Tag nightly versions with date

.github/workflows/nightly.yml

@@ -11,8 +11,9 @@ on:
   pull_request:
     branches:
       - master
+  workflow_dispatch:
   schedule:
-    - cron: '0 0 * * *'
+    - cron: '0 6 * * *'
 
 jobs:
   build:
@@ -80,33 +81,74 @@ jobs:
         uses: docker/setup-buildx-action@v3
       - name: Login to GHCR
         uses: docker/login-action@v3
-        if: github.event_name != 'pull_request'
+        if: (github.event_name == 'schedule' || github.event_name == 'workflow_dispatch') && github.ref == 'refs/heads/master'
         with:
           registry: ghcr.io
           username: rust-lang
           password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Login to Docker Hub
         uses: docker/login-action@v3
-        if: github.event_name != 'pull_request'
+        if: (github.event_name == 'schedule' || github.event_name == 'workflow_dispatch') && github.ref == 'refs/heads/master'
         with:
           username: rustopsbot
           password: ${{ secrets.DOCKER_HUB_TOKEN }}
 
+      - name: Compute nightly date
+        id: date
+        env:
+          EVENT_NAME: ${{ github.event_name }}
+        run: |
+          set -euo pipefail
+          DATE=$(date -u +%Y-%m-%d)
+          URL="https://static.rust-lang.org/dist/${DATE}/channel-rust-nightly.toml"
+          if ! curl -fsI -o /dev/null "$URL"; then
+            case "${EVENT_NAME}" in
+              push|pull_request)
+                echo "Today's nightly manifest is not yet published; falling back to yesterday." >&2
+                DATE=$(date -u -d 'yesterday' +%Y-%m-%d)
+                ;;
+              *)
+                echo "Today's nightly manifest is not yet published; refusing to publish a stale nightly." >&2
+                exit 1
+                ;;
+            esac
+          fi
+          echo "date=${DATE}" >> "$GITHUB_OUTPUT"
+
+      - name: Build dated tag list
+        id: dated_tags
+        env:
+          BASE_TAGS: ${{ matrix.tags }}
+          DATE: ${{ steps.date.outputs.date }}
+        run: |
+          {
+            echo "tags<<EOF"
+            while IFS= read -r tag; do
+              [ -z "$tag" ] && continue
+              echo "type=raw,value=${tag}-${DATE}"
+            done <<< "$BASE_TAGS"
+            echo "EOF"
+          } >> "$GITHUB_OUTPUT"
+
       - name: Docker Metadata
         id: meta
         uses: docker/metadata-action@v5
         with:
           images: |
             rustlang/rust
             ghcr.io/rust-lang/rust
-          tags: ${{ matrix.tags }}
+          tags: |
+            ${{ matrix.tags }}
+            ${{ steps.dated_tags.outputs.tags }}
 
       - name: Build and push image
         uses: docker/build-push-action@v6
         with:
           context: ${{ matrix.context }}
           platforms: ${{ matrix.platforms }}
-          push: ${{ github.event_name != 'pull_request' }}
+          build-args: |
+            RUST_VERSION=nightly-${{ steps.date.outputs.date }}
+          push: ${{ (github.event_name == 'schedule' || github.event_name == 'workflow_dispatch') && github.ref == 'refs/heads/master' }}
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}

Dockerfile-alpine.template

@@ -7,10 +7,11 @@ RUN apk add --no-cache \
         musl-dev \
         gcc
 
+%%RUST-VERSION-ARG%%
 ENV RUSTUP_HOME=/usr/local/rustup \
     CARGO_HOME=/usr/local/cargo \
     PATH=/usr/local/cargo/bin:$PATH \
-    RUST_VERSION=%%RUST-VERSION%%
+    RUST_VERSION=%%RUST-VERSION-VALUE%%
 
 RUN set -eux; \
     \

Dockerfile-debian.template

@@ -2,10 +2,11 @@ FROM buildpack-deps:%%TAG%%
 
 LABEL org.opencontainers.image.source=https://github.com/rust-lang/docker-rust
 
+%%RUST-VERSION-ARG%%
 ENV RUSTUP_HOME=/usr/local/rustup \
     CARGO_HOME=/usr/local/cargo \
     PATH=/usr/local/cargo/bin:$PATH \
-    RUST_VERSION=%%RUST-VERSION%%
+    RUST_VERSION=%%RUST-VERSION-VALUE%%
 
 RUN set -eux; \
     \

Dockerfile-slim.template

@@ -2,10 +2,11 @@ FROM debian:%%TAG%%-slim
 
 LABEL org.opencontainers.image.source=https://github.com/rust-lang/docker-rust
 
+%%RUST-VERSION-ARG%%
 ENV RUSTUP_HOME=/usr/local/rustup \
     CARGO_HOME=/usr/local/cargo \
     PATH=/usr/local/cargo/bin:$PATH \
-    RUST_VERSION=%%RUST-VERSION%%
+    RUST_VERSION=%%RUST-VERSION-VALUE%%
 
 RUN set -eux; \
     \

nightly/alpine3.21/Dockerfile

@@ -7,10 +7,11 @@ RUN apk add --no-cache \
         musl-dev \
         gcc
 
+ARG RUST_VERSION=nightly
 ENV RUSTUP_HOME=/usr/local/rustup \
     CARGO_HOME=/usr/local/cargo \
     PATH=/usr/local/cargo/bin:$PATH \
-    RUST_VERSION=nightly
+    RUST_VERSION=${RUST_VERSION}
 
 RUN set -eux; \
     \

nightly/alpine3.22/Dockerfile

@@ -7,10 +7,11 @@ RUN apk add --no-cache \
         musl-dev \
         gcc
 
+ARG RUST_VERSION=nightly
 ENV RUSTUP_HOME=/usr/local/rustup \
     CARGO_HOME=/usr/local/cargo \
     PATH=/usr/local/cargo/bin:$PATH \
-    RUST_VERSION=nightly
+    RUST_VERSION=${RUST_VERSION}
 
 RUN set -eux; \
     \

nightly/alpine3.23/Dockerfile

@@ -7,10 +7,11 @@ RUN apk add --no-cache \
         musl-dev \
         gcc
 
+ARG RUST_VERSION=nightly
 ENV RUSTUP_HOME=/usr/local/rustup \
     CARGO_HOME=/usr/local/cargo \
     PATH=/usr/local/cargo/bin:$PATH \
-    RUST_VERSION=nightly
+    RUST_VERSION=${RUST_VERSION}
 
 RUN set -eux; \
     \

nightly/bookworm/Dockerfile

@@ -2,10 +2,11 @@ FROM buildpack-deps:bookworm
 
 LABEL org.opencontainers.image.source=https://github.com/rust-lang/docker-rust
 
+ARG RUST_VERSION=nightly
 ENV RUSTUP_HOME=/usr/local/rustup \
     CARGO_HOME=/usr/local/cargo \
     PATH=/usr/local/cargo/bin:$PATH \
-    RUST_VERSION=nightly
+    RUST_VERSION=${RUST_VERSION}
 
 RUN set -eux; \
     \

nightly/bookworm/slim/Dockerfile

@@ -2,10 +2,11 @@ FROM debian:bookworm-slim
 
 LABEL org.opencontainers.image.source=https://github.com/rust-lang/docker-rust
 
+ARG RUST_VERSION=nightly
 ENV RUSTUP_HOME=/usr/local/rustup \
     CARGO_HOME=/usr/local/cargo \
     PATH=/usr/local/cargo/bin:$PATH \
-    RUST_VERSION=nightly
+    RUST_VERSION=${RUST_VERSION}
 
 RUN set -eux; \
     \

nightly/bullseye/Dockerfile

@@ -2,10 +2,11 @@ FROM buildpack-deps:bullseye
 
 LABEL org.opencontainers.image.source=https://github.com/rust-lang/docker-rust
 
+ARG RUST_VERSION=nightly
 ENV RUSTUP_HOME=/usr/local/rustup \
     CARGO_HOME=/usr/local/cargo \
     PATH=/usr/local/cargo/bin:$PATH \
-    RUST_VERSION=nightly
+    RUST_VERSION=${RUST_VERSION}
 
 RUN set -eux; \
     \

nightly/bullseye/slim/Dockerfile

@@ -2,10 +2,11 @@ FROM debian:bullseye-slim
 
 LABEL org.opencontainers.image.source=https://github.com/rust-lang/docker-rust
 
+ARG RUST_VERSION=nightly
 ENV RUSTUP_HOME=/usr/local/rustup \
     CARGO_HOME=/usr/local/cargo \
     PATH=/usr/local/cargo/bin:$PATH \
-    RUST_VERSION=nightly
+    RUST_VERSION=${RUST_VERSION}
 
 RUN set -eux; \
     \

nightly/trixie/Dockerfile

@@ -2,10 +2,11 @@ FROM buildpack-deps:trixie
 
 LABEL org.opencontainers.image.source=https://github.com/rust-lang/docker-rust
 
+ARG RUST_VERSION=nightly
 ENV RUSTUP_HOME=/usr/local/rustup \
     CARGO_HOME=/usr/local/cargo \
     PATH=/usr/local/cargo/bin:$PATH \
-    RUST_VERSION=nightly
+    RUST_VERSION=${RUST_VERSION}
 
 RUN set -eux; \
     \

nightly/trixie/slim/Dockerfile

@@ -2,10 +2,11 @@ FROM debian:trixie-slim
 
 LABEL org.opencontainers.image.source=https://github.com/rust-lang/docker-rust
 
+ARG RUST_VERSION=nightly
 ENV RUSTUP_HOME=/usr/local/rustup \
     CARGO_HOME=/usr/local/cargo \
     PATH=/usr/local/cargo/bin:$PATH \
-    RUST_VERSION=nightly
+    RUST_VERSION=${RUST_VERSION}
 
 RUN set -eux; \
     \

x.py

@@ -156,12 +156,23 @@ def render_template(
     arch_cases,
     rendered_path
 ):
+    if rust_version == "nightly":
+        rust_version_arg = "ARG RUST_VERSION=nightly\n"
+        rust_version_value = "${RUST_VERSION}"
+    else:
+        rust_version_arg = ""
+        rust_version_value = rust_version
+
     template = read_file(template_path)
-    rendered = template \
-        .replace("%%TAG%%", docker_tag) \
-        .replace("%%RUST-VERSION%%", rust_version) \
-        .replace("%%RUSTUP-VERSION%%", rustup_version) \
+    rendered = (
+        template
+        .replace("%%TAG%%", docker_tag)
+        # We match with `\n` here so that the line is removed entirely if the argument is not needed
+        .replace("%%RUST-VERSION-ARG%%\n", rust_version_arg)
+        .replace("%%RUST-VERSION-VALUE%%", rust_version_value)
+        .replace("%%RUSTUP-VERSION%%", rustup_version)
         .replace("%%ARCH-CASE%%", arch_cases)
+    )
     write_file(rendered_path, rendered)
 
 def update_ci():