version/info: format: allow more json variants

Allow more variants to yield json output for `podman version` and
`podman info`.  Instead of comparing strings, use a regex and add
unit and e2e tests.

Fixes: #6927
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/cmd/podman/parse/json.go b/cmd/podman/parse/json.go
new file mode 100644
index 000000000..95a6633b8
--- /dev/null
+++ b/cmd/podman/parse/json.go
@@ -0,0 +1,9 @@
+package parse
+
+import "regexp"
+
+var jsonFormatRegex = regexp.MustCompile(`^(\s*json\s*|\s*{{\s*json\s*\.\s*}}\s*)$`)
+
+func MatchesJSONFormat(s string) bool {
+	return jsonFormatRegex.Match([]byte(s))
+}