dev: Only apply filters when there is a placeholder

* Allows you to respect commas placement
* This is effectively the only way you can safely apply filters
  when there are complicated query expressions.

examples/example_dashboards.yaml

@@ -12,7 +12,7 @@
           tickformat: "~%"
       plots: # List of pluts to show on the graph
         - source: http://heimdall:9001 # Prometheus source uri for this plot
-          query: 'sum by (instance)(irate(node_cpu_seconds_total{job="nodestats"}[5m]))' # The PromQL query for this plot
+          query: 'sum by (instance)(irate(node_cpu_seconds_total{FILTERS, job="nodestats"}[5m]))' # The PromQL query for this plot
           meta: # metadata for this plot
             name_format: "`${labels.instance}`" # javascript template literal to format the trace name
             fill: tozeroy
@@ -39,7 +39,7 @@
         - source: http://heimdall:9001
           # You can use the FILTERS placeholder to indicate where user selected filters should be placed.
           query: |
-            sum by (instance)(irate(node_cpu_seconds_total{FILTERS mode="system",job="nodestats"}[5m])) / sum by (instance)(irate(node_cpu_seconds_total{FILTERS job="nodestats"}[5m]))
+            sum by (instance)(irate(node_cpu_seconds_total{FILTERS mode="system",job="nodestats"}[5m])) / sum by (instance)(irate(node_cpu_seconds_total{FILTERS, job="nodestats"}[5m]))
           meta:
             name_format: "`${labels.instance} system`"
             yaxis: "y"

src/dashboard.rs

@@ -224,6 +224,7 @@ impl Graph {
                 plot.meta.clone(),
             );
             if let Some(filters) = filters {
+                debug!(?filters, "query connection with filters");
                 conn = conn.with_filters(filters);
             }
             // Query params take precendence over all other settings. Then graph settings take

src/query/prom.rs

@@ -24,6 +24,10 @@ use crate::dashboard::PlotMeta;
 
 use super::{DataPoint, QueryResult, QueryType, TimeSpan};
 
+pub const FILTER_PLACEHOLDER: &'static str = "FILTERS";
+pub const FILTER_COMMA_PLACEHOLDER: &'static str = ",FILTERS";
+pub const FILTER_PLACEHOLDER_COMMA: &'static str = "FILTERS,";
+
 #[derive(Debug)]
 pub struct PromQueryConn<'conn> {
     source: &'conn str,
@@ -73,6 +77,7 @@ impl<'conn> PromQueryConn<'conn> {
     fn get_query(&self) -> String {
         let first = true;
         let mut filter_string = String::new();
+        debug!(filters=?self.filters, orig=?self.query, "Filters from request");
         if let Some(filters) = self.filters {
             for (k, v) in filters.iter() {
                 if !first {
@@ -84,16 +89,26 @@ impl<'conn> PromQueryConn<'conn> {
                 filter_string.push_str(*v);
                 filter_string.push('"');
             }
-                filter_string.push(',');
         }
-        if self.query.contains("FILTERS") {
+        if self.query.contains(FILTER_PLACEHOLDER_COMMA) {
-            // TODO(jwall): replace the FILTERS placeholder with our filters
+            debug!("Replacing Filter comma placeholder");
-            self.query.replace("FILTERS", &filter_string)
+            if !filter_string.is_empty() {
+                filter_string.push(',');
+            }
+            self.query.replace(FILTER_PLACEHOLDER, &filter_string)
+        } else if self.query.contains(FILTER_COMMA_PLACEHOLDER) {
+            debug!("Replacing Filter comma placeholder");
+            if !filter_string.is_empty() {
+                let mut temp: String = ",".into();
+                temp.push_str(&filter_string);
+                filter_string = temp;
+            }
+            self.query.replace(FILTER_PLACEHOLDER, &filter_string)
+        } else if self.query.contains(FILTER_PLACEHOLDER) {
+            debug!("Replacing Filter placeholder");
+            self.query.replace(FILTER_PLACEHOLDER, &filter_string)
         } else {
-            let mut filter_string_curly = String::from("{");
+            self.query.to_string()
-            filter_string_curly.push_str(&filter_string);
-            // TODO(jwall): Place them after the first `{`
-            self.query.replace("{", &filter_string_curly)
         }
     }
 

src/routes.rs

@@ -28,7 +28,7 @@ use tracing::debug;
 use crate::dashboard::{
     loki_query_data, prom_query_data, AxisDefinition, Dashboard, Graph, GraphSpan, Orientation, LogStream,
 };
-use crate::query::QueryResult;
+use crate::query::{self, QueryResult};
 
 type Config = State<Arc<Vec<Dashboard>>>;
 
@@ -91,6 +91,7 @@ pub async fn graph_query(
 }
 
 fn query_to_filterset<'v, 'a: 'v>(query: &'a HashMap<String, String>) -> Option<HashMap<&'v str, &'v str>> {
+    debug!(query_params=?query, "Filtering query params to filter requests");
     let mut label_set = HashMap::new();
     for (k, v) in query.iter() {
         if k.starts_with("filter-") {
@@ -153,13 +154,14 @@ pub fn graph_component(dash_idx: usize, graph_idx: usize, graph: &Graph) -> Mark
     let graph_id = format!("graph-{}-{}", dash_idx, graph_idx);
     let graph_data_uri = format!("/api/dash/{}/graph/{}", dash_idx, graph_idx);
     let graph_embed_uri = format!("/embed/dash/{}/graph/{}", dash_idx, graph_idx);
+    let allow_filters = graph.plots.iter().find(|p| p.query.contains(query::FILTER_PLACEHOLDER)).is_some();
     html!(
         div {
             h2 { (graph.title) " - " a href=(graph_embed_uri) { "embed url" } }
             @if graph.d3_tick_format.is_some() {
-                graph-plot uri=(graph_data_uri) id=(graph_id) d3-tick-format=(graph.d3_tick_format.as_ref().unwrap()) { }
+                graph-plot allow-uri-filters=(allow_filters) uri=(graph_data_uri) id=(graph_id) d3-tick-format=(graph.d3_tick_format.as_ref().unwrap()) { }
             } @else {
-                graph-plot uri=(graph_data_uri) id=(graph_id) { }
+                graph-plot allow-uri-filters=(allow_filters) uri=(graph_data_uri) id=(graph_id) { }
             }
         }
     )

static/lib.js

@@ -64,6 +64,8 @@ function getCssVariableValue(variableName) {
 export class GraphPlot extends HTMLElement {
     /** @type {?string} */
     #uri;
+    /** @type {?boolean} */
+    #allowUriFilters;
     /** @type {?number} */
     #width;
     /** @type {?number} */
@@ -103,7 +105,7 @@ export class GraphPlot extends HTMLElement {
         this.#targetNode = this.appendChild(document.createElement("div"));
     }
 
-    static observedAttributes = ['uri', 'width', 'height', 'poll-seconds', 'end', 'duration', 'step-duration', 'd3-tick-format'];
+    static observedAttributes = ['uri', 'width', 'height', 'poll-seconds', 'end', 'duration', 'step-duration', 'd3-tick-format', 'allow-uri-filter'];
 
     /**
      * Callback for attributes changes.
@@ -138,6 +140,9 @@ export class GraphPlot extends HTMLElement {
             case 'd3-tick-format':
                 this.#d3TickFormat = newValue;
                 break;
+            case 'allow-uri-filters':
+                this.#allowUriFilters = Boolean(newValue);
+                break;
             default: // do nothing;
                 break;
         }
@@ -153,6 +158,7 @@ export class GraphPlot extends HTMLElement {
         this.#duration = Number(this.getAttribute('duration')) || null;
         this.#step_duration = this.getAttribute('step-duration') || null;
         this.#d3TickFormat = this.getAttribute('d3-tick-format') || this.#d3TickFormat;
+        this.#allowUriFilters = Boolean(this.getAttribute('allow-uri-filters'));
         this.reset();
     }
 
@@ -211,8 +217,21 @@ export class GraphPlot extends HTMLElement {
      * @returns {string}
      */
     getUri() {
+        //var uriParts = [this.#uri];
+        var uriParts = [];
         if (this.#end && this.#duration && this.#step_duration) {
-            return this.#uri + "?end=" + this.#end + "&duration=" + this.#duration + "&step_duration=" + this.#step_duration;
+            uriParts.push("end=" + this.#end);
+            uriParts.push("duration=" + this.#duration);
+            uriParts.push("step_duration=" + this.#step_duration);
+        }
+        if (this.#allowUriFilters) {
+            for (const filterName in this.#filteredLabelSets) {
+                const filterVals = this.#filteredLabelSets[filterName].join("|");
+                uriParts.push(`filter-${filterName}=${filterVals}`)
+            }
+        }
+        if (uriParts) {
+            return this.#uri + "?" + uriParts.join('&');
         } else {
             return this.#uri;
         }