commit_status::CommitStatusError>>
+    {
+        todo!();
+    }
+
+    fn get_issue(
+        &self,
+        _repo: &crate::message::Repo,
+        _number: u64,
+    ) -> futures_util::future::BoxFuture<Result<crate::vcs::generic::Issue, String>> {
+        todo!();
+    }
+
+    fn get_repository(&self, _repo: &crate::message::Repo) -> crate::vcs::generic::Repository {
+        todo!();
+    }
+
+    fn get_changes(
+        &self,
+        repo: &crate::message::Repo,
+    ) -> futures_util::future::BoxFuture<Vec<crate::message::Change>> {
+        let repo_name = repo.name.to_owned();
+        async move {
+            self.list_changes(&format!("project:{}", &repo_name), None)
+                .await
+                .into_iter()
+                .map(|c| c.into())
+                .collect()
+        }
+        .boxed()
+    }
+
+    fn get_change(
+        &self,
+        repo: &crate::message::Repo,
+        number: u64,
+    ) -> futures_util::future::BoxFuture<Option<crate::message::Change>> {
+        let repo_name = repo.name.to_owned();
+        async move {
+            let change_id = self.get_change_id(&repo_name, number).await;
+            GerritHTTPApi::get_change(&self, &change_id)
+                .await
+                .map(|c| c.into())
+        }
+        .boxed()
+    }
+
+    fn update_labels(
+        &self,
+        repo: &crate::message::Repo,
+        number: u64,
+        add: &[String],
+        remove: &[String],
+    ) -> futures_util::future::BoxFuture<()> {
+        let add = add.to_owned();
+        let remove = remove.to_owned();
+        let repo_name = repo.name.to_owned();
+
+        async move {
+            let change_id = self.get_change_id(&repo_name, number).await;
+            self.set_hashtags(&change_id, &add, &remove).await;
+        }
+        .boxed()
+    }
+
+    fn get_existing_reviewers(
+        &self,
+        repo: &crate::message::Repo,
+        number: u64,
+    ) -> futures_util::future::BoxFuture<crate::vcs::generic::ChangeReviewers> {
+        let repo_name = repo.name.to_owned();
+        async move {
+            let change_id = self.get_change_id(&repo_name, number).await;
+            self.list_reviewers(&change_id).await.into()
+        }
+        .boxed()
+    }
+
+    fn request_reviewers(
+        &self,
+        repo: &crate::message::Repo,
+        number: u64,
+        entity_reviewers: Vec<String>,
+        // FIXME: support group reviews
+        _team_reviewers: Vec<String>,
+    ) -> futures_util::future::BoxFuture<()> {
+        let repo_name = repo.name.to_owned();
+        async move {
+            let change_id = self.get_change_id(&repo_name, number).await;
+            self.set_reviewers(
+                &change_id,
+                "Automatic reviewer request",
+                entity_reviewers
+                    .into_iter()
+                    .map(|reviewer| Account {
+                        username: Some(reviewer),
+                        email: None,
+                        name: None,
+                    })
+                    .collect(),
+            )
+            .await
+        }
+        .boxed()
+    }
+}

ofborg/src/vcs/gerrit/mod.rs

@@ -1,3 +1,5 @@
 pub mod checks;
 pub mod data_structures;
+pub mod http;
+pub mod r#impl;
 // pub mod events;