python: ovs: flowviz: Add html formatting.

Add a HTML Formatter and use it to print OpenFlow flows in an HTML list
with table links.

Examples
$ ovs-flowviz -i offlows.txt --highlight "drop" openflow html >
/tmp/flows.html
$ ovs-flowviz -i offlows.txt --filter "n_packets > 0" openflow html >
/tmp/flows.html

Both light and dark styles are supported.

Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

python/automake.mk

@@ -67,15 +67,16 @@ ovs_flowviz = \
 	python/ovs/flowviz/__init__.py \
 	python/ovs/flowviz/console.py \
 	python/ovs/flowviz/format.py \
+	python/ovs/flowviz/html_format.py \
 	python/ovs/flowviz/main.py \
 	python/ovs/flowviz/odp/__init__.py \
 	python/ovs/flowviz/odp/cli.py \
 	python/ovs/flowviz/ofp/__init__.py \
 	python/ovs/flowviz/ofp/cli.py \
+	python/ovs/flowviz/ofp/html.py \
 	python/ovs/flowviz/ovs-flowviz \
 	python/ovs/flowviz/process.py
 
-
 # These python files are used at build time but not runtime,
 # so they are not installed.
 EXTRA_DIST += \

python/ovs/flowviz/html_format.py

@@ -0,0 +1,138 @@
+# Copyright (c) 2023 Red Hat, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from ovs.flowviz.format import FlowFormatter, FlowBuffer, FlowStyle
+
+
+class HTMLStyle:
+    """HTMLStyle defines a style for html-formatted flows.
+
+    Args:
+        color(str): Optional; a string representing the CSS color to use
+        anchor_gen(callable): Optional; a callable to be used to generate the
+            href
+    """
+
+    def __init__(self, color=None, anchor_gen=None):
+        self.color = color
+        self.anchor_gen = anchor_gen
+
+
+class HTMLBuffer(FlowBuffer):
+    """HTMLBuffer implementes FlowBuffer to provide html-based flow formatting.
+
+    Each flow gets formatted as:
+        <div><span>...</span></div>
+    """
+
+    def __init__(self):
+        self._text = ""
+
+    @property
+    def text(self):
+        return self._text
+
+    def _append(self, string, color, href):
+        """Append a key a string"""
+        style = ' style="color:{}"'.format(color) if color else ""
+        self._text += "<span{}>".format(style)
+        if href:
+            self._text += "<a href={} {}> ".format(
+                href, 'style="color:{}"'.format(color) if color else ""
+            )
+        self._text += string
+        if href:
+            self._text += "</a>"
+        self._text += "</span>"
+
+    def append_key(self, kv, style):
+        """Append a key.
+        Args:
+            kv (KeyValue): the KeyValue instance to append
+            style (HTMLStyle): the style to use
+        """
+        href = style.anchor_gen(kv) if (style and style.anchor_gen) else ""
+        return self._append(
+            kv.meta.kstring, style.color if style else "", href
+        )
+
+    def append_delim(self, kv, style):
+        """Append a delimiter.
+        Args:
+            kv (KeyValue): the KeyValue instance to append
+            style (HTMLStyle): the style to use
+        """
+        href = style.anchor_gen(kv) if (style and style.anchor_gen) else ""
+        return self._append(kv.meta.delim, style.color if style else "", href)
+
+    def append_end_delim(self, kv, style):
+        """Append an end delimiter.
+        Args:
+            kv (KeyValue): the KeyValue instance to append
+            style (HTMLStyle): the style to use
+        """
+        href = style.anchor_gen(kv) if (style and style.anchor_gen) else ""
+        return self._append(
+            kv.meta.end_delim, style.color if style else "", href
+        )
+
+    def append_value(self, kv, style):
+        """Append a value.
+        Args:
+            kv (KeyValue): the KeyValue instance to append
+            style (HTMLStyle): the style to use
+        """
+        href = style.anchor_gen(kv) if (style and style.anchor_gen) else ""
+        return self._append(
+            kv.meta.vstring, style.color if style else "", href
+        )
+
+    def append_extra(self, extra, style):
+        """Append extra string.
+        Args:
+            kv (KeyValue): the KeyValue instance to append
+            style (HTMLStyle): the style to use
+        """
+        return self._append(extra, style.color if style else "", "")
+
+
+class HTMLFormatter(FlowFormatter):
+    """Formts a flow in HTML Format."""
+
+    default_style_obj = FlowStyle(
+        {
+            "value.resubmit": HTMLStyle(
+                anchor_gen=lambda x: "#table_{}".format(x.value["table"])
+            ),
+            "default": HTMLStyle(),
+        }
+    )
+
+    def __init__(self, opts=None):
+        super(HTMLFormatter, self).__init__()
+        self.style = (
+            self._style_from_opts(opts, "html", HTMLStyle) or FlowStyle()
+        )
+
+    def format_flow(self, buf, flow, highlighted=None):
+        """Formats the flow into the provided buffer as a html object.
+
+        Args:
+            buf (FlowBuffer): the flow buffer to append to
+            flow (ovs_dbg.OFPFlow): the flow to format
+            highlighted (list): Optional; list of KeyValues to highlight
+        """
+        return super(HTMLFormatter, self).format_flow(
+            buf, flow, self.style, highlighted
+        )

python/ovs/flowviz/ofp/cli.py

@@ -15,6 +15,7 @@
 import click
 
 from ovs.flowviz.main import maincli
+from ovs.flowviz.ofp.html import HTMLProcessor
 from ovs.flowviz.process import (
     ConsoleProcessor,
     JSONOpenFlowProcessor,
@@ -56,3 +57,12 @@ def console(opts, heat_map):
     )
     proc.process()
     proc.print()
+
+
+@openflow.command()
+@click.pass_obj
+def html(opts):
+    """Print the flows in an linked HTML list arranged by tables."""
+    processor = HTMLProcessor(opts)
+    processor.process()
+    print(processor.html())

python/ovs/flowviz/ofp/html.py

@@ -0,0 +1,100 @@
+# Copyright (c) 2023 Red Hat, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from ovs.flowviz.html_format import HTMLBuffer, HTMLFormatter, HTMLStyle
+from ovs.flowviz.process import (
+    FileProcessor,
+)
+
+
+class HTMLProcessor(FileProcessor):
+    """File processor that prints OpenFlow tables in HTML."""
+
+    def __init__(self, opts):
+        super().__init__(opts, "ofp")
+        self.formatter = HTMLFormatter(self.opts)
+        self.data = dict()
+
+    def start_file(self, name, filename):
+        self.tables = dict()
+
+    def stop_file(self, name, filename):
+        self.data[name] = self.tables
+
+    def process_flow(self, flow, name):
+        table = flow.info.get("table") or 0
+        if not self.tables.get(table):
+            self.tables[table] = list()
+        self.tables[table].append(flow)
+
+    def html(self):
+        bg = (
+            self.formatter.style.get("background").color
+            if self.formatter.style.get("background")
+            else "white"
+        )
+        fg = (
+            self.formatter.style.get("default").color
+            if self.formatter.style.get("default")
+            else "black"
+        )
+        html_obj = """
+        <style>
+        body {{
+            background-color: {bg};
+            color: {fg};
+        }}
+        </style>""".format(
+            bg=bg, fg=fg
+        )
+        for name, tables in self.data.items():
+            name = name.replace(" ", "_")
+            html_obj += "<h1>{}</h1>".format(name)
+            html_obj += "<div id=flow_list>"
+            for table, flows in tables.items():
+
+                def anchor(x):
+                    return "#table_%s_%s" % (name, x.value["table"])
+
+                resubmit_style = self.formatter.style.get("value.resubmit")
+                resubmit_color = resubmit_style.color if resubmit_style else fg
+
+                self.formatter.style.set_value_style(
+                    "resubmit",
+                    HTMLStyle(
+                        resubmit_color,
+                        anchor_gen=anchor,
+                    ),
+                )
+                html_obj += (
+                    "<h2 id=table_{name}_{table}> Table {table}</h2>".format(
+                        name=name, table=table
+                    )
+                )
+                html_obj += "<ul id=table_{}_flow_list>".format(table)
+                for flow in flows:
+                    html_obj += "<li id=flow_{}>".format(flow.id)
+                    highlighted = None
+                    if self.opts.get("highlight"):
+                        result = self.opts.get("highlight").evaluate(flow)
+                        if result:
+                            highlighted = result.kv
+                    buf = HTMLBuffer()
+                    self.formatter.format_flow(buf, flow, highlighted)
+                    html_obj += buf.text
+                    html_obj += "</li>"
+                html_obj += "</ul>"
+            html_obj += "</div>"
+
+        return html_obj

python/ovs/flowviz/ovs-flowviz.conf

@@ -4,7 +4,7 @@
 #
 #  [FORMAT].[PORTION].[SELECTOR].[ELEMENT] = [VALUE]
 #
-#  * FORMAT: console
+#  * FORMAT: console or html
 #  * PORTION: The portion of the flow that the style applies to
 #     - key: Selects how to print the key of a KeyValue pair
 #     - key: Selects how to print the value of a KeyValue pair
@@ -25,6 +25,13 @@
 #     - underline: if set to "true", the selected portion will be underlined
 #
 #[1] https://rich.readthedocs.io/en/stable/appendix/colors.html#standard-colors
+#
+# HTML Styles
+# ==============
+#   * PORTION: An extra portion is supported: "background" which defines the
+#   background color of the page.
+#   * ELEMENT:
+#     - color: defines the color in hex format
 
 [styles.dark]
 
@@ -60,6 +67,23 @@ console.key.highlighted.underline = true
 console.value.highlighted.underline = true
 console.delim.highlighted.underline = true
 
+# html
+html.background.color = #23282e
+html.default.color = white
+html.key.color = #5D86BA
+html.value.color = #B0C4DE
+html.delim.color = #B0C4DE
+
+html.key.resubmit.color = #005f00
+html.key.recirc.color = #005f00
+html.value.resubmit.color = #005f00
+html.value.recirc.color = #005f00
+html.key.output.color = #00d700
+html.value.output.color = #00d700
+html.key.highlighted.color = #FF00FF
+html.value.highlighted.color = #FF00FF
+html.key.drop.color = red
+
 
 [styles.light]
 # If a color is omitted, the default terminal color will be used
@@ -92,3 +116,13 @@ console.value.highlighted.color = #f20905
 console.key.highlighted.underline = true
 console.value.highlighted.underline = true
 console.delim.highlighted.underline = true
+
+# html
+html.background.color = white
+html.key.color =  #00005f
+html.value.color = #870000
+html.key.resubmit.color = #00d700
+html.key.output.color = #005f00
+html.value.output.color = #00d700
+html.key.highlighted.color = #FF00FF
+html.value.highlighted.color = #FF00FF