cosign install

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

src/cosign/dockerfile.ts

@@ -0,0 +1,61 @@
+/**
+ * Copyright 2025 actions-toolkit authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export const dockerfileContent = `
+# syntax=docker/dockerfile:1
+
+ARG GO_VERSION="1.24"
+ARG ALPINE_VERSION="3.22"
+
+FROM --platform=$BUILDPLATFORM tonistiigi/xx:1.7.0 AS xx
+
+FROM --platform=$BUILDPLATFORM golang:\${GO_VERSION}-alpine\${ALPINE_VERSION} AS builder-base
+COPY --from=xx / /
+RUN apk add --no-cache git
+ENV GOTOOLCHAIN=auto
+ENV CGO_ENABLED=0
+WORKDIR /src
+RUN --mount=type=cache,target=/go/pkg/mod \\
+    --mount=type=bind,source=go.mod,target=go.mod \\
+    --mount=type=bind,source=go.sum,target=go.sum \\
+    go mod download
+
+FROM builder-base AS version
+RUN --mount=type=bind,target=. <<'EOT'
+  git rev-parse HEAD 2>/dev/null || {
+    echo >&2 "Failed to get git revision, make sure --build-arg BUILDKIT_CONTEXT_KEEP_GIT_DIR=1 is set when building from Git directly"
+    exit 1
+  }
+  set -ex
+  export PKG=sigs.k8s.io BUILDDATE=$(date -u +"%Y-%m-%dT%H:%M:%SZ") TREESTATE=$(if ! git diff --no-ext-diff --quiet --exit-code; then echo dirty; else echo clean; fi) VERSION=$(git describe --match 'v[0-9]*' --dirty='.m' --always --tags) COMMIT=$(git rev-parse HEAD)$(if ! git diff --no-ext-diff --quiet --exit-code; then echo .m; fi);
+  echo "-X \${PKG}/release-utils/version.gitVersion=\${VERSION} -X \${PKG}/release-utils/version.gitCommit=\${COMMIT} -X \${PKG}/release-utils/version.gitTreeState=\${TREESTATE} -X \${PKG}/release-utils/version.buildDate=\${BUILDDATE}" > /tmp/.ldflags;
+  echo -n "\${VERSION}" > /tmp/.version;
+EOT
+
+FROM builder-base AS builder
+ARG TARGETPLATFORM
+RUN --mount=type=bind,target=. \\
+    --mount=type=cache,target=/root/.cache,id=cosign-$TARGETPLATFORM \\
+    --mount=source=/tmp/.ldflags,target=/tmp/.ldflags,from=version \\
+    --mount=type=cache,target=/go/pkg/mod <<EOT
+  set -ex
+  xx-go build -trimpath -ldflags "-s -w $(cat /tmp/.ldflags)" -o /out/cosign ./cmd/cosign
+  xx-verify --static /out/cosign
+EOT
+
+FROM scratch
+COPY --from=builder /out /
+`;