Fix the diskimage-create tox "build" environment

The recently added tox "build" environment had a few problems:
1. It was not honoring the DIB_* environment variables which meant
in always built a master branch image.
2. It also failed to run repeatedly due to a cache directory path issue.
3. The built images were stored in a hidden folder ".amp_tox_test".

This patch fixes those issues, resolves a confusing
"dpkg Broken pipe" message, and adds a "Successfully built" message
at the end of the built that highlights which branch the image was
built against (master, stable/stein, etc.).

Change-Id: I826c5f753f159b2d5dee97d4e2922826444ea6da

diskimage-create/diskimage-create.sh

@@ -207,6 +207,9 @@ AMP_ARCH=${AMP_ARCH:-"amd64"}
 AMP_BACKEND=${AMP_BACKEND:-"haproxy-octavia"}
 
 AMP_CACHEDIR=${AMP_CACHEDIR:-"$HOME/.cache/image-create"}
+# Make sure we have an absolute path for the cache location
+mkdir -p $AMP_CACHEDIR
+AMP_CACHEDIR="$( cd "$AMP_CACHEDIR" && pwd )"
 
 AMP_BASEOS=${AMP_BASEOS:-"ubuntu-minimal"}
 
@@ -307,7 +310,7 @@ fi
 if [ "$platform" = 'NAME="Ubuntu"' ]; then
     PKG_LIST="qemu-utils git kpartx debootstrap"
     for pkg in $PKG_LIST; do
-        if ! dpkg --get-selections | grep -q "^$pkg[[:space:]]*install$" >/dev/null; then
+        if ! dpkg --get-selections 2> /dev/null | grep -q "^$pkg[[:space:]]*install$" >/dev/null; then
             echo "Required package " $pkg " is not installed.  Exiting."
             echo "Binary dependencies on this platform are: ${PKG_LIST}"
             exit 1
@@ -436,3 +439,9 @@ disk-image-create $AMP_LOGFILE $dib_trace_arg -a $AMP_ARCH -o $AMP_OUTPUTFILENAM
 
 popd > /dev/null # out of $TEMP
 rm -rf $TEMP
+
+if [ -z "$DIB_REPOREF_amphora_agent" ]; then
+    echo "Successfully built the amphora image using amphora-agent from the master branch."
+else
+    echo "Successfully built the amphora using the $DIB_REPOREF_amphora_agent amphora-agent."
+fi

diskimage-create/tox.ini

@@ -7,7 +7,7 @@ skipsdist = True
 basepython = python3
 envdir = {toxworkdir}/venv
 setenv = VIRTUAL_ENV={envdir}
-passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
+passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY DIB_* CLOUD_INIT_DATASOURCES OCTAVIA_REPO_PATH
 install_command = pip install -U {opts} {packages}
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
@@ -27,8 +27,7 @@ commands = bashate diskimage-create.sh
 [testenv:build]
 # NOTE: specify cache directory explicitly with -c as the `diskimage-create.sh`
 # default is based off of `$HOME` which is not passed on in a `tox` environment.
-commands =  mkdir -p {toxinidir}/.amp_tox_test
-            ./diskimage-create.sh -o {toxinidir}/.amp_tox_test/amphora-x64-haproxy -w {toxworkdir} -c {toxworkdir}/.cache
+commands =  ./diskimage-create.sh -o {toxinidir}/amphora-x64-haproxy -w {toxworkdir} -c {toxworkdir}/.cache
 
 [testenv:test]
 # Work around tox limitations with command pipes