Allow specifying configuration params in env vars (#83)

Cargo.lock

@@ -1585,6 +1585,7 @@ dependencies = [
  "serde_json",
  "taskchampion-sync-server-core",
  "taskchampion-sync-server-storage-sqlite",
+ "temp-env",
  "tempfile",
  "thiserror",
  "uuid",
@@ -1617,6 +1618,15 @@ dependencies = [
  "uuid",
 ]
 
+[[package]]
+name = "temp-env"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "96374855068f47402c3121c6eed88d29cb1de8f3ab27090e273e420bdabcf050"
+dependencies = [
+ "parking_lot",
+]
+
 [[package]]
 name = "tempfile"
 version = "3.16.0"

Cargo.toml

@@ -14,7 +14,7 @@ thiserror = "2.0"
 futures = "^0.3.25"
 serde_json = "^1.0"
 serde = { version = "^1.0.147", features = ["derive"] }
-clap = { version = "^4.5.6", features = ["string"] }
+clap = { version = "^4.5.6", features = ["string", "env"] }
 log = "^0.4.17"
 env_logger = "^0.11.5"
 rusqlite = { version = "0.32", features = ["bundled"] }
@@ -22,3 +22,4 @@ chrono = { version = "^0.4.38", features = ["serde"] }
 actix-rt = "2"
 tempfile = "3"
 pretty_assertions = "1"
+temp-env = "0.3"

README.md

@@ -73,12 +73,18 @@ The server is configured with command-line options. See
 
 The `--listen` option specifies the interface and port the server listens on.
 It must contain an IP-Address or a DNS name and a port number. This option is
-mandatory, but can be repeated to specify multiple interfaces or ports.
+mandatory, but can be repeated to specify multiple interfaces or ports. This
+value can be specified in environment variable `LISTEN`, as a comma-separated
+list of values.
 
-The `--data-dir` option specifies where the server should store its data.
+The `--data-dir` option specifies where the server should store its data. This
+value can be specified in the environment variable `DATA_DIR`.
 
 By default, the server allows all client IDs. To limit the accepted client IDs,
-such as when running a personal server, use `--allow-client-id <client-id>`.
+specify them in the environment variable `CLIENT_ID`, as a comma-separated list
+of UUIDs. Client IDs can be specified with `--allow-client-id`, but this should
+not be used on shared systems, as command line arguments are visible to all
+users on the system.
 
 The server only logs errors by default. To add additional logging output, set
 environment variable `RUST_LOG` to `info` to get a log message for every

docker-compose.yml

@@ -56,9 +56,10 @@ services:
         volume:
           nocopy: true
           subpath: tss
-    command: --data-dir /tss/taskchampion-sync-server --listen 0.0.0.0:8080
     environment:
-      - RUST_LOG=info
+      - "RUST_LOG=info"
+      - "DATA_DIR=/tss/taskchampion-sync-server"
+      - "LISTEN=0.0.0.0:8080"
     depends_on:
       mkdir:
         condition: service_completed_successfully

server/Cargo.toml

@@ -24,3 +24,4 @@ chrono.workspace = true
 actix-rt.workspace = true
 tempfile.workspace = true
 pretty_assertions.workspace = true
+temp-env.workspace = true

server/src/bin/taskchampion-sync-server.rs

@@ -23,29 +23,36 @@ fn command() -> Command {
         .arg(
             arg!(-l --listen <ADDRESS>)
                 .help("Address and Port on which to listen on. Can be an IP Address or a DNS name followed by a colon and a port e.g. localhost:8080")
+                .value_delimiter(',')
                 .value_parser(ValueParser::string())
+                .env("LISTEN")
                 .action(ArgAction::Append)
                 .required(true),
         )
         .arg(
             arg!(-d --"data-dir" <DIR> "Directory in which to store data")
                 .value_parser(ValueParser::os_string())
+                .env("DATA_DIR")
                 .default_value("/var/lib/taskchampion-sync-server"),
         )
         .arg(
             arg!(-C --"allow-client-id" <CLIENT_ID> "Client IDs to allow (can be repeated; if not specified, all clients are allowed)")
+                .value_delimiter(',')
                 .value_parser(value_parser!(Uuid))
+                .env("CLIENT_ID")
                 .action(ArgAction::Append)
                 .required(false),
         )
         .arg(
             arg!(--"snapshot-versions" <NUM> "Target number of versions between snapshots")
                 .value_parser(value_parser!(u32))
+                .env("SNAPSHOT_VERSIONS")
                 .default_value(default_snapshot_versions),
         )
         .arg(
             arg!(--"snapshot-days" <NUM> "Target number of days between snapshots")
                 .value_parser(value_parser!(i64))
+                .env("SNAPSHOT_DAYS")
                 .default_value(default_snapshot_days),
         )
 }
@@ -95,6 +102,7 @@ mod test {
     use actix_web::{self, App};
     use clap::ArgMatches;
     use taskchampion_sync_server_core::InMemoryStorage;
+    use temp_env::{with_var, with_var_unset, with_vars, with_vars_unset};
 
     /// Get the list of allowed client IDs
     fn allowed(matches: &ArgMatches) -> Option<Vec<Uuid>> {
@@ -103,14 +111,53 @@ mod test {
             .map(|ids| ids.copied().collect::<Vec<_>>())
     }
 
+    #[test]
+    fn command_listen_two() {
+        with_var_unset("LISTEN", || {
+            let matches = command().get_matches_from([
+                "tss",
+                "--listen",
+                "localhost:8080",
+                "--listen",
+                "otherhost:9090",
+            ]);
+            assert_eq!(
+                matches
+                    .get_many::<String>("listen")
+                    .unwrap()
+                    .cloned()
+                    .collect::<Vec<String>>(),
+                vec!["localhost:8080".to_string(), "otherhost:9090".to_string()]
+            );
+        });
+    }
+
+    #[test]
+    fn command_listen_two_env() {
+        with_var("LISTEN", Some("localhost:8080,otherhost:9090"), || {
+            let matches = command().get_matches_from(["tss"]);
+            assert_eq!(
+                matches
+                    .get_many::<String>("listen")
+                    .unwrap()
+                    .cloned()
+                    .collect::<Vec<String>>(),
+                vec!["localhost:8080".to_string(), "otherhost:9090".to_string()]
+            );
+        });
+    }
+
     #[test]
     fn command_allowed_client_ids_none() {
+        with_var_unset("CLIENT_ID", || {
             let matches = command().get_matches_from(["tss", "--listen", "localhost:8080"]);
             assert_eq!(allowed(&matches), None);
+        });
     }
 
     #[test]
     fn command_allowed_client_ids_one() {
+        with_var_unset("CLIENT_ID", || {
             let matches = command().get_matches_from([
                 "tss",
                 "--listen",
@@ -125,10 +172,30 @@ mod test {
                 )
                 .unwrap()])
             );
+        });
+    }
+
+    #[test]
+    fn command_allowed_client_ids_one_env() {
+        with_var(
+            "CLIENT_ID",
+            Some("711d5cf3-0cf0-4eb8-9eca-6f7f220638c0"),
+            || {
+                let matches = command().get_matches_from(["tss", "--listen", "localhost:8080"]);
+                assert_eq!(
+                    allowed(&matches),
+                    Some(vec![Uuid::parse_str(
+                        "711d5cf3-0cf0-4eb8-9eca-6f7f220638c0"
+                    )
+                    .unwrap()])
+                );
+            },
+        );
     }
 
     #[test]
     fn command_allowed_client_ids_two() {
+        with_var_unset("CLIENT_ID", || {
             let matches = command().get_matches_from([
                 "tss",
                 "--listen",
@@ -145,10 +212,30 @@ mod test {
                     Uuid::parse_str("bbaf4b61-344a-4a39-a19e-8caa0669b353").unwrap()
                 ])
             );
+        });
+    }
+
+    #[test]
+    fn command_allowed_client_ids_two_env() {
+        with_var(
+            "CLIENT_ID",
+            Some("711d5cf3-0cf0-4eb8-9eca-6f7f220638c0,bbaf4b61-344a-4a39-a19e-8caa0669b353"),
+            || {
+                let matches = command().get_matches_from(["tss", "--listen", "localhost:8080"]);
+                assert_eq!(
+                    allowed(&matches),
+                    Some(vec![
+                        Uuid::parse_str("711d5cf3-0cf0-4eb8-9eca-6f7f220638c0").unwrap(),
+                        Uuid::parse_str("bbaf4b61-344a-4a39-a19e-8caa0669b353").unwrap()
+                    ])
+                );
+            },
+        );
     }
 
     #[test]
     fn command_data_dir() {
+        with_var_unset("DATA_DIR", || {
             let matches = command().get_matches_from([
                 "tss",
                 "--data-dir",
@@ -157,6 +244,47 @@ mod test {
                 "localhost:8080",
             ]);
             assert_eq!(matches.get_one::<OsString>("data-dir").unwrap(), "/foo/bar");
+        });
+    }
+
+    #[test]
+    fn command_data_dir_env() {
+        with_var("DATA_DIR", Some("/foo/bar"), || {
+            let matches = command().get_matches_from(["tss", "--listen", "localhost:8080"]);
+            assert_eq!(matches.get_one::<OsString>("data-dir").unwrap(), "/foo/bar");
+        });
+    }
+
+    #[test]
+    fn command_snapshot() {
+        with_vars_unset(["SNAPSHOT_DAYS", "SNAPSHOT_VERSIONS"], || {
+            let matches = command().get_matches_from([
+                "tss",
+                "--listen",
+                "localhost:8080",
+                "--snapshot-days",
+                "13",
+                "--snapshot-versions",
+                "20",
+            ]);
+            assert_eq!(*matches.get_one::<i64>("snapshot-days").unwrap(), 13i64);
+            assert_eq!(*matches.get_one::<u32>("snapshot-versions").unwrap(), 20u32);
+        });
+    }
+
+    #[test]
+    fn command_snapshot_env() {
+        with_vars(
+            [
+                ("SNAPSHOT_DAYS", Some("13")),
+                ("SNAPSHOT_VERSIONS", Some("20")),
+            ],
+            || {
+                let matches = command().get_matches_from(["tss", "--listen", "localhost:8080"]);
+                assert_eq!(*matches.get_one::<i64>("snapshot-days").unwrap(), 13i64);
+                assert_eq!(*matches.get_one::<u32>("snapshot-versions").unwrap(), 20u32);
+            },
+        );
     }
 
     #[actix_rt::test]