How to manage offers

See also: Offer

This document shows how to manage offers.

Contents:

Create an offer

Who: User with offer admin access.

An offer stems from an application endpoint. This is how an offer is created:

juju offer <application>:<application endpoint>

By default, an offer is named after its underlying application but you may also choose to give it a different name:

juju offer <application>:<application endpoint> <offer name>

Example:

juju deploy mysql
juju offer mysql:database hosted-mysql

To view the available application endpoints use juju show-application and check the list below endpoint-bindings. Example:

juju show-application mysql 
mysql:
  charm: mysql
  ...
  endpoint-bindings:
    "": alpha
    certificates: alpha
    cos-agent: alpha
    database: alpha
    ...

To offer both the certificates and database endpoints:

juju deploy mysql
juju offer mysql:database,certificates hosted-mysql

Although an offer may have multiple (offer) endpoints it is always expressed as a single URL:

<user>/<model>.<offer_name>

If the above mysql offer were made in the default model by user admin, the URL would be:

admin/default.hosted-mysql

See more: juju offer

To create an offer, in your Terraform plan, create a resource of the juju_offer type, specifying the offering model and the name of the application and application endpoint from which the offer is created:


resource "juju_offer" "percona-cluster" {
  model            = juju_model.development.name
  application_name = juju_application.percona-cluster.name
  endpoint         = server
}

See more: juju_offer (resource)

To create an offer, use the create_offer() method on a connected Model object.

# Assume a deployed mysql application
await my_model.deploy('mysql')
# Expose the database endpoint of the mysql application
await my_model.create_offer('mysql:database', offer_name='hosted-mysql')

See more: create_offer()

View an offer’s details

Who: User with offer read+ access.

The show-offer command gives details about a given offer.

juju show-offer <offer name>

Example:

juju show-offer hosted-mysql
Store        URL                         Access  Description                                    Endpoint      Interface         Role
foo          admin/default.hosted-mysql  admin   MySQL is a widely used, open-source            certificates  tls-certificates  requirer
                                                 relational database management system          database      mysql_client      provider
                                                 (RDBMS). MySQL InnoDB cluster provides a                                       
                                                 complete high availability solution for MySQL                                  
                                                 via Group Replic...  

For more details, including which users can access the offer, use the yaml format.

Example:

juju show-offer hosted-mysql --format yaml
serverstack:admin/default.hosted-mysql:
  description: |
    MySQL is a widely used, open-source relational database management system
    (RDBMS). MySQL InnoDB cluster provides a complete high availability solution
    for MySQL via Group Replication.

    This charm supports MySQL 8.0 in bare-metal/virtual-machines.
  access: admin
  endpoints:
    certificates:
      interface: tls-certificates
      role: requirer
    database:
      interface: mysql_client
      role: provider
  users:
    admin:
      display-name: admin
      access: admin
    everyone@external:
      access: read

A non-admin user with read/consume access can also view an offer’s details, but they won’t see the information for users with access.

See more: juju show-offer

The terraform juju client does not support this. Please use the juju client.

The python-libjuju client does not currently support this. Please use the juju client.

Control access to an offer

Who: User with offer admin access.

Offers can have one of three access levels:

  • read (a user can see the offer when searching)
  • consume (a user can relate an application to the offer)
  • admin (a user can manage the offer)

These are applied similarly to how standard model access is applied, via the juju grant and juju revoke commands:

juju grant <user> <access-level> <offer-url>
juju revoke <user> <access-level> <offer-url>

Revoking a user’s consume access will result in all relations for that user to that offer to be suspended. If the consume access is granted anew, each relation will need to be individually resumed. Suspending and resuming relations are explained in more detail later.

To grant bob consume access to an offer:

juju grant bob consume admin/default.hosted-mysql

To revoke bob’s consume access (he will be left with read access):

juju revoke bob consume admin/default.hosted-mysql

To revoke all of bob’s access:

juju revoke bob read admin/default.hosted-mysql

See more: juju grant, juju revoke

The terraform juju client does not support this. Please use the juju client.

The access levels for offers can be applied in the same way the model or controller access for a given user. Use the grant() and revoke() methods on a User object to grant or revoke access to an offer.

# Grant Bob consume access to an offer
await user_bob.grant('consume', offer_name='admin/default.hosted-mysql')

# Revoke Bob's consume access (he will be left with read access)
await user_bob.revoke('consume', offer_name='admin/default.hosted-mysql')

See more: User (object), grant(), revoke()

Find an offer to use

Who: User with offer read+ access

Offers can be searched based on various criteria:

  • URL (or part thereof)
  • offer name
  • model name
  • interface

The results will show information about the offer, including the level of access the user making the query has on each offer.

To find all offers on a specified controller:

$ juju find-offers foo:
Store  URL                         Access  Interfaces
foo    admin/default.hosted-mysql  admin   mysql:database
foo    admin/default.postgresql    admin   pgsql:db

As with the show-offer command, the yaml output will show extra information, including users who can access the offer (if an admin makes the query).

juju find-offers --offer hosted-mysql --format yaml
foo:admin/default.hosted-mysql:
  access: admin
  endpoints:
    certificates:
      interface: tls-certificates
      role: requirer
    database:
      interface: mysql_client
      role: provider
  users:
    admin:
      display-name: admin
      access: admin
    bob:
      access: read
    everyone@external:
      access: read

To find offers in a specified model:

juju find-offers admin/another-model
juju find-offers foo:admin/another-model

To find offers with a specified interface on the current controller:

juju find-offers --interface mysql_client
juju find-offers --interface tls-certificates

To find offers with a specified interface on a specific controller:

juju find-offers --interface mysql_client foo:

To find offers with “sql” in the name:

$ juju find-offers --offer sql foo:

See more: juju find-offers

The terraform juju client does not support this. Please use the juju client.

The python-libjuju client does not support this. Please use the juju client.

Integrate with an offer

Who: User with offer consume+ access.

Before Juju 3.0, juju integrate was juju relate.

If a user has consume access to an offer, they can deploy an application in their model and establish an integration with the offer by way of its URL.

juju integrate <application>[:<application endpoint>] <offer-url>[:<offer endpoint>]

Specifying the endpoint for the application and the offer is analogous to normal integrations. They can be added but are often unnecessary:

juju integrate <application> <offer-url>

When you integrate with an offer, a proxy application is made in the consuming model, named after the offer.

Example:

juju deploy mediawiki
juju integrate mediawiki:db admin/default.hosted-mysql

An offer can be consumed without integration. This workflow sets up the proxy application in the consuming model and creates a user-defined alias for the offer. This latter is what’s used to subsequently relate to. Having an offer alias can avoid a namespace conflict with a pre-existing application.

juju consume <offer-url> <offer-alias>
juju integrate <application> <offer alias>

Example:

juju consume admin/prod.hosted_mysql mysql-alias
juju integrate mediawiki:db mysql-alias

Offers which have been consumed show up in juju status in the SAAS section.

The integrations (relations) block in status shows any relevant status information about the integrations to the offer in the Message field. This includes any error information due to rejected ingress, or if the relation is suspended etc.

$ juju status --relations
Model  Controller  Cloud/Region  Version  SLA
test   foo         lxd           2.9.0    unsupported

SAAS          Status  Store  URL
hosted_mysql  active  acme   admin/default.hosted-mysql

App        Version  Status  Scale  Charm      Store     Rev  OS      Notes
mediawiki  1.19.14  active      1  mediawiki  charmhub  19   ubuntu  

Unit          Workload  Agent  Machine  Public address  Ports   Message
mediawiki/0*  active    idle   0        10.200.103.121  80/tcp  Ready

Machine  State    DNS             Inst id        Series  AZ  Message
0        started  10.200.103.121  juju-16fc34-0  trusty      Running

Relation provider  Requirer      Interface  Type     Message
hosted_mysql:db    mediawiki:db  mysql      regular 

To remove a consumed offer:

juju remove-saas <offer alias>

See more: juju integrate, > See more: juju consume, juju remove-saas

To integrate with an offer, in your Terraform plan create a juju_integration resource as usual by specifying two application blocks and a lifecycle > replace_triggered_by block, but for the application representing the offer specify the offer_url, and in the lifecycle block list triggers only for the regular application (not the offer). For example:

resource "juju_integration" "wordpress-db" {
  model = juju_model.development-destination.name

  application {
    name     = juju_application.wordpress.name
    endpoint = "db"
  }

  application {
    offer_url = juju_offer.this.url
  }

lifecycle {
    replace_triggered_by = [
      juju_application.wordpress.name,
      juju_application.wordpress.model,
      juju_application.wordpress.constraints,
      juju_application.wordpress.placement,
      juju_application.wordpress.charm.name,
    ]
  }

}

See more: juju_integration (resource)

To integrate with an offer, use the Model.integrate() method on a connected model, with a consumed offer url.

# Integrate via offer url
await my_model.integrate('mediawiki:db', 'admin/default.hosted-mysql')

# Integrate via an offer alias created when consumed
await my_model.consume('admin/prod.hosted_mysql', application_alias="mysql-alias")
await my_model.integrate('mediawiki:db', 'mysql-alias')

# Remove a consumed offer:
await my_model.remove_saas('mysql-alias')

See more: Model.integrate(), Model.consume(), Model.remove_saas()

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Allow traffic from an integrated offer

Who: User with offer admin access.

When the consuming model is behind a NAT firewall its traffic will typically exit (egress) that firewall with a modified address/network. In this case, the --via option can be used with the juju integrate command to request the firewall on the offering side to allow this traffic. This option specifies the NATed address (or network) in CIDR notation:

juju integrate <application> <offer url> --via <cidr subnet(s)>

Example: juju integrate mediawiki:db ian:admin/default.mysql --via 69.32.56.0/8

The --via value is a comma separated list of subnets in CIDR notation. This includes the /32 case where a single NATed IP address is used for egress.

It’s also possible to set up egress subnets as a model config value so that all cross model integrations use those subnets without needing to use the --via option.

juju model-config egress-subnets=<cidr subnet>

Example: juju model-config egress-subnets=69.32.56.0/8

To be clear, the above command is applied to the consuming model.

To allow control over what ingress can be applied to the offering model, an administrator can set up allowed ingress subnets by creating a firewall rule.

juju set-firewall-rule juju-application-offer --whitelist <cidr subnet>

Where ‘juju-application-offer’ is a well-known string that denotes the firewall rule to apply to any offer in the current model. If a consumer attempts to create a relation with requested ingress outside the bounds of the whitelist subnets, the relation will fail and be marked as in error.

The above command is applied to the offering model.

Example: juju set-firewall-rule juju-application-offer --whitelist 103.37.0.0/16

The juju set-firewall-rule command only affects subsequently created relations, not existing ones. Only new relations will be rejected if the changed firewall rules preclude the requested ingress.

To see what firewall rules have currently been defined, use the list firewall-rules command.

Example:

juju firewall-rules
Service                 Whitelist subnets
juju-application-offer  103.37.0.0/16

Beyond a certain number of firewall rules, which have been dynamically created to allow access from individual integrations, Juju will revert to using the whitelist subnets as the access rules. The number of rules at which this cutover applies is cloud specific.

See more: juju set-firewall-rule, juju firewall-rules

To allow traffic from an integrated offer, in your Terraform plan, in the resource definition where you define the integration with an offer, use the via attribute to specify the list of CIDRs for outbound traffic. For example:

resource "juju_integration" "this" {
...
  via   = "10.0.0.0/24,10.0.1.0/24"

# the rest of your integration definition

}

See more: juju_integration > via

The python-libjuju client does not support this. Please use the juju client.

Inspect integrations with an offer

Who: User with offer admin access.

See also: offers

The offers command is used to see all connections to one more offers.

juju offers [--format (tabular|summary|yaml|json)] [<offer name>]

If offer name is not provided, all offers are included in the result.

The default tabular output shows each user connected (relating to) the offer, the relation id of the relation, and ingress subnets in use with that connection. The summary output shows one row per offer, with a count of active/total relations. Use the yaml output to see extra detail such as the UUID of the consuming model.

The output can be filtered by:

  • interface: the interface name of the endpoint
  • application: the name of the offered application
  • connected user: the name of a user who has an integration to the offer
  • allowed consumer: the name of a user allowed to consume the offer
  • active only: only show offers which are in use (are related to)

See juju help offers for more detail.

Example:

juju offers mysql
Offer  User   Relation id  Status  Endpoint  Interface  Role      Ingress subnets
mysql  admin  2            joined  db        mysql      provider  69.193.151.51/32

juju offers --format summary
Offer         Application  Charm        Connected  Store   URL                      Endpoint  Interface  Role
hosted_mysql  mysql        ch:mysql-57  1/1        myctrl  admin/prod.hosted_mysql  db        mysql      provider

All offers for a given application: juju offers --application mysql

All offers for a given interface: juju offers --interface mysql

All offers for a given user who has related to the offer: juju offers --connected-user fred

All offers for a given user who can consume the offer: juju offers --format summary --allowed-consumer mary

The above command is best run with --format summary as the intent is to see, for a given user, what offers they might relate to, regardless of whether there are existing integrations (which is what the tabular view shows).

See more: juju offers

The terraform juju client does not support this. Please use the juju client.

To see all connections to one or more offers, use the list_offers() method on a connected Model object.

await my_model.list_offers()

See more: list_offers()

Suspend, resume, or remove an integration with an offer

Who: User with offer admin access.

Before you can suspend, resume, or remove an integration (relation), you need to know the integration (relation) ID. (That is because, once you’ve made an offer, there could potentially be many instances of the same application integrating with that offer, so the only way to identify uniquely is via the relation ID.)

Given two related apps (app1: endpoint, app2), the integration (relation) ID can be found as follows:

juju exec --unit $UNIT_FOR_APP1 -- relation-ids endpoint

The output, <ENDPOINT>:<REL_ID>, gives you the relation id.

Once you have the integration (relation) id:

To suspend an integration (relation), do:

juju suspend-relation <id1>

Suspended integrations (relations) will run the relation departed / broken hooks on either end, and any firewall ingress will be closed.

And, to resume an integration (relation), do:

juju resume-relation <id1>

Finally, to remove an integration (relation) entirely:

juju remove-relation <id1>

Removing an integration on the offering side will trigger a removal on the consuming side. An integration can also be removed from the consuming side, as well as the application proxy, resulting in all integrations being removed.

In all cases, more than one integration id can be specified, separated by spaces.

Examples:

juju suspend-relation 2 --message "reason for suspension"
juju suspend-relation 3 4 5 --message "reason for suspension"
juju resume-relation 2

See more: juju suspend-relation, juju resume-relation, juju remove-relation

The terraform juju client does not support this. Please use the juju client.

The python-libjuju client does not support suspending, and resuming integrations. However, to remove an integration, you can use the remove_relation() method on an Application object.

await my_controller.remove_integration('mediawiki', 'mysql:db')

See more: remove_relation()

Remove an offer

Who: User with offer admin access.

An offer can be removed providing it hasn’t been used in any integration. To override this behaviour the --force option is required, in which case the integration is also removed. This is how an offer is removed:

juju remove-offer [--force] <offer-url>

Note that, if the offer resides in the current model, then the shorter offer name can be used instead of the longer URL.

Similarly, if an application is being offered, it cannot be deleted until all its offers are removed.

See more: juju remove-offer

To remove an offer, in your Terraform plan, remove its resource definition.

See more: juju_offer

To remove an offer, use the remove_offer() method on a connected Model. If the offer is used in an integration, then the force=True parameter is required to remove the offer, in which case the integration is also removed.

await my_model.remove_offer('admin/mymodel.ubuntu', force=True)

See more: remove_offer()


Further reading

For more on cross-model relations, see the following scenarios:

  • Scenario #1 A MediaWiki deployment, based within the same controller, used by the admin user, but consumed by multiple models.
  • Scenario #2 A MediaWiki deployment, based within multiple controllers, used by a non-admin user, and consumed by a single model.


Contributors: @anvial, @cderici, @hmlanigan, @manadart, @simonrichardson, @tmihoc

Last updated 17 days ago. Help improve this document in the forum.