Show matching config snippets in search results

CHANGELOG.md

@@ -6,10 +6,17 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 ## [Unreleased]
 
 ### Added
+- Config search results show matching lines with two lines of context, line
+  numbers and highlighted matches. Overlapping or touching context windows are
+  merged into a single snippet (@bpbp-boop)
+- Search form on the results page, with an option to search for literal text
+  instead of a regular expression (@bpbp-boop)
 
 ### Changed
 
 ### Fixed
+- Config search returns 400 on an invalid regular expression instead of
+  crashing (@bpbp-boop)
 
 
 ## [0.18.1 – 2026-01-19]

lib/oxidized/web/views/conf_search.haml

@@ -2,37 +2,71 @@
   .col-8
     %h4
       %a{href: url_for('/nodes')} nodes
-      \/ Nodes that contain 
+      \/ Nodes that contain
       %b
-        &= "#{@to_research}"
+        &= @search_term
   .col-4
     %form.float-end#oxButtons
       %button.btn.btn-primary{type: 'button', onclick: 'history.go();'}
         %i.bi.bi-arrow-clockwise
         Refresh page
 
-.row
-  .table-responsive
-    %table.table.table-sm.table-striped.table-hover#versionsTable
-      %thead
-        %tr
-          %th Name
-          %th Configuration
+.row.mb-3
+  .col-lg-6
+    %form{action: url_for('/nodes/conf_search'), method: 'post'}
+      .input-group
+        %input.form-control{type: 'text',
+                            name: 'search_in_conf_textbox',
+                            value: @search_term,
+                            :'aria-label' => 'Search in Configs'}
+        %button.btn.btn-primary{type: 'submit'}
+          %i.bi.bi-search
+          Search
+      .form-check.mt-1
+        %input{type: 'hidden', name: 'search_regex_checkbox', value: 'off'}
+        %input.form-check-input#conf-search-regex{type: 'checkbox',
+                                                  name: 'search_regex_checkbox',
+                                                  value: 'on',
+                                                  checked: @regex_search}
+        %label.form-check-label{for: 'conf-search-regex'} Use regular expression
+      .form-check
+        %input{type: 'hidden', name: 'search_case_sensitive_checkbox', value: 'off'}
+        %input.form-check-input#conf-search-case-sensitive{type: 'checkbox',
+                                                           name: 'search_case_sensitive_checkbox',
+                                                           value: 'on',
+                                                           checked: @case_sensitive_search}
+        %label.form-check-label{for: 'conf-search-case-sensitive'} Case sensitive
 
-      %tbody
-        - @nodes_match.each do |x|
+- if @error
+  .row
+    .col-lg-6
+      .alert.alert-danger&= @error
+- else
+  .row
+    .table-responsive
+      %table.table.table-sm.table-striped.table-hover#versionsTable
+        %thead
           %tr
-            %td #{x[:node]}
-            %td
-              %a{title: 'configuration',
-                 href: url_for("/node/fetch/#{x[:full_name]}")}
-                %i.bi.bi-cloud-download
+            %th Name
+            %th Matches
 
-:javascript
-  $(function() {
-    $('#versionsTable').dataTable({
-      autoWidth: false,
-      "order": [[0, "asc"]]
-    });
-  });
+        %tbody
+          - @nodes_match.each do |x|
+            %tr
+              %td
+                %a{title: 'configuration',
+                   href: url_for("/node/fetch/#{x[:full_name]}")}
+                  %i.bi.bi-cloud-download
+                  = x[:node]
+              %td
+                - x[:matches].each do |m|
+                  %pre.border.rounded.p-2.mb-2><
+                    != snippet_html(m, @to_research)
 
+  :javascript
+    $(function() {
+      $('#versionsTable').dataTable({
+        autoWidth: false,
+        "order": [[0, "asc"]]
+      });
+    });

lib/oxidized/web/webapp.rb

@@ -65,15 +65,39 @@ class WebApp < Sinatra::Base
       end
 
       post '/nodes/conf_search.?:format?' do
-        @to_research = Regexp.new params[:search_in_conf_textbox]
-        nodes_list = nodes.list.map
+        @search_term = params[:search_in_conf_textbox].to_s
+        redirect url_for('/nodes') if @search_term.empty?
+
+        # regex search is the default; the search form on the results page
+        # sends 'off' (via a hidden field) when the checkbox is unticked
+        @regex_search = params[:search_regex_checkbox] != 'off'
+        # preserve the existing case-sensitive default; the search form sends
+        # 'off' (via a hidden field) when the checkbox is unticked
+        @case_sensitive_search = params[:search_case_sensitive_checkbox] != 'off'
         @nodes_match = []
-        nodes_list.each do |n|
-          node, @json = route_parse n[:name]
-          config = nodes.fetch node, n[:group]
-          @nodes_match.push({ node: n[:name], full_name: n[:full_name] }) if config[@to_research]
+        begin
+          pattern = @regex_search ? @search_term : Regexp.escape(@search_term)
+          options = @case_sensitive_search ? 0 : Regexp::IGNORECASE
+          @to_research = Regexp.new pattern, options
+        rescue RegexpError => e
+          @error = "Invalid regular expression: #{e.message}"
+        end
+
+        if @error
+          status 400
+          @data = { error: @error }
+        else
+          nodes.list.each do |n|
+            node, @json = route_parse n[:name]
+            config = convert_to_utf8 nodes.fetch(node, n[:group]).to_s
+            matches = config_search_matches config, @to_research
+            next if matches.empty?
+
+            @nodes_match.push({ node: n[:name], full_name: n[:full_name],
+                                matches: matches })
+          end
+          @data = @nodes_match
         end
-        @data = @nodes_match
         out :conf_search
       end
 
@@ -225,6 +249,9 @@ class WebApp < Sinatra::Base
       HTML_ESCAPE = { '&' => '&amp;', '<' => '&lt;', '>' => '&gt;', '"' => '&quot;', "'" => '&#39;' }.freeze
       HTML_ESCAPE_ONCE_REGEX = /['"><]|&(?!(?:[a-zA-Z]+|#(?:\d+|[xX][0-9a-fA-F]+));)/
 
+      # lines of context shown around each config search match
+      CONF_SEARCH_CONTEXT_LINES = 2
+
       private
 
       def out(template = :text)
@@ -263,6 +290,80 @@ def route_parse(param)
         [e.join('.'), json]
       end
 
+      # Give one entry per distinct region of the config matching +regexp+.
+      # Context windows that overlap or touch are merged so nearby matches do
+      # not return duplicate snippets. +line_number+ remains the first match
+      # for API compatibility; +line_numbers+ contains every match in the
+      # merged region.
+      def config_search_matches(config, regexp)
+        lines = config.lines.map(&:chomp)
+        match_indexes = lines.each_index.select { |index| lines[index].match?(regexp) }
+        return [] if match_indexes.empty?
+
+        regions = match_indexes.each_with_object([]) do |index, merged|
+          region = {
+            from: [index - CONF_SEARCH_CONTEXT_LINES, 0].max,
+            to: [index + CONF_SEARCH_CONTEXT_LINES, lines.length - 1].min,
+            matches: [index]
+          }
+
+          if merged.any? && region[:from] <= merged.last[:to] + 1
+            merged.last[:to] = [merged.last[:to], region[:to]].max
+            merged.last[:matches] << index
+          else
+            merged << region
+          end
+        end
+
+        regions.map do |region|
+          matching_lines = region[:matches].to_h { |index| [index, true] }
+          snippet = (region[:from]..region[:to]).map do |index|
+            { number: index + 1, text: lines[index], match: matching_lines.has_key?(index) }
+          end
+          line_numbers = region[:matches].map { |index| index + 1 }
+          {
+            line_number: line_numbers.first,
+            line_numbers: line_numbers,
+            snippet: snippet
+          }
+        end
+      end
+
+      # HTML-escape line, wrapping every regexp match in <mark>
+      def highlight_matches(line, regexp)
+        html = +''
+        pos = 0
+        while pos <= line.length && (md = regexp.match(line, pos))
+          if md[0].empty?
+            # zero-width match: emit up to and including the character at the
+            # match position, so the scan always advances
+            html << escape_once(line[pos..md.begin(0)])
+            pos = md.begin(0) + 1
+          else
+            html << escape_once(line[pos...md.begin(0)])
+            html << "<mark>#{escape_once(md[0])}</mark>"
+            pos = md.end(0)
+          end
+        end
+        html << escape_once(line[pos..].to_s)
+        html
+      end
+
+      # HTML for one config search snippet: line-numbered text with the
+      # matches highlighted
+      def snippet_html(match, regexp)
+        width = match[:snippet].last[:number].to_s.length
+        match[:snippet].map do |line|
+          number = line[:number].to_s.rjust(width)
+          text = if line[:match]
+                   highlight_matches(line[:text], regexp)
+                 else
+                   escape_once(line[:text])
+                 end
+          "#{number}: #{text}"
+        end.join("\n")
+      end
+
       # give the time elapsed between now and a date (Time object)
       def time_from_now(date)
         return "no time specified" if date.nil?