refactor: templates api logic

internal/reverseproxy/proxy.go

@@ -87,7 +87,8 @@ func (p *ReverseProxy) handleRequest(c echo.Context) error {
 		return echo.NewHTTPError(http.StatusNotFound)
 	}
 
-	first := strings.Split(subdomain, ".")[0]
+	ps := strings.Split(subdomain, ".")
+	first := ps[len(ps)-1]
 	proxy, ok := p.httpProxies[first]
 	if !ok {
 		return echo.NewHTTPError(http.StatusNotFound)

internal/template/docker_template.go

@@ -1,113 +0,0 @@
-package template
-
-import (
-	"archive/tar"
-	"bytes"
-	"context"
-	"errors"
-	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/client"
-	"github.com/google/uuid"
-	"github.com/uptrace/bun"
-	"io"
-	"time"
-)
-
-type createTemplateOptions struct {
-	name        string
-	description string
-}
-
-type templateBuildOptions struct {
-	imageTag  string
-	buildArgs map[string]*string
-}
-
-func createDockerTemplate(ctx context.Context, tx bun.Tx, opts createTemplateOptions) (*template, error) {
-	id, err := uuid.NewV7()
-	if err != nil {
-		return nil, err
-	}
-
-	now := time.Now().Format(time.RFC3339)
-
-	t := template{
-		ID:             id,
-		Name:           opts.name,
-		Description:    opts.description,
-		CreatedOn:      now,
-		LastModifiedOn: now,
-		IsBuilt:        false,
-	}
-	dockerfile := templateFile{
-		TemplateID: id,
-		FilePath:   "Dockerfile",
-		Content:    make([]byte, 0),
-	}
-	readme := templateFile{
-		TemplateID: id,
-		FilePath:   "README.md",
-		Content:    make([]byte, 0),
-	}
-	files := []*templateFile{&dockerfile, &readme}
-
-	if err = tx.NewInsert().Model(&t).Returning("*").Scan(ctx); err != nil {
-		return nil, err
-	}
-
-	if err = tx.NewInsert().Model(&files).Scan(ctx); err != nil {
-		return nil, err
-	}
-
-	t.Files = files
-
-	return &t, nil
-}
-
-func buildDockerTemplate(ctx context.Context, docker *client.Client, tmpl *template, opts templateBuildOptions) (io.ReadCloser, error) {
-	if len(tmpl.Files) == 0 {
-		return nil, errors.New("cannot build docker template: no files in template")
-	}
-
-	buf := new(bytes.Buffer)
-	tw := tar.NewWriter(buf)
-	defer tw.Close()
-
-	var dockerfile []byte
-	for _, file := range tmpl.Files {
-		if file.FilePath == "Dockerfile" {
-			dockerfile = file.Content
-			break
-		}
-	}
-	if len(dockerfile) == 0 {
-		return nil, errors.New("cannot build docker template: template does not contain Dockerfile")
-	}
-
-	h := tar.Header{
-		Name: "Dockerfile",
-		Size: int64(len(dockerfile)),
-	}
-	err := tw.WriteHeader(&h)
-	if err != nil {
-		return nil, err
-	}
-
-	_, err = tw.Write(dockerfile)
-	if err != nil {
-		return nil, err
-	}
-
-	r := bytes.NewReader(buf.Bytes())
-
-	res, err := docker.ImageBuild(ctx, r, types.ImageBuildOptions{
-		Context:   r,
-		Tags:      []string{opts.imageTag},
-		BuildArgs: opts.buildArgs,
-	})
-	if err != nil {
-		return nil, err
-	}
-
-	return res.Body, nil
-}

internal/template/http_handlers.go

@@ -1,15 +1,12 @@
 package template
 
 import (
-	"bufio"
 	"database/sql"
 	"encoding/json"
 	"errors"
-	"fmt"
 	"github.com/labstack/echo/v4"
 	"io"
 	"net/http"
-	"strings"
 	"tesseract/internal/service"
 )
 
@@ -19,7 +16,7 @@ type createTemplateRequestBody struct {
 	Documentation string `json:"documentation"`
 }
 
-type updateTemplateRequestBody struct {
+type postTemplateRequestBody struct {
 	Description *string        `json:"description"`
 	Files       []templateFile `json:"files"`
 
@@ -27,92 +24,52 @@ type updateTemplateRequestBody struct {
 	BuildArgs map[string]*string `json:"buildArgs"`
 }
 
-type templateBuildLogEvent struct {
-	Type       string `json:"type"`
-	LogContent string `json:"logContent"`
-}
-
-type templateBuildFinishedEvent struct {
-	Type     string    `json:"type"`
-	Template *template `json:"template"`
-}
-
 func fetchAllTemplates(c echo.Context) error {
-	db := service.Database(c)
-
-	var templates []template
-	err := db.NewSelect().Model(&templates).Scan(c.Request().Context())
+	mgr := templateManagerFrom(c)
+	templates, err := mgr.findAllTemplates(c.Request().Context())
 	if err != nil {
-		if errors.Is(err, sql.ErrNoRows) {
-			return c.JSON(http.StatusOK, make([]template, 0))
-		}
 		return err
 	}
-
-	if len(templates) == 0 {
-		return c.JSON(http.StatusOK, make([]template, 0))
-	}
 	return c.JSON(http.StatusOK, templates)
 }
 
 func fetchTemplate(c echo.Context) error {
-	db := service.Database(c)
-
-	name := c.Param("templateName")
-	if strings.TrimSpace(name) == "" {
-		return echo.NewHTTPError(http.StatusNotFound)
-	}
-
-	var tmpl template
-	err := db.NewSelect().Model(&tmpl).
-		Relation("Files").
-		Where("name = ?", name).
-		Scan(c.Request().Context())
+	mgr := templateManagerFrom(c)
+	template, err := mgr.findTemplate(c.Request().Context(), c.Param("templateName"))
 	if err != nil {
-		if errors.Is(err, sql.ErrNoRows) {
+		if errors.Is(err, errTemplateNotFound) {
 			return echo.NewHTTPError(http.StatusNotFound)
 		}
 		return err
 	}
-
-	if len(tmpl.Files) > 0 {
-		tmpl.FileMap = make(map[string]*templateFile)
-	}
-	for _, f := range tmpl.Files {
-		tmpl.FileMap[f.FilePath] = f
-	}
-
-	return c.JSON(http.StatusOK, tmpl)
+	return c.JSON(http.StatusOK, template)
 }
 
 func createOrUpdateTemplate(c echo.Context) error {
-	db := service.Database(c)
-
-	name := c.Param("templateName")
-	if strings.TrimSpace(name) == "" {
-		return echo.NewHTTPError(http.StatusNotFound)
-	}
-
-	exists, err := db.NewSelect().
-		Table("templates").
-		Where("name = ?", name).
-		Exists(c.Request().Context())
+	mgr := templateManagerFrom(c)
+	exists, err := mgr.hasTemplate(c.Request().Context(), c.Param("templateName"))
 	if err != nil {
-		if errors.Is(err, sql.ErrNoRows) {
-			return createTemplate(c)
-		}
 		return err
 	}
-
 	if !exists {
 		return createTemplate(c)
 	}
 
-	return updateTemplate(c)
+	var body postTemplateRequestBody
+	err = json.NewDecoder(c.Request().Body).Decode(&body)
+	if err != nil {
+		return err
+	}
+
+	if body.ImageTag != nil || body.BuildArgs != nil {
+		return buildTemplate(c, body)
+	}
+
+	return updateTemplate(c, body)
 }
 
 func createTemplate(c echo.Context) error {
-	db := service.Database(c)
+	mgr := templateManagerFrom(c)
 	name := c.Param("templateName")
 
 	var body createTemplateRequestBody
@@ -121,208 +78,85 @@ func createTemplate(c echo.Context) error {
 		return err
 	}
 
-	tx, err := db.BeginTx(c.Request().Context(), nil)
-	if err != nil {
-		return err
-	}
-
-	createdTemplate, err := createDockerTemplate(c.Request().Context(), tx, createTemplateOptions{
+	createdTemplate, err := mgr.createTemplate(c.Request().Context(), createTemplateOptions{
 		name:        name,
 		description: body.Description,
 	})
 	if err != nil {
-		_ = tx.Rollback()
-		return err
-	}
-
-	if err = tx.Commit(); err != nil {
-		_ = tx.Rollback()
 		return err
 	}
 
 	return c.JSON(http.StatusOK, createdTemplate)
 }
 
-func updateTemplate(c echo.Context) error {
-	db := service.Database(c)
+func updateTemplate(c echo.Context, body postTemplateRequestBody) error {
 	name := c.Param("templateName")
+	mgr := templateManagerFrom(c)
+	ctx := c.Request().Context()
 
-	var body updateTemplateRequestBody
-	err := json.NewDecoder(c.Request().Body).Decode(&body)
+	updatedTemplate, err := mgr.updateTemplate(ctx, name, updateTemplateOptions{
+		description: *body.Description,
+	})
 	if err != nil {
-		return err
-	}
-
-	if body.BuildArgs != nil && body.ImageTag == nil {
-		return echo.NewHTTPError(http.StatusBadRequest, "Image tag must be specified if buildArgs is passed")
-	}
-
-	tx, err := db.BeginTx(c.Request().Context(), nil)
-	if err != nil {
-		return err
-	}
-
-	var tmpl template
-	err = tx.NewSelect().Model(&tmpl).
-		Where("name = ?", name).
-		Scan(c.Request().Context())
-	if err != nil {
-		if errors.Is(err, sql.ErrNoRows) {
+		if errors.Is(err, errTemplateNotFound) {
 			return echo.NewHTTPError(http.StatusNotFound)
 		}
 		return err
 	}
 
-	if body.Description != nil {
-		tmpl.Description = *body.Description
-		_, err = tx.NewUpdate().Model(&tmpl).
-			Column("description").
-			WherePK().
-			Exec(c.Request().Context())
-		if err != nil {
-			_ = tx.Rollback()
-			return err
+	return c.JSON(http.StatusOK, &updatedTemplate)
+}
+
+func buildTemplate(c echo.Context, body postTemplateRequestBody) error {
+	mgr := templateManagerFrom(c)
+	name := c.Param("templateName")
+	ctx := c.Request().Context()
+
+	template, err := mgr.findTemplate(ctx, name)
+	if err != nil {
+		if errors.Is(err, errTemplateNotFound) {
+			return echo.NewHTTPError(http.StatusNotFound)
 		}
-
-		if err = tx.Commit(); err != nil {
-			_ = tx.Rollback()
-			return err
-		}
-	}
-
-	if body.ImageTag != nil {
-		err = tx.NewSelect().Model(&tmpl.Files).
-			Where("template_id = ?", tmpl.ID).
-			Scan(c.Request().Context())
-		if err != nil {
-			_ = tx.Rollback()
-			return err
-		}
-
-		docker := service.DockerClient(c)
-		log, err := buildDockerTemplate(c.Request().Context(), docker, &tmpl, templateBuildOptions{
-			imageTag:  *body.ImageTag,
-			buildArgs: body.BuildArgs,
-		})
-		if err != nil {
-			return err
-		}
-
-		w := c.Response()
-		w.Header().Set("Content-Type", "text/event-stream")
-		w.Header().Set("Cache-Control", "no-cache")
-		w.Header().Set("Connection", "keep-alive")
-
-		scanner := bufio.NewScanner(log)
-
-		var imageID string
-
-		for scanner.Scan() {
-			t := scanner.Text()
-
-			fmt.Println("DOCKER LOG: ", t)
-
-			var msg map[string]any
-			err = json.Unmarshal([]byte(t), &msg)
-			if err != nil {
-				return err
-			}
-
-			if stream, ok := msg["stream"].(string); ok {
-				if _, err = w.Write([]byte(stream)); err != nil {
-					return err
-				}
-				w.Flush()
-			} else if errmsg, ok := msg["error"].(string); ok {
-				if _, err = w.Write([]byte(errmsg + "\n")); err != nil {
-					return err
-				}
-				w.Flush()
-			} else if status, ok := msg["status"].(string); ok {
-				var text string
-				if progress, ok := msg["progress"].(string); ok {
-					text = fmt.Sprintf("%v: %v\n", status, progress)
-				} else {
-					text = status + "\n"
-				}
-				if _, err = w.Write([]byte(text)); err != nil {
-					return err
-				}
-				w.Flush()
-			} else if aux, ok := msg["aux"].(map[string]any); ok {
-				if id, ok := aux["ID"].(string); ok {
-					imageID = id
-				}
-			}
-		}
-
-		if imageID != "" {
-			img := TemplateImage{
-				TemplateID: tmpl.ID,
-				ImageTag:   *body.ImageTag,
-				ImageID:    imageID,
-			}
-
-			_, err = tx.NewInsert().Model(&img).Exec(c.Request().Context())
-			if err != nil {
-				_ = tx.Rollback()
-				return err
-			}
-		}
-
-		if err = tx.Commit(); err != nil {
-			_ = tx.Rollback()
-			return err
-		}
-
-		return nil
-	}
-
-	if err = tx.Commit(); err != nil {
-		_ = tx.Rollback()
 		return err
 	}
 
-	return c.JSON(http.StatusOK, &tmpl)
+	outputChan, err := mgr.buildTemplate(ctx, template, buildTemplateOptions{
+		imageTag:  *body.ImageTag,
+		buildArgs: body.BuildArgs,
+	})
+	if err != nil {
+		return err
+	}
+
+	w := c.Response()
+	w.Header().Set("Content-Type", "text/event-stream")
+	w.Header().Set("Cache-Control", "no-cache")
+	w.Header().Set("Connection", "keep-alive")
+
+	for o := range outputChan {
+		switch o := o.(type) {
+		case error:
+			return err
+		case string:
+			if _, err = w.Write([]byte(o)); err != nil {
+				return err
+			}
+			w.Flush()
+		}
+	}
+
+	return nil
 }
 
 func deleteTemplate(c echo.Context) error {
-	templateName := c.Param("templateName")
-	if templateName == "" {
-		return echo.NewHTTPError(http.StatusNotFound)
-	}
+	mgr := templateManagerFrom(c)
+	name := c.Param("templateName")
 
-	db := service.Database(c)
-
-	tx, err := db.BeginTx(c.Request().Context(), nil)
+	err := mgr.deleteTemplate(c.Request().Context(), name)
 	if err != nil {
-		return err
-	}
-
-	res, err := tx.NewDelete().Table("templates").
-		Where("name = ?", templateName).
-		Exec(c.Request().Context())
-	if err != nil {
-		if errors.Is(err, sql.ErrNoRows) {
+		if errors.Is(err, errTemplateNotFound) {
 			return echo.NewHTTPError(http.StatusNotFound)
 		}
-		_ = tx.Rollback()
-		return err
-	}
-
-	count, err := res.RowsAffected()
-	if err != nil {
-		_ = tx.Rollback()
-		return err
-	}
-
-	if count != 1 {
-		_ = tx.Rollback()
-		return echo.NewHTTPError(http.StatusInternalServerError)
-	}
-
-	if err = tx.Commit(); err != nil {
-		_ = tx.Rollback()
 		return err
 	}
 
@@ -330,37 +164,13 @@ func deleteTemplate(c echo.Context) error {
 }
 
 func fetchTemplateFile(c echo.Context) error {
+	mgr := templateManagerFrom(c)
 	templateName := c.Param("templateName")
-	if templateName == "" {
-		return echo.NewHTTPError(http.StatusNotFound)
-	}
-
 	filePath := c.Param("filePath")
-	if filePath == "" {
-		return echo.NewHTTPError(http.StatusNotFound)
-	}
 
-	db := service.Database(c)
-
-	var tmpl template
-	err := db.NewSelect().Model(&tmpl).
-		Column("id").
-		Where("name = ?", templateName).
-		Scan(c.Request().Context())
+	file, err := mgr.findTemplateFile(c.Request().Context(), templateName, filePath)
 	if err != nil {
-		if errors.Is(err, sql.ErrNoRows) {
-			return echo.NewHTTPError(http.StatusNotFound)
-		}
-		return err
-	}
-
-	var file templateFile
-	err = db.NewSelect().Model(&file).
-		Where("template_id = ?", tmpl.ID).
-		Where("file_path = ?", filePath).
-		Scan(c.Request().Context())
-	if err != nil {
-		if errors.Is(err, sql.ErrNoRows) {
+		if errors.Is(err, errTemplateNotFound) || errors.Is(err, errTemplateFileNotFound) {
 			return echo.NewHTTPError(http.StatusNotFound)
 		}
 		return err
@@ -370,74 +180,40 @@ func fetchTemplateFile(c echo.Context) error {
 }
 
 func updateTemplateFile(c echo.Context) error {
+	mgr := templateManagerFrom(c)
 	templateName := c.Param("templateName")
-	if templateName == "" {
-		return echo.NewHTTPError(http.StatusNotFound)
-	}
-
 	filePath := c.Param("filePath")
-	if filePath == "" {
-		return echo.NewHTTPError(http.StatusNotFound)
-	}
-
-	db := service.Database(c)
-
-	tx, err := db.BeginTx(c.Request().Context(), nil)
-	if err != nil {
-		return err
-	}
-
-	var tmpl template
-	err = tx.NewSelect().Model(&tmpl).
-		Column("id").
-		Where("name = ?", templateName).
-		Scan(c.Request().Context())
-	if err != nil {
-		if errors.Is(err, sql.ErrNoRows) {
-			return echo.NewHTTPError(http.StatusNotFound)
-		}
-		return err
-	}
 
 	newContent, err := io.ReadAll(c.Request().Body)
 	if err != nil {
 		return err
 	}
 
-	_, err = tx.NewUpdate().Table("template_files").
-		Set("content = ?", newContent).
-		Where("template_id = ?", tmpl.ID).
-		Where("file_path = ?", filePath).
-		Exec(c.Request().Context())
+	err = mgr.updateTemplateFile(c.Request().Context(), templateName, filePath, newContent)
 	if err != nil {
-		if errors.Is(err, sql.ErrNoRows) {
+		if errors.Is(err, errTemplateNotFound) || errors.Is(err, errTemplateFileNotFound) {
 			return echo.NewHTTPError(http.StatusNotFound)
 		}
 		return err
 	}
 
-	if err = tx.Commit(); err != nil {
-		_ = tx.Rollback()
-		return err
-	}
-
 	return c.NoContent(http.StatusOK)
 }
 
 func fetchAllTemplateImages(c echo.Context) error {
 	db := service.Database(c)
 
-	var images []TemplateImage
+	var images []Image
 	err := db.NewSelect().Model(&images).Scan(c.Request().Context())
 	if err != nil {
 		if errors.Is(err, sql.ErrNoRows) {
-			return c.JSON(http.StatusOK, make([]TemplateImage, 0))
+			return c.JSON(http.StatusOK, make([]Image, 0))
 		}
 		return err
 	}
 
 	if len(images) == 0 {
-		return c.JSON(http.StatusOK, make([]TemplateImage, 0))
+		return c.JSON(http.StatusOK, make([]Image, 0))
 	}
 
 	return c.JSON(http.StatusOK, images)

internal/template/middleware.go

@@ -0,0 +1,45 @@
+package template
+
+import (
+	"net/http"
+	"tesseract/internal/service"
+
+	"github.com/labstack/echo/v4"
+)
+
+func newTemplateManagerMiddleware(service service.Services) echo.MiddlewareFunc {
+	mgr := templateManager{
+		db:           service.Database,
+		dockerClient: service.DockerClient,
+	}
+	return func(next echo.HandlerFunc) echo.HandlerFunc {
+		return func(c echo.Context) error {
+			c.Set("templateManager", &mgr)
+			return next(c)
+		}
+	}
+}
+
+func validateTemplateName(next echo.HandlerFunc) echo.HandlerFunc {
+	return func(c echo.Context) error {
+		templateName := c.Param("templateName")
+		if templateName == "" || !templateNameRegex.MatchString(templateName) {
+			return echo.NewHTTPError(http.StatusNotFound)
+		}
+		return next(c)
+	}
+}
+
+func validateTemplateFilePath(next echo.HandlerFunc) echo.HandlerFunc {
+	return func(c echo.Context) error {
+		filePath := c.Param("filePath")
+		if filePath == "" {
+			return echo.NewHTTPError(http.StatusNotFound)
+		}
+		return next(c)
+	}
+}
+
+func templateManagerFrom(c echo.Context) *templateManager {
+	return c.Get("templateManager").(*templateManager)
+}

internal/template/routes.go

@@ -2,14 +2,16 @@ package template
 
 import (
 	"github.com/labstack/echo/v4"
+	"tesseract/internal/service"
 )
 
-func DefineRoutes(g *echo.Group) {
+func DefineRoutes(g *echo.Group, services service.Services) {
+	g.Use(newTemplateManagerMiddleware(services))
 	g.GET("/templates", fetchAllTemplates)
-	g.GET("/templates/:templateName", fetchTemplate)
-	g.POST("/templates/:templateName", createOrUpdateTemplate)
-	g.DELETE("/templates/:templateName", deleteTemplate)
-	g.GET("/templates/:templateName/:filePath", fetchTemplateFile)
-	g.POST("/templates/:templateName/:filePath", updateTemplateFile)
+	g.GET("/templates/:templateName", fetchTemplate, validateTemplateName)
+	g.POST("/templates/:templateName", createOrUpdateTemplate, validateTemplateName)
+	g.DELETE("/templates/:templateName", deleteTemplate, validateTemplateName)
+	g.GET("/templates/:templateName/:filePath", fetchTemplateFile, validateTemplateName, validateTemplateFilePath)
+	g.POST("/templates/:templateName/:filePath", updateTemplateFile, validateTemplateName, validateTemplateFilePath)
 	g.GET("/template-images", fetchAllTemplateImages)
 }

internal/template/template.go

@@ -3,8 +3,12 @@ package template
 import (
 	"github.com/google/uuid"
 	"github.com/uptrace/bun"
+	"regexp"
 )
 
+// templateNameRegex is a regex to test whether a given template name is valid
+var templateNameRegex = regexp.MustCompile("^[\\w-]+$")
+
 type template struct {
 	bun.BaseModel `bun:"table:templates,alias:template"`
 
@@ -27,7 +31,7 @@ type templateFile struct {
 	Content    []byte    `bun:"type:blob" json:"content"`
 }
 
-type TemplateImage struct {
+type Image struct {
 	bun.BaseModel `bun:"table:template_images,alias:template_images"`
 
 	TemplateID uuid.UUID `bun:"type:uuid" json:"-"`

internal/template/template_manager.go

@@ -0,0 +1,417 @@
+package template
+
+import (
+	"archive/tar"
+	"bufio"
+	"bytes"
+	"context"
+	"database/sql"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/client"
+	"github.com/google/uuid"
+	"github.com/uptrace/bun"
+	"time"
+)
+
+type templateManager struct {
+	db           *bun.DB
+	dockerClient *client.Client
+}
+
+type createTemplateOptions struct {
+	name        string
+	description string
+}
+
+type updateTemplateOptions struct {
+	tx          *bun.Tx
+	description string
+}
+
+type buildTemplateOptions struct {
+	tx        *bun.Tx
+	imageTag  string
+	buildArgs map[string]*string
+}
+
+var errTemplateNotFound = errors.New("template not found")
+var errTemplateFileNotFound = errors.New("template file not found")
+
+func (mgr *templateManager) beginTx(ctx context.Context) (bun.Tx, error) {
+	tx, err := mgr.db.BeginTx(ctx, nil)
+	if err != nil {
+		return bun.Tx{}, err
+	}
+	return tx, nil
+}
+
+func (mgr *templateManager) findAllTemplates(ctx context.Context) ([]template, error) {
+	var templates []template
+	err := mgr.db.NewSelect().Model(&templates).Scan(ctx)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return make([]template, 0), nil
+		}
+		return nil, err
+	}
+
+	if len(templates) == 0 {
+		return make([]template, 0), nil
+	}
+
+	return templates, nil
+}
+
+func (mgr *templateManager) findTemplate(ctx context.Context, name string) (*template, error) {
+	var template template
+	err := mgr.db.NewSelect().Model(&template).
+		Relation("Files").
+		Where("name = ?", name).
+		Scan(ctx)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, errTemplateNotFound
+		}
+		return nil, err
+	}
+
+	if len(template.Files) > 0 {
+		template.FileMap = make(map[string]*templateFile)
+	}
+	for _, f := range template.Files {
+		template.FileMap[f.FilePath] = f
+	}
+
+	return &template, nil
+}
+
+func (mgr *templateManager) hasTemplate(ctx context.Context, name string) (bool, error) {
+	exists, err := mgr.db.NewSelect().
+		Table("templates").
+		Where("name = ?", name).
+		Exists(ctx)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return false, nil
+		}
+		return false, err
+	}
+	return exists, nil
+}
+
+func (mgr *templateManager) createTemplate(ctx context.Context, opts createTemplateOptions) (*template, error) {
+	tx, err := mgr.db.BeginTx(ctx, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	id, err := uuid.NewV7()
+	if err != nil {
+		return nil, err
+	}
+
+	now := time.Now().Format(time.RFC3339)
+
+	t := template{
+		ID:             id,
+		Name:           opts.name,
+		Description:    opts.description,
+		CreatedOn:      now,
+		LastModifiedOn: now,
+		IsBuilt:        false,
+	}
+	dockerfile := templateFile{
+		TemplateID: id,
+		FilePath:   "Dockerfile",
+		Content:    make([]byte, 0),
+	}
+	readme := templateFile{
+		TemplateID: id,
+		FilePath:   "README.md",
+		Content:    make([]byte, 0),
+	}
+	files := []*templateFile{&dockerfile, &readme}
+
+	if err = tx.NewInsert().Model(&t).Returning("*").Scan(ctx); err != nil {
+		return nil, err
+	}
+
+	if err = tx.NewInsert().Model(&files).Scan(ctx); err != nil {
+		return nil, err
+	}
+
+	t.Files = files
+
+	if err = tx.Commit(); err != nil {
+		_ = tx.Rollback()
+		return nil, err
+	}
+
+	return &t, nil
+}
+
+func (mgr *templateManager) updateTemplate(ctx context.Context, name string, opts updateTemplateOptions) (*template, error) {
+	tx := opts.tx
+	autoCommit := false
+	if tx == nil {
+		_tx, err := mgr.db.BeginTx(ctx, nil)
+		if err != nil {
+			return nil, err
+		}
+		autoCommit = true
+		tx = &_tx
+	}
+
+	var template template
+	err := tx.NewUpdate().Model(&template).
+		Where("name = ?", name).
+		Set("description = ?", opts.description).
+		Returning("*").
+		Scan(ctx)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, errTemplateNotFound
+		}
+		return nil, err
+	}
+
+	if autoCommit {
+		if err = tx.Commit(); err != nil {
+			_ = tx.Rollback()
+			return nil, err
+		}
+	}
+
+	return &template, nil
+}
+
+func (mgr *templateManager) buildTemplate(ctx context.Context, template *template, opts buildTemplateOptions) (<-chan any, error) {
+	tx := opts.tx
+	autoCommit := false
+	if tx == nil {
+		_tx, err := mgr.db.BeginTx(ctx, nil)
+		if err != nil {
+			return nil, err
+		}
+		autoCommit = true
+		tx = &_tx
+	}
+
+	if len(template.Files) == 0 {
+		return nil, errors.New("cannot build docker template: no files in template")
+	}
+
+	buf := new(bytes.Buffer)
+	tw := tar.NewWriter(buf)
+	defer tw.Close()
+
+	var dockerfile []byte
+	for _, file := range template.Files {
+		if file.FilePath == "Dockerfile" {
+			dockerfile = file.Content
+			break
+		}
+	}
+	if len(dockerfile) == 0 {
+		return nil, errors.New("cannot build docker template: template does not contain Dockerfile")
+	}
+
+	h := tar.Header{
+		Name: "Dockerfile",
+		Size: int64(len(dockerfile)),
+	}
+	err := tw.WriteHeader(&h)
+	if err != nil {
+		return nil, err
+	}
+
+	_, err = tw.Write(dockerfile)
+	if err != nil {
+		return nil, err
+	}
+
+	r := bytes.NewReader(buf.Bytes())
+
+	res, err := mgr.dockerClient.ImageBuild(ctx, r, types.ImageBuildOptions{
+		Context:   r,
+		Tags:      []string{opts.imageTag},
+		BuildArgs: opts.buildArgs,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	outputChan := make(chan any)
+
+	go func() {
+		scanner := bufio.NewScanner(res.Body)
+		var imageID string
+
+		for scanner.Scan() {
+			t := scanner.Text()
+
+			fmt.Println("DOCKER LOG: ", t)
+
+			var msg map[string]any
+			err = json.Unmarshal([]byte(t), &msg)
+			if err != nil {
+				outputChan <- err
+			}
+
+			if stream, ok := msg["stream"].(string); ok {
+				outputChan <- stream
+			} else if errmsg, ok := msg["error"].(string); ok {
+				outputChan <- errmsg + "\n"
+			} else if status, ok := msg["status"].(string); ok {
+				var text string
+				if progress, ok := msg["progress"].(string); ok {
+					text = fmt.Sprintf("%v: %v\n", status, progress)
+				} else {
+					text = status + "\n"
+				}
+				outputChan <- text
+			} else if aux, ok := msg["aux"].(map[string]any); ok {
+				if id, ok := aux["ID"].(string); ok {
+					imageID = id
+				}
+			}
+		}
+
+		var img *Image
+
+		if imageID != "" {
+			img = &Image{
+				TemplateID: template.ID,
+				ImageTag:   opts.imageTag,
+				ImageID:    imageID,
+			}
+
+			_, err = tx.NewInsert().Model(img).Exec(ctx)
+			if err != nil {
+				_ = tx.Rollback()
+				outputChan <- err
+			}
+		}
+
+		if autoCommit {
+			if err = tx.Commit(); err != nil {
+				_ = tx.Rollback()
+				outputChan <- err
+			}
+		}
+
+		if img != nil {
+			outputChan <- img
+		}
+
+		close(outputChan)
+	}()
+
+	return outputChan, nil
+}
+
+func (mgr *templateManager) deleteTemplate(ctx context.Context, name string) error {
+	tx, err := mgr.db.BeginTx(ctx, nil)
+	if err != nil {
+		return err
+	}
+
+	res, err := tx.NewDelete().Table("templates").
+		Where("name = ?", name).
+		Exec(ctx)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return errTemplateNotFound
+		}
+		_ = tx.Rollback()
+		return err
+	}
+
+	count, err := res.RowsAffected()
+	if err != nil {
+		_ = tx.Rollback()
+		return err
+	}
+
+	if count != 1 {
+		_ = tx.Rollback()
+		return errors.New("unexpected number of templates deleted")
+	}
+
+	if err = tx.Commit(); err != nil {
+		_ = tx.Rollback()
+		return err
+	}
+
+	return nil
+}
+
+func (mgr *templateManager) findTemplateFile(ctx context.Context, templateName, filePath string) (*templateFile, error) {
+	var tmpl template
+	err := mgr.db.NewSelect().Model(&tmpl).
+		Column("id").
+		Where("name = ?", templateName).
+		Scan(ctx)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, errTemplateNotFound
+		}
+		return nil, err
+	}
+
+	var file templateFile
+	err = mgr.db.NewSelect().Model(&file).
+		Where("template_id = ?", tmpl.ID).
+		Where("file_path = ?", filePath).
+		Scan(ctx)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, errTemplateFileNotFound
+		}
+		return nil, err
+	}
+
+	return &file, nil
+}
+
+func (mgr *templateManager) updateTemplateFile(ctx context.Context, templateName, filePath string, content []byte) error {
+	tx, err := mgr.db.BeginTx(ctx, nil)
+	if err != nil {
+		return err
+	}
+
+	var template template
+	err = tx.NewSelect().Model(&template).
+		Column("id").
+		Where("name = ?", templateName).
+		Scan(ctx)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return errTemplateNotFound
+		}
+		return err
+	}
+
+	_, err = tx.NewUpdate().Table("template_files").
+		Set("content = ?", content).
+		Where("template_id = ?", template.ID).
+		Where("file_path = ?", filePath).
+		Exec(ctx)
+	if err != nil {
+		_ = tx.Rollback()
+		if errors.Is(err, sql.ErrNoRows) {
+			return errTemplateFileNotFound
+		}
+		return err
+	}
+
+	if err = tx.Commit(); err != nil {
+		_ = tx.Rollback()
+		return err
+	}
+
+	return nil
+}

internal/workspace/middleware.go

@@ -1,8 +1,9 @@
 package workspace
 
 import (
-	"github.com/labstack/echo/v4"
 	"tesseract/internal/service"
+
+	"github.com/labstack/echo/v4"
 )
 
 func newWorkspaceManagerMiddleware(services service.Services) echo.MiddlewareFunc {

internal/workspace/workspace_manager.go

@@ -131,7 +131,7 @@ func (mgr workspaceManager) createWorkspace(ctx context.Context, opts createWork
 		return nil, err
 	}
 
-	var img template.TemplateImage
+	var img template.Image
 	err = tx.NewSelect().Model(&img).
 		Where("image_id = ?", opts.imageID).
 		Scan(ctx)

main.go

@@ -80,7 +80,7 @@ func main() {
 
 	g := apiServer.Group("/api")
 	workspace.DefineRoutes(g, services)
-	template.DefineRoutes(g)
+	template.DefineRoutes(g, services)
 
 	apiServer.HTTPErrorHandler = func(err error, c echo.Context) {
 		var he *echo.HTTPError