credential-helpers

Author: thesayyn

.bazelrc

@@ -9,8 +9,11 @@ test --test_env=DOCKER_HOST
 # Disable bzlmod lockfile
 common --lockfile_mode=off
 
-# TODO(2.0): enable once we drop support for Bazel 5.
-# common --credential_helper=public.ecr.aws=%workspace%/examples/credential_helper/auth.sh
+# On bazel 6.4.0 these are needed to successfully fetch images.
+common:needs_credential_helpers --credential_helper=public.ecr.aws=%workspace%/examples/credential_helper/auth.sh
+common:needs_credential_helpers --credential_helper=index.docker.io=%workspace%/examples/credential_helper/auth.sh
+common:needs_credential_helpers --credential_helper=docker.elastic.co=%workspace%/examples/credential_helper/auth.sh
+common:needs_credential_helpers --credential_helper_cache_duration=0
 
 # Load any settings specific to the current user.
 # .bazelrc.user should appear in .gitignore so that settings are not shared with team members

.github/workflows/ci.yaml

@@ -103,6 +103,18 @@ jobs:
         if: matrix.bzlmodEnabled
         run: echo "bzlmod_flag=--enable_bzlmod" >> $GITHUB_OUTPUT
 
+      - name: Set credential helpers flag
+        # Add --config needs_credential_helpers to add additional credential helpers
+        # to fetch from registries with HTTP headers set by credential helpers.
+        id: set_credential_helper_flag
+        if: matrix.bazelversion == '6.4.0'
+        run: echo "credential_helper_flag=--config=needs_credential_helpers" >> $GITHUB_OUTPUT
+
+      - name: Setup credential helpers
+        uses: imjasonh/[email protected]
+        with:
+          version: "v0.19.1"
+
       - name: Configure Bazel version
         working-directory: ${{ matrix.folder }}
         run: echo "${{ matrix.bazelversion }}" > .bazelversion
@@ -146,4 +158,10 @@ jobs:
         env:
           # Bazelisk will download bazel to here, ensure it is cached between runs.
           XDG_CACHE_HOME: ~/.cache/bazel-repo
-        run: bazel --bazelrc=$GITHUB_WORKSPACE/.github/workflows/ci.bazelrc --bazelrc=.bazelrc test ${{ steps.set_bzlmod_flag.outputs.bzlmod_flag }} //...
+        run: |
+          bazel \
+          --bazelrc=$GITHUB_WORKSPACE/.github/workflows/ci.bazelrc \
+          --bazelrc=.bazelrc  \
+          test //... \
+          ${{ steps.set_bzlmod_flag.outputs.bzlmod_flag }} \
+          ${{ steps.set_credential_helper_flag.outputs.credential_helper_flag }}

examples/credential_helper/auth.sh

@@ -1,14 +1,15 @@
 #!/usr/bin/env bash
 
 # Requirements 
-#   - curl
+#   - crane
 #   - jq
 #   - awk
 #  
 #  ./examples/credential_helper/auth.sh <<< '{"uri":"https://public.ecr.aws/token/?scope\u003drepository:lambda/python:pull\u0026service\u003dpublic.ecr.aws"}'
 #  ./examples/credential_helper/auth.sh <<< '{"uri":"https://public.ecr.aws/v2/lambda/python/manifests/3.11.2024.01.25.10"}'
+
 function log () {
-    echo "$1" >> /tmp/oci_auth.log
+    echo $@ >> "/tmp/oci_auth.log"
 }
 
 log ""
@@ -20,18 +21,39 @@ log "Payload: $input"
 uri=$(jq -r ".uri" <<< $input)
 log "URI: $uri"
 
-host="$(echo $uri | awk -F[/:] '{print $4}')"
+host="$(awk -F[/:] '{print $4}' <<< $uri)"
 log "Host: $host"
 
+
 if [[ $input == *"/token"* ]]; then
     log "Auth: None"
     echo "{}"
-    exit 0
+    exit 1
 fi
 
+repository=$(awk -F'^https?://|v2/|/manifests|/blobs' '{print $2 $3}' <<< "$uri")
+log "Repository: $repository"
+
+
+ACCEPTED_MEDIA_TYPES='[
+    "application/vnd.docker.distribution.manifest.v2+json",
+    "application/vnd.docker.distribution.manifest.list.v2+json",
+    "application/vnd.oci.image.manifest.v1+json",
+    "application/vnd.oci.image.index.v1+json"
+]'
+
+
 # This will write the response to stdout in a format that Bazels credential helper protocol understands.
 # Since this is called by Bazel, users won't bee seeing output of this.
-curl -fsSL https://$host/token | jq '{headers:{"Authorization": [("Bearer " + .token)]}}'
+crane auth token "$repository" | 
+jq --argjson accept "$ACCEPTED_MEDIA_TYPES" \
+'{headers: {Authorization: [("Bearer " + .token)], Accept: [($accept | join(", "))], "Docker-Distribution-API-Version": ["registry/2.0"] }}'
+
+if [[ $? != 0 ]]; then 
+    log "Auth: Failed"
+    exit 1
+fi 
 log "Auth: Complete"
 
-# Alternatively you can call an external program such as `docker-credential-ecr-login` to perform the token exchange.
+
+# Alternatively you can call an external program such as `docker-credential-ecr-login` to perform the token exchange.

oci/private/pull.bzl

@@ -38,10 +38,16 @@ _IMAGE_REFERENCE_ATTRS = {
 SCHEMA1_ERROR = """\
 The registry sent a manifest with schemaVersion=1. 
 This commonly occurs when fetching from a registry that needs the Docker-Distribution-API-Version header to be set.
+See: https://github.com/bazel-contrib/rules_oci/blob/main/docs/pull.md#authentication-using-credential-helpers
 """
 
 OCI_MEDIA_TYPE_OR_AUTHN_ERROR = """\
-Unable to retrieve the manifest. This could be due to authentication problems or an attempt to fetch an image with OCI image media types.
+Unable to retrieve the image manifest. This could be due to authentication problems or an attempt to fetch an image with OCI image media types.
+See: https://github.com/bazel-contrib/rules_oci/blob/main/docs/pull.md#authentication-using-credential-helpers
+"""
+
+OCI_MEDIA_TYPE_OR_AUTHN_ERROR_BAZEL7 = """\
+Unable to retrieve the image manifest. This could be due to authentication problems.
 """
 
 # Supported media types
@@ -142,7 +148,9 @@ def _download_manifest(rctx, authn, identifier, output):
         explanation = authn.explain()
         if explanation:
             util.warning(rctx, explanation)
-        fail(OCI_MEDIA_TYPE_OR_AUTHN_ERROR)
+        fail(
+            OCI_MEDIA_TYPE_OR_AUTHN_ERROR_BAZEL7 if versions.is_at_least("7.1.0", versions.get()) else OCI_MEDIA_TYPE_OR_AUTHN_ERROR,
+        )
 
     return manifest, len(bytes), digest