Hi Sumit,

Thanks for the feedback. I agree an interface would be better for the long
term. For example, a deployment could read bundle definitions directly from
S3 or an internal service, without wrapping the source in a command.

A new public extension point would be loaded by every component, so it
needs an AIP (or an amendment to AIP-66) as discussed in #73209. AIP-85 for
Dag importers is a precedent.

I suggest delivering the _cmd/_secret reload now to main (maybe we could
even backport to 3.4.1?). If you or Sameer want to pursue the interface,
let's start a separate AIP.


Shahar

On Fri, Oct 30, 2026 at 7:40 PM Sumit Maheshwari <[email protected]>
wrote:

> Personally, I prefer the interface approach as it aligns better with
> enterprise-grade software. That said, I am also fine with proceeding via
> the _cmd and _secret route for the time being.
>
> Thanks,
> Sumit
>
> On Fri, Oct 30, 2026 at 11:47 AM Shahar Epstein <[email protected]> wrote:
>
> > Hey Sameer and everyone,
> >
> > +1 to the revised scope in #74915.
> >
> > The need has come up several times: #61645, discussion #59799, #63928,
> and
> > #71111 all asked for this in different forms. I think it’s a good time to
> > add the feature.
> >
> > I think it can proceed without an AIP for the following reasons:
> >
> > 1. The revised scope adds no pluggable abstraction, config entry, API, or
> > DB migration. Reloading uses the existing dag_bundle_config_list format,
> > supplied through Airflow’s existing _cmd / _secret mechanism. The PR
> makes
> > that mechanism available for this key by marking it as sensitive.
> > 2. It’s opt-in. A value set through a plain environment variable or
> > airflow.cfg keeps today’s startup-only behavior. _CMD / _SECRET were not
> > available for this key before, so no existing deployment will start
> > reloading without an explicit change.
> > 3. The trust boundary does not change. Bundle definitions remain under
> the
> > Deployment Manager’s control; users cannot change them through Airflow.
> >
> > Neither of the two previous threads has received a reply yet. Sameer, I
> > suggest waiting few more days (let's say until Monday, Nov. 2nd) to give
> a
> > chance for others to comment on this thread, and following up with a
> [LAZY
> > CONSENSUS] thread on the revised scope if there are no responses by then,
> > or there's consensus.
> >
> > Disclosure: I helped Sameer narrow the scope and I’m reviewing the PR, so
> > please take that into account when weighing my comment.
> >
> >
> > Shahar
> >
> > On Sun, Oct 25, 2026 at 12:33 PM Sameer Raj via dev <
> > [email protected]>
> > wrote:
> >
> > > Hi everyone!
> > >
> > > Following up on this discussion, I would like to share the revised
> scope.
> > > The earlier proposal included a DagBundleProvider abstraction. I have
> > > dropped that abstraction from the current work. It can be proposed
> > > separately through a future AIP if needed. The new PR is limited to
> > > reloading the existing [dag_processor] dag_bundle_config_list through
> > > Airflow’s_CMD or_SECRET mechanism:
> > >
> > > https://github.com/apache/airflow/pull/74915
> > >
> > > Thanks to Shahar for helping me narrow down the scope and for reviewing
> > the
> > > approach.
> > >
> > > In our use case, we need to manage more than 500 DAG bundles, with
> > > additions being automated. Restarting or redeploying Airflow processes
> > > whenever a bundle is added makes this difficult. We want to fetch the
> > > bundle list from an internal API. A deployment managed command can call
> > > that API and return the same JSON list already accepted by
> > > dag_bundle_config_list. The command could also read a file, or the list
> > > could come from a secrets backend.
> > >
> > > The DAG processor checks for changes at
> > > bundle_refresh_check_interval. Users do not need to change their
> > > configuration unless they want to enable reload. Users only need to
> > > configure _CMD or _SECRET if they want reload.
> > >
> > > The expected behavior is:
> > >
> > >    - When a bundle is added, the Dag processor discovers it and starts
> > >    processing its files. Existing bundle instances are reused.
> > >    - When a bundle is removed, the processor stops processing it. An
> > >    unfiltered processor (without --bundle-name) marks it inactive, and
> > the
> > >    existing stale DAG scan marks its dags stale. A successful read
> > > containing
> > >    [] removes all bundles.
> > >    - Failed commands, unavailable secrets, wrong configs, invalid new
> > >    classpaths, and blank reads keep the last accepted list in that
> > process.
> > >    The source must return the complete list. Commands should return a
> non
> > > zero
> > >    exit on failure, rather than returning [].
> > >    - A fresh process has no previous list to fall back to. Invalid or
> > >    unavailable configuration prevents startup. A valid [] starts with
> no
> > >    bundles.
> > >    - Processors started with --bundle-name stop processing removed
> > bundles
> > >    locally, but never deactivate missing bundles globally (retaining
> > > existing
> > >    behaviour). A processor that sees the complete list is needed for
> > global
> > >    deactivation.
> > >    - Multiple Dag processors may see changes at different times (due to
> > >    variance in the refresh interval). Each unfiltered processor
> > reconciles
> > >    bundle in the database even when its own list has not changed, so it
> > can
> > >    correct a stale write from another processor. They eventually
> converge
> > > when
> > >    surviving processors see the same list and continue reconciling.
> > >
> > > All components, i.e. the DAG processor and workers that resolve bundles
> > > need access to the configuration source. Existing Dag runs should
> finish
> > > before removing a bundle if those runs need to complete, since tasks
> and
> > > callbacks can still need its definition.
> > >
> > > For v1, changing an existing bundle’s definition is rejected, and the
> > last
> > > accepted list is retained. This includes changing tracking_ref or
> > classpath
> > > etc. Such a change requires a new bundle name or restarting the
> affected
> > > components. New commits on the already configured branch continue to be
> > > picked up through the existing bundle refresh behavior. Supporting
> > changes
> > > to an existing bundle definition can be added later incase required!
> > >
> > > There is also an optional DagFileParseRequest.bundle_config field
> > > containing the accepted importer settings and team ownership. It allows
> > the
> > > parsing process (to parse the DAG) to use the configuration accepted by
> > its
> > > parent, without reading the command or secrets backend again and
> > > potentially seeing a different list. This does change the parser
> protocol
> > > but the compatibility handling is included in the PR
> > >
> > > The dag_bundle_config_list option is marked sensitive: true to enable
> > _CMD
> > > and _SECRET. This also means the option is hidden in configuration
> views
> > > that hide sensitive values. The Deployment Manager continues to control
> > the
> > > command or secrets backend and its credentials. No API for creating or
> > > changing bundle definitions is added.
> > >
> > > Related discussions by various users:
> > >
> > >    - Runtime bundle management:
> > >    https://github.com/apache/airflow/issues/61645
> > >    - Automatic bundle configuration loading:
> > >    https://github.com/apache/airflow/discussions/59799
> > >    - Earlier file-based reload PR:
> > >    https://github.com/apache/airflow/pull/71111
> > >    - Earlier dev-list discussion on runtime reload:
> > >    https://lists.apache.org/thread/co0z6yxc1g6ctqqmt7rdszjhjsq0w2hx
> > >
> > > I would appreciate feedback on this revised scope, proposed flow and
> the
> > > state v1 limitation.
> > >
> > > Thanks,
> > > Sameer Raj
> > >
> > > On Wed, Sep 23, 2026 at 3:35 PM Sameer Raj <[email protected]>
> wrote:
> > >
> > > > Hi everyone!
> > > > I would like to discuss adding support for dynamically discovering
> new
> > > DAG
> > > > bundle configurations without requiring Airflow restarts. (following
> up
> > > on
> > > > comment:
> > > >
> https://github.com/apache/airflow/issues/61645#issuecomment-5017217627
> > )
> > > >
> > > > There's also multiple PRs/discussion going over for the same feature:
> > > > - Runtime CRUD proposal:
> > > >   https://github.com/apache/airflow/issues/61645
> > > > - Automatic bundle configuration loading:
> > > >   https://github.com/apache/airflow/discussions/59799
> > > > - File-based hot-reload PR:
> > > >   https://github.com/apache/airflow/pull/63928
> > > > - Add dynamic DAG bundle configuration from file path
> > > >   https://github.com/apache/airflow/pull/71111
> > > >
> > > > *The Problem:*
> > > >
> > > > Today, Dag bundles are configured through [dag_processor]
> > > > dag_bundle_config_list. DagBundlesManager loads this configuration
> when
> > > > the process starts, and the Dag processor uses the same bundle list.
> > > >
> > > > This becomes operationally difficult for deployments that manage many
> > > > bundles and regularly add (or remove) them. Each configuration change
> > > > currently requires restarting or redeploying the affected Airflow
> > > processes.
> > > >
> > > > *Proposal*
> > > >
> > > > The proposal has two parts:
> > > >
> > > > First, introduce a DagBundleProvider abstraction into
> > DagBundlesManager.
> > > > It would allow Airflow to discover the bundle configurations
> construct
> > > > bundles accordingly. Thus, the responsibility to fetch bundles is
> > passed
> > > on
> > > > to DagBundleProvider by DagBundleManager.
> > > >
> > > > The configured class could obtain bundle information from a file,
> blob
> > > > storage, an internal service, or another deployment-specific source
> > (and
> > > > this will decouple Airflow being aware of the source). Airflow would
> > > define
> > > > the class contract without adding direct support for every possible
> > > source.
> > > >
> > > > The existing dag_bundle_config_list would remain the default
> > > > implementation, so current deployments would keep the same behavior.
> > > >
> > > > Second, allow the Dag processor to periodically ask the configured
> > class
> > > > for the latest bundle configurations from its existing processing
> loop.
> > > >
> > > > When a bundle is added, the Dag processor would discover it and begin
> > > > processing its files. When a bundle is removed, the Dag processor
> would
> > > > stop processing it and use the existing removed-file handling for its
> > > Dags.
> > > >
> > > > Each Dag processor performs this reconciliation periodically.
> > Processors
> > > > may observe a change at slightly different times, but they will
> > converge
> > > on
> > > > the configuration returned by the provider.
> > > >
> > > > *Why use a configurable class?*
> > > >
> > > > In this comment
> > > > <
> > https://github.com/apache/airflow/issues/61645#issuecomment-5017217627
> > > >,
> > > > Jarek asked why a custom dynamic manager would be preferable to
> > managing
> > > > Airflow configuration dynamically.
> > > >
> > > > On this, having this abstraction can allow users to implement their
> way
> > > by
> > > > which they plan to reload the configs, for example, fetch from
> external
> > > > system etc. Also changing the environment variable for bundle list
> wont
> > > > automatically reload the bundles, and the capability need to be built
> > for
> > > > the same.
> > > >
> > > > *Security*
> > > >
> > > > The security implications of changing bundle definitions through the
> > > > Airflow API were raised in issue #61645
> > > > <
> > https://github.com/apache/airflow/issues/61645#issuecomment-4212433885
> > > >.
> > > >
> > > > This proposal keeps management of bundle definitions within the
> > existing
> > > > Deployment Manager trust boundary.
> > > >
> > > >    - The Deployment Manager selects and deploys the DagBundleProvider
> > > >    implementation.
> > > >    - The Deployment Manager controls access to its configuration
> > source.
> > > >    - Credentials and authorization for that source remain deployment
> > > >    managed.
> > > >    - The Airflow API does not expose operations for creating or
> > changing
> > > >    bundle definitions.
> > > >    - No new Airflow user role is introduced for managing bundles.
> > > >
> > > > *Compatibility*
> > > >
> > > > The existing dag_bundle_config_list remains the default source and
> > keeps
> > > > its current behavior.
> > > >
> > > > *Value Addition*
> > > >
> > > > Multiple users have raised PR/discuss thread on Airflow Github for
> the
> > > > same, and this feature will be very useful for the community who are
> > > > managing multiple bundles. Reference for the threads is shared above.
> > > >
> > > > *Current work*
> > > >
> > > > I have split the work into two PRs so each part can be reviewed
> > > separately:
> > > >
> > > >    - Provider abstraction:
> > > >    https://github.com/apache/airflow/pull/73209
> > > >    - Runtime configuration reload:
> > > >    https://github.com/apache/airflow/pull/73217
> > > >
> > > > I would appreciate feedback on this!
> > > >
> > > > Thanks,
> > > > Sameer Raj
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> >
>

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