Merge pull request #52 from ufoscout/feature/wait_for_path

Feature/wait for path

Author: ufoscout

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "wait"
-version = "2.8.0"
+version = "2.9.0"
 authors = ["ufoscout <[email protected]>"]
 edition = "2018"
 
@@ -12,7 +12,7 @@ env_logger = { version = "0.8", default-features = false }
 [dev-dependencies]
 atomic-counter = "1.0"
 lazy_static = "1.4"
-time = "0.1.40"
+rand = "0.8"
 
 [profile.release]
 opt-level = 'z'  # Optimize for size.

Cargo.toml

@@ -5,8 +5,12 @@
 [![Codacy Badge](https://api.codacy.com/project/badge/Grade/e9c2359ba5534f58a4b178191acb836a)](https://www.codacy.com/manual/edumco/docker-compose-wait?utm_source=github.com&utm_medium=referral&utm_content=edumco/docker-compose-wait&utm_campaign=Badge_Grade)
 [![FOSSA Status](https://app.fossa.io/api/projects/git%2Bgithub.com%2Fedumco%2Fdocker-compose-wait.svg?type=shield)](https://app.fossa.io/projects/git%2Bgithub.com%2Fedumco%2Fdocker-compose-wait?ref=badge_shield)
 
-A small command line utility to wait for other docker images to be started while using docker-compose.
-It permits to wait for a fixed amount of seconds and/or to wait until a TCP port is open on a target image.
+A small command-line utility to wait for other docker images to be started while using docker-compose.
+
+It permits waiting for:
+- a fixed amount of seconds
+- until a TCP port is open on a target image
+- until a file or directory is present on the local filesystem
 
 ## Usage
 
@@ -18,13 +22,13 @@ For example, your application "MySuperApp" uses MongoDB, Postgres and MySql (wow
 ## Use whatever base image
 FROM alpine
 
-## Add your application to the docker image
-ADD MySuperApp.sh /MySuperApp.sh
-
 ## Add the wait script to the image
-ADD https://github.com/ufoscout/docker-compose-wait/releases/download/2.8.0/wait /wait
+ADD https://github.com/ufoscout/docker-compose-wait/releases/download/2.9.0/wait /wait
 RUN chmod +x /wait
 
+## Add your application to the docker image
+ADD MySuperApp.sh /MySuperApp.sh
+
 ## Launch the wait tool and then your application
 CMD /wait && /MySuperApp.sh
 ```
@@ -82,11 +86,12 @@ Instead the recommendation for base Docker images are ones offering a shell like
 The behaviour of the wait utility can be configured with the following environment variables:
 
 - _WAIT_LOGGER_LEVEL_ : the output logger level. Valid values are: _debug_, _info_, _error_, _off_. the default is _debug_. 
-- _WAIT_HOSTS_: comma separated list of pairs host:port for which you want to wait.
-- _WAIT_HOSTS_TIMEOUT_: max number of seconds to wait for all the hosts to be available before failure. The default is 30 seconds.
+- _WAIT_HOSTS_: comma-separated list of pairs host:port for which you want to wait.
+- _WAIT_PATHS_: comma-separated list of paths (i.e. files or directories) on the local filesystem for which you want to wait until they exist.
+- _WAIT_TIMEOUT_: max number of seconds to wait for all the hosts/paths to be available before failure. The default is 30 seconds.
 - _WAIT_HOST_CONNECT_TIMEOUT_: The timeout of a single TCP connection to a remote host before attempting a new connection. The default is 5 seconds.
-- _WAIT_BEFORE_HOSTS_: number of seconds to wait (sleep) before start checking for the hosts availability
-- _WAIT_AFTER_HOSTS_: number of seconds to wait (sleep) once all the hosts are available
+- _WAIT_BEFORE_: number of seconds to wait (sleep) before start checking for the hosts/paths availability
+- _WAIT_AFTER_: number of seconds to wait (sleep) once all the hosts/paths are available
 - _WAIT_SLEEP_INTERVAL_: number of seconds to sleep between retries. The default is 1 second.
 
 ## Using on non-linux systems

README.md

@@ -7,11 +7,13 @@ pub fn env_var(key: &str, default: String) -> String {
     }
 }
 
+pub fn env_var_exists(key: &str) -> bool {
+    env::var(key).is_ok()
+}
+
 #[cfg(test)]
 mod test {
 
-    extern crate time;
-
     use super::*;
     use std::env;
 
@@ -30,15 +32,18 @@ mod test {
 
         println!("Result Variable [{}]: [{}]", env_key, env_value);
 
+        assert!(env_var_exists(&env_key));
         assert_ne!(env_value, String::from(""));
         assert_eq!(env_value, env_var(&env_key, String::from("")));
     }
 
     #[test]
     fn should_return_the_default_value_if_env_variable_not_present() {
-        let mut nanosec = time::get_time().nsec;
-        let env_key = nanosec.to_string();
-        nanosec = nanosec + 10;
-        assert_eq!(nanosec.to_string(), env_var(&env_key, nanosec.to_string()));
+        let mut random: i64 = rand::random();
+        let env_key = random.to_string();
+        random = random + 10;
+
+        assert!(!env_var_exists(&env_key));
+        assert_eq!(random.to_string(), env_var(&env_key, random.to_string()));
     }
 }

src/env_reader/mod.rs

@@ -1,11 +1,14 @@
+use crate::env_reader::env_var_exists;
 use log::*;
+use std::path::Path;
 use std::time::Duration;
 
 pub mod env_reader;
 pub mod sleeper;
 
 pub struct Config {
     pub hosts: String,
+    pub paths: String,
     pub global_timeout: u64,
     pub tcp_connection_timeout: u64,
     pub wait_before: u64,
@@ -25,6 +28,7 @@ pub fn wait(
     info!("---------------------------");
     debug!("Starting with configuration:");
     debug!(" - Hosts to be waiting for: [{}]", config.hosts);
+    debug!(" - Paths to be waiting for: [{}]", config.paths);
     debug!(
         " - Timeout before failure: {} seconds ",
         config.global_timeout
@@ -34,11 +38,11 @@ pub fn wait(
         config.tcp_connection_timeout
     );
     debug!(
-        " - Sleeping time before checking for hosts availability: {} seconds",
+        " - Sleeping time before checking for hosts/paths availability: {} seconds",
         config.wait_before
     );
     debug!(
-        " - Sleeping time once all hosts are available: {} seconds",
+        " - Sleeping time once all hosts/paths are available: {} seconds",
         config.wait_after
     );
     debug!(
@@ -49,22 +53,23 @@ pub fn wait(
 
     if config.wait_before > 0 {
         info!(
-            "Waiting {} seconds before checking for hosts availability",
+            "Waiting {} seconds before checking for hosts/paths availability",
             config.wait_before
         );
         info!("{}", LINE_SEPARATOR);
         sleep.sleep(config.wait_before);
     }
 
+    sleep.reset();
+
     if !config.hosts.trim().is_empty() {
-        sleep.reset();
         for host in config.hosts.trim().split(',') {
-            info!("Checking availability of {}", host);
+            info!("Checking availability of host [{}]", host);
             while !port_check::is_port_reachable_with_timeout(
                 &host.trim().to_string(),
                 Duration::from_secs(config.tcp_connection_timeout),
             ) {
-                info!("Host {} not yet available...", host);
+                info!("Host [{}] not yet available...", host);
                 if sleep.elapsed(config.global_timeout) {
                     error!(
                         "Timeout! After {} seconds some hosts are still not reachable",
@@ -75,14 +80,34 @@ pub fn wait(
                 }
                 sleep.sleep(config.wait_sleep_interval);
             }
-            info!("Host {} is now available!", host);
+            info!("Host [{}] is now available!", host);
+            info!("{}", LINE_SEPARATOR);
+        }
+    }
+
+    if !config.paths.trim().is_empty() {
+        for path in config.paths.trim().split(',') {
+            info!("Checking availability of path [{}]", path);
+            while !Path::new(path.trim()).exists() {
+                info!("Path {} not yet available...", path);
+                if sleep.elapsed(config.global_timeout) {
+                    error!(
+                        "Timeout! After [{}] seconds some paths are still not reachable",
+                        config.global_timeout
+                    );
+                    on_timeout();
+                    return;
+                }
+                sleep.sleep(config.wait_sleep_interval);
+            }
+            info!("Path [{}] is now available!", path);
             info!("{}", LINE_SEPARATOR);
         }
     }
 
     if config.wait_after > 0 {
         info!(
-            "Waiting {} seconds after hosts availability",
+            "Waiting {} seconds after hosts/paths availability",
             config.wait_after
         );
         info!("{}", LINE_SEPARATOR);
@@ -95,30 +120,35 @@ pub fn wait(
 
 pub fn config_from_env() -> Config {
     Config {
-        hosts: crate::env_reader::env_var(&"WAIT_HOSTS".to_string(), "".to_string()),
-        global_timeout: to_int(
-            &crate::env_reader::env_var(&"WAIT_HOSTS_TIMEOUT".to_string(), "".to_string()),
-            30,
-        ),
+        hosts: crate::env_reader::env_var("WAIT_HOSTS", "".to_string()),
+        paths: crate::env_reader::env_var("WAIT_PATHS", "".to_string()),
+        global_timeout: to_int(&legacy_or_new("WAIT_HOSTS_TIMEOUT", "WAIT_TIMEOUT", ""), 30),
         tcp_connection_timeout: to_int(
-            &crate::env_reader::env_var(&"WAIT_HOST_CONNECT_TIMEOUT".to_string(), "".to_string()),
+            &crate::env_reader::env_var("WAIT_HOST_CONNECT_TIMEOUT", "".to_string()),
             5,
         ),
-        wait_before: to_int(
-            &crate::env_reader::env_var(&"WAIT_BEFORE_HOSTS".to_string(), "".to_string()),
-            0,
-        ),
-        wait_after: to_int(
-            &crate::env_reader::env_var(&"WAIT_AFTER_HOSTS".to_string(), "".to_string()),
-            0,
-        ),
+        wait_before: to_int(&legacy_or_new("WAIT_BEFORE_HOSTS", "WAIT_BEFORE", ""), 0),
+        wait_after: to_int(&legacy_or_new("WAIT_AFTER_HOSTS", "WAIT_AFTER", ""), 0),
         wait_sleep_interval: to_int(
-            &crate::env_reader::env_var(&"WAIT_SLEEP_INTERVAL".to_string(), "".to_string()),
+            &crate::env_reader::env_var("WAIT_SLEEP_INTERVAL", "".to_string()),
             1,
         ),
     }
 }
 
+fn legacy_or_new(legacy_var_name: &str, var_name: &str, default: &str) -> String {
+    let mut temp_value = default.to_string();
+    if env_var_exists(legacy_var_name) {
+        warn!(
+            "Environment variable [{}] is deprecated. Use [{}] instead.",
+            legacy_var_name, var_name
+        );
+        temp_value = crate::env_reader::env_var(legacy_var_name, temp_value);
+    }
+    temp_value = crate::env_reader::env_var(var_name, temp_value);
+    temp_value
+}
+
 fn to_int(number: &str, default: u64) -> u64 {
     match number.parse::<u64>() {
         Ok(value) => value,

src/lib.rs

@@ -1,8 +1,9 @@
 #!/bin/bash
 
 export WAIT_HOSTS=localhost:4748
-export WAIT_HOSTS_TIMEOUT=10
-export WAIT_BEFORE_HOSTS=1
-export WAIT_AFTER_HOSTS=2
+#export WAIT_PATHS=./target/one
+export WAIT_TIMEOUT=10
+export WAIT_BEFORE=1
+export WAIT_AFTER=2
 
 ./target/x86_64-unknown-linux-musl/release/wait && echo 'DOOOOOOONEEEEEE'