feat: initial pi-review Docker action

Reusable Gitea/GitHub action that runs Pi coding agent for AI-powered code reviews on pull requests. - Docker image based on node:24-slim (112 packages) - Supports built-in providers (zai, anthropic, openai, deepseek, openrouter) and custom OpenAI-compatible endpoints - Generates git diff (excludes lockfiles/generated code by default) - Posts review as idempotent PR comment (updates existing on re-run) - Read-only tools only: agent investigates but never modifies code - 80KB default diff truncation to stay within LLM context windows - No curl/python3 dependency — uses Node.js for HTTP and JSON
2026-05-18 22:09:46 +02:00
commit 28b4b23550
10 changed files with 428 additions and 0 deletions
--- a/scripts/review.sh
+++ b/scripts/review.sh
@@ -0,0 +1,242 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# ─── Pi Code Review Action ───────────────────────────────────────────────────
+# Configures Pi, generates a diff, runs the agent in --print mode, and posts
+# the review as a PR comment. Works with both Gitea and GitHub.
+#
+# Runs inside a Docker container. Pi is pre-installed in the image.
+# The calling repo is at $GITHUB_WORKSPACE (set by the CI platform).
+# ──────────────────────────────────────────────────────────────────────────────
+
+# ─── Phase 1: Configure Pi ────────────────────────────────────────────────────
+echo "::group::Configure Pi"
+mkdir -p ~/.pi/agent
+
+AUTH_FILE=~/.pi/agent/auth.json
+
+# Map provider name to auth.json key
+case "$PI_PROVIDER" in
+  zai)         AUTH_KEY="zai" ;;
+  anthropic)   AUTH_KEY="anthropic" ;;
+  openai)      AUTH_KEY="openai" ;;
+  deepseek)    AUTH_KEY="deepseek" ;;
+  openrouter)  AUTH_KEY="openrouter" ;;
+  *)           AUTH_KEY="" ;;
+esac
+
+if [ -n "$AUTH_KEY" ]; then
+  # Built-in provider: write auth.json
+  cat > "$AUTH_FILE" << EOF
+{
+  "${AUTH_KEY}": { "type": "api_key", "key": "${PI_API_KEY}" }
+}
+EOF
+  PROVIDER_FLAG="--provider ${PI_PROVIDER}"
+else
+  # Custom provider: write models.json
+  if [ -z "$PI_BASE_URL" ]; then
+    echo "::error::Custom provider requires base_url input"
+    exit 1
+  fi
+  cat > ~/.pi/agent/models.json << EOF
+{
+  "providers": {
+    "custom-review": {
+      "baseUrl": "${PI_BASE_URL}",
+      "api": "openai-completions",
+      "apiKey": "${PI_API_KEY}",
+      "compat": {
+        "supportsDeveloperRole": false,
+        "supportsReasoningEffort": false
+      },
+      "models": [
+        {
+          "id": "${PI_MODEL}",
+          "reasoning": false,
+          "input": ["text"],
+          "contextWindow": 128000,
+          "maxTokens": 16384
+        }
+      ]
+    }
+  }
+}
+EOF
+  PROVIDER_FLAG="--provider custom-review"
+fi
+
+chmod 600 "$AUTH_FILE"
+echo "Configured provider: ${PI_PROVIDER}"
+echo "::endgroup::"
+
+# ─── Phase 2: Generate diff ───────────────────────────────────────────────────
+echo "::group::Generate diff"
+
+# Ensure we have full history (runner may have done a shallow checkout)
+git fetch --unshallow --filter=blob:none origin 2>/dev/null || true
+git fetch origin main 2>/dev/null || git fetch origin master 2>/dev/null || true
+
+BASE="origin/main"
+if ! git rev-parse --verify "$BASE" >/dev/null 2>&1; then
+  BASE="origin/master"
+fi
+
+# Build exclude pathspecs
+EXCLUDE_ARGS=""
+for pattern in $PI_EXCLUDE; do
+  EXCLUDE_ARGS="$EXCLUDE_ARGS ':!$pattern'"
+done
+
+eval "git diff ${BASE}...HEAD ${EXCLUDE_ARGS}" > /tmp/pi-diff.txt 2>/dev/null || true
+
+# Truncate if needed
+if [ "${PI_MAX_DIFF}" -gt 0 ]; then
+  head -c "${PI_MAX_DIFF}" /tmp/pi-diff.txt > /tmp/pi-diff-trunc.txt
+  mv /tmp/pi-diff-trunc.txt /tmp/pi-diff.txt
+fi
+
+DIFF_SIZE=$(wc -c < /tmp/pi-diff.txt || echo 0)
+echo "Diff size: ${DIFF_SIZE} bytes"
+echo "::endgroup::"
+
+if [ "${DIFF_SIZE}" -eq 0 ]; then
+  echo "No changes to review. Skipping."
+  exit 0
+fi
+
+# ─── Phase 3: Run Pi ──────────────────────────────────────────────────────────
+echo "::group::Run Pi review"
+
+# Prompt: custom (from calling repo) or default (baked into Docker image)
+ACTION_DIR="/action"
+
+if [ -n "${PI_REVIEW_PROMPT}" ] && [ -f "${PI_REVIEW_PROMPT}" ]; then
+  PROMPT=$(cat "${PI_REVIEW_PROMPT}")
+  echo "Using custom prompt: ${PI_REVIEW_PROMPT}"
+else
+  PROMPT=$(cat "${ACTION_DIR}/prompts/default.md")
+  echo "Using default prompt"
+fi
+
+# Append diff instruction
+PROMPT="${PROMPT}
+
+The git diff is at /tmp/pi-diff.txt. Start by reading it, then read any files you need for full context."
+
+# Run Pi in print mode (non-interactive, no session persistence)
+pi --no-session \
+  ${PROVIDER_FLAG} \
+  --model "${PI_MODEL}" \
+  --tools "${PI_TOOLS}" \
+  -p "${PROMPT}" \
+  > /tmp/pi-review.md 2>/dev/null
+
+if [ ! -s /tmp/pi-review.md ]; then
+  echo "::error::Pi generated no output"
+  exit 1
+fi
+
+echo "Review generated successfully."
+echo "::endgroup::"
+
+# ─── Phase 4: Post comment ────────────────────────────────────────────────────
+echo "::group::Post review comment"
+
+# Detect Gitea vs GitHub
+if [ -n "${GITEA_SERVER_URL:-}" ]; then
+  API_BASE="${GITEA_SERVER_URL}/api/v1"
+  PR_NUMBER="${GITEA_EVENT_PULL_REQUEST_NUMBER:-}"
+  REPO="${GITEA_REPOSITORY:-}"
+else
+  API_BASE="${GITHUB_API_URL:-https://api.github.com}"
+  PR_NUMBER="${GITHUB_EVENT_PULL_REQUEST_NUMBER:-}"
+  REPO="${GITHUB_REPOSITORY:-}"
+fi
+
+if [ -z "$PR_NUMBER" ]; then
+  echo "Not a pull request event. Review written to /tmp/pi-review.md only."
+  echo "::endgroup::"
+  exit 0
+fi
+
+MARKER="<!-- pi-code-review -->"
+
+# Use Node.js for all HTTP and JSON — avoids needing curl in the image.
+# Node's built-in https module is already available since we need it for Pi.
+node -e "
+const http = require('http');
+const https = require('https');
+const fs = require('fs');
+
+const apiBase = '${API_BASE}';
+const repo = '${REPO}';
+const prNumber = '${PR_NUMBER}';
+const token = '${PI_TOKEN}';
+const marker = '${MARKER}';
+
+const review = fs.readFileSync('/tmp/pi-review.md', 'utf8');
+const body = '## Pi Code Review\n\n' + review + '\n\n' + marker;
+
+function apiRequest(method, path, data) {
+  return new Promise((resolve, reject) => {
+    const url = new URL(apiBase + path);
+    const transport = url.protocol === 'http:' ? http : https;
+    const options = {
+      hostname: url.hostname,
+      port: url.port || (url.protocol === 'http:' ? 80 : 443),
+      path: url.pathname + url.search,
+      method,
+      headers: {
+        'Authorization': 'token ' + token,
+        'Content-Type': 'application/json',
+      },
+    };
+    const req = transport.request(options, (res) => {
+      let body = '';
+      res.on('data', (chunk) => { body += chunk; });
+      res.on('end', () => {
+        if (res.statusCode >= 200 && res.statusCode < 300) {
+          try { resolve(JSON.parse(body)); } catch { resolve(null); }
+        } else {
+          console.error('API error ' + res.statusCode + ': ' + body.slice(0, 200));
+          resolve(null);
+        }
+      });
+    });
+    req.on('error', (e) => { console.error('Request failed:', e.message); resolve(null); });
+    if (data) req.write(JSON.stringify(data));
+    req.end();
+  });
+}
+
+async function main() {
+  // Find existing review comment
+  const comments = await apiRequest('GET', '/repos/' + repo + '/issues/' + prNumber + '/comments');
+  let existingId = null;
+  if (Array.isArray(comments)) {
+    for (const c of comments) {
+      if (c.body && c.body.includes(marker)) {
+        existingId = c.id;
+        break;
+      }
+    }
+  }
+
+  const payload = { body };
+
+  if (existingId) {
+    console.log('Updating existing comment ' + existingId);
+    await apiRequest('PATCH', '/repos/' + repo + '/issues/comments/' + existingId, payload);
+    console.log('Comment updated.');
+  } else {
+    console.log('Creating new review comment');
+    await apiRequest('POST', '/repos/' + repo + '/issues/' + prNumber + '/comments', payload);
+    console.log('Comment posted.');
+  }
+}
+
+main().catch((e) => { console.error(e.message); process.exit(1); });
+"
+
+echo "::endgroup::"