Vendor go dependencies

.github/workflows/main.yaml

@@ -240,3 +240,14 @@ jobs:
         docker exec test docker info
         docker exec test ./integration-docker.sh
         docker rm -f test
+  deps:
+    runs-on: ubuntu-24.04
+    steps:
+    - uses: actions/checkout@v4
+    - name: install go
+      uses: actions/setup-go@v5
+      with:
+        go-version: "1.24"
+        check-latest: true
+    - name: verify deps
+      run: make verify-dependencies

Makefile

@@ -10,15 +10,15 @@ clean:
 	$(RM) -r bin/ _artifact/
 
 bin/rootlesskit: $(GO_FILES)
-	$(GO) build -o $@ -v ./cmd/rootlesskit
+	$(GO) build -mod=vendor -o $@ -v ./cmd/rootlesskit
 
 bin/rootlessctl: $(GO_FILES)
-	$(GO) build -o $@ -v ./cmd/rootlessctl
+	$(GO) build -mod=vendor -o $@ -v ./cmd/rootlessctl
 
 bin/rootlesskit-docker-proxy: $(GO_FILES)
 	@echo "NOTE: rootlesskit-docker-proxy is required only if you use Docker prior to v28."
 	@echo "NOTE: rootlesskit-docker-proxy is DEPRECATED and will be removed in RootlessKit v3."
-	$(GO) build -o $@ -v ./cmd/rootlesskit-docker-proxy
+	$(GO) build -mod=vendor -o $@ -v ./cmd/rootlesskit-docker-proxy
 
 .PHONY: cross
 cross:
@@ -30,3 +30,15 @@ install:
 	install -D -m 755 $(CURDIR)/bin/rootlesskit $(DESTDIR)$(BINDIR)/rootlesskit
 	install -D -m 755 $(CURDIR)/bin/rootlessctl $(DESTDIR)$(BINDIR)/rootlessctl
 	install -D -m 755 $(CURDIR)/bin/rootlesskit-docker-proxy $(DESTDIR)$(BINDIR)/rootlesskit-docker-proxy
+
+.PHONY: vendor
+vendor:
+	$(GO) mod tidy
+	$(GO) mod vendor
+	$(GO) mod verify
+
+.PHONY: verify-dependencies
+verify-dependencies: vendor
+	@test -z "$$(git status --porcelain -- go.mod go.sum vendor/)" \
+		|| (echo -e "git status:\n $$(git status -- go.mod go.sum vendor/)\nerror: vendor/, go.mod and/or go.sum not up to date. Run \"make vendor\" to update"; exit 1) \
+		&& echo "all vendor files are up to date."