diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..6b8710a
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1 @@
+.git
diff --git a/Dockerfile b/Dockerfile
index 97fc567..cfa7fd7 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,7 +7,7 @@ WORKDIR /app
 COPY go.mod go.sum /app/
 RUN go mod download
 
-COPY *.go /app/
+COPY . /app/
 RUN go build -o app .
 
 FROM docker.io/alpine:3.22
diff --git a/github.go b/github.go
index 75635b7..dbec0e3 100644
--- a/github.go
+++ b/github.go
@@ -6,11 +6,11 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"mime"
 	"mime/multipart"
 	"net/http"
 	"os"
-	"strings"
+
+	"code.geekeey.de/actions/sdk"
 )
 
 type ApiClient interface {
@@ -43,24 +43,6 @@ func NewGitHub(client ApiClient) *GitHub {
 	return &GitHub{client: client}
 }
 
-func HasContentType(r *http.Response, mimetype string) bool {
-	contentType := r.Header.Get("content-type")
-	if contentType == "" {
-		return mimetype == "application/octet-stream"
-	}
-
-	for _, v := range strings.Split(contentType, ",") {
-		t, _, err := mime.ParseMediaType(v)
-		if err != nil {
-			break
-		}
-		if t == mimetype {
-			return true
-		}
-	}
-	return false
-}
-
 type GitTag struct {
 	Commit struct {
 		Created string `json:"created,omitempty"`
@@ -87,7 +69,7 @@ func (gh *GitHub) GetGitTagInfo(repository, tag string, ctx context.Context) (*G
 		return nil, err
 	}
 	defer res.Body.Close()
-	if !HasContentType(res, "application/json") {
+	if !sdk.HasContentType(res, "application/json") {
 		return nil, fmt.Errorf("content-type: %q should be %q",
 			res.Header.Get("content-type"), "application/json")
 	}
@@ -161,7 +143,7 @@ func (gh *GitHub) CreateRelease(creq *CreateReleaseRequest, ctx context.Context)
 		return nil, err
 	}
 	defer res.Body.Close()
-	if !HasContentType(res, "application/json") {
+	if !sdk.HasContentType(res, "application/json") {
 		return nil, fmt.Errorf("content-type: %q should be %q",
 			res.Header.Get("content-type"), "application/json")
 	}
@@ -264,7 +246,7 @@ func (gh *GitHub) CreateReleaseArtifact(creq *CreateReleaseArtifactRequest, ctx
 		return nil, err
 	}
 	defer res.Body.Close()
-	if !HasContentType(res, "application/json") {
+	if !sdk.HasContentType(res, "application/json") {
 		return nil, fmt.Errorf("content-type: %q should be %q",
 			res.Header.Get("content-type"), "application/json")
 	}
diff --git a/go.mod b/go.mod
index 540a83f..6bdc712 100644
--- a/go.mod
+++ b/go.mod
@@ -2,4 +2,4 @@ module code.geekeey.de/actions/release
 
 go 1.23.2
 
-require code.geekeey.de/actions/sdk v1.2.0
+require code.geekeey.de/actions/sdk v1.5.0
diff --git a/go.sum b/go.sum
index 6a21fc7..b25cf65 100644
--- a/go.sum
+++ b/go.sum
@@ -1,2 +1,2 @@
-code.geekeey.de/actions/sdk v1.2.0 h1:qQvOdTBtZVpR1xATNnApeiW78y34Jh83OjsQg1ajPjA=
-code.geekeey.de/actions/sdk v1.2.0/go.mod h1:7iIOi3YUmdDe2BCz9s59wK1t0Ckec34e664q+TOreiE=
+code.geekeey.de/actions/sdk v1.5.0 h1:7Ly8QsBniiwDVbv2Gm14l28+ccK1Z9fVUqsPHw9lSMg=
+code.geekeey.de/actions/sdk v1.5.0/go.mod h1:7iIOi3YUmdDe2BCz9s59wK1t0Ckec34e664q+TOreiE=
diff --git a/main.go b/main.go
index 7a4ba84..897c0b4 100644
--- a/main.go
+++ b/main.go
@@ -39,8 +39,6 @@ type ReleaseAction struct {
 }
 
 func (action *ReleaseAction) setup() error {
-	var err error
-
 	action.repository = action.GetInput("repository")
 	if ok, err := regexp.MatchString(`^(\w+)/(\w+)$`, action.repository); !ok || err != nil {
 		return fmt.Errorf("input 'repository': is empty or does not match <onwer>/<repo>")
@@ -69,17 +67,19 @@ func (action *ReleaseAction) setup() error {
 
 	// draft might be a bool constant or a regex which determins if it is
 	// a draft by matching against the input version
-	action.draft, err = pattern("draft")
+	draft, err := pattern("draft")
 	if err != nil {
 		return fmt.Errorf("input 'draft': is not a bool or a valid regex")
 	}
+	action.draft = draft
 
 	// prerelease might be a bool constant or a regex which determins if it is
 	// a prelease by matching against the input version
-	action.prerelease, err = pattern("prerelease")
+	prerelease, err := pattern("prerelease")
 	if err != nil {
 		return fmt.Errorf("input 'prerelease': is not a bool or a valid regex")
 	}
+	action.prerelease = prerelease
 
 	action.label = action.GetInput("label")
 	action.notes = action.GetInput("notes")