fix: correctly set docker_container devices (#843)

docs/resources/container.md

@@ -127,7 +127,7 @@ Required:
 
 Optional:
 
-- `container_path` (String) The path in the container where the device will be bound.
+- `container_path` (String) The path in the container where the device will be bound. If not set, it defaults to the value of `host_path`.
 - `permissions` (String) The cgroup permissions given to the container to access the device. Defaults to `rwm`.
 
 

docs/v3_v4_migration.md

@@ -7,10 +7,12 @@ Bump of minimum terraform version to `1.1.5` or newer. This is done as part of i
 
 ## `docker_container`
 
-Reworked handling of stopped containers: If a container is stopped (or exists for some other reason), Terraform now correctly shows a change on `plan` and restarts the container on `apply`. To trigger the change, the `must_run` attribute is exploited. `must_run` defaults to `true` and when a container is in a not running state, the provider sets `must_run` to `false` to trigger a state change.
-This fixes the cases where a stopped container gets deleted during a `plan`
+**Reworked handling of stopped containers:** If a container is stopped (or exists for some other reason), Terraform now correctly shows a change on `plan` and restarts the container on `apply`. To trigger the change, the `must_run` attribute is exploited. `must_run` defaults to `true` and when a container is in a not running state, the provider sets `must_run` to `false` to trigger a state change. This fixes the cases where a stopped container gets deleted during a `plan`. No migration needed.
+
+`ports` - **Ports on stopped container force replacement:** This is now fixed through https://github.com/kreuzwerker/terraform-provider-docker/pull/842, no migration needed.
+
+`devices` - **Fix the replacement of devices** Using `devices` blocks with not all 3 attributes now does not trigger resource replacements anymore. This fixes https://github.com/kreuzwerker/terraform-provider-docker/issues/603.
 
-* Fixes Ports on stopped container force replacement bug (https://github.com/kreuzwerker/terraform-provider-docker/issues/77)
 
 ## `docker_network`
 

internal/provider/resource_docker_container.go

@@ -649,7 +649,7 @@ func resourceDockerContainer() *schema.Resource {
 						},
 						"container_path": {
 							Type:        schema.TypeString,
-							Description: "The path in the container where the device will be bound.",
+							Description: "The path in the container where the device will be bound. If not set, it defaults to the value of `host_path`.",
 							Optional:    true,
 							ForceNew:    true,
 						},
@@ -658,6 +658,7 @@ func resourceDockerContainer() *schema.Resource {
 							Description: "The cgroup permissions given to the container to access the device. Defaults to `rwm`.",
 							Optional:    true,
 							ForceNew:    true,
+							Default:     "rwm",
 						},
 					},
 				},

internal/provider/resource_docker_container_funcs.go

@@ -797,7 +797,7 @@ func resourceDockerContainerRead(ctx context.Context, d *schema.ResourceData, me
 	// https://github.com/terraform-providers/terraform-provider-docker/pull/269
 
 	d.Set("privileged", container.HostConfig.Privileged)
-	if err = d.Set("devices", flattenDevices(container.HostConfig.Devices)); err != nil {
+	if err = d.Set("devices", flattenDevices(container.HostConfig.Devices, d.Get("devices").(*schema.Set))); err != nil {
 		log.Printf("[WARN] failed to set container hostconfig devices from API: %s", err)
 	}
 	// "destroy_grace_seconds" can't be imported

internal/provider/resource_docker_container_structures.go

@@ -241,12 +241,9 @@ func deviceSetToDockerDevices(devices *schema.Set) []container.DeviceMapping {
 		containerPath := deviceMap["container_path"].(string)
 		permissions := deviceMap["permissions"].(string)
 
-		switch {
-		case len(containerPath) == 0:
+		// Default container_path to host_path if not specified
+		if len(containerPath) == 0 {
 			containerPath = hostPath
-			fallthrough
-		case len(permissions) == 0:
-			permissions = "rwm"
 		}
 
 		device := container.DeviceMapping{
@@ -338,14 +335,23 @@ func flattenUlimits(in []*units.Ulimit) []interface{} {
 	return ulimits
 }
 
-func flattenDevices(in []container.DeviceMapping) []interface{} {
+func flattenDevices(in []container.DeviceMapping, configuredDevices *schema.Set) []interface{} {
 	devices := make([]interface{}, len(in))
+	list := configuredDevices.List()
 	for i, device := range in {
-		devices[i] = map[string]interface{}{
-			"host_path":      device.PathOnHost,
-			"container_path": device.PathInContainer,
-			"permissions":    device.CgroupPermissions,
+		configuredDevice := list[i].(map[string]interface{})
+
+		deviceMap := map[string]interface{}{
+			"host_path":   device.PathOnHost,
+			"permissions": device.CgroupPermissions,
 		}
+
+		// Only set container_path if it was explicitly configured by the user
+		if value, ok := configuredDevice["container_path"].(string); ok && value != "" {
+			deviceMap["container_path"] = device.PathInContainer
+		}
+
+		devices[i] = deviceMap
 	}
 
 	return devices

testdata/resources/docker_container/testAccDockerContainerDeviceConfig.tf

@@ -11,4 +11,8 @@ resource "docker_container" "foo" {
     container_path = "/dev/zero_test"
     permissions    = "rwm"
   }
+
+  devices {
+    host_path = "/dev/null"
+  }
 }