buildbot_nix/__init__.py

@@ -2,7 +2,7 @@ import json
 import multiprocessing
 import os
 import sys
-import uuid
+import graphlib
 from collections import defaultdict
 from collections.abc import Generator
 from dataclasses import dataclass
@@ -20,6 +20,12 @@ from buildbot.util import asyncSleep
 from buildbot.www.authz.endpointmatchers import EndpointMatcherBase, Match
 from buildbot.www.oauth2 import OAuth2Auth
 from buildbot.changes.gerritchangesource import GerritChangeSource
+from buildbot.reporters.utils import getURLForBuild
+from buildbot.reporters.utils import getURLForBuildrequest
+from buildbot.process.buildstep import CANCELLED
+from buildbot.process.buildstep import EXCEPTION
+from buildbot.process.buildstep import SUCCESS
+from buildbot.process.results import worst_status
 
 if TYPE_CHECKING:
     from buildbot.process.log import Log
@@ -32,8 +38,6 @@ from .github_projects import (
     slugify_project_name,
 )
 
-SKIPPED_BUILDER_NAME = "skipped-builds"
-
 log = Logger()
 
 class LixSystemsOAuth2(OAuth2Auth):
@@ -52,43 +56,52 @@ class GerritProject:
     # `project` field.
     name: str
 
-class BuildTrigger(Trigger):
+class BuildTrigger(steps.BuildStep):
-    """Dynamic trigger that creates a build for every attribute."""
-
     def __init__(
         self,
         builds_scheduler: str,
-        skipped_builds_scheduler: str,
         jobs: list[dict[str, Any]],
+        all_deps: dict[str, Any],
         **kwargs: Any,
     ) -> None:
-        if "name" not in kwargs:
-            kwargs["name"] = "trigger"
         self.jobs = jobs
+        self.all_deps = all_deps
         self.config = None
         self.builds_scheduler = builds_scheduler
-        self.skipped_builds_scheduler = skipped_builds_scheduler
+        self._result_list = []
-        Trigger.__init__(
+        self.ended = False
-            self,
+        self.waitForFinishDeferred = None
-            waitForFinish=True,
+        self.brids = []
-            schedulerNames=[builds_scheduler, skipped_builds_scheduler],
+        self.description = f"building {len(jobs)} hydra jobs"
-            haltOnFailure=True,
+        super().__init__(**kwargs)
-            flunkOnFailure=True,
+
-            sourceStamps=[],
+    def interrupt(self, reason):
-            alwaysUseLatest=False,
+        # We cancel the buildrequests, as the data api handles
-            updateSourceStamp=False,
+        # both cases:
-            **kwargs,
+        # - build started: stop is sent,
+        # - build not created yet: related buildrequests are set to CANCELLED.
+        # Note that there is an identified race condition though (more details
+        # are available at buildbot.data.buildrequests).
+        for brid in self.brids:
+            self.master.data.control(
+                "cancel", {'reason': 'parent build was interrupted'}, ("buildrequests", brid)
             )
+        if self.running and not self.ended:
+            self.ended = True
+            # if we are interrupted because of a connection lost, we interrupt synchronously
+            if self.build.conn is None and self.waitForFinishDeferred is not None:
+                self.waitForFinishDeferred.cancel()
 
-    def createTriggerProperties(self, props: Any) -> Any:  # noqa: N802
+    def getSchedulerByName(self, name):
-        return props
+        schedulers = self.master.scheduler_manager.namedServices
+        if name not in schedulers:
+            raise ValueError(f"unknown triggered scheduler: {repr(name)}")
+        sch = schedulers[name]
+        # todo: check ITriggerableScheduler
+        return sch
 
-    def getSchedulersAndProperties(self) -> list[tuple[str, Properties]]:  # noqa: N802
+    def schedule_one(self, build_props, job):
-        build_props = self.build.getProperties()
         source = f"nix-eval-lix"
-
-        triggered_schedulers = []
-        for job in self.jobs:
         attr = job.get("attr", "eval-error")
         name = attr
         name = f"hydraJobs.{name}"
@@ -100,12 +113,7 @@ class BuildTrigger(Trigger):
 
         if error is not None:
             props.setProperty("error", error, source)
-                triggered_schedulers.append((self.skipped_builds_scheduler, props))
+            return (self.builds_scheduler, props)
-                continue
-
-            if job.get("isCached"):
-                triggered_schedulers.append((self.skipped_builds_scheduler, props))
-                continue
 
         drv_path = job.get("drvPath")
         system = job.get("system")
@@ -118,16 +126,136 @@ class BuildTrigger(Trigger):
         props.setProperty("system", system, source)
         props.setProperty("drv_path", drv_path, source)
         props.setProperty("out_path", out_path, source)
-            # we use this to identify builds when running a retry
+        props.setProperty("isCached", job.get("isCached"), source)
-            props.setProperty("build_uuid", str(uuid.uuid4()), source)
 
-            triggered_schedulers.append((self.builds_scheduler, props))
+        return (self.builds_scheduler, props)
-        return triggered_schedulers
+
+    @defer.inlineCallbacks
+    def _add_results(self, brid):
+        @defer.inlineCallbacks
+        def _is_buildrequest_complete(brid):
+            buildrequest = yield self.master.db.buildrequests.getBuildRequest(brid)
+            return buildrequest['complete']
+
+        event = ('buildrequests', str(brid), 'complete')
+        yield self.master.mq.waitUntilEvent(event, lambda: _is_buildrequest_complete(brid))
+        builds = yield self.master.db.builds.getBuilds(buildrequestid=brid)
+        for build in builds:
+            self._result_list.append(build["results"])
+        self.updateSummary()
+
+    def prepareSourcestampListForTrigger(self):
+        ss_for_trigger = {}
+        objs_from_build = self.build.getAllSourceStamps()
+        for ss in objs_from_build:
+            ss_for_trigger[ss.codebase] = ss.asDict()
+
+        trigger_values = [ss_for_trigger[k] for k in sorted(ss_for_trigger.keys())]
+        return trigger_values
+
+    @defer.inlineCallbacks
+    def run(self):
+        self.running = True
+        build_props = self.build.getProperties()
+        source = f"nix-eval-lix"
+
+        builds_to_schedule = list(self.jobs)
+        build_schedule_order = []
+        sorter = graphlib.TopologicalSorter(self.all_deps)
+        for item in sorter.static_order():
+            i = 0
+            while i < len(builds_to_schedule):
+                if item == builds_to_schedule[i].get("drvPath"):
+                    build_schedule_order.append(builds_to_schedule[i])
+                    del builds_to_schedule[i]
+                else:
+                    i += 1
+
+        done = []
+        scheduled = []
+        failed = {}
+        all_results = SUCCESS
+        ss_for_trigger = self.prepareSourcestampListForTrigger()
+        while not self.ended and (len(build_schedule_order) > 0 or len(scheduled) > 0):
+            print('Scheduling..')
+            schedule_now = []
+            for build in list(build_schedule_order):
+                if self.all_deps.get(build.get("drvPath"), []) == []:
+                    build_schedule_order.remove(build)
+                    schedule_now.append(build)
+            if len(schedule_now) == 0:
+                print('    No builds to schedule found.')
+            for job in schedule_now:
+                print(f"    - {job.get('attr')}")
+                (scheduler, props) = self.schedule_one(build_props, job)
+                scheduler = self.getSchedulerByName(scheduler)
+
+                idsDeferred, resultsDeferred = scheduler.trigger(
+                    waited_for = True,
+                    sourcestamps = ss_for_trigger,
+                    set_props = props,
+                    parent_buildid = self.build.buildid,
+                    parent_relationship = "Triggered from",
+                )
+
+                brids = {}
+                try:
+                    _, brids = yield idsDeferred
+                except Exception as e:
+                    yield self.addLogWithException(e)
+                    results = EXCEPTION
+                scheduled.append((job, brids, resultsDeferred))
+
+                for brid in brids.values():
+                    url = getURLForBuildrequest(self.master, brid)
+                    yield self.addURL(f"{scheduler.name} #{brid}", url)
+                    self._add_results(brid)
+                    self.brids.append(brid)
+            print('Waiting..')
+            wait_for_next = defer.DeferredList([results for _, _, results in scheduled], fireOnOneCallback = True, fireOnOneErrback=True)
+            self.waitForFinishDeferred = wait_for_next
+            results, index = yield wait_for_next
+            job, brids, _ = scheduled[index]
+            done.append((job, brids, results))
+            del scheduled[index]
+            result = results[0]
+            print(f'    Found finished build {job.get("attr")}, result {util.Results[result].upper()}')
+            if result != SUCCESS:
+                failed_checks = []
+                failed_paths = [job.get('drvPath')]
+                removed = []
+                while True:
+                    old_paths = list(failed_paths)
+                    for build in list(build_schedule_order):
+                        deps = self.all_deps.get(build.get("drvPath"), [])
+                        for path in old_paths:
+                            if path in deps:
+                                failed_checks.append(build)
+                                failed_paths.append(build.get("drvPath"))
+                                build_schedule_order.remove(build)
+                                removed.append(build.get("attr"))
+                                failed[build.get("attr")] = (f"dependency {job.get('attr')} failed", [])
+
+                                break
+                    if old_paths == failed_paths:
+                        break
+                failed[job.get("attr")] = (
+                    "failed",
+                    [ getURLForBuildrequest(self.master, brid) for brid in brids.values() ]
+                )
+                print('    Removed jobs: ' + ', '.join(removed))
+            all_results = worst_status(result, all_results)
+            print(f'    New result: {util.Results[all_results].upper()}')
+            for dep in self.all_deps:
+                if job.get("drvPath") in self.all_deps[dep]:
+                    self.all_deps[dep].remove(job.get("drvPath"))
+        print('Done!')
+        build_props.setProperty("failed_builds", failed, "nix-eval-lix")
+        if self.ended:
+            return util.CANCELLED
+        return all_results
 
     def getCurrentSummary(self) -> dict[str, str]:  # noqa: N802
-        """The original build trigger will the generic builder name `nix-build` in this case, which is not helpful"""
-        if not self.triggeredNames:
-            return {"step": "running"}
         summary = []
         if self._result_list:
             for status in ALL_RESULTS:
@@ -178,13 +306,42 @@ class NixEvalCommand(buildstep.ShellMixin, steps.BuildStep):
                 if not system or system in self.supported_systems:  # report eval errors
                     filtered_jobs.append(job)
 
+            drv_show_log: Log = yield self.getLog("stdio")
+            drv_show_log.addStdout(f"getting derivation infos\n")
+            cmd = yield self.makeRemoteShellCommand(
+                stdioLogName=None,
+                collectStdout=True,
+                command=(
+                    ["nix", "derivation", "show", "--recursive"]
+                    + [ drv for drv in (job.get("drvPath") for job in filtered_jobs) if drv ]
+                ),
+            )
+            yield self.runCommand(cmd)
+            drv_show_log.addStdout(f"done\n")
+            try:
+                drv_info = json.loads(cmd.stdout)
+            except json.JSONDecodeError as e:
+                msg = f"Failed to parse `nix derivation show` output for {cmd.command}"
+                raise BuildbotNixError(msg) from e
+            all_deps = dict()
+            for drv, info in drv_info.items():
+                all_deps[drv] = set(info.get("inputDrvs").keys())
+            def closure_of(key, deps):
+                r, size = set([key]), 0
+                while len(r) != size:
+                    size = len(r)
+                    r.update(*[ deps[k] for k in r ])
+                return r.difference([key])
+            job_set = set(( drv for drv in ( job.get("drvPath") for job in filtered_jobs ) if drv ))
+            all_deps = { k: list(closure_of(k, all_deps).intersection(job_set)) for k in job_set }
+
             self.build.addStepsAfterCurrentStep(
                 [
                     BuildTrigger(
                         builds_scheduler=f"lix-nix-build",
-                        skipped_builds_scheduler=f"lix-nix-skipped-build",
                         name="build flake",
                         jobs=filtered_jobs,
+                        all_deps=all_deps,
                     ),
                 ],
             )
@@ -192,37 +349,6 @@ class NixEvalCommand(buildstep.ShellMixin, steps.BuildStep):
         return result
 
 
-# FIXME this leaks memory... but probably not enough that we care
-class RetryCounter:
-    def __init__(self, retries: int) -> None:
-        self.builds: dict[uuid.UUID, int] = defaultdict(lambda: retries)
-
-    def retry_build(self, build_id: uuid.UUID) -> int:
-        retries = self.builds[build_id]
-        if retries > 1:
-            self.builds[build_id] = retries - 1
-            return retries
-        return 0
-
-
-# For now we limit this to two. Often this allows us to make the error log
-# shorter because we won't see the logs for all previous succeeded builds
-RETRY_COUNTER = RetryCounter(retries=2)
-
-
-class EvalErrorStep(steps.BuildStep):
-    """Shows the error message of a failed evaluation."""
-
-    @defer.inlineCallbacks
-    def run(self) -> Generator[Any, object, Any]:
-        error = self.getProperty("error")
-        attr = self.getProperty("attr")
-        # show eval error
-        error_log: Log = yield self.addLog("nix_error")
-        error_log.addStderr(f"{attr} failed to evaluate:\n{error}")
-        return util.FAILURE
-
-
 class NixBuildCommand(buildstep.ShellMixin, steps.BuildStep):
     """Builds a nix derivation."""
 
@@ -232,16 +358,25 @@ class NixBuildCommand(buildstep.ShellMixin, steps.BuildStep):
 
     @defer.inlineCallbacks
     def run(self) -> Generator[Any, object, Any]:
+        if error := self.getProperty("error"):
+            attr = self.getProperty("attr")
+            # show eval error
+            error_log: Log = yield self.addLog("nix_error")
+            error_log.addStderr(f"{attr} failed to evaluate:\n{error}")
+            return util.FAILURE
+
+        if self.getProperty("isCached"):
+            yield self.addCompleteLog(
+                "cached outpath from previous builds",
+                # buildbot apparently hides the first line in the ui?
+                f'\n{self.getProperty("out_path")}\n')
+            return util.SKIPPED
+
         # run `nix build`
         cmd: remotecommand.RemoteCommand = yield self.makeRemoteShellCommand()
         yield self.runCommand(cmd)
 
-        res = cmd.results()
+        return cmd.results()
-        if res == util.FAILURE:
-            retries = RETRY_COUNTER.retry_build(self.getProperty("build_uuid"))
-            if retries > 0:
-                return util.RETRY
-        return res
 
 
 class UpdateBuildOutput(steps.BuildStep):
@@ -269,32 +404,6 @@ class UpdateBuildOutput(steps.BuildStep):
         return util.SUCCESS
 
 
-# The builtin retry mechanism doesn't seem to work for github,
-# since github is sometimes not delivering the pull request ref fast enough.
-class GitWithRetry(steps.Git):
-    @defer.inlineCallbacks
-    def run_vc(
-        self,
-        branch: str,
-        revision: str,
-        patch: str,
-    ) -> Generator[Any, object, Any]:
-        retry_counter = 0
-        while True:
-            try:
-                res = yield super().run_vc(branch, revision, patch)
-            except Exception as e:  # noqa: BLE001
-                retry_counter += 1
-                if retry_counter == 3:
-                    msg = "Failed to clone"
-                    raise BuildbotNixError(msg) from e
-                log: Log = yield self.addLog("log")
-                yield log.addStderr(f"Retrying git clone (error: {e})\n")
-                yield asyncSleep(2 << retry_counter)  # 2, 4, 8
-            else:
-                return res
-
-
 def nix_eval_config(
     project: GerritProject,
     gerrit_private_key: str,
@@ -318,8 +427,12 @@ def nix_eval_config(
             sshPrivateKey=gerrit_private_key
         ),
     )
+    # use one gcroots directory per worker. this should be scoped to the largest unique resource
+    # in charge of builds (ie, buildnumber is too narrow) to not litter the system with permanent
+    # gcroots in case of worker restarts.
+    # TODO perhaps we should clean the entire /drvs/ directory up too during startup.
     drv_gcroots_dir = util.Interpolate(
-        "/nix/var/nix/gcroots/per-user/buildbot-worker/%(prop:project)s/drvs/",
+        "/nix/var/nix/gcroots/per-user/buildbot-worker/%(prop:project)s/drvs/%(prop:workername)s/",
     )
 
     factory.addStep(
@@ -356,6 +469,7 @@ def nix_eval_config(
                 "-rf",
                 drv_gcroots_dir,
             ],
+            alwaysRun=True,
         ),
     )
 
@@ -368,25 +482,9 @@ def nix_eval_config(
     )
 
 
-@dataclass
-class CachixConfig:
-    name: str
-    signing_key_secret_name: str | None = None
-    auth_token_secret_name: str | None = None
-
-    def cachix_env(self) -> dict[str, str]:
-        env = {}
-        if self.signing_key_secret_name is not None:
-            env["CACHIX_SIGNING_KEY"] = util.Secret(self.signing_key_secret_name)
-        if self.auth_token_secret_name is not None:
-            env["CACHIX_AUTH_TOKEN"] = util.Secret(self.auth_token_secret_name)
-        return env
-
-
 def nix_build_config(
     project: GerritProject,
     worker_names: list[str],
-    cachix: CachixConfig | None = None,
     outputs_path: Path | None = None,
 ) -> util.BuilderConfig:
     """Builds one nix flake attribute."""
@@ -417,19 +515,6 @@ def nix_build_config(
             haltOnFailure=True,
         ),
     )
-    if cachix:
-        factory.addStep(
-            steps.ShellCommand(
-                name="Upload cachix",
-                env=cachix.cachix_env(),
-                command=[
-                    "cachix",
-                    "push",
-                    cachix.name,
-                    util.Interpolate("result-%(prop:attr)s"),
-                ],
-            ),
-        )
 
     factory.addStep(
         steps.ShellCommand(
@@ -471,38 +556,6 @@ def nix_build_config(
     )
 
 
-def nix_skipped_build_config(
-    project: GerritProject,
-    worker_names: list[str],
-) -> util.BuilderConfig:
-    """Dummy builder that is triggered when a build is skipped."""
-    factory = util.BuildFactory()
-    factory.addStep(
-        EvalErrorStep(
-            name="Nix evaluation",
-            doStepIf=lambda s: s.getProperty("error"),
-            hideStepIf=lambda _, s: not s.getProperty("error"),
-        ),
-    )
-
-    # This is just a dummy step showing the cached build
-    factory.addStep(
-        steps.BuildStep(
-            name="Nix build (cached)",
-            doStepIf=lambda _: False,
-            hideStepIf=lambda _, s: s.getProperty("error"),
-        ),
-    )
-    return util.BuilderConfig(
-        name=f"{project.name}/nix-skipped-build",
-        project=project.name,
-        workernames=worker_names,
-        collapseRequests=False,
-        env={},
-        factory=factory,
-    )
-
-
 def read_secret_file(secret_name: str) -> str:
     directory = os.environ.get("CREDENTIALS_DIRECTORY")
     if directory is None:
@@ -520,7 +573,6 @@ def config_for_project(
     nix_eval_worker_count: int,
     nix_eval_max_memory_size: int,
     eval_lock: util.MasterLock,
-    cachix: CachixConfig | None = None,
     outputs_path: Path | None = None,
 ) -> Project:
     config["projects"].append(Project(project.name))
@@ -540,11 +592,6 @@ def config_for_project(
                 name=f"{project.name}-nix-build",
                 builderNames=[f"{project.name}/nix-build"],
             ),
-            # this is triggered from `nix-eval` when the build is skipped
-            schedulers.Triggerable(
-                name=f"{project.name}-nix-skipped-build",
-                builderNames=[f"{project.name}/nix-skipped-build"],
-            ),
             # allow to manually trigger a nix-build
             schedulers.ForceScheduler(
                 name=f"{project.name}-force",
@@ -582,10 +629,8 @@ def config_for_project(
             nix_build_config(
                 project,
                 worker_names,
-                cachix=cachix,
                 outputs_path=outputs_path,
             ),
-            nix_skipped_build_config(project, [SKIPPED_BUILDER_NAME]),
         ],
     )
 
@@ -608,62 +653,22 @@ def gerritReviewCB(builderName, build, result, master, arg):
     if builderName != 'lix/nix-eval':
         return dict()
 
-    all_checks = {}
+    failed = build['properties'].get('failed_builds', [{}])[0]
-    for step in build['steps']:
-        if step['name'] != 'build flake':
-            continue
 
-        for url in step['urls']:
+    labels = {
-            if url['name'].startswith('success: hydraJobs.'):
+        'Verified': -1 if failed else 1,
-                path = url['name'].split(' ')[1]
+    }
-                all_checks[path] = (True, url['url'])
-            elif url['name'].startswith('failure: hydraJobs.'):
-                path = url['name'].split(' ')[1]
-                all_checks[path] = (False, url['url'])
-
-    collected_oses = {}
-    for check in all_checks:
-        arch = check.split('.')[-1]
-        if not arch.endswith('-linux') and not arch.endswith('-darwin'):
-            # Not an architecture-specific job, just a test
-            os = "test"
-        else:
-            os = arch.split('-')[1]
-        (success, failure) = collected_oses.get(os, (0, 0))
-        if all_checks[check][0]:
-            success += 1
-        else:
-            failure += 1
-
-        collected_oses[os] = (success, failure)
-    labels = {}
-
-    if 'linux' in collected_oses:
-        (success, failure) = collected_oses['linux']
-        if success > 0 and failure == 0:
-            labels['Verified-On-Linux'] = 1
-        elif failure > 0:
-            labels['Verified-On-Linux'] = -1
-
-    if 'darwin' in collected_oses:
-        (success, failure) = collected_oses['darwin']
-        if success > 0 and failure == 0:
-            labels['Verified-On-Darwin'] = 1
-        elif failure > 0:
-            labels['Verified-On-Darwin'] = -1
 
     message =  "Buildbot finished compiling your patchset!\n"
     message += "The result is: %s\n" % util.Results[result].upper()
     if result != util.SUCCESS:
-        successful_checks = []
+        message += "\nFailed checks:\n"
-        failed_checks = []
+        for check, context in sorted(failed.items()):
-        for check in all_checks:
+            how, urls = context
-            if not all_checks[check][0]:
+            message += f" - {check}: {how}"
-                failed_checks.append(f" - {check} (see {all_checks[check][1]})")
+            if urls:
-
+                message += f" (see {', '.join(urls)})"
-        if len(failed_checks) > 0:
+            message += "\n"
-            message += "Failed checks:\n" + "\n".join(failed_checks) + "\n"
-
 
     if arg:
         message += "\nFor more details visit:\n"
@@ -724,7 +729,6 @@ class GerritNixConfigurator(ConfiguratorBase):
         nix_eval_worker_count: int | None,
         nix_eval_max_memory_size: int,
         nix_workers_secret_name: str = "buildbot-nix-workers",  # noqa: S107
-        cachix: CachixConfig | None = None,
         outputs_path: str | None = None,
     ) -> None:
         super().__init__()
@@ -737,7 +741,6 @@ class GerritNixConfigurator(ConfiguratorBase):
         self.nix_supported_systems = nix_supported_systems
         self.gerrit_change_source = GerritChangeSource(gerrit_server, gerrit_user, gerritport=gerrit_port, identity_file=gerrit_sshkey_path)
         self.url = url
-        self.cachix = cachix
         if outputs_path is None:
             self.outputs_path = None
         else:
@@ -769,12 +772,10 @@ class GerritNixConfigurator(ConfiguratorBase):
             self.nix_eval_worker_count or multiprocessing.cpu_count(),
             self.nix_eval_max_memory_size,
             eval_lock,
-            self.cachix,
             self.outputs_path,
         )
 
         config["change_source"] = self.gerrit_change_source
-        config["workers"].append(worker.LocalWorker(SKIPPED_BUILDER_NAME))
         config["services"].append(
             reporters.GerritStatusPush(self.gerrit_server, self.gerrit_user,
                                        port=2022,

examples/default.nix

@@ -46,14 +46,6 @@ in
           # optional nix-eval-jobs settings
           # evalWorkerCount = 8; # limit number of concurrent evaluations
           # evalMaxMemorySize = "2048"; # limit memory usage per evaluation
-
-          # optional cachix
-          #cachix = {
-          #  name = "my-cachix";
-          #  # One of the following is required:
-          #  signingKey = "/var/lib/secrets/cachix-key";
-          #  authToken = "/var/lib/secrets/cachix-token";
-          #};
         };
       })
       buildbot-nix.nixosModules.buildbot-master

nix/coordinator.nix

@@ -15,25 +15,6 @@ in
         default = "postgresql://@/buildbot";
         description = "Postgresql database url";
       };
-      cachix = {
-        name = lib.mkOption {
-          type = lib.types.nullOr lib.types.str;
-          default = null;
-          description = "Cachix name";
-        };
-
-        signingKeyFile = lib.mkOption {
-          type = lib.types.nullOr lib.types.path;
-          default = null;
-          description = "Cachix signing key";
-        };
-
-        authTokenFile = lib.mkOption {
-          type = lib.types.nullOr lib.types.str;
-          default = null;
-          description = "Cachix auth token";
-        };
-      };
       workersFile = lib.mkOption {
         type = lib.types.path;
         description = "File containing a list of nix workers";
@@ -88,13 +69,6 @@ in
       isSystemUser = true;
     };
 
-    assertions = [
-      {
-        assertion = cfg.cachix.name != null -> cfg.cachix.signingKeyFile != null || cfg.cachix.authTokenFile != null;
-        message = "if cachix.name is provided, then cachix.signingKeyFile and cachix.authTokenFile must be set";
-      }
-    ];
-
     services.buildbot-master = {
       enable = true;
 
@@ -106,7 +80,7 @@ in
       home = "/var/lib/buildbot";
       extraImports = ''
         from datetime import timedelta
-        from buildbot_nix import GerritNixConfigurator, CachixConfig
+        from buildbot_nix import GerritNixConfigurator
       '';
       configurators = [
         ''
@@ -150,11 +124,7 @@ in
         LoadCredential = [
           "buildbot-nix-workers:${cfg.workersFile}"
           "buildbot-oauth2-secret:${cfg.oauth2SecretFile}"
-        ]
+        ];
-        ++ lib.optional (cfg.cachix.signingKeyFile != null)
-          "cachix-signing-key:${builtins.toString cfg.cachix.signingKeyFile}"
-        ++ lib.optional (cfg.cachix.authTokenFile != null)
-          "cachix-auth-token:${builtins.toString cfg.cachix.authTokenFile}";
       };
     };