--- title: Charmhub | Deploy PgBouncer using Charmhub - The Open Operator Collection description: Deploy the latest version of PgBouncer on any cloud. url: https://charmhub.io/pgbouncer/docs/e-legacy-charm --- # PgBouncer [Canonical](https://charmhub.io/publisher/data-platform "View all packages from Canonical") * [Canonical](https://charmhub.io/publisher/data-platform "View all packages from Canonical") * [Databases](https://charmhub.io/?filter=databases) Platform: 24.04 22.04 20.04 18.04 16.04 1/stable 1092 ``` juju deploy pgbouncer --channel 1/stable ``` [Learn to deploy on juju >](https://juju.is/docs/juju/manage-applications) --- #### Relevant links * [Homepage](https://ubuntu.com/data/postgresql) --- #### Contacts ##### Maintainers + [Canonical Data Platform](mailto:data-platform@lists.launchpad.net) * [Submit a bug](https://github.com/canonical/pgbouncer-operator/issues) --- Share your thoughts on this charm with the community on discourse. [Join the discussion](https://discourse.charmhub.io/) # Legacy charms This page contains explanations regarding the legacy version of this charm. This includes clarification about Charmhub tracks, supported endpoints and interfaces, config options, and other important information. ## [Summary](https://charmhub.io/pgbouncer/docs/e-legacy-charm#p-31184-summary) * [Charm types: “legacy” vs. “modern”](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--charm-types) * [Default track `latest/` vs. track `1/`](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--default-track) * [How to migrate to the modern charm](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--how-to-migrate) * [How to deploy the legacy charm](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--how-to-deploy-legacy) * [Features supported by the modern charm](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--features-supported-by-modern) + [Config options](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--config-options) + [Extensions](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--extensions) + [Roles](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--roles) + [PostgreSQL versions](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--postgresql-versions) + [Architectures](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--architectures) * [Contact us](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--contact-us) --- ## [Charm types: “legacy” vs. “modern”](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--charm-types) There are [two types of charms](https://juju.is/docs/sdk/charm-taxonomy#heading--charm-types-by-generation) stored under the same charm name `pgbouncer`: 1. [Reactive](https://juju.is/docs/sdk/charm-taxonomy#heading--reactive) charm in the channel `latest/stable` (called `legacy`) 2. [Ops-based](https://juju.is/docs/sdk/ops) charm in the channel `1/stable` (called `modern`) The legacy charm was a [**principal charm**](https://juju.is/docs/sdk/charm-taxonomy#heading--principal-charms), while the modern charm is [**subordinated**](https://juju.is/docs/sdk/charm-taxonomy#heading--subordinate-charms). The legacy charm provided SQL endpoints `db` and `db-admin` (for the interface `pgsql`). The modern charm provides those old endpoints and a new endpoint `database` (for the interface `postgresql_client`). Read more details about the available endpoints and interfaces [here](https://charmhub.io/pgbouncer/docs/e-interfaces?channel=1/stable). The interface `hacluster` [supported](https://charmhub.io/pgbouncer/docs/h-external-access) on both legacy and modern charms. Non-SQL legacy charm interfaces (e.g. `pgbouncer-extra-config`, `nrpe-external-master`) are currently NOT supported by the modern charm. [Contact us](https://charmhub.io/pgbouncer/docs/r-requirements) with your use cases for those interfaces! **Note**: Please choose one endpoint to use. No need to relate all of them simultaneously! ## [Default track `latest/` vs. track `1/`](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--default-track) The [default track](https://docs.openstack.org/charm-guide/yoga/project/charm-delivery.html) will be switched from the `latest` to `1` soon. This is to ensure all new deployments use a modern codebase. We strongly advise against using the latest track, since a future charm upgrade may result in a PgBouncer version incompatible with an integrated application. Track `1/` guarantees a PgBouncer major version 1 deployment only. The track `latest/` will be closed after all applications migrated from reactive to the ops-based charm. ## [How to migrate to the modern charm](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--how-to-migrate) The modern charm provides temporary support for the legacy interfaces: **Quick try**: relate the current application with new charm using endpoint `db` (set the channel to `1/stable`). No extra changes necessary: ``` pgbouncer: charm: pgbouncer channel: 1/stable ``` **Proper migration**: migrate the application to the new interface [`postgresql_client`](https://github.com/canonical/charm-relation-interfaces). The application will connect PgBouncer using the [data\_interfaces](https://charmhub.io/data-platform-libs/libraries/data_interfaces) library from [data-platform-libs](https://github.com/canonical/data-platform-libs/) via the endpoint `database`. **Warning**: In-place upgrades are NOT possible! The reactive charm cannot be upgraded to the operator-framework-based one. The second/modern charm application must be launched nearby and relations should be switched from the legacy application to the modern one. ## [How to deploy the legacy charm](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--how-to-deploy-legacy) Deploy the charm using the channel `latest/stable`: ``` pgbouncer: charm: pgbouncer channel: latest/stable ``` **Note**: remove Charm store prefix `cs:` from the bundle. Otherwise the modern charm will be chosen by Juju (due to the default track will be pointing to `1/stable` and not `latest/stable`). The common error message is: `cannot deploy application "postgresql": unknown option "..."`. ## [Features supported by the modern charm](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--features-supported-by-modern) This section goes over the key differences in feature support and functionality between the legacy and modern charm. ### [Config options](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--config-options) The legacy charm config options were not moved to the modern charm, since the modern charm applies the best possible configuration automatically. Feel free to [contact us](https://charmhub.io/pgbouncer/docs/r-contacts) about the PgBouncer config options. ### [Extensions](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--extensions) The legacy charm provided plugins/extensions through the relation (interface `pgsql`). This is NOT supported by the modern charm - neither through `pgsql` nor the `postgresql_client` interface. To enable extensions on modern PgBouncer, enable them on PostgreSQL charm using the appropriate `plugin_*_enable` [config option](https://charmhub.io/postgresql/configure) of the modern charm. The modern charm will then provide plugins support for both `pgsql` and `postgresql_client` interfaces. ### [Roles](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--roles) In the legacy charm, the user could request roles by setting the `roles` field to a comma separated list of desired roles. This is NOT supported by the modern charm implementation of the legacy `pgsql` interface. The same functionality is provided via the modern `postgresql_client` using “extra-user-roles”. ### [PostgreSQL versions](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--postgresql-versions) At the moment, the modern PgBouncer charms support relation to the modern Charmed PostgreSQL 14 (based on Jammy/22.04 series) only. Please [contact us](https://charmhub.io/pgbouncer/docs/r-contacts) if you need different versions/series. ### [Architectures](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--architectures) Currently, the charm supports architecture `amd64` and `arm64` only. For more technical details, see the [Supported architectures](https://charmhub.io/pgbouncer/docs/r-requirements?channel=1/stable) reference. ### [Interfaces](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--architectures) The modern charm also support the legacy interface `pgsql` (endpoints `db` and `db-admin`) ([see Integrations](https://charmhub.io/pgbouncer/integrations?channel=1/stable#db)) however migration to the modern interface `postgresql_client` is [trivial and highly recommended](https://charmhub.io/postgresql/docs/h-integrate-with-your-charm). The legacy charm also supports interface `ha` which is not yet supported by modern charm. Feel free to contact us if you are interested in the `ha` interface support. ## [Report issues](https://charmhub.io/pgbouncer/docs/e-legacy-charm#heading--contact-us) The “legacy charm” (from `latest/stable`) is stored on [Launchpad](https://git.launchpad.net/pgbouncer-charm/). Report legacy charm issues [here](https://bugs.launchpad.net/pgbouncer-charm). The “modern charm” (from `1/stable`) is stored on [GitHub](https://github.com/canonical/pgbouncer-operator). Report modern charm issues [here](https://github.com/canonical/pgbouncer-operator/issues/new/choose). Do you have questions? [Reach out](https://charmhub.io/pgbouncer/docs/r-requirements) to us! ---