Add json api

Cargo.toml

@@ -19,24 +19,10 @@ duplicate = "0.2"
 handlebars = "3"
 http = "0.2"
 ron = "0.6.4"
-
-[dependencies.rocket]
-#version = "0.4"
-git = "https://github.com/SergioBenitez/Rocket"
-branch = "master"
-features = ["secrets"]
-
-[dependencies.rocket_contrib]
-#version = "0.4"
-git = "https://github.com/SergioBenitez/Rocket"
-branch = "master"
-features = ["handlebars_templates", "uuid"]
-
-[dependencies.tokio]
-version = "1"
-features = ["fs"]
-
-[dependencies.reqwest]
-version = "0.11"
-default-features = false
-features = ["rustls-tls"]
+rocket = { version = "0.5", features = ["secrets", "msgpack", "json"] }
+rocket_dyn_templates = { version = "0.1.0", features = ["handlebars"] }
+tokio = { version = "1", features = ["fs"] }
+reqwest = { version = "0.11", default-features = false, features = ["rustls-tls"] }
+clap = { version = "4.4.18", features = ["derive", "env"] }
+eyre = "0.6.11"
+color-eyre = "0.6.2"

LICENSE

@@ -0,0 +1,373 @@
+Mozilla Public License Version 2.0
+==================================
+
+1. Definitions
+--------------
+
+1.1. "Contributor"
+    means each individual or legal entity that creates, contributes to
+    the creation of, or owns Covered Software.
+
+1.2. "Contributor Version"
+    means the combination of the Contributions of others (if any) used
+    by a Contributor and that particular Contributor's Contribution.
+
+1.3. "Contribution"
+    means Covered Software of a particular Contributor.
+
+1.4. "Covered Software"
+    means Source Code Form to which the initial Contributor has attached
+    the notice in Exhibit A, the Executable Form of such Source Code
+    Form, and Modifications of such Source Code Form, in each case
+    including portions thereof.
+
+1.5. "Incompatible With Secondary Licenses"
+    means
+
+    (a) that the initial Contributor has attached the notice described
+        in Exhibit B to the Covered Software; or
+
+    (b) that the Covered Software was made available under the terms of
+        version 1.1 or earlier of the License, but not also under the
+        terms of a Secondary License.
+
+1.6. "Executable Form"
+    means any form of the work other than Source Code Form.
+
+1.7. "Larger Work"
+    means a work that combines Covered Software with other material, in 
+    a separate file or files, that is not Covered Software.
+
+1.8. "License"
+    means this document.
+
+1.9. "Licensable"
+    means having the right to grant, to the maximum extent possible,
+    whether at the time of the initial grant or subsequently, any and
+    all of the rights conveyed by this License.
+
+1.10. "Modifications"
+    means any of the following:
+
+    (a) any file in Source Code Form that results from an addition to,
+        deletion from, or modification of the contents of Covered
+        Software; or
+
+    (b) any new file in Source Code Form that contains any Covered
+        Software.
+
+1.11. "Patent Claims" of a Contributor
+    means any patent claim(s), including without limitation, method,
+    process, and apparatus claims, in any patent Licensable by such
+    Contributor that would be infringed, but for the grant of the
+    License, by the making, using, selling, offering for sale, having
+    made, import, or transfer of either its Contributions or its
+    Contributor Version.
+
+1.12. "Secondary License"
+    means either the GNU General Public License, Version 2.0, the GNU
+    Lesser General Public License, Version 2.1, the GNU Affero General
+    Public License, Version 3.0, or any later versions of those
+    licenses.
+
+1.13. "Source Code Form"
+    means the form of the work preferred for making modifications.
+
+1.14. "You" (or "Your")
+    means an individual or a legal entity exercising rights under this
+    License. For legal entities, "You" includes any entity that
+    controls, is controlled by, or is under common control with You. For
+    purposes of this definition, "control" means (a) the power, direct
+    or indirect, to cause the direction or management of such entity,
+    whether by contract or otherwise, or (b) ownership of more than
+    fifty percent (50%) of the outstanding shares or beneficial
+    ownership of such entity.
+
+2. License Grants and Conditions
+--------------------------------
+
+2.1. Grants
+
+Each Contributor hereby grants You a world-wide, royalty-free,
+non-exclusive license:
+
+(a) under intellectual property rights (other than patent or trademark)
+    Licensable by such Contributor to use, reproduce, make available,
+    modify, display, perform, distribute, and otherwise exploit its
+    Contributions, either on an unmodified basis, with Modifications, or
+    as part of a Larger Work; and
+
+(b) under Patent Claims of such Contributor to make, use, sell, offer
+    for sale, have made, import, and otherwise transfer either its
+    Contributions or its Contributor Version.
+
+2.2. Effective Date
+
+The licenses granted in Section 2.1 with respect to any Contribution
+become effective for each Contribution on the date the Contributor first
+distributes such Contribution.
+
+2.3. Limitations on Grant Scope
+
+The licenses granted in this Section 2 are the only rights granted under
+this License. No additional rights or licenses will be implied from the
+distribution or licensing of Covered Software under this License.
+Notwithstanding Section 2.1(b) above, no patent license is granted by a
+Contributor:
+
+(a) for any code that a Contributor has removed from Covered Software;
+    or
+
+(b) for infringements caused by: (i) Your and any other third party's
+    modifications of Covered Software, or (ii) the combination of its
+    Contributions with other software (except as part of its Contributor
+    Version); or
+
+(c) under Patent Claims infringed by Covered Software in the absence of
+    its Contributions.
+
+This License does not grant any rights in the trademarks, service marks,
+or logos of any Contributor (except as may be necessary to comply with
+the notice requirements in Section 3.4).
+
+2.4. Subsequent Licenses
+
+No Contributor makes additional grants as a result of Your choice to
+distribute the Covered Software under a subsequent version of this
+License (see Section 10.2) or under the terms of a Secondary License (if
+permitted under the terms of Section 3.3).
+
+2.5. Representation
+
+Each Contributor represents that the Contributor believes its
+Contributions are its original creation(s) or it has sufficient rights
+to grant the rights to its Contributions conveyed by this License.
+
+2.6. Fair Use
+
+This License is not intended to limit any rights You have under
+applicable copyright doctrines of fair use, fair dealing, or other
+equivalents.
+
+2.7. Conditions
+
+Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted
+in Section 2.1.
+
+3. Responsibilities
+-------------------
+
+3.1. Distribution of Source Form
+
+All distribution of Covered Software in Source Code Form, including any
+Modifications that You create or to which You contribute, must be under
+the terms of this License. You must inform recipients that the Source
+Code Form of the Covered Software is governed by the terms of this
+License, and how they can obtain a copy of this License. You may not
+attempt to alter or restrict the recipients' rights in the Source Code
+Form.
+
+3.2. Distribution of Executable Form
+
+If You distribute Covered Software in Executable Form then:
+
+(a) such Covered Software must also be made available in Source Code
+    Form, as described in Section 3.1, and You must inform recipients of
+    the Executable Form how they can obtain a copy of such Source Code
+    Form by reasonable means in a timely manner, at a charge no more
+    than the cost of distribution to the recipient; and
+
+(b) You may distribute such Executable Form under the terms of this
+    License, or sublicense it under different terms, provided that the
+    license for the Executable Form does not attempt to limit or alter
+    the recipients' rights in the Source Code Form under this License.
+
+3.3. Distribution of a Larger Work
+
+You may create and distribute a Larger Work under terms of Your choice,
+provided that You also comply with the requirements of this License for
+the Covered Software. If the Larger Work is a combination of Covered
+Software with a work governed by one or more Secondary Licenses, and the
+Covered Software is not Incompatible With Secondary Licenses, this
+License permits You to additionally distribute such Covered Software
+under the terms of such Secondary License(s), so that the recipient of
+the Larger Work may, at their option, further distribute the Covered
+Software under the terms of either this License or such Secondary
+License(s).
+
+3.4. Notices
+
+You may not remove or alter the substance of any license notices
+(including copyright notices, patent notices, disclaimers of warranty,
+or limitations of liability) contained within the Source Code Form of
+the Covered Software, except that You may alter any license notices to
+the extent required to remedy known factual inaccuracies.
+
+3.5. Application of Additional Terms
+
+You may choose to offer, and to charge a fee for, warranty, support,
+indemnity or liability obligations to one or more recipients of Covered
+Software. However, You may do so only on Your own behalf, and not on
+behalf of any Contributor. You must make it absolutely clear that any
+such warranty, support, indemnity, or liability obligation is offered by
+You alone, and You hereby agree to indemnify every Contributor for any
+liability incurred by such Contributor as a result of warranty, support,
+indemnity or liability terms You offer. You may include additional
+disclaimers of warranty and limitations of liability specific to any
+jurisdiction.
+
+4. Inability to Comply Due to Statute or Regulation
+---------------------------------------------------
+
+If it is impossible for You to comply with any of the terms of this
+License with respect to some or all of the Covered Software due to
+statute, judicial order, or regulation then You must: (a) comply with
+the terms of this License to the maximum extent possible; and (b)
+describe the limitations and the code they affect. Such description must
+be placed in a text file included with all distributions of the Covered
+Software under this License. Except to the extent prohibited by statute
+or regulation, such description must be sufficiently detailed for a
+recipient of ordinary skill to be able to understand it.
+
+5. Termination
+--------------
+
+5.1. The rights granted under this License will terminate automatically
+if You fail to comply with any of its terms. However, if You become
+compliant, then the rights granted under this License from a particular
+Contributor are reinstated (a) provisionally, unless and until such
+Contributor explicitly and finally terminates Your grants, and (b) on an
+ongoing basis, if such Contributor fails to notify You of the
+non-compliance by some reasonable means prior to 60 days after You have
+come back into compliance. Moreover, Your grants from a particular
+Contributor are reinstated on an ongoing basis if such Contributor
+notifies You of the non-compliance by some reasonable means, this is the
+first time You have received notice of non-compliance with this License
+from such Contributor, and You become compliant prior to 30 days after
+Your receipt of the notice.
+
+5.2. If You initiate litigation against any entity by asserting a patent
+infringement claim (excluding declaratory judgment actions,
+counter-claims, and cross-claims) alleging that a Contributor Version
+directly or indirectly infringes any patent, then the rights granted to
+You by any and all Contributors for the Covered Software under Section
+2.1 of this License shall terminate.
+
+5.3. In the event of termination under Sections 5.1 or 5.2 above, all
+end user license agreements (excluding distributors and resellers) which
+have been validly granted by You or Your distributors under this License
+prior to termination shall survive termination.
+
+************************************************************************
+*                                                                      *
+*  6. Disclaimer of Warranty                                           *
+*  -------------------------                                           *
+*                                                                      *
+*  Covered Software is provided under this License on an "as is"       *
+*  basis, without warranty of any kind, either expressed, implied, or  *
+*  statutory, including, without limitation, warranties that the       *
+*  Covered Software is free of defects, merchantable, fit for a        *
+*  particular purpose or non-infringing. The entire risk as to the     *
+*  quality and performance of the Covered Software is with You.        *
+*  Should any Covered Software prove defective in any respect, You     *
+*  (not any Contributor) assume the cost of any necessary servicing,   *
+*  repair, or correction. This disclaimer of warranty constitutes an   *
+*  essential part of this License. No use of any Covered Software is   *
+*  authorized under this License except under this disclaimer.         *
+*                                                                      *
+************************************************************************
+
+************************************************************************
+*                                                                      *
+*  7. Limitation of Liability                                          *
+*  --------------------------                                          *
+*                                                                      *
+*  Under no circumstances and under no legal theory, whether tort      *
+*  (including negligence), contract, or otherwise, shall any           *
+*  Contributor, or anyone who distributes Covered Software as          *
+*  permitted above, be liable to You for any direct, indirect,         *
+*  special, incidental, or consequential damages of any character      *
+*  including, without limitation, damages for lost profits, loss of    *
+*  goodwill, work stoppage, computer failure or malfunction, or any    *
+*  and all other commercial damages or losses, even if such party      *
+*  shall have been informed of the possibility of such damages. This   *
+*  limitation of liability shall not apply to liability for death or   *
+*  personal injury resulting from such party's negligence to the       *
+*  extent applicable law prohibits such limitation. Some               *
+*  jurisdictions do not allow the exclusion or limitation of           *
+*  incidental or consequential damages, so this exclusion and          *
+*  limitation may not apply to You.                                    *
+*                                                                      *
+************************************************************************
+
+8. Litigation
+-------------
+
+Any litigation relating to this License may be brought only in the
+courts of a jurisdiction where the defendant maintains its principal
+place of business and such litigation shall be governed by laws of that
+jurisdiction, without reference to its conflict-of-law provisions.
+Nothing in this Section shall prevent a party's ability to bring
+cross-claims or counter-claims.
+
+9. Miscellaneous
+----------------
+
+This License represents the complete agreement concerning the subject
+matter hereof. If any provision of this License is held to be
+unenforceable, such provision shall be reformed only to the extent
+necessary to make it enforceable. Any law or regulation which provides
+that the language of a contract shall be construed against the drafter
+shall not be used to construe this License against a Contributor.
+
+10. Versions of the License
+---------------------------
+
+10.1. New Versions
+
+Mozilla Foundation is the license steward. Except as provided in Section
+10.3, no one other than the license steward has the right to modify or
+publish new versions of this License. Each version will be given a
+distinguishing version number.
+
+10.2. Effect of New Versions
+
+You may distribute the Covered Software under the terms of the version
+of the License under which You originally received the Covered Software,
+or under the terms of any subsequent version published by the license
+steward.
+
+10.3. Modified Versions
+
+If you create software not governed by this License, and you want to
+create a new license for such software, you may create and use a
+modified version of this License if you rename the license and remove
+any references to the name of the license steward (except to note that
+such modified license differs from this License).
+
+10.4. Distributing Source Code Form that is Incompatible With Secondary
+Licenses
+
+If You choose to distribute Source Code Form that is Incompatible With
+Secondary Licenses under the terms of this version of the License, the
+notice described in Exhibit B of this License must be attached.
+
+Exhibit A - Source Code Form License Notice
+-------------------------------------------
+
+  This Source Code Form is subject to the terms of the Mozilla Public
+  License, v. 2.0. If a copy of the MPL was not distributed with this
+  file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+If it is not possible or desirable to put the notice in a particular
+file, then You may include the notice in a location (such as a LICENSE
+file in a relevant directory) where a recipient would be likely to look
+for such a notice.
+
+You may add additional accurate notices of copyright ownership.
+
+Exhibit B - "Incompatible With Secondary Licenses" Notice
+---------------------------------------------------------
+
+  This Source Code Form is "Incompatible With Secondary Licenses", as
+  defined by the Mozilla Public License, v. 2.0.

example.config.ron

@@ -1,8 +1,12 @@
 (
+    update_period: 30,
     services: {
         "example": (
             url: "https://example.org",
-            mode: Check200,
+            mode: (
+                up_status_codes: [Status2XX],
+                down_status_codes: [Status(404)],
+            ),
         ),
     },
 )

src/health/mod.rs

@@ -1,20 +1,21 @@
 use chrono::{DateTime, Utc};
 use futures::lock::Mutex;
-use log::info;
+use log::{error, info};
+use reqwest::{Response, StatusCode};
 use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
 
 pub type ServiceId = String;
 
-#[derive(Debug)]
+#[derive(Debug, Copy, Clone, Serialize)]
 pub enum HealthStatus {
     /// The service is up and running
     Up,
 
-    /// The service gave an error when performing the health check
+    /// The service gave a valid error when performing the health check
     Errored,
 
-    /// The service did not respond to the health check
+    /// The service seems to be completely offline
     Down,
 }
 
@@ -25,44 +26,115 @@ pub struct ServiceConfig {
 }
 
 #[derive(Serialize, Deserialize)]
-pub enum HttpHealthCheckMode {
-    /// Expect the server to return a 200 status code. The body is ignored.
-    Check200,
+pub enum PartialStatusCode {
+    Any,
+    Status1XX,
+    Status2XX,
+    Status3XX,
+    Status4XX,
+    Status5XX,
+    Status(u16),
+}
+
+/// If the response status code matches matches any in `ok_status_codes`, status will be Up
+/// else if it matches any in `down_status_codes` status will be Down, else status will be Errored
+#[derive(Serialize, Deserialize)]
+pub struct HttpHealthCheckMode {
+    /// If the response status code matches one in this list, the status will be Up
+    pub up_status_codes: Vec<PartialStatusCode>,
+
+    /// If the response status code matches one in this list, the status will be Down
+    #[serde(default)]
+    pub down_status_codes: Vec<PartialStatusCode>,
 }
 
 pub struct HealthState {
+    pub last_update: Mutex<Option<DateTime<Utc>>>,
     pub health: HashMap<ServiceId, Mutex<Option<HealthStatus>>>,
     pub config: HealthConfig,
 }
 
 #[derive(Serialize, Deserialize)]
 pub struct HealthConfig {
+    /// The time between updates (in seconds)
+    pub update_period: u64,
+
+    /// The list of services
     pub services: HashMap<ServiceId, ServiceConfig>,
 }
 
 impl HealthState {
     pub fn new(config: HealthConfig) -> HealthState {
         HealthState {
+            last_update: Mutex::new(None),
             health: config
                 .services
-                .iter()
-                .map(|(id, _config)| (id.clone(), Mutex::new(None)))
+                .keys()
+                .map(|id| (id.clone(), Mutex::new(None)))
                 .collect(),
             config,
         }
     }
 
     pub async fn update(&self) {
+        *self.last_update.lock().await = Some(Utc::now());
+
         for (id, status) in &self.health {
-            let url = &self.config.services[id].url;
+            let service_config = &self.config.services[id];
+            let url = &service_config.url;
             info!("service [{}] querying {}", id, url);
             let new_status = match reqwest::get(url).await {
                 Err(_) => HealthStatus::Down,
-                Ok(response) if response.status().is_success() => HealthStatus::Up,
-                Ok(_response) => HealthStatus::Errored,
+                Ok(response) => service_config.mode.status_of(&response),
             };
             info!("service [{}] new status {:?}", id, new_status);
             *status.lock().await = Some(new_status);
         }
     }
 }
+
+impl HttpHealthCheckMode {
+    fn status_of(&self, response: &Response) -> HealthStatus {
+        let response_status = response.status();
+
+        fn validate_status(
+            expected: &PartialStatusCode,
+            actual: StatusCode,
+            if_valid: HealthStatus,
+        ) -> Option<HealthStatus> {
+            let if_valid = Some(if_valid);
+            match expected {
+                PartialStatusCode::Any => if_valid,
+                &PartialStatusCode::Status(code) => StatusCode::from_u16(code)
+                    .map_err(|e| error!("invalid status code: {}", e))
+                    .ok()
+                    .filter(|status| status == &actual)
+                    .and(if_valid),
+                PartialStatusCode::Status5XX if actual.is_server_error() => if_valid,
+                PartialStatusCode::Status4XX if actual.is_server_error() => if_valid,
+                PartialStatusCode::Status3XX if actual.is_redirection() => if_valid,
+                PartialStatusCode::Status2XX if actual.is_success() => if_valid,
+                PartialStatusCode::Status1XX if actual.is_informational() => if_valid,
+                _ => None,
+            }
+        }
+
+        // Check if response status matches expected status codes for Up
+        let check_up = self
+            .up_status_codes
+            .iter()
+            .flat_map(|up_code| validate_status(up_code, response_status, HealthStatus::Up));
+
+        // Check if response status matches expected status codes for Down
+        let check_down = self
+            .down_status_codes
+            .iter()
+            .flat_map(|down_code| validate_status(down_code, response_status, HealthStatus::Down));
+
+        // Compute status, defaulting to Errored if neigher Up nor Down matched
+        check_up
+            .chain(check_down)
+            .next()
+            .unwrap_or(HealthStatus::Errored)
+    }
+}

src/main.rs

@@ -1,36 +1,58 @@
 mod health;
 mod routes;
 
+use clap::Parser;
 use dotenv::dotenv;
+use eyre::Context;
 use health::HealthState;
-use rocket_contrib::serve::StaticFiles;
-use rocket_contrib::templates::Template;
+use rocket::fs::FileServer;
+use rocket_dyn_templates::Template;
+use std::path::PathBuf;
 use std::sync::Arc;
-use std::{env, io};
-use tokio::fs;
+use std::time::Duration;
+use tokio::{fs, task, time::sleep};
+
+#[derive(Parser)]
+struct Opt {
+    /// Path to the config file.
+    #[clap(short, long, env = "CONFIG_PATH", default_value = "config.ron")]
+    config: PathBuf,
+}
 
 #[rocket::main]
-async fn main() -> io::Result<()> {
+async fn main() -> eyre::Result<()> {
     dotenv().ok();
+    let opt = Opt::parse();
+    color_eyre::install()?;
 
-    let config_path = env::var("CONFIG_PATH").unwrap_or("config.ron".into());
-
-    let config = fs::read_to_string(&config_path)
+    let config = fs::read_to_string(&opt.config)
         .await
-        .expect("failed to read config file");
-    let config = ron::from_str(&config).expect("failed to parse config file");
-    let state = HealthState::new(config);
+        .wrap_err_with(|| format!("failed to read config file: {:?}", opt.config))?;
+    let config = ron::from_str(&config)
+        .wrap_err_with(|| format!("failed to parse config file: {:?}", opt.config))?;
+    let state = Arc::new(HealthState::new(config));
 
-    let rocket = rocket::ignite()
-        //.attach(Template::custom(|engines| {
-        //handlebars_util::register_helpers(engines)
-        //}))
-        .manage(Arc::new(state))
-        .mount("/static", StaticFiles::from("static"))
-        .mount("/", rocket::routes![routes::pages::index,]);
-    //.register(rocket::catchers![auth::login_page,]);
+    let rocket = rocket::build()
+        .attach(Template::fairing())
+        .manage(Arc::clone(&state))
+        .mount("/static", FileServer::from("static"))
+        .mount(
+            "/",
+            rocket::routes![routes::pages::dashboard, routes::api::status],
+        );
 
-    rocket.launch().await.expect("rocket failed to launch");
+    start_poller(state);
+
+    rocket.launch().await.wrap_err("rocket failed to launch")?;
 
     Ok(())
 }
+
+fn start_poller(state: Arc<HealthState>) {
+    task::spawn(async move {
+        loop {
+            state.update().await;
+            sleep(Duration::from_secs(state.config.update_period)).await;
+        }
+    });
+}

src/routes/api/mod.rs

@@ -0,0 +1,33 @@
+use crate::health::HealthState;
+use crate::health::HealthStatus;
+use chrono::DateTime;
+use chrono::Utc;
+use rocket::serde::json::Json;
+use rocket::{get, State};
+use serde::Serialize;
+use std::collections::BTreeMap;
+use std::sync::Arc;
+
+#[derive(Serialize)]
+pub struct Status {
+    last_update: Option<DateTime<Utc>>,
+    services: BTreeMap<String, HealthStatus>,
+}
+
+#[get("/status")]
+pub async fn status(state: &State<Arc<HealthState>>) -> Json<Status> {
+    let last_update = *state.last_update.lock().await;
+    let mut services = BTreeMap::new();
+
+    for (id, status) in &state.health {
+        let Some(status) = *status.lock().await else {
+            continue;
+        };
+        services.insert(id.clone(), status);
+    }
+
+    Json(Status {
+        last_update,
+        services,
+    })
+}

src/routes/pages/mod.rs

@@ -1,22 +1,56 @@
 use crate::health::HealthState;
+use crate::health::HealthStatus;
+use chrono::Utc;
 use rocket::{get, State};
+use rocket_dyn_templates::Template;
+use serde::Serialize;
 use std::sync::Arc;
-use tokio::task::spawn;
 
 #[get("/")]
-pub async fn index(state: State<'_, Arc<HealthState>>) -> String {
-    {
-        let state = Arc::clone(state.inner());
-        spawn(async move {
-            state.update().await;
-        });
+pub async fn dashboard(state: &State<Arc<HealthState>>) -> Template {
+    #[derive(Debug, Serialize)]
+    struct Service {
+        name: String,
+        status_text: &'static str,
+        status_color: &'static str,
     }
 
-    let mut out = String::new();
+    #[derive(Debug, Serialize)]
+    struct TemplateContext {
+        last_update: String,
+        services: Vec<Service>,
+    }
+
+    let last_update = *state.last_update.lock().await;
+
+    let mut context = TemplateContext {
+        last_update: last_update
+            .map(|last_update| {
+                let now = Utc::now();
+                if now.date_naive() == last_update.date_naive() {
+                    format!("UTC {}", last_update.format("%H:%M:%S"))
+                } else {
+                    format!("UTC {}", last_update.format("%Y-%m-%d %H:%M:%S"))
+                }
+            })
+            .unwrap_or_else(|| "never".to_string()),
+        services: vec![],
+    };
 
     for (id, status) in &state.health {
-        out.push_str(&format!("{}: {:?}\n", id, &*status.lock().await));
+        let (status_color, status_text) = match *status.lock().await {
+            Some(HealthStatus::Up) => ("green", "UP"),
+            Some(HealthStatus::Down) => ("red", "DOWN"),
+            Some(HealthStatus::Errored) => ("orange", "ERRORED"),
+            None => ("#5b5b5b", "UNKNOWN"),
+        };
+
+        context.services.push(Service {
+            name: id.clone(),
+            status_color,
+            status_text,
+        })
     }
 
-    out
+    Template::render("dashboard", &context)
 }

static/styles/common.css

@@ -0,0 +1,40 @@
+body {
+    font-family: Ubuntu;
+    background-color: #302f3b;
+    color: #e0c1c1;
+}
+
+h1 {
+    color: #a8a8a8;
+    text-decoration: underline;
+    text-decoration-color: gray;
+    margin-top: 0.1em;
+    margin-bottom: 0.4em;
+    font-style: italic;
+    letter-spacing: 0.1em;
+    font-size: 2em;
+}
+
+.service_list {
+}
+
+.service_entry {
+    margin-top: 0.6em;
+    margin-bottom: 0.6em;
+}
+
+.service_name {
+    color: #6ca4fb;
+}
+
+.service_status {
+    padding: 0.2em;
+    color: white;
+}
+
+.last_update {
+}
+
+.last_update_time {
+    color: #d57ad5;
+}

templates/dashboard.html.hbs

@@ -0,0 +1,41 @@
+<!DOCTYPE html>
+<html lang="en">
+    <head>
+        <meta charset="utf-8">
+        <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
+        <meta name="description" content="">
+
+        <link rel="icon" type="image/svg+xml" href="/static/icon.svg">
+        <link rel="stylesheet" href="/static/styles/common.css">
+        <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Ubuntu|Ubuntu+Mono&display=swap">
+
+        <title>healthpot</title>
+
+	<script>
+            // refresh the page after 30 seconds
+            setTimeout(location.reload.bind(location), 30000);
+	</script>
+    </head>
+
+    <body>
+        <h1 class="title">healthpot</h1>
+
+        <div class="last_update">
+            <span>last update:</span>
+            <span class="last_update_time">{{last_update}}</span>
+        </div>
+
+        <ul class="service_list">
+        {{#each services}}
+            <li class="service_entry">
+                <span class="service_name">{{this.name}}</span>
+                <span> is </span>
+                <span class="service_status"
+                    style="background-color: {{this.status_color}}">
+                    {{this.status_text}}
+                </span>
+            </li>
+        {{/each}}
+        </ul>
+    </body>
+</html>