feat: Flag to validate config and queries succeeed.

examples/example_bad_dashboard.yaml

@@ -0,0 +1,18 @@
+--- # A list of dashboards
+- title: Invalid Dasbboard
+  graphs: # Each Dashboard can have 1 or more graphs in it.
+    - title: Node cpu # Graphs have titles
+      query_type: Range # The type of graph. Range for timeseries and Scalar for point in time
+      d3_tick_format: "~s" # Default tick format for the graph y axis
+      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])' # syntax error in query
+          meta: # metadata for this plot
+            name_format: "`${labels.instance}`" # javascript template literal to format the trace name
+            fill: tozeroy
+            #d3_tick_format: "~%" # d3 tick format override for this plot's yaxis
+            #named_axis: "y" # yaxis name to use for this subplots traces
+      span: # The span for this range query
+        end: now # Where the span ends. RFC3339 format with special handling for the now keyword
+        duration: 1d # duration of the span. Uses SI formatting for duration amounts.
+        step_duration: 10min # step size for the duration amounts.

src/dashboard.rs

@@ -18,8 +18,9 @@ use chrono::Duration;
 use serde::Deserialize;
 use serde_yaml;
 use tracing::{debug, error};
+use anyhow::Result;
 
-use crate::query::{QueryConn, QueryType, PlotMeta};
+use crate::query::{QueryConn, QueryType, QueryResult, PlotMeta, to_samples};
 
 #[derive(Deserialize, Debug)]
 pub struct GraphSpan {
@@ -52,6 +53,21 @@ pub struct Graph {
     pub d3_tick_format: Option<String>,
 }
 
+pub async fn query_data(graph: &Graph, dash: &Dashboard, query_span: Option<GraphSpan>) -> Result<Vec<QueryResult>> {
+    let connections = graph.get_query_connections(&dash.span, &query_span);
+    let mut data = Vec::new();
+    for conn in connections {
+        data.push(to_samples(
+            conn.get_results()
+                .await?
+                .data()
+                .clone(),
+            conn.meta,
+        ));
+    }
+    Ok(data)
+}
+
 fn duration_from_string(duration_string: &str) -> Option<Duration> {
     match parse_duration::parse(duration_string) {
         Ok(d) => match Duration::from_std(d) {

src/main.rs

@@ -12,12 +12,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 use std::path::PathBuf;
-
 use anyhow;
 use axum::{self, extract::State, routing::*, Router};
 use clap::{self, Parser, ValueEnum};
+use dashboard::{Dashboard, query_data};
 use tokio::net::TcpListener;
 use tower_http::trace::TraceLayer;
+use tracing::{error, info};
 use tracing::Level;
 use tracing_subscriber::FmtSubscriber;
 
@@ -43,6 +44,19 @@ struct Cli {
     pub config: PathBuf,
     #[arg(long, value_enum, default_value_t = Verbosity::INFO)]
     pub verbose: Verbosity,
+    #[arg(long, default_value_t = false)]
+    pub validate: bool,
+}
+
+async fn validate(dash: &Dashboard) -> anyhow::Result<()> {
+    for graph in dash.graphs.iter() {
+        let data = query_data(graph, &dash, None).await;
+        if data.is_err() {
+            error!(err=?data, "Invalid dashboard query or queries");
+        }
+        let _ = data?;
+    }
+    return Ok(());
 }
 
 #[tokio::main]
@@ -61,6 +75,14 @@ async fn main() -> anyhow::Result<()> {
     .expect("setting default subscriber failed");
 
     let config = std::sync::Arc::new(dashboard::read_dashboard_list(args.config.as_path())?);
+
+    if args.validate {
+        for dash in config.iter() {
+            validate(&dash).await?;
+            info!("All Queries successfully run against source");
+            return Ok(());
+        }
+    }
     let router = Router::new()
         // JSON api endpoints
         .nest("/js", routes::mk_js_routes(config.clone()))

src/routes.rs

@@ -24,7 +24,7 @@ use axum::{
 use maud::{html, Markup};
 use tracing::debug;
 
-use crate::dashboard::{Dashboard, Graph, GraphSpan};
+use crate::dashboard::{Dashboard, Graph, GraphSpan, query_data};
 use crate::query::{to_samples, QueryResult};
 
 type Config = State<Arc<Vec<Dashboard>>>;
@@ -54,18 +54,7 @@ pub async fn graph_query(
             None
         }
     };
-    let connections = graph.get_query_connections(&dash.span, &query_span);
+    let data = query_data(graph, dash, query_span).await.expect("Unable to get query results");
-    let mut data = Vec::new();
-    for conn in connections {
-        data.push(to_samples(
-            conn.get_results()
-                .await
-                .expect("Unable to get query results")
-                .data()
-                .clone(),
-            conn.meta,
-        ));
-    }
     Json(data)
 }