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GitHub Action Investigator

This is an in-depth guide to build a script that interactively investigates GitHub Actions failures.

Full source (GitHub)

gai.genai.mts
/* spellchecker: disable */


// Script for analyzing GitHub Action runs to determine the cause of a failure.
script({
    title: "GitHub Action Investigator",
    description:
        "Analyze GitHub Action runs to find the root cause of a failure",
    parameters: {
        workflow: { type: "string" }, // Workflow name
        failure_run_id: { type: "number" }, // ID of the failed run
        success_run_id: { type: "number" }, // ID of the successful run
        branch: { type: "string" }, // Branch name
    },
    system: ["system", "system.files"],
    flexTokens: 30000,
    cache: "gai",
    tools: ["fs_read_file"],
})


// Assign the 'workflow' parameter from environment variables
let workflow = env.vars.workflow


// If no workflow provided, select from available workflows
if (!workflow) {
    const workflows = await github.listWorkflows()
    workflow = await host.select(
        "Select a workflow",
        workflows.map(({ path, name }) => ({ value: path, name }))
    )
    if (!workflow) cancel("No workflow selected")
}


// Assign failure and success run IDs from environment variables
const ffid = env.vars.failure_run_id
const lsid = env.vars.success_run_id


// Retrieve repository information
const { owner, repo, refName } = await github.info()


// Assign branch name, defaulting to current reference name if not provided
let branch = env.vars.branch || refName


// If no branch provided, select from available branches
if (!branch) {
    const branches = await github.listBranches()
    branch = await host.select("Select a branch", branches)
    if (!branch) cancel("No branch selected")
}


// List workflow runs for the specified workflow and branch
const runs = await github.listWorkflowRuns(workflow, { branch })
if (!runs.length) cancel("No runs found")


// Find the index of the failed run using the provided or default criteria
let ffi = ffid
    ? runs.findIndex(({ id }) => id === ffid)
    : runs.findIndex(({ conclusion }) => conclusion === "failure")


// Default to the first run if no failed run is found
if (ffi < 0) ffi = 0
const ff = runs[ffi]


// Log details of the failed run
console.log(`  run: ${ff.display_title}, ${ff.html_url}`)


// Find the index of the last successful run before the failure
const runsAfterFailure = runs.slice(ffi)
const lsi = lsid
    ? runs.findIndex(({ id }) => id === lsid)
    : runsAfterFailure.findIndex(({ conclusion }) => conclusion === "success")


const ls = runsAfterFailure[lsi]
if (ls) {
    if (ls.head_sha === ff.head_sha) cancel("No previous successful run found")


    // Log details of the last successful run
    console.log(`  last success: ${ls.display_title}, ${ls.html_url}`)


    // Execute git diff between the last success and failed run commits
    const gitDiff = await git.diff({
        base: ls.head_sha,
        head: ff.head_sha,
        excludedPaths: "**/genaiscript.d.ts",
    })
    if (gitDiff)
        def("GIT_DIFF", gitDiff, {
            language: "diff",
            lineNumbers: true,
            flex: 1,
        })
}


// Download logs of the failed job
const ffjobs = await github.listWorkflowJobs(ff.id)
const ffjob =
    ffjobs.find(({ conclusion }) => conclusion === "failure") ?? ffjobs[0]
const fflog = ffjob.content
if (!fflog) cancel("No logs found")


if (!ls) {
    // Define log content if no last successful run is available
    def("LOG", fflog, { maxTokens: 20000, lineNumbers: false })
} else {
    const lsjobs = await github.listWorkflowJobs(ls.id)
    const lsjob = lsjobs.find(({ name }) => ffjob.name === name)
    if (!lsjob)
        console.log(`could not find job ${ffjob.name} in last success run`)
    else {
        const lslog = lsjob.content
        // Generate a diff of logs between the last success and failed runs
        defDiff("LOG_DIFF", lslog, fflog, {
            lineNumbers: false,
            flex: 4,
        })
    }
}


// Instruction for generating a report based on the analysis
$`Your are an expert software engineer and you are able to analyze the logs and find the root cause of the failure.


${ls ? "- GIT_DIFF contains a diff of 2 run commits" : ""}
${ls ? "- LOG_DIFF contains a diff of 2 runs in GitHub Action" : "- LOG contains the log of the failed run"}
- The first run is the last successful run and the second run is the first failed run


Add links to run logs.


Analyze the diff in LOG_DIFF and provide a summary of the root cause of the failure. Show the code that is responsible for the failure.


If you cannot find the root cause, stop.


Generate a diff with suggested fixes. Use a diff format.
- If you cannot locate the error, do not generate a diff.`


// Write the investigator report
writeText(
    `## Investigator report
- [run failure](${ff.html_url})
${ls ? `, [run last success](${ls.html_url})` : ""}
, [${ff.head_sha.slice(0, 7)}](${ff.html_url})
${ls ? `, [diff ${ls.head_sha.slice(0, 7)}...${ff.head_sha.slice(0, 7)}](https://github.com/${owner}/${repo}/compare/${ls.head_sha}...${ff.head_sha})` : ""}


`,
    { assistant: true }
)
gai.yml
name: genai investigator
on:
    workflow_run:
        workflows: ["build", "playwright", "ollama"]
        types:
            - completed
concurrency:
    group: ${{ github.workflow }}-${{ github.ref }}-${{ github.event.workflow_run.event }}-${{ github.event.workflow_run.conclusion }}
    cancel-in-progress: true
permissions:
    contents: read
    actions: read
    pull-requests: write
jobs:
    investigate:
        # Only run this job if the workflow run concluded with a failure
        # and was triggered by a pull request event
        if: ${{ github.event.workflow_run.conclusion == 'failure' && github.event.workflow_run.event == 'pull_request' }}
        runs-on: ubuntu-latest
        steps:
            - uses: actions/checkout@v4
              with:
                  submodules: "recursive"
                  fetch-depth: 10
            - uses: actions/setup-node@v4
              with:
                  node-version: "20"
                  cache: yarn
            - run: yarn install --frozen-lockfile
            - name: compile
              run: yarn compile
            - name: genaiscript gai
              run: node packages/cli/built/genaiscript.cjs run gai -pr ${{ github.event.workflow_run.pull_requests[0].number }} -prc --vars "workflow=${{ github.event.workflow_run.workflow_id }}" --vars "failure_run_id=${{ github.event.workflow_run.id }}" --out-trace $GITHUB_STEP_SUMMARY
              env:
                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
                  OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
                  OPENAI_API_TYPE: ${{ secrets.OPENAI_API_TYPE }}
                  OPENAI_API_BASE: ${{ secrets.OPENAI_API_BASE }}
                  GENAISCRIPT_VAR_BRANCH: ${{ github.event.workflow_run.head_branch }}
            - name: genaiscript github-agent
              run: node packages/cli/built/genaiscript.cjs run github-agent -pr ${{ github.event.workflow_run.pull_requests[0].number }} -prc --vars "workflow=${{ github.event.workflow_run.workflow_id }}" --vars "run=${{ github.event.workflow_run.id }}" --out-trace $GITHUB_STEP_SUMMARY
              env:
                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
                  OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
                  OPENAI_API_TYPE: ${{ secrets.OPENAI_API_TYPE }}
                  OPENAI_API_BASE: ${{ secrets.OPENAI_API_BASE }}
                  GENAISCRIPT_VAR_BRANCH: ${{ github.event.workflow_run.head_branch }}
            - name: genaiscript github-one
              run: node packages/cli/built/genaiscript.cjs run github-one -pr ${{ github.event.workflow_run.pull_requests[0].number }} -prc --vars "workflow=${{ github.event.workflow_run.workflow_id }}" --vars "run=${{ github.event.workflow_run.id }}" --out-trace $GITHUB_STEP_SUMMARY
              env:
                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
                  OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
                  OPENAI_API_TYPE: ${{ secrets.OPENAI_API_TYPE }}
                  OPENAI_API_BASE: ${{ secrets.OPENAI_API_BASE }}
                  GENAISCRIPT_VAR_BRANCH: ${{ github.event.workflow_run.head_branch }}