coder · Emyrk · May 6, 2025 · May 7, 2025 · May 7, 2025 · May 7, 2025
diff --git a/coderd/provisionerdserver/provisionerdserver.go b/coderd/provisionerdserver/provisionerdserver.go
@@ -543,6 +543,30 @@ func (s *server) acquireProtoJob(ctx context.Context, job database.ProvisionerJo
 			return nil, failJob(fmt.Sprintf("convert workspace transition: %s", err))
 		}
 
+		// A previous workspace build exists
+		var lastWorkspaceBuildParameters []database.WorkspaceBuildParameter
+		if workspaceBuild.BuildNumber > 1 {
+			// TODO: Should we fetch the last build that succeeded? This fetches the
+			//   previous build regardless of the status of the build.
+			buildNum := workspaceBuild.BuildNumber - 1
+			previous, err := s.Database.GetWorkspaceBuildByWorkspaceIDAndBuildNumber(ctx, database.GetWorkspaceBuildByWorkspaceIDAndBuildNumberParams{
+				WorkspaceID: workspaceBuild.WorkspaceID,
+				BuildNumber: buildNum,
+			})
+
+			// If the error is ErrNoRows, then assume previous values are empty.
+			if err != nil && !xerrors.Is(err, sql.ErrNoRows) {
+				return nil, xerrors.Errorf("get last build with number=%d: %w", buildNum, err)
+			}
+
+			if err == nil {
+				lastWorkspaceBuildParameters, err = s.Database.GetWorkspaceBuildParameters(ctx, previous.ID)
+				if err != nil {
+					return nil, xerrors.Errorf("get last build parameters %q: %w", previous.ID, err)
+				}
+			}
+		}
+
 		workspaceBuildParameters, err := s.Database.GetWorkspaceBuildParameters(ctx, workspaceBuild.ID)
 		if err != nil {
 			return nil, failJob(fmt.Sprintf("get workspace build parameters: %s", err))
@@ -619,12 +643,13 @@ func (s *server) acquireProtoJob(ctx context.Context, job database.ProvisionerJo
 
 		protoJob.Type = &proto.AcquiredJob_WorkspaceBuild_{
 			WorkspaceBuild: &proto.AcquiredJob_WorkspaceBuild{
-				WorkspaceBuildId:      workspaceBuild.ID.String(),
-				WorkspaceName:         workspace.Name,
-				State:                 workspaceBuild.ProvisionerState,
-				RichParameterValues:   convertRichParameterValues(workspaceBuildParameters),
-				VariableValues:        asVariableValues(templateVariables),
-				ExternalAuthProviders: externalAuthProviders,
+				WorkspaceBuildId:        workspaceBuild.ID.String(),
+				WorkspaceName:           workspace.Name,
+				State:                   workspaceBuild.ProvisionerState,
+				RichParameterValues:     convertRichParameterValues(workspaceBuildParameters),
+				PreviousParameterValues: convertRichParameterValues(lastWorkspaceBuildParameters),
+				VariableValues:          asVariableValues(templateVariables),
+				ExternalAuthProviders:   externalAuthProviders,
 				Metadata: &sdkproto.Metadata{
 					CoderUrl:                      s.AccessURL.String(),
 					WorkspaceTransition:           transition,

diff --git a/go.mod b/go.mod
@@ -488,7 +488,7 @@ require (
 
 require (
 	github.com/anthropics/anthropic-sdk-go v0.2.0-beta.3
-	github.com/coder/preview v0.0.2-0.20250509141204-fc9484dbe506
+	github.com/coder/preview v0.0.2-0.20250509154224-be151070d1ca
 	github.com/fsnotify/fsnotify v1.9.0
 	github.com/kylecarbs/aisdk-go v0.0.8
 	github.com/mark3labs/mcp-go v0.25.0

diff --git a/go.sum b/go.sum
@@ -907,8 +907,8 @@ github.com/coder/pq v1.10.5-0.20240813183442-0c420cb5a048 h1:3jzYUlGH7ZELIH4XggX
 github.com/coder/pq v1.10.5-0.20240813183442-0c420cb5a048/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
 github.com/coder/pretty v0.0.0-20230908205945-e89ba86370e0 h1:3A0ES21Ke+FxEM8CXx9n47SZOKOpgSE1bbJzlE4qPVs=
 github.com/coder/pretty v0.0.0-20230908205945-e89ba86370e0/go.mod h1:5UuS2Ts+nTToAMeOjNlnHFkPahrtDkmpydBen/3wgZc=
-github.com/coder/preview v0.0.2-0.20250509141204-fc9484dbe506 h1:rQ7Queq1IZwEBjEIk9EJsVx7XHQ+Rvo2h72/A88BnPg=
-github.com/coder/preview v0.0.2-0.20250509141204-fc9484dbe506/go.mod h1:wXVvHiSmZv/7Q+Ug5I0B45TGM2U+YAjY4K3aB/6+KKo=
+github.com/coder/preview v0.0.2-0.20250509154224-be151070d1ca h1:7DUCQgu0uatLCWd+y/DUtWrLOROJY8it7vLeh9igjrI=
+github.com/coder/preview v0.0.2-0.20250509154224-be151070d1ca/go.mod h1:GfkwIv5gQLpL01qeGU1/YoxoFtt5trzCqnWZLo77clU=
 github.com/coder/quartz v0.1.3 h1:hA2nI8uUA2fNN9uhXv2I4xZD4aHkA7oH3g2t03v4xf8=
 github.com/coder/quartz v0.1.3/go.mod h1:vsiCc+AHViMKH2CQpGIpFgdHIEQsxwm8yCscqKmzbRA=
 github.com/coder/retry v1.5.1 h1:iWu8YnD8YqHs3XwqrqsjoBTAVqT9ml6z9ViJ2wlMiqc=

diff --git a/provisioner/terraform/provision.go b/provisioner/terraform/provision.go
@@ -152,7 +152,8 @@ func (s *server) Plan(
 
 	s.logger.Debug(ctx, "ran initialization")
 
-	env, err := provisionEnv(sess.Config, request.Metadata, request.RichParameterValues, request.ExternalAuthProviders)
+	// plan step does not require previous values
+	env, err := provisionEnv(sess.Config, request.Metadata, nil, request.RichParameterValues, request.ExternalAuthProviders)
 	if err != nil {
 		return provisionersdk.PlanErrorf("setup env: %s", err)
 	}
@@ -205,7 +206,7 @@ func (s *server) Apply(
 
 	// Earlier in the session, Plan() will have written the state file and the plan file.
 	statefilePath := getStateFilePath(sess.WorkDirectory)
-	env, err := provisionEnv(sess.Config, request.Metadata, nil, nil)
+	env, err := provisionEnv(sess.Config, request.Metadata, nil, nil, nil)
 	if err != nil {
 		return provisionersdk.ApplyErrorf("provision env: %s", err)
 	}
@@ -236,7 +237,7 @@ func planVars(plan *proto.PlanRequest) ([]string, error) {
 
 func provisionEnv(
 	config *proto.Config, metadata *proto.Metadata,
-	richParams []*proto.RichParameterValue, externalAuth []*proto.ExternalAuthProvider,
+	previousParams, richParams []*proto.RichParameterValue, externalAuth []*proto.ExternalAuthProvider,
 ) ([]string, error) {
 	env := safeEnviron()
 	ownerGroups, err := json.Marshal(metadata.GetWorkspaceOwnerGroups())
@@ -277,6 +278,9 @@ func provisionEnv(
 	for key, value := range provisionersdk.AgentScriptEnv() {
 		env = append(env, key+"="+value)
 	}
+	for _, param := range previousParams {
+		env = append(env, provider.ParameterEnvironmentVariablePrevious(param.Name)+"="+param.Value)
+	}
 	for _, param := range richParams {
 		env = append(env, provider.ParameterEnvironmentVariable(param.Name)+"="+param.Value)
 	}