# This is our main "CI tests" workflow. It runs everything that should run on
# both PRs and merged commits, and for the latter reports failures to slack.
name: CI

env:
  # Our fuzz job, powered by OSS-Fuzz, fails periodically because we upgrade to
  # new Go versions very eagerly. OSS-Fuzz is a little more conservative, and
  # ends up being unable to compile our code.
  #
  # When this happens, we want to disable the fuzz target until OSS-Fuzz catches
  # up. However, we also don't want to forget to turn it back on when OSS-Fuzz
  # can once again build our code.
  #
  # This variable toggles the fuzz job between two modes:
  #  - false: we expect fuzzing to be happy, and should report failure if it's not.
  #  - true: we expect fuzzing is broken, and should report failure if it start working.
  TS_FUZZ_CURRENTLY_BROKEN: false
  # GOMODCACHE is the same definition on all OSes. Within the workspace, we use
  # toplevel directories "src" (for the checked out source code), and "gomodcache"
  # and other caches as siblings to follow.
  GOMODCACHE: ${{ github.workspace }}/gomodcache

on:
  push:
    branches:
      - "main"
      - "release-branch/*"
  pull_request:
    # all PRs on all branches
  merge_group:
    branches:
      - "main"

concurrency:
  # For PRs, later CI runs preempt previous ones. e.g. a force push on a PR
  # cancels running CI jobs and starts all new ones.
  #
  # For non-PR pushes, concurrency.group needs to be unique for every distinct
  # CI run we want to have happen. Use run_id, which in practice means all
  # non-PR CI runs will be allowed to run without preempting each other.
  group: ${{ github.workflow }}-$${{ github.pull_request.number || github.run_id }}
  cancel-in-progress: true

jobs:
  gomod-cache:
    runs-on: ubuntu-24.04
    outputs:
      cache-key: ${{ steps.hash.outputs.key }}
    steps:
      - name: Checkout
        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          path: src
      - name: Compute cache key from go.{mod,sum}
        id: hash
        run: echo "key=gomod-cross3-${{ hashFiles('src/go.mod', 'src/go.sum') }}" >> $GITHUB_OUTPUT
      # See if the cache entry already exists to avoid downloading it
      # and doing the cache write again.
      - id: check-cache
        uses: actions/cache/restore@v4
        with:
          path: gomodcache # relative to workspace; see env note at top of file
          key: ${{ steps.hash.outputs.key }}
          lookup-only: true
          enableCrossOsArchive: true
      - name: Download modules
        if: steps.check-cache.outputs.cache-hit != 'true'
        working-directory: src
        run: go mod download
      - name: Cache Go modules
        if: steps.check-cache.outputs.cache-hit != 'true'
        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
        with:
          path: gomodcache # relative to workspace; see env note at top of file
          key: ${{ steps.hash.outputs.key }}
          enableCrossOsArchive: true

  race-root-integration:
    runs-on: ubuntu-24.04
    needs: gomod-cache
    strategy:
      fail-fast: false # don't abort the entire matrix if one element fails
      matrix:
        include:
          - shard: '1/4'
          - shard: '2/4'
          - shard: '3/4'
          - shard: '4/4'
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: build test wrapper
      working-directory: src
      run: ./tool/go build -o /tmp/testwrapper ./cmd/testwrapper
    - name: integration tests as root
      working-directory: src
      run: PATH=$PWD/tool:$PATH /tmp/testwrapper -exec "sudo -E" -race ./tstest/integration/
      env:
        TS_TEST_SHARD: ${{ matrix.shard }}

  test:
    strategy:
      fail-fast: false # don't abort the entire matrix if one element fails
      matrix:
        include:
          - goarch: amd64
          - goarch: amd64
            buildflags: "-race"
            shard: '1/3'
          - goarch: amd64
            buildflags: "-race"
            shard: '2/3'
          - goarch: amd64
            buildflags: "-race"
            shard: '3/3'
          - goarch: "386" # thanks yaml
    runs-on: ubuntu-24.04
    needs: gomod-cache
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: Restore Cache
      uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        # Note: unlike the other setups, this is only grabbing the mod download
        # cache, rather than the whole mod directory, as the download cache
        # contains zips that can be unpacked in parallel faster than they can be
        # fetched and extracted by tar
        path: |
          ~/.cache/go-build
          ~\AppData\Local\go-build
        # The -2- here should be incremented when the scheme of data to be
        # cached changes (e.g. path above changes).
        key: ${{ github.job }}-${{ runner.os }}-${{ matrix.goarch }}-${{ matrix.buildflags }}-go-2-${{ hashFiles('**/go.sum') }}-${{ github.run_id }}
        restore-keys: |
          ${{ github.job }}-${{ runner.os }}-${{ matrix.goarch }}-${{ matrix.buildflags }}-go-2-${{ hashFiles('**/go.sum') }}
          ${{ github.job }}-${{ runner.os }}-${{ matrix.goarch }}-${{ matrix.buildflags }}-go-2-
    - name: build all
      if: matrix.buildflags == '' # skip on race builder
      working-directory: src
      run: ./tool/go build ${{matrix.buildflags}} ./...
      env:
        GOARCH: ${{ matrix.goarch }}
    - name: build variant CLIs
      if: matrix.buildflags == '' # skip on race builder
      working-directory: src
      run: |
        ./build_dist.sh --extra-small ./cmd/tailscaled
        ./build_dist.sh --box ./cmd/tailscaled
        ./build_dist.sh --extra-small --box ./cmd/tailscaled
        rm -f tailscaled
      env:
        GOARCH: ${{ matrix.goarch }}
    - name: get qemu # for tstest/archtest
      if: matrix.goarch == 'amd64' && matrix.buildflags == ''
      run: |
        sudo apt-get -y update
        sudo apt-get -y install qemu-user
    - name: build test wrapper
      working-directory: src
      run: ./tool/go build -o /tmp/testwrapper ./cmd/testwrapper
    - name: test all
      working-directory: src
      run: NOBASHDEBUG=true PATH=$PWD/tool:$PATH /tmp/testwrapper ./... ${{matrix.buildflags}}
      env:
        GOARCH: ${{ matrix.goarch }}
        TS_TEST_SHARD: ${{ matrix.shard }}
    - name: bench all
      working-directory: src
      run: ./tool/go test ${{matrix.buildflags}} -bench=. -benchtime=1x -run=^$ $(for x in $(git grep -l "^func Benchmark" | xargs dirname | sort | uniq); do echo "./$x"; done)
      env:
        GOARCH: ${{ matrix.goarch }}
    - name: check that no tracked files changed
      working-directory: src
      run: git diff --no-ext-diff --name-only --exit-code || (echo "Build/test modified the files above."; exit 1)
    - name: check that no new files were added
      working-directory: src
      run: |
        # Note: The "error: pathspec..." you see below is normal!
        # In the success case in which there are no new untracked files,
        # git ls-files complains about the pathspec not matching anything.
        # That's OK. It's not worth the effort to suppress. Please ignore it.
        if git ls-files --others --exclude-standard --directory --no-empty-directory --error-unmatch -- ':/*'
        then
          echo "Build/test created untracked files in the repo (file names above)."
          exit 1
        fi
    - name: Tidy cache
      working-directory: src
      shell: bash
      run: |
        find $(go env GOCACHE) -type f -mmin +90 -delete

  windows:
    # windows-8vpu is a 2022 GitHub-managed runner in our
    # org with 8 cores and 32 GB of RAM:
    # https://github.com/organizations/tailscale/settings/actions/github-hosted-runners/1
    runs-on: windows-8vcpu
    needs: gomod-cache
    name: Windows (${{ matrix.name || matrix.shard}})
    strategy:
      fail-fast: false # don't abort the entire matrix if one element fails
      matrix:
        include:
          - key: "win-bench"
            name: "benchmarks"
          - key: "win-tool-go"
            name: "./tool/go"
          - key: "win-shard-1-2"
            shard: "1/2"
          - key: "win-shard-2-2"
            shard: "2/2"
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src

    - name: Install Go
      if: matrix.key != 'win-tool-go'
      uses: actions/setup-go@d35c59abb061a4a6fb18e82ac0862c26744d6ab5 # v5.5.0
      with:
        go-version-file: src/go.mod
        cache: false

    - name: Restore Go module cache
      if: matrix.key != 'win-tool-go'
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true

    - name: Restore Cache
      if: matrix.key != 'win-tool-go'
      uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: |
          ~/.cache/go-build
          ~\AppData\Local\go-build
        # The -2- here should be incremented when the scheme of data to be
        # cached changes (e.g. path above changes).
        key: ${{ github.job }}-${{ matrix.key }}-go-2-${{ hashFiles('**/go.sum') }}-${{ github.run_id }}
        restore-keys: |
          ${{ github.job }}-${{ matrix.key }}-go-2-${{ hashFiles('**/go.sum') }}
          ${{ github.job }}-${{ matrix.key }}-go-2-

    - name: test-tool-go
      if: matrix.key == 'win-tool-go'
      working-directory: src
      run: ./tool/go version

    - name: test
      if: matrix.key != 'win-bench' && matrix.key != 'win-tool-go' # skip on bench builder
      working-directory: src
      run: go run ./cmd/testwrapper sharded:${{ matrix.shard }}

    - name: bench all
      if: matrix.key == 'win-bench'
      working-directory: src
      # Don't use -bench=. -benchtime=1x.
      # Somewhere in the layers (powershell?)
      # the equals signs cause great confusion.
      run: go test ./... -bench . -benchtime 1x -run "^$"

    - name: Tidy cache
      if: matrix.key != 'win-tool-go'
      working-directory: src
      shell: bash
      run: |
        find $(go env GOCACHE) -type f -mmin +90 -delete

  privileged:
    needs: gomod-cache
    runs-on: ubuntu-24.04
    container:
      image: golang:latest
      options: --privileged
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: chown
      working-directory: src
      run: chown -R $(id -u):$(id -g) $PWD
    - name: privileged tests
      working-directory: src
      run: ./tool/go test ./util/linuxfw ./derp/xdp

  vm:
    needs: gomod-cache
    runs-on: ["self-hosted", "linux", "vm"]
    # VM tests run with some privileges, don't let them run on 3p PRs.
    if: github.repository == 'tailscale/tailscale'
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: Run VM tests
      working-directory: src
      run: ./tool/go test ./tstest/integration/vms -v -no-s3 -run-vm-tests -run=TestRunUbuntu2004
      env:
        HOME: "/var/lib/ghrunner/home"
        TMPDIR: "/tmp"
        XDG_CACHE_HOME: "/var/lib/ghrunner/cache"

  cross: # cross-compile checks, build only.
    needs: gomod-cache
    strategy:
      fail-fast: false # don't abort the entire matrix if one element fails
      matrix:
        include:
          # Note: linux/amd64 is not in this matrix, because that goos/goarch is
          # tested more exhaustively in the 'test' job above.
          - goos: linux
            goarch: arm64
          - goos: linux
            goarch: "386" # thanks yaml
          - goos: linux
            goarch: loong64
          - goos: linux
            goarch: arm
            goarm: "5"
          - goos: linux
            goarch: arm
            goarm: "7"
          # macOS
          - goos: darwin
            goarch: amd64
          - goos: darwin
            goarch: arm64
          # Windows
          - goos: windows
            goarch: amd64
          - goos: windows
            goarch: arm64
          # BSDs
          - goos: freebsd
            goarch: amd64
          - goos: openbsd
            goarch: amd64

    runs-on: ubuntu-24.04
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src
    - name: Restore Cache
      uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        # Note: unlike the other setups, this is only grabbing the mod download
        # cache, rather than the whole mod directory, as the download cache
        # contains zips that can be unpacked in parallel faster than they can be
        # fetched and extracted by tar
        path: |
          ~/.cache/go-build
          ~\AppData\Local\go-build
        # The -2- here should be incremented when the scheme of data to be
        # cached changes (e.g. path above changes).
        key: ${{ github.job }}-${{ runner.os }}-${{ matrix.goos }}-${{ matrix.goarch }}-go-2-${{ hashFiles('**/go.sum') }}-${{ github.run_id }}
        restore-keys: |
          ${{ github.job }}-${{ runner.os }}-${{ matrix.goos }}-${{ matrix.goarch }}-go-2-${{ hashFiles('**/go.sum') }}
          ${{ github.job }}-${{ runner.os }}-${{ matrix.goos }}-${{ matrix.goarch }}-go-2-
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: build all
      working-directory: src
      run: ./tool/go build ./cmd/...
      env:
        GOOS: ${{ matrix.goos }}
        GOARCH: ${{ matrix.goarch }}
        GOARM: ${{ matrix.goarm }}
        CGO_ENABLED: "0"
    - name: build tests
      working-directory: src
      run: ./tool/go test -exec=true ./...
      env:
        GOOS: ${{ matrix.goos }}
        GOARCH: ${{ matrix.goarch }}
        CGO_ENABLED: "0"
    - name: Tidy cache
      working-directory: src
      shell: bash
      run: |
        find $(go env GOCACHE) -type f -mmin +90 -delete

  ios: # similar to cross above, but iOS can't build most of the repo. So, just
       # make it build a few smoke packages.
    runs-on: ubuntu-24.04
    needs: gomod-cache
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: build some
      working-directory: src
      run: ./tool/go build ./ipn/... ./ssh/tailssh ./wgengine/ ./types/... ./control/controlclient
      env:
        GOOS: ios
        GOARCH: arm64

  crossmin: # cross-compile for platforms where we only check cmd/tailscale{,d}
    needs: gomod-cache
    strategy:
      fail-fast: false # don't abort the entire matrix if one element fails
      matrix:
        include:
          # Plan9
          - goos: plan9
            goarch: amd64
          # AIX
          - goos: aix
            goarch: ppc64
          # Solaris
          - goos: solaris
            goarch: amd64
          # illumos
          - goos: illumos
            goarch: amd64

    runs-on: ubuntu-24.04
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src
    - name: Restore Cache
      uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        # Note: unlike the other setups, this is only grabbing the mod download
        # cache, rather than the whole mod directory, as the download cache
        # contains zips that can be unpacked in parallel faster than they can be
        # fetched and extracted by tar
        path: |
          ~/.cache/go-build
          ~\AppData\Local\go-build
        # The -2- here should be incremented when the scheme of data to be
        # cached changes (e.g. path above changes).
        key: ${{ github.job }}-${{ runner.os }}-${{ matrix.goos }}-${{ matrix.goarch }}-go-2-${{ hashFiles('**/go.sum') }}-${{ github.run_id }}
        restore-keys: |
          ${{ github.job }}-${{ runner.os }}-${{ matrix.goos }}-${{ matrix.goarch }}-go-2-${{ hashFiles('**/go.sum') }}
          ${{ github.job }}-${{ runner.os }}-${{ matrix.goos }}-${{ matrix.goarch }}-go-2-
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: build core
      working-directory: src
      run: ./tool/go build ./cmd/tailscale ./cmd/tailscaled
      env:
        GOOS: ${{ matrix.goos }}
        GOARCH: ${{ matrix.goarch }}
        GOARM: ${{ matrix.goarm }}
        CGO_ENABLED: "0"
    - name: Tidy cache
      working-directory: src
      shell: bash
      run: |
        find $(go env GOCACHE) -type f -mmin +90 -delete

  android:
    # similar to cross above, but android fails to build a few pieces of the
    # repo. We should fix those pieces, they're small, but as a stepping stone,
    # only test the subset of android that our past smoke test checked.
    runs-on: ubuntu-24.04
    needs: gomod-cache
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src
      # Super minimal Android build that doesn't even use CGO and doesn't build everything that's needed
      # and is only arm64. But it's a smoke build: it's not meant to catch everything. But it'll catch
      # some Android breakages early.
      # TODO(bradfitz): better; see https://github.com/tailscale/tailscale/issues/4482
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: build some
      working-directory: src
      run: ./tool/go install ./net/netns ./ipn/ipnlocal ./wgengine/magicsock/ ./wgengine/ ./wgengine/router/ ./wgengine/netstack ./util/dnsname/ ./ipn/ ./net/netmon ./wgengine/router/ ./tailcfg/ ./types/logger/ ./net/dns ./hostinfo ./version ./ssh/tailssh
      env:
        GOOS: android
        GOARCH: arm64

  wasm: # builds tsconnect, which is the only wasm build we support
    runs-on: ubuntu-24.04
    needs: gomod-cache
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src
    - name: Restore Cache
      uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        # Note: unlike the other setups, this is only grabbing the mod download
        # cache, rather than the whole mod directory, as the download cache
        # contains zips that can be unpacked in parallel faster than they can be
        # fetched and extracted by tar
        path: |
          ~/.cache/go-build
          ~\AppData\Local\go-build
        # The -2- here should be incremented when the scheme of data to be
        # cached changes (e.g. path above changes).
        key: ${{ github.job }}-${{ runner.os }}-go-2-${{ hashFiles('**/go.sum') }}-${{ github.run_id }}
        restore-keys: |
          ${{ github.job }}-${{ runner.os }}-go-2-${{ hashFiles('**/go.sum') }}
          ${{ github.job }}-${{ runner.os }}-go-2-
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: build tsconnect client
      working-directory: src
      run: ./tool/go build ./cmd/tsconnect/wasm ./cmd/tailscale/cli
      env:
        GOOS: js
        GOARCH: wasm
    - name: build tsconnect server
      working-directory: src
      # Note, no GOOS/GOARCH in env on this build step, we're running a build
      # tool that handles the build itself.
      run: |
        ./tool/go run ./cmd/tsconnect --fast-compression build
        ./tool/go run ./cmd/tsconnect --fast-compression build-pkg
    - name: Tidy cache
      working-directory: src
      shell: bash
      run: |
        find $(go env GOCACHE) -type f -mmin +90 -delete

  tailscale_go: # Subset of tests that depend on our custom Go toolchain.
    runs-on: ubuntu-24.04
    needs: gomod-cache
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
    - name: Set GOMODCACHE env
      run: echo "GOMODCACHE=$HOME/.cache/go-mod" >> $GITHUB_ENV
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: test tailscale_go
      run: ./tool/go test -tags=tailscale_go,ts_enable_sockstats ./net/sockstats/...


  fuzz:
    # This target periodically breaks (see TS_FUZZ_CURRENTLY_BROKEN at the top
    # of the file), so it's more complex than usual: the 'build fuzzers' step
    # might fail, and depending on the value of 'TS_FUZZ_CURRENTLY_BROKEN', that
    # might or might not be fine. The steps after the build figure out whether
    # the success/failure is expected, and appropriately pass/fail the job
    # overall accordingly.
    #
    # Practically, this means that all steps after 'build fuzzers' must have an
    # explicit 'if' condition, because the default condition for steps is
    # 'success()', meaning "only run this if no previous steps failed".
    if: github.event_name == 'pull_request'
    runs-on: ubuntu-24.04
    steps:
    - name: build fuzzers
      id: build
      uses: google/oss-fuzz/infra/cifuzz/actions/build_fuzzers@master
      # continue-on-error makes steps.build.conclusion be 'success' even if
      # steps.build.outcome is 'failure'. This means this step does not
      # contribute to the job's overall pass/fail evaluation.
      continue-on-error: true
      with:
       oss-fuzz-project-name: 'tailscale'
       dry-run: false
       language: go
    - name: report unexpectedly broken fuzz build
      if: steps.build.outcome == 'failure' && env.TS_FUZZ_CURRENTLY_BROKEN != 'true'
      run: |
        echo "fuzzer build failed, see above for why"
        echo "if the failure is due to OSS-Fuzz not being on the latest Go yet,"
        echo "set TS_FUZZ_CURRENTLY_BROKEN=true in .github/workflows/test.yml"
        echo "to temporarily disable fuzzing until OSS-Fuzz works again."
        exit 1
    - name: report unexpectedly working fuzz build
      if: steps.build.outcome == 'success' && env.TS_FUZZ_CURRENTLY_BROKEN == 'true'
      run: |
        echo "fuzzer build succeeded, but we expect it to be broken"
        echo "please set TS_FUZZ_CURRENTLY_BROKEN=false in .github/workflows/test.yml"
        echo "to reenable fuzz testing"
        exit 1
    - name: run fuzzers
      id: run
      # Run the fuzzers whenever they're able to build, even if we're going to
      # report a failure because TS_FUZZ_CURRENTLY_BROKEN is set to the wrong
      # value.
      if: steps.build.outcome == 'success'
      uses: google/oss-fuzz/infra/cifuzz/actions/run_fuzzers@master
      with:
        oss-fuzz-project-name: 'tailscale'
        fuzz-seconds: 150
        dry-run: false
        language: go
    - name: Set artifacts_path in env (workaround for actions/upload-artifact#176)
      if: steps.run.outcome != 'success' && steps.build.outcome == 'success'
      run: |
        echo "artifacts_path=$(realpath .)" >> $GITHUB_ENV
    - name: upload crash
      uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
      if: steps.run.outcome != 'success' && steps.build.outcome == 'success'
      with:
        name: artifacts
        path: ${{ env.artifacts_path }}/out/artifacts

  depaware:
    runs-on: ubuntu-24.04
    needs: gomod-cache
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src
    - name: Set GOMODCACHE env
      run: echo "GOMODCACHE=$HOME/.cache/go-mod" >> $GITHUB_ENV
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: check depaware
      working-directory: src
      run: make depaware

  go_generate:
    runs-on: ubuntu-24.04
    needs: gomod-cache
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: check that 'go generate' is clean
      working-directory: src
      run: |
        pkgs=$(./tool/go list ./... | grep -Ev 'dnsfallback|k8s-operator|xdp')
        ./tool/go generate $pkgs
        echo
        echo
        git diff --name-only --exit-code || (echo "The files above need updating. Please run 'go generate'."; exit 1)

  go_mod_tidy:
    runs-on: ubuntu-24.04
    needs: gomod-cache
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: check that 'go mod tidy' is clean
      working-directory: src
      run: |
        ./tool/go mod tidy
        echo
        echo
        git diff --name-only --exit-code || (echo "Please run 'go mod tidy'."; exit 1)

  licenses:
    runs-on: ubuntu-24.04
    needs: gomod-cache
    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: check licenses
      working-directory: src
      run: |
        grep -q TestLicenseHeaders *.go || (echo "Expected a test named TestLicenseHeaders"; exit 1)
        ./tool/go test -v -run=TestLicenseHeaders

  staticcheck:
    runs-on: ubuntu-24.04
    needs: gomod-cache
    name: staticcheck (${{ matrix.name }})
    strategy:
      fail-fast: false # don't abort the entire matrix if one element fails
      matrix:
        include:
          - name: "macOS"
            goos: "darwin"
            goarch: "arm64"
            flags: "--with-tags-all=darwin"
          - name: "Windows"
            goos: "windows"
            goarch: "amd64"
            flags: "--with-tags-all=windows"
          - name: "Linux"
            goos: "linux"
            goarch: "amd64"
            flags: "--with-tags-all=linux"
          - name: "Portable (1/4)"
            goos: "linux"
            goarch: "amd64"
            flags: "--without-tags-any=windows,darwin,linux --shard=1/4"
          - name: "Portable (2/4)"
            goos: "linux"
            goarch: "amd64"
            flags: "--without-tags-any=windows,darwin,linux --shard=2/4"
          - name: "Portable (3/4)"
            goos: "linux"
            goarch: "amd64"
            flags: "--without-tags-any=windows,darwin,linux --shard=3/4"
          - name: "Portable (4/4)"
            goos: "linux"
            goarch: "amd64"
            flags: "--without-tags-any=windows,darwin,linux --shard=4/4"

    steps:
    - name: checkout
      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
      with:
        path: src
    - name: Restore Go module cache
      uses: actions/cache/restore@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
      with:
        path: gomodcache
        key: ${{ needs.gomod-cache.outputs.cache-key }}
        enableCrossOsArchive: true
    - name: run staticcheck (${{ matrix.name }})
      working-directory: src
      run: |
        export GOROOT=$(./tool/go env GOROOT)
        ./tool/go run -exec \
          "env GOOS=${{ matrix.goos }} GOARCH=${{ matrix.goarch }}" \
           honnef.co/go/tools/cmd/staticcheck -- \
           $(./tool/go run ./tool/listpkgs --ignore-3p --goos=${{ matrix.goos }} --goarch=${{ matrix.goarch }} ${{ matrix.flags }} ./...)

  notify_slack:
    if: always()
    # Any of these jobs failing causes a slack notification.
    needs: 
      - android
      - test
      - windows
      - vm
      - cross
      - ios
      - wasm
      - tailscale_go
      - fuzz
      - depaware
      - go_generate
      - go_mod_tidy
      - licenses
      - staticcheck
    runs-on: ubuntu-24.04
    steps:
    - name: notify  
      # Only notify slack for merged commits, not PR failures.
      #
      # It may be tempting to move this condition into the job's 'if' block, but
      # don't: Github only collapses the test list into "everything is OK" if
      # all jobs succeeded. A skipped job results in the list staying expanded.
      # By having the job always run, but skipping its only step as needed, we
      # let the CI output collapse nicely in PRs.
      if: failure() && github.event_name == 'push'
      uses: slackapi/slack-github-action@91efab103c0de0a537f72a35f6b8cda0ee76bf0a # v2.1.1
      with:
        webhook: ${{ secrets.SLACK_WEBHOOK_URL }}
        webhook-type: incoming-webhook
        payload: |
          {
            "attachments": [{
              "title": "Failure: ${{ github.workflow }}",
              "title_link": "https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks",         
              "text": "${{ github.repository }}@${{ github.ref_name }}: <https://github.com/${{ github.repository }}/commit/${{ github.sha }}|${{ github.sha }}>",
              "fields": [{ "value": ${{ toJson(github.event.head_commit.message) }}, "short": false }],
              "footer": "${{ github.event.head_commit.committer.name }} at ${{ github.event.head_commit.timestamp }}",
              "color": "danger"
            }]
          }

  merge_blocker:
    if: always()
    runs-on: ubuntu-24.04
    needs:
      - android
      - test
      - windows
      - vm
      - cross
      - ios
      - wasm
      - tailscale_go
      - fuzz
      - depaware
      - go_generate
      - go_mod_tidy
      - licenses
      - staticcheck
    steps:
    - name: Decide if change is okay to merge
      if: github.event_name != 'push'
      uses: re-actors/alls-green@05ac9388f0aebcb5727afa17fcccfecd6f8ec5fe # v1.2.2
      with:
        jobs: ${{ toJSON(needs) }}

   # This waits on all the jobs which must never fail. Branch protection rules
   # enforce these. No flaky tests are allowed in these jobs. (We don't want flaky
   # tests anywhere, really, but a flaky test here prevents merging.)
  check_mergeability_strict:
    if: always()
    runs-on: ubuntu-24.04
    needs:
      - android
      - cross
      - crossmin
      - ios
      - tailscale_go
      - depaware
      - go_generate
      - go_mod_tidy
      - licenses
      - staticcheck
    steps:
    - name: Decide if change is okay to merge
      if: github.event_name != 'push'
      uses: re-actors/alls-green@05ac9388f0aebcb5727afa17fcccfecd6f8ec5fe # v1.2.2
      with:
        jobs: ${{ toJSON(needs) }}

  check_mergeability:
    if: always()
    runs-on: ubuntu-24.04
    needs:
      - check_mergeability_strict
      - test
      - windows
      - vm
      - wasm
      - fuzz
      - race-root-integration
      - privileged
    steps:
    - name: Decide if change is okay to merge
      if: github.event_name != 'push'
      uses: re-actors/alls-green@05ac9388f0aebcb5727afa17fcccfecd6f8ec5fe # v1.2.2
      with:
        jobs: ${{ toJSON(needs) }}