Add geoserver-create-and-apply-sld worker

docker-compose.yml

@@ -67,6 +67,12 @@ services:
       context: ./
       dockerfile: ./src/geoserver-publish-sld/Dockerfile
 
+  geoserver-create-and-apply-sld:
+    image: ghcr.io/klips-project/mqm-worker/geoserver-create-and-apply-sld:latest
+    build:
+      context: ./
+      dockerfile: ./src/geoserver-create-and-apply-sld/Dockerfile
+
   gunzip-file:
     image: ghcr.io/klips-project/mqm-worker/gunzip-file:latest
     build:

src/geoserver-create-and-apply-sld/Dockerfile

@@ -0,0 +1,19 @@
+FROM osgeo/gdal:alpine-small-3.5.3
+
+RUN apk add --update nodejs npm
+
+ENV GSHOST http://localhost:8080/geoserver/rest/
+ENV GSUSER admin
+ENV GSPASS geoserver
+ENV RABBITHOST amqp://rabbitmq
+ENV WORKERQUEUE geoserver-create-and-apply-sld
+ENV RESULTSQUEUE results
+
+COPY src/geoserver-create-and-apply-sld/package.json src/geoserver-create-and-apply-sld/package-lock.json /home/
+WORKDIR /home/
+RUN npm install
+COPY src/geoserver-create-and-apply-sld/index.js worker/
+COPY src/workerTemplate.js .
+COPY src/geoserver-create-and-apply-sld/child-logger.js worker/
+COPY src/logger.js .
+CMD ["sh", "-c", "node worker/index.js ${GSHOST} ${GSUSER} ${GSPASS}"]

src/geoserver-create-and-apply-sld/child-logger.js

@@ -0,0 +1,3 @@
+import { logger } from '../logger.js';
+
+export default logger.child({ type: 'geoserver-create-and-apply-sld' });

src/geoserver-create-and-apply-sld/index.js

@@ -0,0 +1,208 @@
+import {GeoServerRestClient} from 'geoserver-node-client';
+import { initialize } from '../workerTemplate.js';
+import logger from './child-logger.js';
+import pg from 'pg';
+const { Client } = pg;
+import { exec } from 'child_process';
+
+const url = process.env.GEOSERVER_REST_URL;
+const user = process.env.GEOSERVER_USER;
+const pw = process.env.GEOSERVER_PASSWORD;
+const workerQueue = process.env.WORKERQUEUE;
+const resultQueue = process.env.RESULTSQUEUE;
+const rabbitHost = process.env.RABBITHOST;
+const rabbitUser = process.env.RABBITUSER;
+const rabbitPass = process.env.RABBITPASS;
+const pgpasswd = process.env.POSTGRES_PASSWORD;
+const pghost = process.env.POSTGRES_HOST;
+const pgport = process.env.POSTGRES_PORT;
+const pguser = process.env.POSTGRES_USER;
+const pgdb = process.env.POSTGRES_DB;
+const grc = new GeoServerRestClient(url, user, pw);
+
+/**
+ * Creates and publishes SLD with colorramp matching the time enabled datasets min and max values.
+ * @param {Object} workerJob The job object
+ * @param {Array} inputs The inputs for this process
+ *   First input is the name that should be used for publishing the SLD
+ *   Second input is the workspace the SLD should be created in.
+ *   Third is the table name of the coveragestore
+ * @example
+ *   {
+       "type": "geoserver-create-and-apply-sld",
+       "inputs": [
+         "myCustomStyleName",
+         "mySldWorkspace",
+         "myCoverageDbTable"
+       ]
+     }
+ */
+const geoServerCreateAndApplySld = async (workerJob, inputs) => {
+  const sldName = inputs[0];
+  const sldWorkspace = inputs[1];
+  const dbTable = inputs[2];
+
+  logger.debug('Checking GeoServer connectivity …')
+  const gsExists = await grc.about.exists();
+  if (!gsExists) {
+    throw 'GeoServer not found';
+  }
+  const workspaceExists = await grc.workspaces.get(sldWorkspace);
+  if (!workspaceExists) {
+    logger.debug('Workspace does not exist, creating …');
+    const workspaceCreated = grc.workspaces.create(sldWorkspace);
+    if (!workspaceCreated) {
+      throw 'Could not create workspace';
+    } else {
+      logger.debug('Workspace created');
+    }
+  }
+
+  let pgClient;
+  let locations = [];
+  try {
+    pgClient = new Client({
+      host: pghost,
+      port: pgport,
+      database: pgdb,
+      user: pguser,
+      password: pgpasswd,
+    });
+    await pgClient.connect();
+
+    const sqlQuery = `SELECT location FROM "${dbTable}"`;
+    const res = await pgClient.query(sqlQuery);
+
+    locations = res.rows.map(row => row.location);
+    logger.debug("Locations found for coveragestore: " + locations);
+  } catch (e) {
+    logger.error(e);
+    throw 'SQL execution aborted: ' + e;
+  } finally {
+    if (pgClient) {
+      await pgClient.end();   
+    }
+  }
+
+  let min = 0;
+  let max = 0;
+  // for every dataset in the coveragestore, get min and max statistics and compute total min and max
+  for (let i = 0; i < locations.length; i++) {
+    // TODO: make sure we get the stat for channel 1
+    const infoCmd = `gdalinfo -mm ${locations[i]} | grep "Computed Min/Max"`;
+    try {
+      const response = await execShellCommand(infoCmd);
+      logger.debug('gdal response: ' + response);
+      if (response && response.indexOf('Min/Max=' > -1)) {
+        // TODO: make failsafe
+        const currentMin = parseInt(response.split('=')[1].split(',')[0].trim());
+        const currentMax = parseInt(response.split('=')[1].split(',')[1].trim());
+
+        // on first iteration, we need to set the values unconditionally as starting point
+        if (i === 0) {
+          min = currentMin;
+          max = currentMax;
+        } else {
+          if (currentMin < min) {
+            min = currentMin;
+          }
+          if (currentMax > max) {
+            max = currentMax;
+          }
+        }
+      } else {
+        continue;
+      }
+    } catch (e) {
+      throw 'GDAL Info execution aborted: ' + e;
+    }
+  }
+  // apply default color ramp if no values detected
+  if (min === 0 && max === 0) {
+    min = -20;
+    max = 50;
+  }
+
+  // as parseInt removes decimals, we add a full integer
+  max = max + 1;
+
+  logger.debug("Calculated min and max values for whole dataset: " + min + ", " + max);
+
+  const sldBody = sldTemplate(min, max);
+  logger.debug("Generated SLD: " + sldBody);
+
+  // we have to delete the old style first as publish can not override existing styles
+  try {
+    await grc.styles.delete(sldWorkspace, sldName);
+    logger.debug('Succesfully deleted previous SLD');
+  } catch {
+    logger.error('Could not delete old SLD');
+  }
+
+  try {
+    await grc.styles.publish(sldWorkspace, sldName, sldBody);
+    logger.debug('Succesfully published SLD');
+  } catch {
+    throw('Could not publish SLD');
+  }
+
+  logger.debug('GeoServer worker finished');
+
+  workerJob.status = 'success';
+  workerJob.outputs = [];
+};
+
+const sldTemplate = (minValue, maxValue) => {
+  const range = maxValue - minValue;
+  const step = Math.round(range / 5);
+  return `<?xml version="1.0" encoding="UTF-8"?>
+    <sld:StyledLayerDescriptor xmlns="http://www.opengis.net/sld" xmlns:sld="http://www.opengis.net/sld" xmlns:gml="http://www.opengis.net/gml" xmlns:ogc="http://www.opengis.net/ogc" version="1.0.0">
+      <sld:NamedLayer>
+          <sld:Name>Custom Color Ramp</sld:Name>
+          <sld:UserStyle>
+            <sld:Name>Custom Color Ramp</sld:Name>
+            <sld:FeatureTypeStyle>
+              <sld:Rule>
+                <sld:RasterSymbolizer>
+                  <sld:ChannelSelection>
+                    <sld:GrayChannel>
+                      <sld:SourceChannelName>1</sld:SourceChannelName>
+                    </sld:GrayChannel>
+                  </sld:ChannelSelection>
+                <sld:ColorMap type="ramp">
+                  <sld:ColorMapEntry color="#000000" quantity="${minValue}" label="${minValue}"/>
+                  <sld:ColorMapEntry color="#3a3a3a" quantity="${minValue  + step}" label="${minValue + step}"/>
+                  <sld:ColorMapEntry color="#6a6a6a" quantity="${minValue + 2 * step}" label="${minValue + 2 * step}"/>
+                  <sld:ColorMapEntry color="#9a9a9a" quantity="${minValue + 3 * step}" label="${minValue + 3 * step}"/>
+                  <sld:ColorMapEntry color="#cacaca" quantity="${minValue + 4 * step}" label="${minValue + 4 * step}"/>
+                  <sld:ColorMapEntry color="#ffffff" quantity="${maxValue}" label="${maxValue}"/>
+                </sld:ColorMap>
+              </sld:RasterSymbolizer>
+            </sld:Rule>
+          </sld:FeatureTypeStyle>
+        </sld:UserStyle>
+      </sld:NamedLayer>
+    </sld:StyledLayerDescriptor>`;
+}
+
+/**
+ * Executes a shell command and return it as a Promise.
+ * Kudos to https://ali-dev.medium.com/how-to-use-promise-with-exec-in-node-js-a39c4d7bbf77
+ *
+ * @param cmd {String} The command to execute
+ * @return {Promise<String>} A Promise returning the console output
+ */
+const execShellCommand = (cmd) => {
+  return new Promise((resolve, reject) => {
+      exec(cmd, (error, stdout, stderr) => {
+          if (error) {
+              logger.warn(error);
+              reject(error);
+          }
+          resolve(stdout ? stdout : stderr);
+      });
+  });
+}
+
+// Initialize and start the worker process
+initialize(rabbitHost, rabbitUser, rabbitPass, workerQueue, resultQueue, geoServerCreateAndApplySld);