[libvirt] [RFC PATCH 7/8] virsh: Add JSON support to the 'define' subcommand

[Andrea Bolognani]

In order not to break user expectations (and scripts!) we need
to keep parsing input files as XML by default, so JSON support
is implemented as opt-in through the new --json option; a brand
new --xml option is also added for consistency.

That said, if the name of the input file ends in .json it's fair
to assume the contents are not going to be in XML format: we can
use this heuristic to make virsh more user-friendly by not
requiring the user to specify --json in this single case.

Signed-off-by: Andrea Bolognani <abologna at redhat.com>
---
 tools/virsh-domain.c | 36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c
index afcd0a5f8d..0ebea3fe13 100644
--- a/tools/virsh-domain.c
+++ b/tools/virsh-domain.c
@@ -8208,6 +8208,14 @@ static const vshCmdOptDef opts_define[] = {
      .type = VSH_OT_BOOL,
      .help = N_("validate the XML against the schema")
     },
+    {.name = "xml",
+     .type = VSH_OT_BOOL,
+     .help = N_("Input file is in XML format")
+    },
+    {.name = "json",
+     .type = VSH_OT_BOOL,
+     .help = N_("Input file is in JSON format")
+    },
     {.name = NULL}
 };
 
@@ -8220,6 +8228,9 @@ cmdDefine(vshControl *ctl, const vshCmd *cmd)
     char *buffer;
     unsigned int flags = 0;
     virshControlPtr priv = ctl->privData;
+    bool xmlInput;
+
+    VSH_EXCLUSIVE_OPTIONS("xml", "json");
 
     if (vshCommandOptStringReq(ctl, cmd, "file", &from) < 0)
         return false;
@@ -8227,13 +8238,30 @@ cmdDefine(vshControl *ctl, const vshCmd *cmd)
     if (vshCommandOptBool(cmd, "validate"))
         flags |= VIR_DOMAIN_DEFINE_VALIDATE;
 
+    /* If the input filename ends with .json, it's fair to assume that
+     * the format is going to be JSON. We default to XML otherwise */
+    xmlInput = true;
+    if (virStringHasCaseSuffix(from, ".json"))
+        xmlInput = false;
+
+    /* User asked for a specific input format: override both defaults
+     * and automatic detection */
+    if (vshCommandOptBool(cmd, "xml"))
+        xmlInput = true;
+    else if (vshCommandOptBool(cmd, "json"))
+        xmlInput = false;
+
     if (virFileReadAll(from, VSH_MAX_XML_FILE, &buffer) < 0)
         return false;
 
-    if (flags)
-        dom = virDomainDefineXMLFlags(priv->conn, buffer, flags);
-    else
-        dom = virDomainDefineXML(priv->conn, buffer);
+    if (xmlInput) {
+        if (flags)
+            dom = virDomainDefineXMLFlags(priv->conn, buffer, flags);
+        else
+            dom = virDomainDefineXML(priv->conn, buffer);
+    } else {
+        dom = virDomainDefineJSONFlags(priv->conn, buffer, flags);
+    }
     VIR_FREE(buffer);
 
     if (dom != NULL) {
-- 
2.20.1