with more generic way, but still wonky

Dockerfile

@@ -8,7 +8,7 @@ RUN go build -o dist/dagger-go main.go
 
 FROM harbor.front.kjuulh.io/docker-proxy/library/docker:dind
 
-WORKDIR /src/docker
+WORKDIR /src
 
-COPY --from=builder /src/builder/dist/dagger-go .
+COPY --from=builder /src/builder/dist/dagger-go /usr/bin/
 

dagger_go_template.yaml

@@ -1,5 +1,3 @@
-{{ $imageTag := "harbor.front.kjuulh.io/library/${DRONE_REPO_NAME}"  }}
-
 type: docker
 kind: pipeline
 name: "drone-dagger-test"
@@ -18,7 +16,7 @@ steps:
       - mkdir -p tmp/dagger-go
       - git clone "https://git.front.kjuulh.io/kjuulh/dagger-go.git" tmp/dagger-go
       - docker build -t dagger-go-builder:${DRONE_COMMIT} -f tmp/dagger-go/Dockerfile .
-      - 'docker run -v /var/run/docker.sock:/var/run/docker.sock dagger-go-builder:${DRONE_COMMIT} ./dagger-go build --image-tag "{{ or .input.imageTag $imageTag }}"'
+      - 'docker run -v "$PWD/:/src/" -v /var/run/docker.sock:/var/run/docker.sock dagger-go-builder:${DRONE_COMMIT} dagger-go build'
 
 services:
   - name: docker

example/main.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"context"
+	"log"
+
+	"git.front.kjuulh.io/kjuulh/dagger-go/internal"
+	"git.front.kjuulh.io/kjuulh/dagger-go/pkg/tasks"
+)
+
+func main() {
+	ctx := context.Background()
+
+	if err := run(ctx); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func run(ctx context.Context) error {
+	builder, err := internal.New(ctx)
+	if err != nil {
+		return err
+	}
+	defer builder.CleanUp()
+
+	return tasks.Build(builder, "some-image", "example/main.go")
+}

pkg/cli/cli.go

@@ -1,18 +1,17 @@
 package cli
 
 import (
+	"errors"
+	"fmt"
 	"log"
+	"os"
 
 	"git.front.kjuulh.io/kjuulh/dagger-go/internal"
 	"git.front.kjuulh.io/kjuulh/dagger-go/pkg/tasks"
 	"github.com/spf13/cobra"
 )
 
-func Build() *cobra.Command {
-	var (
-		imageTag string
-	)
-
+func Build(mainGoPath string, imageTag string) *cobra.Command {
 	cmd := &cobra.Command{
 		Use: "build",
 		RunE: func(cmd *cobra.Command, args []string) error {
@@ -20,6 +19,14 @@ func Build() *cobra.Command {
 				return err
 			}
 
+			if imageTag == "" {
+				repoName := os.Getenv("DRONE_REPO_NAME")
+				if repoName == "" {
+					return errors.New("could not find DRONE_REPO_NAME")
+				}
+				imageTag = fmt.Sprintf("harbor.front.kjuulh.io/library/%s", repoName)
+			}
+
 			ctx := cmd.Context()
 
 			log.Printf("Building image: %s\n", imageTag)
@@ -30,12 +37,9 @@ func Build() *cobra.Command {
 			}
 			defer client.CleanUp()
 
-			return tasks.Build(client, imageTag)
+			return tasks.Build(client, imageTag, mainGoPath)
 		},
 	}
 
-	cmd.PersistentFlags().StringVar(&imageTag, "image-tag", "", "the url for which to tag the docker image, defaults to private url, with repo as image name")
-	cmd.MarkPersistentFlagRequired("image-tag")
-
 	return cmd
 }

pkg/tasks/build.go

@@ -9,7 +9,7 @@ import (
 	"git.front.kjuulh.io/kjuulh/dagger-go/internal"
 )
 
-func Build(builder *internal.Builder, imageTag string) error {
+func Build(builder *internal.Builder, imageTag string, buildPath string) error {
 	log.Printf("building image: %s", imageTag)
 
 	client := builder.Dagger
@@ -33,7 +33,7 @@ func Build(builder *internal.Builder, imageTag string) error {
 					golang := client.Container().From("golang:latest")
 					golang = golang.WithMountedDirectory("/src", src).WithWorkdir("/src")
 					_, err = golang.Exec(dagger.ContainerExecOpts{
-						Args: []string{"go", "build", "-o", "build/"},
+						Args: []string{"go", "build", "-o", "build/", buildPath},
 					}).ExitCode(ctx)
 
 					return err