Append to MIRRORS instead of PREMIRRORS to limit egress

For the first deployment of the S3 download mirror we will
err on the side of cost savings, and use the mirror as a
fallback not the primary source of downloads.

Revert this if we want the benefits of using our own mirrors
as the primary source, like download speed and no rate limits.

Change-type: patch
Signed-off-by: Kyle Harding <[email protected]>

.github/workflows/yocto-build-deploy.yml

@@ -510,22 +510,27 @@ jobs:
           EOF
           cat "${AUTO_CONF_FILE}"
 
-      # FIXME: We should probably change this to MIRRORS:append instead of PREMIRRORS:prepend
-      # to avoid using our S3 egress as much as possible?
       # https://docs.yoctoproject.org/4.0.10/ref-manual/classes.html?highlight=source_mirror#own-mirrors-bbclass
       # https://github.com/openembedded/openembedded/blob/master/classes/own-mirrors.bbclass
       # The own-mirrors class makes it easier to set up your own PREMIRRORS from which to first fetch source before
       # attempting to fetch it from the upstream specified in SRC_URI within each recipe.
-      - name: Add S3 shared-downloads to PREMIRRORS
+      - name: Add S3 shared-downloads to MIRRORS
         if: env.SOURCE_MIRROR_URL
         env:
           SOURCE_MIRROR_URL: ${{ env.SOURCE_MIRROR_URL }}
         run: |
           mkdir -p "$(dirname "${AUTO_CONF_FILE}")"
           cat <<EOF >> "${AUTO_CONF_FILE}"
 
-          INHERIT += "own-mirrors"
-          SOURCE_MIRROR_URL = "${SOURCE_MIRROR_URL}"
+          MIRRORS:append = "\\
+            cvs://.*/.* ${SOURCE_MIRROR_URL} \\
+            svn://.*/.* ${SOURCE_MIRROR_URL} \\
+            git://.*/.* ${SOURCE_MIRROR_URL} \\
+            hg://.*/.* ${SOURCE_MIRROR_URL} \\
+            bzr://.*/.* ${SOURCE_MIRROR_URL} \\
+            https?$://.*/.* ${SOURCE_MIRROR_URL} \\
+            ftp://.*/.*  ${SOURCE_MIRROR_URL} \\
+          "
 
           EOF
           cat "${AUTO_CONF_FILE}"