test.apiv2: add testing for image and deal with API returning binary

Add testing for displaying image history and exporting image

Deal with API returning binary (Content-Type =~ 'octet').
When so, set $output to the output of 'file'.

Bug fix: in 't' helper, declare loop var $i as local
to avoid contaminating caller

Signed-off-by: Ed Santiago <santiago@redhat.com>
Signed-off-by: Alex Jia <chuanchang.jia@gmail.com>

test/apiv2/10-images.at

@@ -33,4 +33,27 @@ t GET images/$iid/json 200 \
 
 #t POST images/create fromImage=alpine 201 foo
 
+# Display the image history
+t GET libpod/images/nonesuch/history 404
+
+for i in $iid ${iid:0:12} $PODMAN_TEST_IMAGE_NAME; do
+  t GET libpod/images/$i/history 200 \
+    .[0].Id=$iid \
+    .[0].Created~[0-9]\\{10\\} \
+    .[0].Tags=null \
+    .[0].Size=0 \
+    .[0].Comment=
+done
+
+# Export an image on the local
+t GET libpod/images/nonesuch/get 404
+t GET libpod/images/$iid/get?format=foo 500
+t GET libpod/images/$PODMAN_TEST_IMAGE_NAME/get?compress=bar 400
+
+for i in $iid ${iid:0:12} $PODMAN_TEST_IMAGE_NAME; do
+  t GET "libpod/images/$i/get"                200 '[POSIX tar archive]'
+  t GET "libpod/images/$i/get?compress=true"  200 '[POSIX tar archive]'
+  t GET "libpod/images/$i/get?compress=false" 200 '[POSIX tar archive]'
+done
+
 # vim: filetype=sh

test/apiv2/test-apiv2

@@ -207,14 +207,22 @@ function t() {
     fi
 
     cat $WORKDIR/curl.headers.out >>$LOG 2>/dev/null || true
+
+    # Log results, if text. If JSON, filter through jq for readability.
+    content_type=$(sed -ne 's/^Content-Type:[ ]\+//pi' <$WORKDIR/curl.headers.out)
+
+    if [[ $content_type =~ /octet ]]; then
+        output="[$(file --brief $WORKDIR/curl.result.out)]"
+        echo "$output" >>$LOG
+    else
         output=$(< $WORKDIR/curl.result.out)
 
-    # Log results. If JSON, filter through jq for readability
-    if egrep -qi '^Content-Type: application/json' $WORKDIR/curl.headers.out; then
+        if [[ $content_type =~ application/json ]]; then
             jq . <<<"$output" >>$LOG
         else
             echo "$output" >>$LOG
         fi
+    fi
 
     # Test return code
     actual_code=$(head -n1 $WORKDIR/curl.headers.out | awk '/^HTTP/ { print $2}')
@@ -232,6 +240,7 @@ function t() {
         return
     fi
 
+    local i
     for i; do
         case "$i" in
             # Exact match on json field