Added Error handling, switched to using "Result" type for many methods

src/cloudflare/mod.rs

@@ -1,6 +1,6 @@
 use reqwest::{blocking::{Response, Client}, Url};
 use serde_derive::{Deserialize, Serialize};
-use reqwest::header::{HeaderMap, HeaderValue};
+use reqwest::{Error, header::{HeaderMap, HeaderValue}};
 use std::{string::String, collections::HashMap};
 use strum_macros::{Display, IntoStaticStr};
 
@@ -64,12 +64,15 @@ impl Instance {
     /// 
     /// * `email` : E-Mail Address associated with the Zone, required for [`generate_headers()`]
     /// * `zone_id` : Zone to be used for the Request
-    pub fn load_entries(&mut self, email: &String, zone_id: &String) {
+    /// * `return` : Returns true if a recoverable Error was encountered, true otherwise
+    pub fn load_entries(&mut self, email: &String, zone_id: &String) -> Result<(), Error> {
         self.dns_email = email.clone();
         let endpoint = format!("{}zones/{}/dns_records", API_BASE, zone_id);
 
-        let api_response = self.get(&endpoint);
+        match self.get(&endpoint) {
-        let entries = match api_response.json::<CloudflareDnsZone>() {
+            Ok(response) => {
+                let entries = match response
+                        .json::<CloudflareDnsZone>() {
                     Ok(data) => {data},
                     Err(e) => panic!("{:#?}", e)
                 };
@@ -77,6 +80,13 @@ impl Instance {
                 for entry in entries.result {
                     self.dns_entries.append(&mut vec!(entry));
                 }
+
+                return Ok(())
+            },
+            Err(e) => { return Err(e) }
+        }
+
+
     }
 
     /// Shorthand for Cloudflare API Requests
@@ -84,67 +94,77 @@ impl Instance {
     /// Automatically appends Auth Headers and parses the URL
     /// 
     /// * `url` : URL for the request, will be parsed to [`Url`]
-    /// * `email` : E-Mail Address associated with the Zone, required for [`generate_headers()`]
+    fn get(&self, url: &str) -> Result<Response, Error> {
-    fn get(&self, url: &str) -> Response {
         let url_parsed = match Url::parse(url) {
             Ok(url) => {url},
-            Err(e) => panic!("{:#?}", e)
+            Err(e) => panic!("{:#?}", e) // If this call fails the API changed
-        };
+        };                                           // Continuing without a code update is not possible
 
-        let client = Client::new();
+        let result = match Client::new()
-        let res = client.get(url_parsed)
+            .get(url_parsed)
             .headers(self.generate_headers())
-            .send();
+            .send() {
-
+                Ok(res) => { Ok(res) },
-        let response = match res {
+                Err(e) => { Err(e) } 
-            Ok(res) => {res},
-            Err(e) => panic!("{:#?}", e) 
         };
 
-        response
+        return result;
     }
 
-    fn put(&self, url: &str, data: &HashMap<&str, &str>) -> Response {
+    /// Shorthand for Cloudflare API Requests
+    /// 
+    /// Automatically appends Auth Headers and parses the URL
+    /// 
+    /// * `url` : URL for the request, will be parsed to [`Url`]
+    /// * `data` : PUT request body
+    fn put(&self, url: &str, data: &HashMap<&str, &str>) -> Result<Response, Error> {
         let url_parsed = match Url::parse(url) {
             Ok(url) => {url},
-            Err(e) => panic!("{:#?}", e)
+            Err(e) => panic!("{:#?}", e)// If this call fails the API changed
-        };
+        };                                           // Continuing without a code update is not possible
         
-        let client = Client::new();
+        let result = match Client::new()
-        let res = client.put(url_parsed)
+            .put(url_parsed)
             .headers(self.generate_headers())
             .json(data)
-            .send();
+            .send() {
-        
+                Ok(res) => { Ok(res) },
-        let response = match res {
+                Err(e) => { Err(e) }
-            Ok(res) => {res},
-            Err(e) => panic!("{:#?}", e)
         };
 
-        response
+        return result;
     }
 
-    fn post(&self, url: &str, data: &HashMap<&str, &str>) -> Response {
+    /// Shorthand for Cloudflare API Requests
+    /// 
+    /// Automatically appends Auth Headers and parses the URL
+    /// 
+    /// * `url` : URL for the request, will be parsed to [`Url`]
+    /// * `data` : POST request body
+    fn post(&self, url: &str, data: &HashMap<&str, &str>) -> Result<Response, Error> {
         let url_parsed = match Url::parse(url) {
             Ok(url) => {url},
-            Err(e) => panic!("{:#?}", e)
+            Err(e) => panic!("{:#?}", e) // If this call fails the API changed
-        };
+        };                                           // Continuing without a code update is not possible
         
-        let client = Client::new();
+        let result = match Client::new()
-        let res = client.post(url_parsed)
+            .post(url_parsed)
             .headers(self.generate_headers())
             .json(data)
-            .send();
+            .send() {
-        
+                Ok(res) => { Ok(res) },
-        let response = match res {
+                Err(e) => { Err(e) }
-            Ok(res) => {res},
-            Err(e) => panic!("{:#?}", e)
         };
 
-        response
+        return result;
     }
 
-    pub fn update_entry(&self, entry: &CloudflareDnsEntry, new_ip: &String) -> bool {
+    /// Updates the given DNS entry with the given IP
+    /// 
+    /// * `entry` : DNS entry to update
+    /// * `new_ip` : IP used to Update the DNS entry, can be IPv4 or IPv6
+    /// * `return1` : Returns success of the API call, extracted from the HTTP Response body
+    pub fn update_entry(&self, entry: &CloudflareDnsEntry, new_ip: &String) -> Result<bool, Error> {
         let endpoint = format!("{}zones/{}/dns_records/{}", API_BASE, entry.zone_id, entry.id);
 
         let mut json_body = HashMap::new();
@@ -153,16 +173,22 @@ impl Instance {
         json_body.insert("content", new_ip);
         json_body.insert("ttl", "1");
 
-        let api_response = self.put(&endpoint, &json_body);
+        match self.put(&endpoint, &json_body) {
+            Ok(response) => {
+                let data = response
+                    .json::<serde_json::Value>()
+                    .expect("Response should always be valid JSON");
 
-        let data = api_response.json::<serde_json::Value>().unwrap();
+                let success = data["success"]
-
+                    .as_bool()
-        let ret = data["success"].as_bool().unwrap();
+                    .expect("JSON should always include success bool");
-
+                return Ok(success);
-        ret
+            },
+            Err(e) => { return Err(e) },
+        }
     }
 
-    pub fn create_entry(&self, zone_id: &String, r#type: &str, name: &str, ip: &String) -> bool {
+    pub fn create_entry(&self, zone_id: &String, r#type: &str, name: &str, ip: &String) -> Result<bool, Error> {
         let endpoint = format!("{}zones/{}/dns_records", API_BASE, zone_id);
 
         let mut json_body = HashMap::new();
@@ -171,13 +197,20 @@ impl Instance {
         json_body.insert("content", ip);
         json_body.insert("ttl", "1");
 
-        let api_response = self.post(&endpoint, &json_body);
+        match self.post(&endpoint, &json_body) {
+            Ok(response) => {
+                let data = response
+                    .json::<serde_json::Value>()
+                    .expect("Response should always be valid JSON");
 
-        let data = api_response.json::<serde_json::Value>().unwrap();
+                let success = data["success"]
+                    .as_bool()
+                    .expect("JSON should always include success bool");
 
-        let ret = data["success"].as_bool().unwrap();
+                return Ok(success)
-
+            },
-        ret
+            Err(e) => { return Err(e) },
+        }
     }
 
     /// Generate Cloudflare API v4 Auth Headers

src/main.rs

@@ -55,31 +55,46 @@ struct DnsEntry {
 }
 
 impl DnsEntry {
+    /// Updates a single DNS Entry
+    /// 
+    /// * `change4` : IPv4 DNS change tracker, used to print details about the results of the update run after it concludes
+    /// * `change6` : Same as `change4` but for IPv6
+    /// * `ips` : Enum of current IPv4 and IPv6 base, used to check against and update the DNS record
+    /// * `agent` : Cloudflare Auth Agent, provides the needed Authentication headers for the API Calls
+    /// * `zone_id` : Cloudfalre ID of the Zone this DNS entry resides in, needed for the API Calls 
+    /// 
+    /// * `return` : Returns true if the DNS Update failed due to an Error, otherwise returns false
     fn update(
             &self, 
             change4: &mut ChangeTracker, 
             change6: &mut ChangeTracker, 
-            agent: &Instance, 
             ips: &Ips,
-            zone: &DnsZone
+            agent: &Instance, 
-        ) {
+            zone_id: &String
+        ) -> bool {
         let mut found4 = false;
         let mut found6 = false;
 
+        // Loops over every Entry in the List fetched from the Cloudflare API
+        // If the entry is in this List we need to update it, if not it needs to be created
         for cloudflare_entry in &agent.dns_entries {
-            // Update IPv4 Entry
             if cloudflare_entry.is_equal(&self.name) {
-                found4 = true;
+                // Update IPv4 Entry
                 if cloudflare_entry.r#type == CloudflareDnsType::A && self.type4 {
-                    let success = agent.update_entry(cloudflare_entry, &ips.ipv4);
+                    found4 = true;
 
                     if cloudflare_entry.is_ip_new(&ips.ipv4) {
+                        match agent.update_entry(cloudflare_entry, &ips.ipv4) {
+                            Ok(success) => {
                                 if success {
                                     change4.updated += 1;
                                 } 
                                 else {
                                     change4.error += 1;
                                 }
+                            },
+                            Err(_e) => { return true } // if an error is detected any subsequent calls are likely to fail as well
+                        };
                     } 
                     else {
                         change4.unchanged += 1;
@@ -91,13 +106,17 @@ impl DnsEntry {
                     let ipv6 = ips.ipv6base.clone() + self.interface.as_ref().unwrap();
 
                     if cloudflare_entry.is_ip_new(&ipv6) {
-                        let success = agent.update_entry(cloudflare_entry, &ipv6);
+                        match agent.update_entry(cloudflare_entry, &ipv6) {
+                            Ok(success) => {
                                 if success {
                                     change6.updated += 1
                                 } 
                                 else {
                                     change6.error += 1
                                 }
+                            },
+                            Err(_e) => { return true } // if an error is detected any subsequent calls are likely to fail as well
+                        };
                     } 
                     else {
                         change6.unchanged += 1;
@@ -109,25 +128,35 @@ impl DnsEntry {
         }
 
         if !found4 && self.type4 {
-            let success = agent.create_entry(&zone.id, "A", &self.name, &ips.ipv4);
+            match agent.create_entry(zone_id, "A", &self.name, &ips.ipv4) {
+                Ok(success) => {
                     if success {
                         change4.created += 1;
                     }
                     else {
                         change4.error += 1;
                     };
+                },
+                Err(_e) => { return true } // early return since if an error is detected any subsequent calls are likely to fail as well
+            }
         }
 
         if !found6 && self.type6 {
             let ipv6 = ips.ipv6base.clone() + self.interface.as_ref().unwrap();
-            let success = agent.create_entry(&zone.id, "AAAA", &self.name, &ipv6);
+            match agent.create_entry(zone_id, "AAAA", &self.name, &ipv6) {
+                Ok(success) => {
                     if success {
                         change6.created += 1;
                     }
                     else {
                         change6.error += 1;
                     };
+                },
+                Err(_e) => { return true } // if an error is detected any subsequent calls are likely to fail as well
+            };
         }
+
+        return false; // If this point is reached no error has been caught therefore returning false
     }
 }
 
@@ -140,13 +169,40 @@ struct DnsZone {
 }
 
 impl DnsZone {
-    fn update(&self, change4: &mut ChangeTracker, change6: &mut ChangeTracker, ips: &Ips, config: &DnsConfig ) {
+    /// Attempts to Update the DNS Entries of the Zone with a new IP
-        let mut agent = Instance::new(&config.api_key);
+    /// 
+    /// * `change4` : IPv4 DNS change tracker, used to print details about the results of the update run after it concludes
+    /// * `change6` : Same as `change4` but for IPv6
+    /// * `ips` : Enum of current IPv4 and IPv6 base, used to check against and update the DNS record
+    /// * `key` : API Key needed to create the Auth Agent for the API
+    /// 
+    /// * `return` : Returns true if the DNS Updates failed due to an Error, false otherwise
+    fn update(
+        &self, 
+        change4: &mut ChangeTracker, 
+        change6: &mut ChangeTracker, 
+        ips: &Ips, 
+        key: &String 
+    ) -> bool {
+        let mut agent = Instance::new(key);
 
-        agent.load_entries(&self.email, &self.id);
+        match agent.load_entries(&self.email, &self.id) {
+            Ok(_) => {
+                let mut results = Vec::<bool>::new();
 
                 for entry in &self.dns_entries {
-            entry.update(change4, change6, &agent, &ips, &self);
+                    let result = entry.update(change4, change6, &ips, &agent, &self.id);
+                    results.append(&mut vec!(result));
+                    if result {
+                        break; // if one update fails all others are likely to fail as well
+                    }
+                }
+
+                let result = results.contains(&true);
+
+                return result;
+            },
+            Err(_e) => { return true }, // Early return since an Error likely means subsequent calls will also fail
         }
     }
 }
@@ -205,14 +261,16 @@ impl Ips {
         }
     }
 
+    /// Get the current IPv4 address and IPv6 prefix from Mullvad API
+    ///
+    /// Returns true if the get succeeded and false if it failed. 
+    /// The IPv6 Prefix is generated by removing the IPv6 Interface from the fetched IPv6 address
     fn get(&mut self, ipv6_interface: &str) -> bool {
         let ipv4uri = "https://am.i.mullvad.net/ip";
         let ipv6uri = "https://ipv6.am.i.mullvad.net/ip";
         let mut ret;
 
-        let response = get(ipv4uri);
+        match get(ipv4uri) {
-
-        match response {
             Ok(data) => {
                 self.ipv4 = data.text().expect("0.0.0.0").trim_end().to_owned();
                 ret = true;
@@ -220,12 +278,12 @@ impl Ips {
             Err(_e) => {
                 println!("Could not fetch IPv4");
                 ret = false;
+
+                return ret; // Early return since a fail on IPv4 means a likely fail on IPv6
             }
         }
 
-        let response = get(ipv6uri);
+        match get(ipv6uri) {
-
-        match response {
             Ok(data) => {
                 let ipv6 = match data.text() {
                     Ok(ip) => {ip},
@@ -248,26 +306,42 @@ impl Ips {
     }
 }
 
+/// Loops over all DNS Entries in the config and calls an update on them
 fn update_dns() {
     let mut config = DnsConfig::new();
     config.load();
 
     let mut ips = Ips::new();
     if ips.get(&config.ipv6_interface) {
+        println!("Current IPv4: {}", ips.ipv4);
+        println!("Current IPv6: {}{}", ips.ipv6base, &config.ipv6_interface);
+
         let mut change4 = ChangeTracker::new();
 
         let mut change6 = ChangeTracker::new();
 
+        let mut update_results = Vec::<bool>::new();
+
         // Iterator does not work here
         for zone in &config.zones {
-            zone.update(&mut change4, &mut change6, &ips, &config)
+            let error = zone.update(&mut change4, &mut change6, &ips, &config.api_key);
+            update_results.append(&mut vec!(error));
+            if error {
+                break; // if one update fails all others are likely to fail as well
+            }   
         }
 
+        if update_results.contains(&true) {
+            println!("DNS Update failed due to Network Error")
+        }
+        else {
             println!("++++A Records+++");
             change4.print("simple");
             println!("++AAAA Records++");
             change6.print("simple")
         }
+
+    }
 }
 
 fn main() {