Make list_images.sh emit the etcd3 tarball

We need this for every devstack run now, so downloading it from github
every time isn't the most awesome thing in the world.

Add an extra variable EXTRA_CACHE_URLS which will be appended to the
output of tools/image_list.sh.  This way, these files will be
downloaded during the daily nodepool build, but they will not be in
the IMAGE_LIST and hence be considered as images to upload.

Add a function get_extra_file which echos the path to a file given the
URL.  It will first check the cache at $FILES, and if not present
download it.

Update the documentation in image_list.sh to reflect what's happening.

Move the defaults for etcd variables into stackrc, since it is a base
service now.

Change-Id: I86104824a29d973a6288df1f24b7891feb86267c

functions

@@ -45,6 +45,37 @@ function short_source {
 # export it so child shells have access to the 'short_source' function also.
 export -f short_source
 
+# Download a file from a URL
+#
+# Will check cache (in $FILES) or download given URL.
+#
+# Argument is the URL to the remote file
+#
+# Will echo the local path to the file as the output.  Will die on
+# failure to download.
+#
+# Files can be pre-cached for CI environments, see EXTRA_CACHE_URLS
+# and tools/image_list.sh
+function get_extra_file {
+    local file_url=$1
+
+    file_name=$(basename "$file_url")
+    if [[ $file_url != file* ]]; then
+        # If the file isn't cache, download it
+        if [[ ! -f $FILES/$file_name ]]; then
+            wget --progress=dot:giga -c $file_url -O $FILES/$file_name
+            if [[ $? -ne 0 ]]; then
+                die "$file_url could not be downloaded"
+            fi
+        fi
+        echo "$FILES/$file_name"
+        return
+    else
+        # just strip the file:// bit and that's the path to the file
+        echo $file_url | sed 's/$file:\/\///g'
+    fi
+}
+
 
 # Retrieve an image from a URL and upload into Glance.
 # Uses the following variables:

lib/etcd3

@@ -24,15 +24,9 @@ set +o xtrace
 # --------
 
 # Set up default values for etcd
-ETCD_DOWNLOAD_URL=${ETCD_DOWNLOAD_URL:-https://github.com/coreos/etcd/releases/download}
-ETCD_VERSION=${ETCD_VERSION:-v3.1.7}
 ETCD_DATA_DIR="$DATA_DIR/etcd"
 ETCD_SYSTEMD_SERVICE="devstack@etcd.service"
 ETCD_BIN_DIR="$DEST/bin"
-ETCD_SHA256_AMD64="4fde194bbcd259401e2b5c462dfa579ee7f6af539f13f130b8f5b4f52e3b3c52"
-# NOTE(sdague): etcd v3.1.7 doesn't have anything for these architectures, though 3.2.0 does.
-ETCD_SHA256_ARM64=""
-ETCD_SHA256_PPC64=""
 ETCD_PORT=2379
 
 if is_ubuntu ; then
@@ -95,37 +89,19 @@ function cleanup_etcd3 {
 function install_etcd3 {
     echo "Installing etcd"
 
-    # Make sure etcd3 downloads the correct architecture
-    if is_arch "x86_64"; then
-        ETCD_ARCH="amd64"
-        ETCD_SHA256=${ETCD_SHA256:-$ETCD_SHA256_AMD64}
-    elif is_arch "aarch64"; then
-        ETCD_ARCH="arm64"
-        ETCD_SHA256=${ETCD_SHA256:-$ETCD_SHA256_ARM64}
-    elif is_arch "ppc64le"; then
-        ETCD_ARCH="ppc64le"
-        ETCD_SHA256=${ETCD_SHA256:-$ETCD_SHA256_PPC64}
-    else
-        exit_distro_not_supported "invalid hardware type - $ETCD_ARCH"
-    fi
-
-    ETCD_NAME=etcd-$ETCD_VERSION-linux-$ETCD_ARCH
-
     # Create the necessary directories
     sudo mkdir -p $ETCD_BIN_DIR
     sudo mkdir -p $ETCD_DATA_DIR
 
     # Download and cache the etcd tgz for subsequent use
+    local etcd_file
+    etcd_file="$(get_extra_file $ETCD_DOWNLOAD_LOCATION)"
     if [ ! -f "$FILES/etcd-$ETCD_VERSION-linux-$ETCD_ARCH/etcd" ]; then
-        ETCD_DOWNLOAD_FILE=$ETCD_NAME.tar.gz
+        echo "${ETCD_SHA256} $etcd_file" > $FILES/etcd.sha256sum
-        if [ ! -f "$FILES/$ETCD_DOWNLOAD_FILE" ]; then
-            wget $ETCD_DOWNLOAD_URL/$ETCD_VERSION/$ETCD_DOWNLOAD_FILE -O $FILES/$ETCD_DOWNLOAD_FILE
-        fi
-        echo "${ETCD_SHA256} $FILES/${ETCD_DOWNLOAD_FILE}" > $FILES/etcd.sha256sum
         # NOTE(sdague): this should go fatal if this fails
         sha256sum -c $FILES/etcd.sha256sum
 
-        tar xzvf $FILES/$ETCD_DOWNLOAD_FILE -C $FILES
+        tar xzvf $etcd_file -C $FILES
         sudo cp $FILES/$ETCD_NAME/etcd $ETCD_BIN_DIR/etcd
     fi
     if [ ! -f "$ETCD_BIN_DIR/etcd" ]; then

stackrc

@@ -732,6 +732,40 @@ if [[ "$DOWNLOAD_DEFAULT_IMAGES" == "True" ]]; then
     DOWNLOAD_DEFAULT_IMAGES=False
 fi
 
+# This is a comma separated list of extra URLS to be listed for
+# download by the tools/image_list.sh script.  CI environments can
+# pre-download these URLS and place them in $FILES.  Later scripts can
+# then use "get_extra_file <url>" which will print out the path to the
+# file; it will either be downloaded on demand or acquired from the
+# cache if there.
+EXTRA_CACHE_URLS=""
+
+# etcd3 defaults
+ETCD_VERSION=${ETCD_VERSION:-v3.1.7}
+ETCD_SHA256_AMD64="4fde194bbcd259401e2b5c462dfa579ee7f6af539f13f130b8f5b4f52e3b3c52"
+# NOTE(sdague): etcd v3.1.7 doesn't have anything for these architectures, though 3.2.0 does.
+ETCD_SHA256_ARM64=""
+ETCD_SHA256_PPC64=""
+# Make sure etcd3 downloads the correct architecture
+if is_arch "x86_64"; then
+    ETCD_ARCH="amd64"
+    ETCD_SHA256=${ETCD_SHA256:-$ETCD_SHA256_AMD64}
+elif is_arch "aarch64"; then
+    ETCD_ARCH="arm64"
+    ETCD_SHA256=${ETCD_SHA256:-$ETCD_SHA256_ARM64}
+elif is_arch "ppc64le"; then
+    ETCD_ARCH="ppc64le"
+    ETCD_SHA256=${ETCD_SHA256:-$ETCD_SHA256_PPC64}
+else
+    exit_distro_not_supported "invalid hardware type - $ETCD_ARCH"
+fi
+ETCD_DOWNLOAD_URL=${ETCD_DOWNLOAD_URL:-https://github.com/coreos/etcd/releases/download}
+ETCD_NAME=etcd-$ETCD_VERSION-linux-$ETCD_ARCH
+ETCD_DOWNLOAD_FILE=$ETCD_NAME.tar.gz
+ETCD_DOWNLOAD_LOCATION=$ETCD_DOWNLOAD_URL/$ETCD_VERSION/$ETCD_DOWNLOAD_FILE
+# etcd is always required, so place it into list of pre-cached downloads
+EXTRA_CACHE_URLS+=",$ETCD_DOWNLOAD_LOCATION"
+
 # Detect duplicate values in IMAGE_URLS
 for image_url in ${IMAGE_URLS//,/ }; do
     if [ $(echo "$IMAGE_URLS" | grep -o -F "$image_url" | wc -l) -gt 1 ]; then

tools/image_list.sh

@@ -1,5 +1,14 @@
 #!/bin/bash
 
+# Print out a list of image and other files to download for caching.
+# This is mostly used by the OpenStack infrasturucture during daily
+# image builds to save the large images to /opt/cache/files (see [1])
+#
+# The two lists of URL's downloaded are the IMAGE_URLS and
+# EXTRA_CACHE_URLS, which are setup in stackrc
+#
+# [1] project-config:nodepool/elements/cache-devstack/extra-data.d/55-cache-devstack-repos
+
 # Keep track of the DevStack directory
 TOP_DIR=$(cd $(dirname "$0")/.. && pwd)
 
@@ -31,12 +40,20 @@ for driver in $DRIVERS; do
     ALL_IMAGES+=$URLS
 done
 
-# Make a nice list
-echo $ALL_IMAGES | tr ',' '\n' | sort | uniq
-
 # Sanity check - ensure we have a minimum number of images
 num=$(echo $ALL_IMAGES | tr ',' '\n' | sort | uniq | wc -l)
 if [[ "$num" -lt 4 ]]; then
     echo "ERROR: We only found $num images in $ALL_IMAGES, which can't be right."
     exit 1
 fi
+
+# This is extra non-image files that we want pre-cached.  This is kept
+# in a separate list because devstack loops over the IMAGE_LIST to
+# upload files glance and these aren't images.  (This was a bit of an
+# after-thought which is why the naming around this is very
+# image-centric)
+URLS=$(source $TOP_DIR/stackrc && echo $EXTRA_CACHE_URLS)
+ALL_IMAGES+=$URLS
+
+# Make a nice combined list
+echo $ALL_IMAGES | tr ',' '\n' | sort | uniq