Merge pull request #1696 from MatthewMassey/tc_qdisc_parsing

tc qdisc plugin

2 files changed, 185 insertions, 0 deletions

diff --git a/lib/ohai/plugins/linux/tc.rb b/lib/ohai/plugins/linux/tc.rb
new file mode 100644
index 00000000..0471bb59
--- /dev/null
+++ b/lib/ohai/plugins/linux/tc.rb
@@ -0,0 +1,61 @@
+#
+# Author:: Matthew Massey <matthewmassey@fb.com>
+# Copyright:: Copyright (c) 2021 Facebook
+# License:: Apache License, Version 2.0
+#
+# 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.
+#
+
+Ohai.plugin(:Tc) do
+  provides "tc"
+  optional true
+
+  collect_data(:linux) do
+    tc_path = which("tc")
+    if tc_path
+      cmd = "#{tc_path} qdisc show"
+      tc_output = shell_out(cmd)
+
+      tc_data = Mash.new
+      tc_data[:qdisc] = Mash.new
+
+      tc_output.stdout.split("\n").each do |line|
+        line = line.strip
+        if /dev (\w+)/ =~ line
+          dev = $1
+          tc_data[:qdisc][dev] ||= Mash.new
+        else
+          next
+        end
+        if /qdisc (\w+)/ =~ line
+          qdisc = $1
+          tc_data[:qdisc][dev][:qdiscs] ||= []
+          tc_data[:qdisc][dev][:qdiscs] << Mash.new
+          qdisc_idx = tc_data[:qdisc][dev][:qdiscs].length - 1
+          tc_data[:qdisc][dev][:qdiscs][qdisc_idx] ||= Mash.new
+          tc_data[:qdisc][dev][:qdiscs][qdisc_idx][:type] = qdisc
+          tc_data[:qdisc][dev][:qdiscs][qdisc_idx][:parms] ||= Mash.new
+        else
+          next
+        end
+        if qdisc == "fq" && /buckets (\d+)/ =~ line
+          buckets = $1.to_i
+          tc_data[:qdisc][dev][:qdiscs][qdisc_idx][:parms][:buckets] = buckets
+        end
+      end
+      tc tc_data
+    else
+      logger.trace("Plugin Tc: Could not find tc. Skipping plugin.")
+    end
+  end
+end
diff --git a/spec/unit/plugins/linux/tc_spec.rb b/spec/unit/plugins/linux/tc_spec.rb
new file mode 100644
index 00000000..d04e963e
--- /dev/null
+++ b/spec/unit/plugins/linux/tc_spec.rb
@@ -0,0 +1,124 @@
+#
+# Author:: Matthew Massey <matthewmassey@fb.com>
+# Copyright:: Copyright (c) 2021 Facebook
+# License:: Apache License, Version 2.0
+#
+# 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.
+#
+
+require "spec_helper"
+
+describe Ohai::System, "Linux tc plugin" do
+  let(:plugin) { get_plugin("linux/tc") }
+
+  before do
+    allow(plugin).to receive(:collect_os).and_return(:linux)
+  end
+
+  it "populates tc if tc is found" do
+    tc_out = <<-TC_OUT
+        qdisc noqueue 0: dev lo root refcnt 2
+        qdisc mq 1234: dev eth0 root
+        qdisc fq 8001: dev eth0 parent 1234:4 limit 10000p flow_limit 100p buckets 2048 orphan_mask 1023 quantum 3028b initial_quantum 15140b low_rate_threshold 550Kbit refill_delay 40.0ms
+        qdisc fq_codel 0: dev eth0 parent 1234:7 limit 10240p flows 1024 quantum 1514 target 5.0ms interval 100.0ms memory_limit 32Mb ecn
+        qdisc fq_codel 0: dev eth0 parent 1234:5 limit 10240p flows 1024 quantum 1514 target 5.0ms interval 100.0ms memory_limit 32Mb ecn
+        qdisc fq_codel 0: dev eth0 parent 1234:3 limit 10240p flows 1024 quantum 1514 target 5.0ms interval 100.0ms memory_limit 32Mb ecn
+        qdisc fq_codel 0: dev eth0 parent 1234:1 limit 10240p flows 1024 quantum 1514 target 5.0ms interval 100.0ms memory_limit 32Mb ecn
+        qdisc fq 8003: dev eth0 parent 1234:6 limit 10000p flow_limit 100p buckets 8192 orphan_mask 1023 quantum 3028b initial_quantum 15140b low_rate_threshold 550Kbit refill_delay 40.0ms
+        qdisc fq 8002: dev eth0 parent 1234:2 limit 10000p flow_limit 100p buckets 4096 orphan_mask 1023 nopacing quantum 3028b initial_quantum 15140b low_rate_threshold 550Kbit refill_delay 40.0ms
+        qdisc pfifo_fast 8004: dev eth0 parent 1234:8 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
+        qdisc clsact ffff: dev eth0 parent ffff:fff1
+        garbage line, this won't parse and should not break anything
+        dev eth99 garbage line but with a device name
+        qdisc fq 1234: dev eth0 fq but with no parms
+    TC_OUT
+    allow(plugin).to receive(:which).with("tc").and_return("/sbin/tc")
+    cmd = "/sbin/tc qdisc show"
+    allow(plugin).to receive(:shell_out).with(cmd).and_return(mock_shell_out(0, tc_out, ""))
+    plugin.run
+
+    expect(plugin[:tc].to_hash).to eq({
+      "qdisc" => {
+        "lo" => {
+          "qdiscs" => [
+            {
+              "type" =>  "noqueue",
+              "parms" => {},
+            },
+          ],
+        },
+        "eth0" =>  {
+          "qdiscs" => [
+            {
+              "type" => "mq",
+              "parms" => {},
+            },
+            {
+              "type" => "fq",
+              "parms" => {
+                "buckets" => 2048,
+              },
+            },
+            {
+              "type" => "fq_codel",
+              "parms" => {},
+            },
+            {
+              "type" => "fq_codel",
+              "parms" => {},
+            },
+            {
+              "type" => "fq_codel",
+              "parms" => {},
+            },
+            {
+              "type" => "fq_codel",
+              "parms" => {},
+            },
+            {
+              "type" => "fq",
+              "parms" => {
+                "buckets" => 8192,
+              },
+            },
+            {
+              "type" => "fq",
+              "parms" => {
+                "buckets" => 4096,
+              },
+            },
+            {
+              "type" => "pfifo_fast",
+              "parms" => {},
+            },
+            {
+              "type" => "clsact",
+              "parms" => {},
+            },
+            {
+              "type" => "fq",
+              "parms" => {},
+            },
+          ],
+        },
+        "eth99" => {},
+        },
+    })
+  end
+
+  it "does not populate tc if tc is not found" do
+    allow(plugin).to receive(:which).with("tc").and_return(false)
+    plugin.run
+    expect(plugin[:tc]).to be(nil)
+  end
+end