Promql to LogQL emulation (#190)

* promql handler prototype Signed-off-by: Lorenzo Mangani <[email protected]> * Update qryn.js Signed-off-by: Lorenzo Mangani <[email protected]> * Update package.json Signed-off-by: Lorenzo Mangani <[email protected]> * Create prom_query.js Signed-off-by: Lorenzo Mangani <[email protected]> * Update qryn.js Signed-off-by: Lorenzo Mangani <[email protected]> * update logql2promql library Signed-off-by: Lorenzo Mangani <[email protected]> * Update package.json Signed-off-by: Lorenzo Mangani <[email protected]> * Update qryn.js Signed-off-by: Lorenzo Mangani <[email protected]> * Update prom_query.js Signed-off-by: Lorenzo Mangani <[email protected]> * resync * Update qryn.js Signed-off-by: Lorenzo Mangani <[email protected]> * start/end s -> ns conv * nodejs "standard" standard cleanup * Update package.json Signed-off-by: Lorenzo Mangani <[email protected]> * labels and values prom support * Update package.json Signed-off-by: Lorenzo Mangani <[email protected]> * Update package.json Signed-off-by: Lorenzo Mangani <[email protected]> * Update package.json Signed-off-by: Lorenzo Mangani <[email protected]> * Update package.json Signed-off-by: Lorenzo Mangani <[email protected]> Signed-off-by: Lorenzo Mangani <[email protected]> Co-authored-by: akvlad <[email protected]>
metrico · Aug 21, 2022 · 4c076b7 · 4c076b7
1 parent ccc4493
commit 4c076b7
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diff --git a/lib/handlers/prom_default.js b/lib/handlers/prom_default.js
@@ -0,0 +1,10 @@
+/* Emulated PromQL Query Handler */
+
+async function handler (req, res) {
+  req.log.debug('GET /api/v1/*')
+  const resp = {"status": "success", "data": {}};
+  res.send(resp)
+  return
+}
+
+module.exports = handler
diff --git a/lib/handlers/prom_query.js b/lib/handlers/prom_query.js
@@ -0,0 +1,35 @@
+/* Emulated PromQL Query Handler */
+
+const { p2l } = require('@qxip/promql2logql');
+const empty = '{"status" : "success", "data" : {"resultType" : "scalar", "result" : []}}'; // to be removed
+
+async function handler (req, res) {
+  req.log.debug('GET /loki/api/v1/query')
+  const resp = { streams: [] }
+  if (!req.query.query) {
+    res.send(resp)
+    return
+  }
+  /* remove newlines */
+  req.query.query = req.query.query.replace(/\n/g, ' ')
+  /* transpile to logql */
+  try {
+    req.query.query = p2l(req.query.query);
+  } catch(e) {
+    req.log.error({ err })
+    res.send(empty)
+  }
+  /* scan fingerprints */
+  /* TODO: handle time tag + direction + limit to govern the query output */
+  try {
+    await this.instantQueryScan(
+      req.query,
+      { res: res.raw }
+    )
+  } catch (err) {
+    req.log.error({ err })
+    res.send(empty)
+  }
+}
+
+module.exports = handler
diff --git a/lib/handlers/prom_query_range.js b/lib/handlers/prom_query_range.js
@@ -0,0 +1,45 @@
+/* Emulated PromQL Query Handler */
+/*
+  Converts PromQL to LogQL queries, accepts the following parameters in the query-string:
+  query: a PromQL query
+  limit: max number of entries to return
+  start: the start time for the query, as a nanosecond Unix epoch (nanoseconds since 1970)
+  end: the end time for the query, as a nanosecond Unix epoch (nanoseconds since 1970)
+  direction: forward or backward, useful when specifying a limit
+  regexp: a regex to filter the returned results, will eventually be rolled into the query language
+*/
+
+const { p2l } = require('@qxip/promql2logql')
+
+async function handler (req, res) {
+  req.log.debug('GET /api/v1/query_range')
+  const resp = { streams: [] }
+  if (!req.query.query) {
+    res.send(resp)
+    return
+  }
+  /* remove newlines */
+  req.query.query = req.query.query.replace(/\n/g, ' ')
+  if (!req.query.query) {
+    res.code(400).send('invalid query')
+    return
+  }
+  // Convert PromQL to LogQL and execute
+  try {
+    req.query.query = p2l(req.query.query)
+    await this.scanFingerprints(
+      {
+        ...req.query,
+        start: parseInt(req.query.start) * 1e9,
+        end: parseInt(req.query.end) * 1e9
+      },
+      { res: res.raw }
+    )
+    res.sent = true
+  } catch (err) {
+    req.log.error({ err })
+    res.send(resp)
+  }
+}
+
+module.exports = handler
diff --git a/lib/handlers/promlabel.js b/lib/handlers/promlabel.js
@@ -0,0 +1,25 @@
+/* Label Handler */
+/*
+   For retrieving the names of the labels one can query on.
+   Responses looks like this:
+{
+  "values": [
+    "instance",
+    "job",
+    ...
+  ]
+}
+*/
+
+async function handler (req, res) {
+  await require('./label.js')({
+    ...req,
+    query: {
+      ...req.query,
+      start: req.query.start ? parseInt(req.query.start) * 1e9 : undefined,
+      end: req.query.end ? parseInt(req.query.end) * 1e9 : undefined
+    }
+  }, res)
+}
+
+module.exports = handler
diff --git a/lib/handlers/promlabel_values.js b/lib/handlers/promlabel_values.js
@@ -0,0 +1,25 @@
+/* Label Value Handler */
+/*
+   For retrieving the label values one can query on.
+   Responses looks like this:
+  {
+  "values": [
+    "default",
+    "cortex-ops",
+    ...
+  ]
+}
+*/
+
+async function handler (req, res) {
+  await require('./label_values.js')({
+    ...req,
+    query: {
+      ...req.query,
+      start: req.query.start ? parseInt(req.query.start) * 1e9 : undefined,
+      end: req.query.end ? parseInt(req.query.end) * 1e9 : undefined
+    }
+  }, res)
+}
+
+module.exports = handler
diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -64,6 +64,7 @@
     "xxhash-wasm": "^0.4.2",
     "yaml": "^1.10.2",
     "json-stable-stringify": "^1.0.1",
+    "@qxip/promql2logql": "^1.0.10",
     "@qxip/influx-line-protocol-parser": "^0.2.1"
   },
   "devDependencies": {

diff --git a/qryn.js b/qryn.js
@@ -389,6 +389,23 @@ fastify.get('/prometheus/api/v1/rules', require('./lib/handlers/alerts/prom_get_
 fastify.post('/api/v1/prom/remote/write', require('./lib/handlers/prom_push.js').bind(this))
 fastify.post('/api/prom/remote/write', require('./lib/handlers/prom_push.js').bind(this))
 
+/* PROMQETHEUS API EMULATION */
+const handlerPromQueryRange = require('./lib/handlers/prom_query_range.js').bind(this)
+fastify.get('/api/v1/query_range', handlerPromQueryRange)
+const handlerPromQuery = require('./lib/handlers/prom_query.js').bind(this)
+fastify.get('/api/v1/query', handlerPromQuery)
+const handlerPromLabel = require('./lib/handlers/promlabel.js').bind(this)
+const handlerPromLabelValues = require('./lib/handlers/promlabel_values.js').bind(this)
+fastify.get('/api/v1/labels', handlerPromLabel) // piggyback on qryn labels
+fastify.get('/api/v1/label/:name/values', handlerPromLabelValues) // piggyback on qryn values
+fastify.post('/api/v1/labels', handlerPromLabel) // piggyback on qryn labels
+fastify.post('/api/v1/label/:name/values', handlerPromLabelValues) // piggyback on qryn values
+const handlerPromDefault = require('./lib/handlers/prom_default.js').bind(this)
+fastify.get('/api/v1/metadata', handlerPromDefault) // default handler TBD
+fastify.get('/api/v1/rules', handlerPromDefault) // default handler TBD
+fastify.get('/api/v1/query_exemplars', handlerPromDefault) // default handler TBD
+fastify.get('/api/v1/status/buildinfo', handlerPromDefault) // default handler TBD
+
 /* INFLUX WRITE Handlers */
 const handlerInfluxWrite = require('./lib/handlers/influx_write.js').bind(this)
 fastify.post('/write', handlerInfluxWrite)