Docs: Updates (grafana#136)

lasertiger · May 7, 2020 · 5b002c5 · 5b002c5
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diff --git a/devenv/docker/custom-config/config.json b/devenv/docker/custom-config/config.json
@@ -0,0 +1,45 @@
+{
+  "service": {
+    "host": null,
+    "port": 8081,
+
+    "metrics": {
+      "enabled": true,
+      "collectDefaultMetrics": true,
+      "requestDurationBuckets": [1, 5, 7, 9, 11, 13, 15, 20, 30]
+    },
+
+    "logging": {
+      "level": "debug",
+      "console": {
+        "json": true,
+        "colorize": false
+      }
+    }
+  },
+  "rendering": {
+    "chromeBin": null,
+    "args": [
+      "--no-sandbox"
+    ],
+    "ignoresHttpsErrors": false,
+
+    "timezone": null,
+    "acceptLanguage": null,
+    "width": 1000,
+    "height": 500,
+    "deviceScaleFactor": 1,
+    "maxWidth": 3080,
+    "maxHeight": 3000,
+    "maxDeviceScaleFactor": 3,
+
+    "mode": "clustered",
+    "clustering": {
+      "mode": "context",
+      "maxConcurrency": 5
+    },
+
+    "verboseLogging": false,
+    "dumpio": false
+  }
+}
diff --git a/devenv/docker/custom-config/docker-compose.yaml b/devenv/docker/custom-config/docker-compose.yaml
@@ -0,0 +1,17 @@
+version: '2'
+
+services:
+  grafana:
+    image: grafana/grafana:latest
+    ports:
+      - 3000
+    environment:
+      GF_RENDERING_SERVER_URL: http://renderer:8081/render
+      GF_RENDERING_CALLBACK_URL: http://grafana:3000/
+      GF_LOG_FILTERS: rendering:debug
+  renderer:
+    image: grafana/grafana-image-renderer:latest
+    ports:
+      - 8081
+    volumes:
+      - ./config.json:/usr/src/app/config.json
diff --git a/devenv/docker/simple/docker-compose.yaml b/devenv/docker/simple/docker-compose.yaml
@@ -2,9 +2,9 @@ version: '2'
 
 services:
   grafana:
-    image: grafana/grafana:master
+    image: grafana/grafana:latest
     ports:
-     - "3000:3000"
+      - 3000
     environment:
       GF_RENDERING_SERVER_URL: http://renderer:8081/render
       GF_RENDERING_CALLBACK_URL: http://grafana:3000/
@@ -13,3 +13,5 @@ services:
     image: grafana/grafana-image-renderer:latest
     ports:
       - 8081
+    environment:
+      ENABLE_METRICS: 'true'
diff --git a/docs/remote_rendering_using_docker.md b/docs/remote_rendering_using_docker.md
@@ -84,6 +84,28 @@ Additional arguments to pass to the headless browser instance. Default is `--no-
 RENDERING_ARGS=--no-sandbox,--disable-setuid-sandbox,--disable-dev-shm-usage,--disable-accelerated-2d-canvas,--disable-gpu,--window-size=1280x758
 ```
 
+**Change how browser instances are created:**
+
+You can instruct how headless browser instances are created by configuring a rendering mode (`RENDERING_MODE`). Default is `default` and will create a new browser instance on each request. Other supported values are `clustered` and `reusable`.
+
+```bash
+RENDERING_MODE=default
+```
+
+When using `clustered` you can configure a clustering mode to define how many browser instances or incognito pages that can execute concurrently. Default is `browser` and will ensure a maximum amount of browser instances can execute concurrently. Mode `context` will ensure a maximum amount of incognito pages can execute concurrently. You can also configure the maximum concurrency allowed which per default is `5`.
+
+```bash
+RENDERING_MODE=clustered
+RENDERING_CLUSTERING_MODE=default
+RENDERING_CLUSTERING_MAX_CONCURRENCY=5
+```
+
+When using the rendering mode `reusable` one browser instance will be created and reused. A new incognito page will be opened on each request for. This mode is a bit experimental since if the browser instance crashes it will not automatically be restarted.
+
+```bash
+RENDERING_MODE=reusable
+```
+
 ## Configuration file
 
 You can override certain settings by using a configuration file, see [default.json](https://github.com/grafana/grafana-image-renderer/tree/master/default.json) for defaults. Note that any configured environment variable takes precedence over configuration file settings.
@@ -94,6 +116,8 @@ You can volume mount your custom configuration file when starting the docker con
 docker run -d --name=renderer --network=host -v /some/path/config.json:/usr/src/app/config.json grafana/grafana-image-renderer:latest
 ```
 
+You can see a docker-compose example using a custom configuration file [here/](https://github.com/grafana/grafana-image-renderer/tree/master/devenv/docker/custom-config).
+
 ## Docker Compose example
 
 The following docker-compose example can also be found in [docker/](https://github.com/grafana/grafana-image-renderer/tree/master/devenv/docker/simple).
@@ -103,9 +127,9 @@ version: '2'
 
 services:
   grafana:
-    image: grafana/grafana:master
+    image: grafana/grafana:latest
     ports:
-     - "3000:3000"
+      - 3000
     environment:
       GF_RENDERING_SERVER_URL: http://renderer:8081/render
       GF_RENDERING_CALLBACK_URL: http://grafana:3000/
@@ -114,6 +138,8 @@ services:
     image: grafana/grafana-image-renderer:latest
     ports:
       - 8081
+    environment:
+      ENABLE_METRICS: 'true'
 ```
 
 1. Start containers:
@@ -124,7 +150,11 @@ services:
 3. Create a dashboard, add a panel and save the dashboard.
 4. Panel context menu -> Share -> Direct link rendered image
 
-## Prometheus metrics endpoint output example
+## Enable Prometheus metrics endpoint
+
+The service can be configured to expose a Prometheus metrics endpoint. There's [dashboard](https://grafana.com/grafana/dashboards/12203) published that explains the details of how to configure and monitor the rendering service using Prometheus as a data source.
+
+**Metrics endpoint output example:**
 
 ```
 # HELP process_cpu_user_seconds_total Total user CPU time spent in seconds.