docs: update offer_url use in integration resource

Per juju#449, indicate that offer_url and name/endpoint are mutually
exclusive in an integration resource.

docs/resources/integration.md

@@ -68,13 +68,14 @@ resource "juju_integration" "this" {
 
 Optional:
 
-- `endpoint` (String) The endpoint name.
-- `name` (String) The name of the application.
-- `offer_url` (String) The URL of a remote application.
+- `endpoint` (String) The endpoint name. This attribute may not be used at the same time as the offer_url.
+- `name` (String) The name of the application. This attribute may not be used at the same time as the offer_url.
+- `offer_url` (String) The URL of a remote application. This attribute may not be used at the same time as name and endpoint.
 
 
 ### Notes
-When creating this resource the `offer_url` property will show `(known after apply)` as below:
+When creating this resource the `offer_url` property will show `(known after apply)` if a `name` or
+ `name` and `endpoint` are supplied as below:
 ```
   + resource "juju_integration" "this" {
       + id    = (known after apply)
@@ -88,7 +89,8 @@ When creating this resource the `offer_url` property will show `(known after app
         }
     }
 ```
-This is due to a bug in the sdk this provider uses - this property will never be computed and can only be provided by the user.
+This is due to an integration requiring a name/endpoint combination or an offer_url, but not both
+bits of data together.
 
 ## Import
 

docs/resources/offer.md

@@ -13,23 +13,22 @@ A resource that represent a Juju Offer.
 ## Example Usage
 
 ```terraform
-resource "juju_offer" "this" {
+resource "juju_offer" "myoffer" {
   model            = juju_model.development.name
   application_name = juju_application.percona-cluster.name
   endpoint         = server
 }
 
-// an offer can then be used in an integration as below:
-resource "juju_integration" "this" {
+// an offer can then be used in an cross model integration as below:
+resource "juju_integration" "myintegration" {
   model = juju_model.development-destination.name
 
   application {
     name     = juju_application.wordpress.name
     endpoint = "db"
   }
-
   application {
-    offer_url = juju_offer.this.url
+    offer_url = juju_offer.myoffer.url
   }
 }
 ```

examples/resources/juju_offer/resource.tf

@@ -1,19 +1,18 @@
-resource "juju_offer" "this" {
+resource "juju_offer" "myoffer" {
   model            = juju_model.development.name
   application_name = juju_application.percona-cluster.name
   endpoint         = server
 }
 
-// an offer can then be used in an integration as below:
-resource "juju_integration" "this" {
+// an offer can then be used in an cross model integration as below:
+resource "juju_integration" "myintegration" {
   model = juju_model.development-destination.name
 
   application {
     name     = juju_application.wordpress.name
     endpoint = "db"
   }
-
   application {
-    offer_url = juju_offer.this.url
+    offer_url = juju_offer.myoffer.url
   }
 }

internal/provider/resource_integration.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 
 	"github.com/hashicorp/terraform-plugin-framework-validators/setvalidator"
+	"github.com/hashicorp/terraform-plugin-framework-validators/stringvalidator"
 	"github.com/hashicorp/terraform-plugin-framework/diag"
 	"github.com/hashicorp/terraform-plugin-framework/path"
 	"github.com/hashicorp/terraform-plugin-framework/resource"
@@ -138,20 +139,39 @@ func (r *integrationResource) Schema(_ context.Context, _ resource.SchemaRequest
 				NestedObject: schema.NestedBlockObject{
 					Attributes: map[string]schema.Attribute{
 						"name": schema.StringAttribute{
-							Description: "The name of the application.",
-							Optional:    true,
+							Description: "The name of the application. This attribute may not be used at the" +
+								" same time as the offer_url.",
+							Optional: true,
+							Validators: []validator.String{
+								stringvalidator.ConflictsWith(path.Expressions{
+									path.MatchRelative().AtParent().AtName("offer_url"),
+								}...),
+							},
 						},
 						"endpoint": schema.StringAttribute{
-							Description: "The endpoint name.",
-							Optional:    true,
-							Computed:    true,
+							Description: "The endpoint name. This attribute may not be used at the" +
+								" same time as the offer_url.",
+							Optional: true,
+							Computed: true,
+							Validators: []validator.String{
+								stringvalidator.ConflictsWith(path.Expressions{
+									path.MatchRelative().AtParent().AtName("offer_url"),
+								}...),
+							},
 						},
 						"offer_url": schema.StringAttribute{
-							Description: "The URL of a remote application.",
-							Optional:    true,
+							Description: "The URL of a remote application. This attribute may not be used at the" +
+								" same time as name and endpoint.",
+							Optional: true,
 							PlanModifiers: []planmodifier.String{
 								stringplanmodifier.UseStateForUnknown(),
 							},
+							Validators: []validator.String{
+								stringvalidator.ConflictsWith(path.Expressions{
+									path.MatchRelative().AtParent().AtName("name"),
+									path.MatchRelative().AtParent().AtName("endpoint"),
+								}...),
+							},
 						},
 					},
 				},

templates/resources/integration.md.tmpl

@@ -19,7 +19,8 @@ description: |-
 
 
 ### Notes
-When creating this resource the `offer_url` property will show `(known after apply)` as below:
+When creating this resource the `offer_url` property will show `(known after apply)` if a `name` or
+ `name` and `endpoint` are supplied as below:
 ```
   + resource "juju_integration" "this" {
       + id    = (known after apply)
@@ -33,7 +34,8 @@ When creating this resource the `offer_url` property will show `(known after app
         }
     }
 ```
-This is due to a bug in the sdk this provider uses - this property will never be computed and can only be provided by the user.
+This is due to an integration requiring a name/endpoint combination or an offer_url, but not both
+bits of data together.
 
 {{ if .HasImport -}}
 ## Import