Addressing pagerduty_slack_connection unable to set "No Priority" vs "Any Priority" for priorities configuration

pagerduty/resource_pagerduty_slack_connection.go

@@ -12,6 +12,7 @@ import (
 )
 
 const AppBaseUrl = "https://app.pagerduty.com"
+const StarWildcardConfig = "*"
 
 func resourcePagerDutySlackConnection() *schema.Resource {
 	return &schema.Resource{
@@ -215,7 +216,7 @@ func expandConnectionConfig(v interface{}) pagerduty.ConnectionConfig {
 
 	config = pagerduty.ConnectionConfig{
 		Events:     expandConfigList(c["events"].([]interface{})),
-		Priorities: expandConfigList(c["priorities"].([]interface{})),
+		Priorities: expandStarWildcardConfig(expandConfigList(c["priorities"].([]interface{}))),
 		Urgency:    nil,
 	}
 	if val, ok := c["urgency"]; ok {
@@ -228,18 +229,30 @@ func expandConnectionConfig(v interface{}) pagerduty.ConnectionConfig {
 }
 
 func expandConfigList(v interface{}) []string {
-	var items []string
+	items := []string{}
 	for _, i := range v.([]interface{}) {
 		items = append(items, i.(string))
 	}
 	return items
 }
 
+//Expands the use of star wildcard ("*") configuration for an attribute to its
+//matching expected value by PagerDuty's API, which is nil. This is necessary
+//when the API accepts and interprets nil and empty configurations as valid
+//settings. The state produced by this kind of config can be reverted to the API
+//expected values with sibbling function `flattenStarWildcardConfig`.
+func expandStarWildcardConfig(c []string) []string {
+	if isUsingStarWildcardConfig := len(c) == 1 && c[0] == StarWildcardConfig; isUsingStarWildcardConfig {
+		c = nil
+	}
+	return c
+}
+
 func flattenConnectionConfig(config pagerduty.ConnectionConfig) []map[string]interface{} {
 	var configs []map[string]interface{}
 	configMap := map[string]interface{}{
 		"events":     flattenConfigList(config.Events),
-		"priorities": flattenConfigList(config.Priorities),
+		"priorities": flattenConfigList(flattenStarWildcardConfig(config.Priorities)),
 	}
 	if config.Urgency != nil {
 		configMap["urgency"] = *config.Urgency
@@ -258,6 +271,17 @@ func flattenConfigList(list []string) interface{} {
 	return items
 }
 
+// Flattens a `nil` configuration to its corresponding star wildcard ("*")
+// configuration value for an attribute which is meant to be accepting this kind
+// of configuration, with the only purpose to match the config stored in the
+// Terraform's state.
+func flattenStarWildcardConfig(c []string) []string {
+	if hasStarWildcardConfigSet := c[:] == nil; hasStarWildcardConfigSet {
+		c = append(c, StarWildcardConfig)
+	}
+	return c
+}
+
 func resourcePagerDutySlackConnectionImport(d *schema.ResourceData, meta interface{}) ([]*schema.ResourceData, error) {
 	client, err := meta.(*Config).SlackClient()
 	if err != nil {

pagerduty/resource_pagerduty_slack_connection_test.go

@@ -103,6 +103,41 @@ func TestAccPagerDutySlackConnection_Envar(t *testing.T) {
 	})
 }
 
+func TestAccPagerDutySlackConnection_NonAndAnyPriorities(t *testing.T) {
+	username := fmt.Sprintf("tf-%s", acctest.RandString(5))
+	email := fmt.Sprintf("%s@foo.test", username)
+	escalationPolicy := fmt.Sprintf("tf-%s", acctest.RandString(5))
+	service := fmt.Sprintf("tf-%s", acctest.RandString(5))
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckPagerDutySlackConnectionDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccCheckPagerDutySlackConnectionConfigNonAndAnyPriorities(username, email, escalationPolicy, service, workspaceID, channelID),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckPagerDutySlackConnectionExists("pagerduty_slack_connection.foo"),
+					resource.TestCheckResourceAttr(
+						"pagerduty_slack_connection.foo", "source_name", service),
+					resource.TestCheckResourceAttr(
+						"pagerduty_slack_connection.foo", "config.0.priorities.#", "0"),
+				),
+			},
+			{
+				Config: testAccCheckPagerDutySlackConnectionConfigNonAndAnyPrioritiesUpdated(username, email, escalationPolicy, service, workspaceID, channelID),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckPagerDutySlackConnectionExists("pagerduty_slack_connection.foo"),
+					resource.TestCheckResourceAttr(
+						"pagerduty_slack_connection.foo", "config.0.priorities.#", "1"),
+					resource.TestCheckResourceAttr(
+						"pagerduty_slack_connection.foo", "config.0.priorities.0", "*"),
+				),
+			},
+		},
+	})
+}
+
 func testAccCheckPagerDutySlackConnectionDestroy(s *terraform.State) error {
 	config := &pagerduty.Config{
 		Token:   os.Getenv("PAGERDUTY_USER_TOKEN"),
@@ -388,3 +423,129 @@ func testAccCheckPagerDutySlackConnectionConfigEnvar(team, channelID string) str
 		}
 		`, team, channelID)
 }
+
+func testAccCheckPagerDutySlackConnectionConfigNonAndAnyPriorities(username, useremail, escalationPolicy, service, workspaceID, channelID string) string {
+	return fmt.Sprintf(`
+  resource "pagerduty_user" "foo" {
+    name        = "%s"
+    email       = "%s"
+  }
+
+  resource "pagerduty_escalation_policy" "foo" {
+    name        = "%s"
+    description = "foo"
+    num_loops   = 1
+
+    rule {
+      escalation_delay_in_minutes = 10
+
+      target {
+        type = "user_reference"
+        id   = pagerduty_user.foo.id
+      }
+    }
+  }
+
+  resource "pagerduty_service" "foo" {
+    name                    = "%s"
+    description             = "foo"
+    auto_resolve_timeout    = 1800
+    acknowledgement_timeout = 1800
+    escalation_policy       = pagerduty_escalation_policy.foo.id
+
+    incident_urgency_rule {
+      type = "constant"
+      urgency = "high"
+    }
+  }
+  resource "pagerduty_slack_connection" "foo" {
+    source_id = pagerduty_service.foo.id
+    source_type = "service_reference"
+    workspace_id = "%s"
+    channel_id = "%s"
+    notification_type = "responder"
+    config {
+      events = [
+        "incident.triggered",
+        "incident.acknowledged",
+        "incident.escalated",
+        "incident.resolved",
+        "incident.reassigned",
+        "incident.annotated",
+        "incident.unacknowledged",
+        "incident.delegated",
+        "incident.priority_updated",
+        "incident.responder.added",
+        "incident.responder.replied",
+        "incident.status_update_published",
+        "incident.reopened"
+      ]
+      priorities = []
+      urgency = "high"
+    }
+  }
+  `, username, useremail, escalationPolicy, service, workspaceID, channelID)
+}
+
+func testAccCheckPagerDutySlackConnectionConfigNonAndAnyPrioritiesUpdated(username, email, escalationPolicy, service, workspaceID, channelID string) string {
+	return fmt.Sprintf(`
+  resource "pagerduty_user" "foo" {
+    name        = "%s"
+    email       = "%s"
+  }
+
+  resource "pagerduty_escalation_policy" "foo" {
+    name        = "%s"
+    description = "foo"
+    num_loops   = 1
+
+    rule {
+      escalation_delay_in_minutes = 10
+
+      target {
+        type = "user_reference"
+        id   = pagerduty_user.foo.id
+      }
+    }
+  }
+
+  resource "pagerduty_service" "foo" {
+    name                    = "%s"
+    description             = "foo"
+    auto_resolve_timeout    = 1800
+    acknowledgement_timeout = 1800
+    escalation_policy       = pagerduty_escalation_policy.foo.id
+
+    incident_urgency_rule {
+      type = "constant"
+      urgency = "high"
+    }
+  }
+  resource "pagerduty_slack_connection" "foo" {
+    source_id = pagerduty_service.foo.id
+    source_type = "service_reference"
+    workspace_id = "%s"
+    channel_id = "%s"
+    notification_type = "responder"
+    config {
+      events = [
+        "incident.triggered",
+        "incident.acknowledged",
+        "incident.escalated",
+        "incident.resolved",
+        "incident.reassigned",
+        "incident.annotated",
+        "incident.unacknowledged",
+        "incident.delegated",
+        "incident.priority_updated",
+        "incident.responder.added",
+        "incident.responder.replied",
+        "incident.status_update_published",
+        "incident.reopened"
+      ]
+      priorities = ["*"]
+      urgency = "high"
+    }
+  }
+  `, username, email, escalationPolicy, service, workspaceID, channelID)
+}

website/docs/r/slack_connection.html.markdown

@@ -80,6 +80,8 @@ The following arguments are supported:
     - `incident.status_update_published`
     - `incident.reopened`
   * `priorities` - (Optional) Allows you to filter events by priority. Needs to be an array of PagerDuty priority IDs. Available through [pagerduty_priority](https://registry.terraform.io/providers/PagerDuty/pagerduty/latest/docs/data-sources/priority) data source.
+    - When omitted or set to an empty array (`[]`) in the configuration for a Slack Connection, its default behaviour is to set `priorities` to `No Priority` value.
+    - When set to `["*"]` its corresponding value for `priorities` in Slack Connection's configuration will be `Any Priority`.
   * `urgency` - (Optional) Allows you to filter events by urgency. Either `high` or `low`.
 
 ## Attributes Reference