fix: enable pubkey login on dstack 0.6 guests

.github/workflows/ghcr.yml

@@ -0,0 +1,59 @@
+name: GHCR
+
+on:
+  push:
+    branches: [main]
+    tags:
+      - 'v*'
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  packages: write
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Log in to GHCR
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Docker metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ghcr.io/${{ github.repository }}
+          tags: |
+            type=raw,value=latest,enable={{is_default_branch}}
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=ref,event=branch
+            type=sha
+            type=raw,value={{date 'YYYYMMDDHHmmss'}},enable=${{ github.event_name == 'workflow_dispatch' }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: docker/Dockerfile
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          platforms: linux/amd64
+          provenance: false
+          build-args: |
+            DSTACK_REV=${{ github.sha }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

README.md

@@ -30,6 +30,13 @@ docker run --rm --privileged --pid=host --net=host -v /:/host \
   $NS/dstack-openssh-installer:latest
 ```
 
+**Import ssh public keys from multiple GitHub usernames:**
+```bash
+docker run --rm --privileged --pid=host --net=host -v /:/host \
+  -e SSH_GITHUB_USER="alice,bob" \
+  $NS/dstack-openssh-installer:latest
+```
+
 **Custom port:**
 ```bash
 docker run --rm --privileged --pid=host --net=host -v /:/host \
@@ -44,7 +51,7 @@ docker run --rm --privileged --pid=host --net=host -v /:/host \
 |----------|---------|-------------|
 | `SSH_PORT` | `22` | SSH listening port |
 | `SSH_PUBKEY` | - | SSH public key for root login |
-| `SSH_GITHUB_USER` | - | GitHub username to import public keys from |
+| `SSH_GITHUB_USER` | - | GitHub username(s) to import public keys from (comma-separated) |
 | `SSH_PERMIT_ROOT_LOGIN` | `prohibit-password` | Root login policy (`yes`, `no`, `prohibit-password`) |
 
 ## Usage After Installation

docker/Dockerfile

@@ -10,7 +10,8 @@ RUN apk add --no-cache \
     openssl-libs-static \
     zlib-dev \
     zlib-static \
-    wget
+    wget \
+    file
 
 WORKDIR /build
 
@@ -40,7 +41,7 @@ RUN wget https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-${OPENSSH_
           /build/install/usr/libexec/sshd-session
 
 # Verify static linking
-RUN file /build/install/usr/sbin/sshd | grep -q "statically linked" && \
+RUN file /build/install/usr/sbin/sshd | grep -Eq "statically linked|static-pie linked" && \
     echo "sshd is statically linked"
 
 # Final image

scripts/install-openssh.sh

@@ -199,26 +199,36 @@ setup_authorized_keys() {
         keys_added=1
     fi
 
-    # Fetch keys from GitHub user
+    # Fetch keys from GitHub user(s). SSH_GITHUB_USER accepts a comma-separated list.
     if [[ -n "${SSH_GITHUB_USER}" ]]; then
-        local github_url="https://github.com/${SSH_GITHUB_USER}.keys"
-        log_info "Fetching public keys from GitHub user: ${SSH_GITHUB_USER}..."
-        local fetched_keys
-        if fetched_keys=$(wget -qO- "${github_url}" 2>/dev/null); then
-            if [[ -n "${fetched_keys}" ]]; then
-                if [[ -n "${managed_keys}" ]]; then
-                    managed_keys="${managed_keys}"$'\n'"${fetched_keys}"
+        local github_users
+        IFS=',' read -r -a github_users <<< "${SSH_GITHUB_USER}"
+        local github_user
+        for github_user in "${github_users[@]}"; do
+            github_user="${github_user//[[:space:]]/}"
+            if [[ -z "${github_user}" ]]; then
+                continue
+            fi
+
+            local github_url="https://github.com/${github_user}.keys"
+            log_info "Fetching public keys from GitHub user: ${github_user}..."
+            local fetched_keys
+            if fetched_keys=$(wget -qO- "${github_url}" 2>/dev/null); then
+                if [[ -n "${fetched_keys}" ]]; then
+                    if [[ -n "${managed_keys}" ]]; then
+                        managed_keys="${managed_keys}"$'\n'"${fetched_keys}"
+                    else
+                        managed_keys="${fetched_keys}"
+                    fi
+                    keys_added=1
+                    log_success "Public keys imported from GitHub (${github_user})"
                 else
-                    managed_keys="${fetched_keys}"
+                    log_warning "No keys found for GitHub user: ${github_user}"
                 fi
-                keys_added=1
-                log_success "Public keys imported from GitHub (${SSH_GITHUB_USER})"
             else
-                log_warning "No keys found for GitHub user: ${SSH_GITHUB_USER}"
+                log_error "Failed to fetch keys from GitHub for user: ${github_user}"
             fi
-        else
-            log_error "Failed to fetch keys from GitHub for user: ${SSH_GITHUB_USER}"
-        fi
+        done
     fi
 
     # Update authorized_keys file with markers
@@ -304,6 +314,8 @@ AuthorizedKeysFile ${SSH_HOME_DIR}/%u/.ssh/authorized_keys
 PasswordAuthentication no
 PermitEmptyPasswords no
 KbdInteractiveAuthentication no
+# dstack guest rootfs has / as 0777; sshd StrictModes would refuse AuthorizedKeysFile
+StrictModes no
 
 # Security
 X11Forwarding no