scripts: add helper to list all build dependencies

This script will download vyos-world debian/control file and build a
denpendency list which in the end outputs the commands required to setup
a build host (either native or via Docker) with all required packages.

1 files changed, 115 insertions, 0 deletions

diff --git a/scripts/list-build-dependencies b/scripts/list-build-dependencies
new file mode 100755
index 0000000..e7fc330
--- /dev/null
+++ b/scripts/list-build-dependencies
@@ -0,0 +1,115 @@
+#!/bin/bash
+#
+# Copyright (C) 2018 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# in order to easy exprort images built to "external" world
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Parse debian/control like content and extract packages required by the
+# Build-Depends statement. Return a string with all required packages.
+get_build_depends () {
+    echo $(awk '
+        /^Build-Depends:/ || /^ / && deps {
+        sub(/^[^ ]+: /, "")
+        deps = 1
+        dep_str = dep_str ", " $0
+        next
+      }
+      { deps=0 }
+      END {
+        split(dep_str, dep_array, /, */)
+        for (d in dep_array) {
+          dep = dep_array[d]
+          gsub(/[^a-z0-9_.-].*$/, "", dep)
+          if (dep && !seen[dep]++) print dep
+        }
+      }' $1)
+}
+
+get_runtime_depends () {
+    echo $(awk '
+        /^Depends:/ || /^ / && deps {
+        sub(/^[^ ]+: /, "")
+        deps = 1
+        dep_str = dep_str ", " $0
+        next
+      }
+      { deps=0 }
+      END {
+        split(dep_str, dep_array, /, */)
+        for (d in dep_array) {
+          dep = dep_array[d]
+          gsub(/[^a-z0-9_.-].*$/, "", dep)
+          if (dep && !seen[dep]++) print dep
+        }
+      }' $1)
+}
+
+# Some packages are required prior to running this script
+BOOTSTRAP_PACKAGES="devscripts curl equivs"
+for pkg in $BOOTSTRAP_PACKAGES
+do
+    dpkg -s $pkg >/dev/null 2>&1
+    if [ $? -ne 0 ]; then
+        echo "Required package \"$pkg\" not installed"
+        exit 1
+    fi
+done
+
+echo ""
+echo "Below you can find a list of packages that are required as build time"
+echo "dependency for the individual package"
+echo ""
+echo "The generated content can be used to populate a file to provision"
+echo "e.g. a native build host or a Docker container"
+echo ""
+echo ""
+
+# First we need to get vyos-world so we know all individual packages for VyOS
+curl -L https://github.com/vyos/vyos-world/raw/current/debian/control \
+  --output /tmp/vyos-world.control --retry 100 --retry-delay 1 --silent
+
+VYOS_PACKAGES=$(get_runtime_depends /tmp/vyos-world.control)
+for pkg in $VYOS_PACKAGES
+do
+    # Check if repo exists
+    res=$(curl -o /dev/null --silent -Iw '%{http_code}' https://github.com/vyos/$pkg)
+    if [[ $res -ne 200 ]]; then
+        continue
+    fi
+
+    CTRLFILE=/tmp/$pkg.control
+    curl -L https://github.com/vyos/$pkg/raw/current/debian/control \
+      --output $CTRLFILE --retry 100 --retry-delay 1 --silent
+
+    declare -a array
+    declare -i length current
+
+    array=($(get_build_depends $CTRLFILE))
+    length=${#array[@]}
+    current=0
+
+    echo "# Packages needed to build '$pkg' from https://github.com/vyos/$pkg"
+    echo "apt-get install -y \\"
+    for name in "${array[@]}"; do
+        current=$((current + 1))
+        if [[ "$current" -eq "$length" ]]; then
+            echo "  $name"
+        else
+            echo "  $name \\"
+        fi
+    done
+    rm -f $CTRLFILE
+    echo ""
+done
+