Merge branch 'master' into frcc-kvm

.github/workflows/diff-pr.yml

@@ -17,18 +17,10 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          ref: ${{ github.event.pull_request.head.sha }}
           fetch-depth: 0
 
-      - name: merge base branch
-        run: |
-          git config user.email "ci@localhost"
-          git config user.name "CI"
-          git fetch origin ${{ github.event.pull_request.base.ref }}
-          git merge --no-edit origin/${{ github.event.pull_request.base.ref }}
-
       - name: worktree base for diff
-        run: git worktree add "$RUNNER_TEMP/base" "origin/${{ github.event.pull_request.base.ref }}"
+        run: git worktree add "$RUNNER_TEMP/base" "${{ github.event.pull_request.base.sha }}"
 
       - name: build closures and render diff
         run: |

.github/workflows/flake-update.yml

@@ -5,19 +5,21 @@ on:
     - cron: "17 4 * * *"
   workflow_dispatch:
 
+permissions:
+  contents: write
+  pull-requests: write
+
 jobs:
   update:
     runs-on: nix
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
 
       - run: nix flake update -L
 
       - name: open/update PR
         env:
-          GH_TOKEN: ${{ secrets.BOT_TOKEN }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           API: ${{ github.api_url }}
           REPO: ${{ github.repository }}
         run: |

.github/workflows/lint.yml

@@ -19,18 +19,18 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: pick reporter
+        run: |
+          if [ "${{ github.event_name }}" = pull_request ]; then
+            echo "REPORTER=gitea-pr-review" >> "$GITHUB_ENV"
+          else
+            echo "REPORTER=local" >> "$GITHUB_ENV"
+          fi
+
       - name: run linters
         run: nix run -L .#ci -- lint . "$RUNNER_TEMP/findings"
 
       - name: report findings
-        if: always()
         env:
-          REVIEWDOG_GITEA_API_TOKEN: ${{ secrets.GITEA_TOKEN }}
+          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          GITEA_ADDRESS: ${{ github.server_url }}
+        run: nix run -L .#ci -- lint-report "$REPORTER" "$RUNNER_TEMP/findings"
-        run: |
-          if [ "${{ github.event_name }}" = pull_request ]; then
-            nix run -L .#ci -- lint-report gitea-pr-review "$RUNNER_TEMP/findings"
-          else
-            nix run -L .#ci -- lint-summary "$RUNNER_TEMP/findings" \
-              | tee -a "$GITHUB_STEP_SUMMARY"
-          fi

.github/workflows/vulnix.yml

@@ -5,6 +5,10 @@ on:
     - cron: "0 6 * * 1"
   workflow_dispatch:
 
+permissions:
+  contents: read
+  issues: write
+
 jobs:
   scan:
     runs-on: nix
@@ -21,7 +25,7 @@ jobs:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           API: ${{ github.api_url }}
           REPO: ${{ github.repository }}
-        run: 'nix run -L .#ci -- upsert-issue vulnix "vulnix: known vulnerabilities in system closure" "$RUNNER_TEMP/issue.md"'
+        run: nix run -L .#ci -- upsert-issue vulnix "vulnix: known vulnerabilities in system closure" "$RUNNER_TEMP/issue.md"
 
       - name: close resolved issue
         if: steps.scan.outputs.count == '0'

ci.nix

@@ -1,17 +1,9 @@
 { lib, pkgs }:
-let
-  # vulnix's bundled nix-2.34 broke its own --experimental-features detection
-  nixConf = pkgs.writeText "ci-nix.conf" "experimental-features = nix-command flakes";
-in
 # tools must track ci.py's subprocess calls; nix stays ambient (uses the
 # runner's own nix, not a pinned one).
 pkgs.writers.writePython3Bin "ci" {
   flakeIgnore = [ "E501" ];
-  libraries = [ pkgs.python3Packages.subprocess-tee ];
   makeWrapperArgs = [
-    "--set-default"
-    "NIX_USER_CONF_FILES"
-    (toString nixConf)
     "--prefix"
     "PATH"
     ":"

ci.py

@@ -6,9 +6,7 @@ import json
 import os
 import re
 import subprocess
-import subprocess_tee
 import sys
-import urllib.error
 import urllib.request
 from collections import Counter
 from pathlib import Path
@@ -19,18 +17,13 @@ def run(*args, **kw):
 
 
 def nix(*args):
-    # tee to stderr - stdout leaks into GITHUB_OUTPUT $() captures
+    return run("nix", "--extra-experimental-features", "nix-command flakes", "-L", *args, check=True, stdout=subprocess.PIPE).stdout
-    return subprocess_tee.run(("nix", "--extra-experimental-features", "nix-command flakes", "-L", *args), check=True, text=True, stdout=sys.stderr).stdout
 
 
 def git(*args, check=True):
     return run("git", *args, check=check, capture_output=True)
 
 
-class GiteaError(Exception):
-    pass
-
-
 def gitea(method, path, body=None):
     url = f'{os.environ["API"]}/repos/{os.environ["REPO"]}{path}'
     data = json.dumps(body).encode() if body is not None else None
@@ -38,20 +31,13 @@ def gitea(method, path, body=None):
     req.add_header("Authorization", f'token {os.environ["GH_TOKEN"]}')
     if data is not None:
         req.add_header("Content-Type", "application/json")
-    try:
+    with urllib.request.urlopen(req) as resp:
-        with urllib.request.urlopen(req) as resp:
+        raw = resp.read()
-            raw = resp.read()
-    except urllib.error.HTTPError as e:
-        try:
-            detail = json.loads(e.read()).get("message", e.reason)
-        except (json.JSONDecodeError, UnicodeDecodeError):
-            detail = e.reason
-        raise GiteaError(f"{method} {path}: {e.code} {detail}") from None
     return json.loads(raw) if raw else None
 
 
 def find_open_issue(label):
-    issues = gitea("GET", f"/issues?state=open&type=issues&labels={label}")
+    issues = gitea("GET", f"/issues?state=open&labels={label}")
     return issues[0] if issues else None
 
 
@@ -248,7 +234,7 @@ def format_vulnix(vulns):
     for v in vulns:
         for cve in v["affected_by"]:
             score = v.get("cvssv3_basescore", {}).get(cve)
-            desc = v.get("description", {}).get(cve, "").replace("\n", " ").replace("|", "∣")
+            desc = v.get("description", {}).get(cve, "")
             if len(desc) > 120:
                 desc = desc[:117] + "..."
             rows.append((v["pname"], v["version"], cve, score, desc))
@@ -376,63 +362,10 @@ def lint_report(args):
 
     codes = [reviewdog(f"{args.dir}/{name}", flags)
              for name, flags in LINTERS
-             if os.path.isfile(f"{args.dir}/{name}") and os.path.getsize(f"{args.dir}/{name}") > 0]
+             if os.path.getsize(f"{args.dir}/{name}") > 0]
     sys.exit(1 if any(codes) else 0)
 
 
-def has_findings(path):
-    return os.path.isfile(path) and os.path.getsize(path) > 0
-
-
-def fmt_rdjsonl(path):
-    lines = []
-    with open(path) as f:
-        for raw in f:
-            rec = json.loads(raw)
-            loc = rec["location"]
-            r = loc.get("range", {}).get("start")
-            pos = f"{loc['path']}:{r['line']}:{r['column']}" if r else loc["path"]
-            lines.append(f"- `{pos}`: {rec['message']}")
-    return "\n".join(lines)
-
-
-def fmt_errfmt(path):
-    lines = []
-    with open(path) as f:
-        for raw in f:
-            parts = raw.strip().split(">", 1)
-            if len(parts) == 2:
-                lines.append(f"- `{parts[0]}:{parts[1].split(':', 3)[-1].strip()}`" if ":" in parts[1] else f"- `{raw.strip()}`")
-            elif raw.strip():
-                lines.append(f"- `{raw.strip()}`")
-    return "\n".join(lines)
-
-
-def lint_summary(args):
-    sections = []
-    d = args.dir
-
-    if has_findings(f"{d}/nixfmt.diff"):
-        with open(f"{d}/nixfmt.diff") as f:
-            sections.append(f"## nixfmt\n\n```diff\n{f.read().rstrip()}\n```")
-
-    if has_findings(f"{d}/statix.errfmt"):
-        sections.append(f"## statix\n\n{fmt_errfmt(f'{d}/statix.errfmt')}")
-
-    if has_findings(f"{d}/deadnix.rdjsonl"):
-        sections.append(f"## deadnix\n\n{fmt_rdjsonl(f'{d}/deadnix.rdjsonl')}")
-
-    if has_findings(f"{d}/cycles.rdjsonl"):
-        sections.append(f"## systemd ordering cycles\n\n{fmt_rdjsonl(f'{d}/cycles.rdjsonl')}")
-
-    if sections:
-        print("\n\n".join(["# Lint findings"] + sections))
-        sys.exit(1)
-    else:
-        print("No lint findings.")
-        sys.exit(0)
-
-
 def post_comment(args):
     body = args.marker + "\n" + Path(args.body_file).read_text()
     pr = os.environ["PR"]
@@ -475,24 +408,16 @@ def open_pr(args):
 
     host = os.environ["API"].removesuffix("/api/v1")
     auth = base64.b64encode(f'token:{os.environ["GH_TOKEN"]}'.encode()).decode()
-    push = git("-c", f"http.extraHeader=Authorization: Basic {auth}",
+    git("-c", f"http.extraHeader=Authorization: Basic {auth}",
-               "push", "-f", f'{host}/{os.environ["REPO"]}.git', f"HEAD:{args.branch}",
+        "push", "-f", f'{host}/{os.environ["REPO"]}.git', f"HEAD:{args.branch}")
-               check=False)
-    if push.returncode != 0:
-        raise RuntimeError(f"git push failed:\n{push.stderr}")
 
-    pulls = gitea("GET", f"/pulls?state=open&base_branch={args.base}")
+    owner = os.environ["REPO"].split("/")[0]
-    existing = next((pr for pr in pulls if pr["head"]["ref"] == args.branch), None)
+    if gitea("GET", f"/pulls?state=open&head={owner}:{args.branch}"):
-    if existing:
-        print(f"PR #{existing['number']} already open, pushed update")
         return
     labels = [label_id(args.label)] if args.label else []
-    pr = gitea("POST", "/pulls",
+    gitea("POST", "/pulls",
-               {"title": args.title, "head": args.branch, "base": args.base,
+          {"title": args.title, "head": args.branch, "base": args.base,
-                "body": Path(args.body_file).read_text(), "labels": labels})
+           "body": Path(args.body_file).read_text(), "labels": labels})
-    if not pr or "number" not in pr:
-        raise GiteaError(f"POST /pulls: unexpected response: {json.dumps(pr)}")
-    print(f"opened PR #{pr['number']}")
 
 
 def main():
@@ -513,7 +438,6 @@ def main():
     command("vulnix", vulnix, "ref", "body_out")
     command("lint", lint, "target", "out")
     command("lint-report", lint_report, "reporter", "dir")
-    command("lint-summary", lint_summary, "dir")
     command("post-comment", post_comment, "marker", "body_file")
     command("upsert-issue", upsert_issue, "label", "title", "body_file")
     command("close-issue", close_issue, "label")

containers/common/overseer.nix

@@ -381,6 +381,6 @@ let
         };
       };
     };
-  inherit (c) hostAddr;
+  hostAddr = c.hostAddr;
 in
 c

containers/server-n0/git.nix

@@ -55,179 +55,151 @@ in
     net.expose.tcp = [ 3000 ];
   };
 
-  ci-runner =
+  ci-runner = mkVm {
-    mkVm {
+    name = "ci-runner";
-      name = "ci-runner";
+    includedInTests = false;
-      includedInTests = false;
+    net.access = [
-      net.access = [
+      {
-        {
+        to = "git";
-          to = "git";
+        tcp = [ 3000 ];
-          tcp = [ 3000 ];
+      }
-        }
+      { to = "@internet"; }
-        { to = "@internet"; }
+    ];
-      ];
+    svc.autoStart = true;
-      svc.autoStart = true;
+    resources.cpu = 4;
-      resources.cpu = 4;
+    resources.mem = "32G";
-      resources.mem = "32G";
+    resources.fs = [
-      resources.fs = [
+      {
-        {
+        proto = "virtiofs";
-          proto = "virtiofs";
+        tag = "nix-rw-store";
-          tag = "nix-rw-store";
+        source = "${ciRunnerData}/nix-rw-store";
-          source = "${ciRunnerData}/nix-rw-store";
+        mountPoint = "/nix/.rw-store";
-          mountPoint = "/nix/.rw-store";
+      }
-        }
+      {
-        {
+        proto = "virtiofs";
-          proto = "virtiofs";
+        tag = "docker-data";
-          tag = "nix-db";
+        source = "${ciRunnerData}/docker";
-          source = "${ciRunnerData}/nix-db";
+        mountPoint = "/var/lib/docker";
-          mountPoint = "/nix/var/nix/db";
+      }
-        }
+      {
-        {
+        proto = "virtiofs";
-          proto = "virtiofs";
+        tag = "runner-state";
-          tag = "docker-data";
+        source = "${ciRunnerData}/runner-state";
-          source = "${ciRunnerData}/docker";
+        mountPoint = "/var/lib/private/gitea-runner";
-          mountPoint = "/var/lib/docker";
+      }
-        }
+      {
-        {
+        proto = "virtiofs";
-          proto = "virtiofs";
+        tag = "runner-token";
-          tag = "runner-state";
+        source = ciRunnerSecrets;
-          source = "${ciRunnerData}/runner-state";
+        mountPoint = "/run/ci-runner-secrets";
-          mountPoint = "/var/lib/private/gitea-runner";
+        readOnly = true;
-        }
+      }
-        {
+      {
-          proto = "virtiofs";
+        proto = "virtiofs";
-          tag = "runner-token";
+        tag = "tmp";
-          source = ciRunnerSecrets;
+        source = "/tmp";
-          mountPoint = "/run/ci-runner-secrets";
+        mountPoint = "/tmp";
-          readOnly = true;
+      }
-        }
+    ];
-        {
+    guestConfig =
-          proto = "virtiofs";
+      {
-          tag = "tmp";
+        pkgs,
-          source = "/tmp";
+        utils,
-          mountPoint = "/tmp";
+        lib,
-        }
+        ...
-      ];
+      }:
-      guestConfig =
+      let
-        {
+        runnerInstanceName = "ci-runner";
-          pkgs,
-          utils,
-          lib,
-          ...
-        }:
-        let
-          runnerInstanceName = "ci-runner";
 
-          ciJobContents = with pkgs; [
+        ciJobContents = with pkgs; [
-            bashInteractive
+          bashInteractive
-            coreutils
+          coreutils
-            gitMinimal
+          gitMinimal
-            nixVersions.latest
+          nixVersions.latest
-            nodejs
+          nodejs
-            cacert
+          cacert
-            (writeTextDir "etc/nix/nix.conf" "experimental-features = nix-command flakes\n")
+          (writeTextDir "etc/nix/nix.conf" "experimental-features = nix-command flakes\n")
-          ];
+        ];
 
-          ciJobImage = pkgs.dockerTools.buildLayeredImage {
+        ciJobImage = pkgs.dockerTools.buildLayeredImage {
-            name = "ci-job-image";
+          name = "ci-job-image";
-            tag = "latest";
+          tag = "latest";
-            contents = ciJobContents;
+          contents = ciJobContents;
-            config = {
+          config = {
-              Cmd = [ "/bin/sh" ];
+            Cmd = [ "/bin/sh" ];
-              Env = [
+            Env = [
-                "PATH=${lib.makeBinPath ciJobContents}"
+              "PATH=${lib.makeBinPath ciJobContents}"
-                "SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt"
+              "SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt"
-                "NIX_SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt"
+              "NIX_SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt"
-                "NIX_REMOTE=daemon"
+              "NIX_REMOTE=daemon"
-              ];
+            ];
-            };
           };
-        in
+        };
-        {
+      in
-          boot.kernelModules = [ "kvm-intel" ];
+      {
-          boot.extraModprobeConfig = "options kvm_intel nested=1";
+        boot.kernelModules = [ "kvm-intel" ];
+        boot.extraModprobeConfig = "options kvm_intel nested=1";
 
-          # volume-mounted into CI containers; must be in VM's store so
+        # volume-mounted into CI containers; must be in VM's store so
-          # image symlinks (/bin/node etc.) resolve through the mount
+        # image symlinks (/bin/node etc.) resolve through the mount
-          system.extraDependencies = ciJobContents;
+        system.extraDependencies = ciJobContents;
 
-          microvm.writableStoreOverlay = "/nix/.rw-store";
+        microvm.writableStoreOverlay = "/nix/.rw-store";
 
-          nix.settings = {
+        nix.settings = {
-            experimental-features = [
+          experimental-features = [
-              "nix-command"
+            "nix-command"
-              "flakes"
+            "flakes"
+          ];
+          max-jobs = "auto";
+        };
+
+        nix.gc = {
+          automatic = true;
+          dates = "daily";
+          options = "--delete-older-than 14d";
+        };
+        # nix.optimise.automatic = true; - doesn't work with microvm.writableStoreOverlay
+
+        services.journald.extraConfig = "ForwardToConsole=yes";
+
+        virtualisation.containerd.enable = true;
+        virtualisation.containerd.settings.plugins."io.containerd.snapshotter.v1.overlayfs".mount_options = [ "userxattr" ];
+
+        virtualisation.docker.enable = true;
+        virtualisation.docker.extraOptions = "--containerd /run/containerd/containerd.sock";
+        systemd.services.docker.wants = [ "containerd.service" ];
+        systemd.services.docker.after = [ "containerd.service" ];
+
+        systemd.services.load-ci-job-image = {
+          description = "Load the CI job Docker image";
+          wantedBy = [ "multi-user.target" ];
+          after = [ "docker.service" ];
+          requires = [ "docker.service" ];
+          before = [ "gitea-runner-${utils.escapeSystemdPath runnerInstanceName}.service" ];
+          serviceConfig = {
+            Type = "oneshot";
+            RemainAfterExit = true;
+            ExecStart = "${lib.getExe' pkgs.docker "docker"} load -i ${ciJobImage}";
+          };
+        };
+
+        services.gitea-actions-runner.instances.${runnerInstanceName} = {
+          enable = true;
+          name = runnerInstanceName;
+          url = "http://git:3000/";
+          tokenFile = "/run/ci-runner-secrets/token";
+          labels = [
+            "nix:docker://ci-job-image:latest"
+          ];
+          settings.container = {
+            options = "--device=/dev/kvm --volume=/nix/store:/nix/store:ro --volume=/nix/var/nix/daemon-socket:/nix/var/nix/daemon-socket";
+            valid_volumes = [
+              "/nix/store"
+              "/nix/var/nix/daemon-socket"
             ];
-            max-jobs = "auto";
-            substituters = [ "https://microvm.cachix.org" ];
-            trusted-public-keys = [ "microvm.cachix.org-1:oXnBc6hRE3eX5rSYdRyMYXnfzcCxC7yKPTbZXALsqys=" ];
-          };
-
-          nix.settings = {
-            min-free = 5 * 1024 * 1024 * 1024;
-            max-free = 10 * 1024 * 1024 * 1024;
-          };
-          # nix.optimise.automatic = true; - doesn't work with microvm.writableStoreOverlay
-
-          services.openssh = {
-            enable = true;
-            settings = {
-              PermitRootLogin = "yes";
-              PermitEmptyPasswords = "yes";
-            };
-          };
-          users.users.root.initialHashedPassword = "";
-          services.journald.extraConfig = "ForwardToConsole=yes";
-
-          virtualisation.containerd.enable = true;
-          virtualisation.containerd.settings.plugins."io.containerd.snapshotter.v1.overlayfs".mount_options =
-            [ "userxattr" ];
-
-          virtualisation.docker.enable = true;
-          virtualisation.docker.extraOptions = "--containerd /run/containerd/containerd.sock";
-          virtualisation.docker.daemon.settings.exec-opts = [ "native.cgroupdriver=cgroupfs" ];
-          systemd.services.docker.wants = [ "containerd.service" ];
-          systemd.services.docker.after = [ "containerd.service" ];
-
-          systemd.services.load-ci-job-image = {
-            description = "Load the CI job Docker image";
-            wantedBy = [ "multi-user.target" ];
-            after = [ "docker.service" ];
-            requires = [ "docker.service" ];
-            before = [ "gitea-runner-${utils.escapeSystemdPath runnerInstanceName}.service" ];
-            serviceConfig = {
-              Type = "oneshot";
-              RemainAfterExit = true;
-              ExecStart = "${lib.getExe' pkgs.docker "docker"} load -i ${ciJobImage}";
-            };
-          };
-
-          services.gitea-actions-runner.instances.${runnerInstanceName} = {
-            enable = true;
-            name = runnerInstanceName;
-            url = "http://git:3000/";
-            tokenFile = "/run/ci-runner-secrets/token";
-            labels = [
-              "nix:docker://ci-job-image:latest"
-            ];
-            settings.container = {
-              options = "--device=/dev/kvm --volume=/nix/store:/nix/store:ro --volume=/nix/var/nix/daemon-socket:/nix/var/nix/daemon-socket";
-              valid_volumes = [
-                "/nix/store"
-                "/nix/var/nix/daemon-socket"
-              ];
-            };
           };
         };
-    }
-    // {
-      hostConfig = {
-        systemd.tmpfiles.rules = [
-          "d ${ciRunnerData}/nix-rw-store 0755 server server -"
-          "d ${ciRunnerData}/nix-db 0755 server server -"
-          "d ${ciRunnerData}/docker 0755 server server -"
-          "d ${ciRunnerData}/runner-state 0755 server server -"
-        ];
       };
-    };
+  };
 }

containers/server-n0/nginx.nix

@@ -210,6 +210,6 @@ let
     };
     inherit (setup) containerConfig;
   };
-  inherit (c) hostAddr;
+  hostAddr = c.hostAddr;
 in
 c

containers/server-n0/ssh.nix

@@ -67,10 +67,7 @@ let
       inherit name;
       inherit net resources;
       svc.autoStart = true;
-      isolation = {
+      isolation = { nixDaemon = nixDaemon; } // isolation;
-        inherit nixDaemon;
-      }
-      // isolation;
       traits = [ sshTrait ] ++ traits;
       packages = with pkgs; [ tmux ] ++ packages;
       miscProperties = self._sshpiperRegister routingInfo;
@@ -80,7 +77,8 @@ let
     containerConfig =
       { pkgs, ... }:
       {
-        users.users.runner.extraGroups = [ "kvm" ];
+        users.users.runner.extraGroups = [ "wheel" ];
+        security.sudo.wheelNeedsPassword = false;
         environment.systemPackages = [ pkgs.qemu_kvm ];
       };
   };

dsl.nix

@@ -572,10 +572,7 @@ rec {
               Gateway = hostAddr;
             };
             networkConfig.DNS = [ hostAddr ];
-            networkConfig.Domains = [
+            networkConfig.Domains = [ "~." "containers" ];
-              "~."
-              "containers"
-            ];
             linkConfig.RequiredForOnline = if allowInternet then "routable" else "degraded";
           };
           networking.enableIPv6 = false;

flake.nix

@@ -129,10 +129,11 @@
     {
       nixosConfigurations = lib.mapAttrs (_: host: host.hostCfg) allHosts;
 
-      inspect = lib.mapAttrs (
+      inspect = lib.mapAttrs
-        name: host:
+        (name: host:
-        pkgs.writeText "inspect-${name}.json" (builtins.toJSON (introspect.hostReport { inherit host; }))
+          pkgs.writeText "inspect-${name}.json"
-      ) allHosts;
+            (builtins.toJSON (introspect.hostReport { inherit host; })))
+        allHosts;
 
       packages.${system} = customPkgs // {
         inherit ci;

tests/server-n0/integration.py

@@ -205,7 +205,12 @@ with subtest("(isolation): edges are one-way"):
     server.fail(ct_connect("git", ADDR["nginx"], 443, timeout=2))
 
 with subtest("(isolation): host access allowlist"):
-    server.succeed(ct_connect("overseer", HOST_ADDR["overseer"], HOST_EXPORTER_PORT))
+    server.succeed(
+        net_cmd(
+            "overseer",
+            f"{CURL} -sf --max-time 5 http://{HOST_ADDR['overseer']}:{HOST_EXPORTER_PORT}/metrics >&2",
+        )
+    )
     for port in (HOST_EXPORTER_PORT, HOST_CADVISOR_PORT):
         server.fail(ct_connect("git", HOST_ADDR["git"], port, timeout=2))
         server.fail(ct_connect("git", HOST_ADDR["overseer"], port, timeout=2))