Create missing directories (#274)

The following directories are created if they do not exist:
* config
* data
* log
* package
* directory of the certificate file if the file does not exist
* directory of the key file if the file does not exist

Author: siegfriedweber

CHANGELOG.adoc

@@ -6,11 +6,13 @@
 :267: https://github.com/stackabletech/agent/pull/267[#267]
 :270: https://github.com/stackabletech/agent/pull/270[#270]
 :273: https://github.com/stackabletech/agent/pull/273[#273]
+:274: https://github.com/stackabletech/agent/pull/274[#274]
 
 === Added
 * Prints self-diagnostic information on startup ({270})
 * Check added on startup if the configured directories exist and are
   writable by the Stackable agent ({273}).
+* Missing directories are created ({274}).
 
 === Changed
 * Lazy validation of repository URLs changed to eager validation

src/bin/stackable-agent.rs

@@ -7,7 +7,7 @@ use std::path::PathBuf;
 use kubelet::config::{Config, ServerConfig};
 use kubelet::Kubelet;
 use log::{error, info};
-use tokio::fs::File;
+use tokio::fs::{create_dir_all, File};
 
 use stackable_agent::config::AgentConfig;
 use stackable_agent::fsext::check_dir_is_writable;
@@ -56,6 +56,7 @@ async fn main() -> anyhow::Result<()> {
     );
 
     check_optional_files(&agent_config).await;
+    create_missing_directories(&agent_config).await;
     check_configured_directories(&agent_config).await;
 
     // Currently the only way to _properly_ configure the Krustlet is via these environment exports,
@@ -168,6 +169,33 @@ async fn check_optional_files(config: &AgentConfig) {
     }
 }
 
+/// Creates the directories where write access is required and which do
+/// not exist yet.
+///
+/// If a directory could not be created then an error is logged.
+async fn create_missing_directories(config: &AgentConfig) {
+    for (config_option, directory) in directories_where_write_access_is_required(config).await {
+        if directory.components().count() != 0 && !directory.exists() {
+            if let Err(error) = create_dir_all(&directory).await {
+                error!(
+                    "Could not create the directory [{}] which is \
+                    specified in the configuration option [{}]. {}",
+                    directory.to_string_lossy(),
+                    config_option.name,
+                    error
+                );
+            } else {
+                info!(
+                    "Directory [{}] created which is specified in the \
+                    configuration option [{}].",
+                    directory.to_string_lossy(),
+                    config_option.name
+                );
+            }
+        };
+    }
+}
+
 /// Checks the configured directories if they are writable by the
 /// current process. If this is not the case then errors are logged.
 ///