Merge pull request #844 from initard/feature/790/log-request-plugin

Closes #790 Log Request Plugin

23 files changed, 851 insertions, 309 deletions

diff --git a/.github/workflows/build-workflow.yml b/.github/workflows/build-workflow.yml
index 6d930ac1..a20eb9c7 100644
--- a/.github/workflows/build-workflow.yml
+++ b/.github/workflows/build-workflow.yml
@@ -75,6 +75,13 @@ jobs:
           command: deb
           args: -p tedge_agent
 
+      - name: Build tedge_logfile_request_plugin debian package
+        uses: actions-rs/cargo@v1
+        # https://github.com/marketplace/actions/rust-cargo
+        with:
+          command: deb
+          args: -p tedge_logfile_request_plugin
+
       - name: build sawtooth-publisher for amd64
         uses: actions-rs/cargo@v1
         # https://github.com/marketplace/actions/rust-cargo
@@ -187,6 +194,9 @@ jobs:
       - name: Strip tedge_apama_plugin
         run: arm-linux-gnueabihf-strip target/${{ matrix.target }}/release/tedge_apama_plugin || aarch64-linux-gnu-strip target/${{ matrix.target }}/release/tedge_apama_plugin
 
+      - name: Strip tedge_logfile_request_plugin
+        run: arm-linux-gnueabihf-strip target/${{ matrix.target }}/release/tedge_logfile_request_plugin || aarch64-linux-gnu-strip target/${{ matrix.target }}/release/tedge_logfile_request_plugin
+
       - name: build tedge debian package for target
         uses: actions-rs/cargo@v1
         # https://github.com/marketplace/actions/rust-cargo
@@ -222,6 +232,13 @@ jobs:
           command: deb
           args: -p tedge_apama_plugin --no-strip --no-build --target=${{ matrix.target }}
 
+      - name: build tedge_logfile_request_plugin debian package for target
+        uses: actions-rs/cargo@v1
+        # https://github.com/marketplace/actions/rust-cargo
+        with:
+          command: deb
+          args: -p tedge_logfile_request_plugin --no-strip --no-build --target=${{ matrix.target }}
+
       - name: build sawtooth publisher
         uses: actions-rs/cargo@v1
         # https://github.com/marketplace/actions/rust-cargo
diff --git a/Cargo.lock b/Cargo.lock
index 0632b98a..7df83970 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -330,6 +330,35 @@ dependencies = [
 ]
 
 [[package]]
+name = "c8y_api"
+version = "0.1.0"
+dependencies = [
+ "agent_interface",
+ "async-trait",
+ "c8y_smartrest",
+ "chrono",
+ "clock",
+ "csv",
+ "download",
+ "futures",
+ "mockall",
+ "mqtt_channel",
+ "reqwest",
+ "serde",
+ "serde_json",
+ "tedge_config",
+ "tedge_utils",
+ "tempfile",
+ "test-case",
+ "thin_edge_json",
+ "thiserror",
+ "time 0.3.5",
+ "tokio",
+ "toml",
+ "tracing",
+]
+
+[[package]]
 name = "c8y_smartrest"
 version = "0.5.2"
 dependencies = [
@@ -339,12 +368,18 @@ dependencies = [
  "assert_matches",
  "csv",
  "download",
+ "mqtt_channel",
+ "reqwest",
  "serde",
  "serde_json",
+ "tedge_config",
+ "tempfile",
  "test-case",
  "thin_edge_json",
  "thiserror",
  "time 0.3.5",
+ "tokio",
+ "toml",
 ]
 
 [[package]]
@@ -424,6 +459,8 @@ dependencies = [
  "libc",
  "num-integer",
  "num-traits",
+ "serde",
+ "time 0.1.43",
  "winapi",
 ]
 
@@ -2691,6 +2728,30 @@ dependencies = [
 ]
 
 [[package]]
+name = "tedge_logfile_request_plugin"
+version = "0.5.2"
+dependencies = [
+ "anyhow",
+ "async-trait",
+ "c8y_api",
+ "c8y_smartrest",
+ "chrono",
+ "csv",
+ "futures",
+ "mockall",
+ "mqtt_channel",
+ "reqwest",
+ "serde",
+ "serde_json",
+ "tedge_config",
+ "tempfile",
+ "thiserror",
+ "tokio",
+ "toml",
+ "tracing",
+]
+
+[[package]]
 name = "tedge_mapper"
 version = "0.5.2"
 dependencies = [
@@ -2700,6 +2761,7 @@ dependencies = [
  "assert_matches",
  "async-trait",
  "batcher",
+ "c8y_api",
  "c8y_smartrest",
  "c8y_translator",
  "clock",
@@ -2753,13 +2815,13 @@ dependencies = [
 
 [[package]]
 name = "tempfile"
-version = "3.2.0"
+version = "3.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dac1c663cfc93810f88aed9b8941d48cabf856a1b111c29a40439018d870eb22"
+checksum = "5cdb1ef4eaeeaddc8fbd371e5017057064af0911902ef36b39801f67cc6d79e4"
 dependencies = [
  "cfg-if 1.0.0",
+ "fastrand",
  "libc",
- "rand",
  "redox_syscall",
  "remove_dir_all",
  "winapi",
diff --git a/Cargo.toml b/Cargo.toml
index 0bd9467e..99fec7f6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,12 +1,12 @@
 [workspace]
-
 members = [
     "crates/common/*",
     "crates/core/*",
     "crates/tests/*",
     "plugins/tedge_apt_plugin",
     "plugins/tedge_dummy_plugin",
-    "plugins/tedge_apama_plugin"
+    "plugins/tedge_apama_plugin",
+    "plugins/log_request_plugin",
 ]
 
 [profile.release]
diff --git a/configuration/contrib/operations/c8y/c8y_LogfileRequest b/configuration/contrib/operations/c8y/c8y_LogfileRequest
new file mode 100644
index 00000000..b30c550d
--- /dev/null
+++ b/configuration/contrib/operations/c8y/c8y_LogfileRequest
@@ -0,0 +1,4 @@
+[exec]
+topic = "c8y/s/ds"
+on_message = "522"
+command = "/usr/bin/tedge_logfile_request_plugin"
diff --git a/crates/common/tedge_config/src/tedge_config.rs b/crates/common/tedge_config/src/tedge_config.rs
index 52e0178e..32587a15 100644
--- a/crates/common/tedge_config/src/tedge_config.rs
+++ b/crates/common/tedge_config/src/tedge_config.rs
@@ -2,6 +2,13 @@ use crate::*;
 use certificate::{CertificateError, PemCertificate};
 use std::convert::{TryFrom, TryInto};
 
+/// loads tedge config from system default
+pub fn get_tedge_config() -> Result<TEdgeConfig, TEdgeConfigError> {
+    let tedge_config_location = TEdgeConfigLocation::from_default_system_location();
+    let config_repository = TEdgeConfigRepository::new(tedge_config_location);
+    Ok(config_repository.load()?)
+}
+
 /// Represents the complete configuration of a thin edge device.
 /// This configuration is a wrapper over the device specific configurations
 /// as well as the IoT cloud provider specific configurations.
diff --git a/crates/core/c8y_api/Cargo.toml b/crates/core/c8y_api/Cargo.toml
new file mode 100644
index 00000000..ea116f84
--- /dev/null
+++ b/crates/core/c8y_api/Cargo.toml
@@ -0,0 +1,33 @@
+[package]
+name = "c8y_api"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+agent_interface = { path = "../agent_interface"}
+async-trait = "0.1"
+c8y_smartrest = { path = "../c8y_smartrest" }
+chrono = "0.4"
+clock = { path = "../../common/clock" }
+csv = "1.1"
+download = { path = "../../common/download" }
+futures = "0.3"
+mockall = "0.10"
+mqtt_channel = { path = "../../common/mqtt_channel" }
+reqwest = { version = "0.11", default-features = false, features = ["json", "rustls-tls"] }
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+tedge_config = { path = "../../common/tedge_config" }
+tedge_utils = { path = "../../common/tedge_utils", features = ["logging"] }
+thin_edge_json = { path = "../thin_edge_json" }
+thiserror = "1.0"
+time = { version = "0.3", features = ["formatting"] }
+tokio = { version = "1.8", features = ["rt", "sync", "time"] }
+toml = "0.5"
+tracing = { version = "0.1", features = ["attributes", "log"] }
+
+[dev-dependencies]
+tempfile = "3.3"
+test-case = "1.2"
diff --git a/crates/core/tedge_mapper/src/sm_c8y_mapper/http_proxy.rs b/crates/core/c8y_api/src/http_proxy.rs
index 4013bc0a..dfd3c811 100644
--- a/crates/core/tedge_mapper/src/sm_c8y_mapper/http_proxy.rs
+++ b/crates/core/c8y_api/src/http_proxy.rs
@@ -1,10 +1,9 @@
-use crate::sm_c8y_mapper::error::SMCumulocityMapperError;
-use crate::sm_c8y_mapper::json_c8y::{
+use crate::json_c8y::{
     C8yCreateEvent, C8yManagedObject, C8yUpdateSoftwareListResponse, InternalIdResponse,
 };
-use crate::sm_c8y_mapper::mapper::SmartRestLogEvent;
 use async_trait::async_trait;
-use c8y_smartrest::smartrest_deserializer::SmartRestJwtResponse;
+use c8y_smartrest::{error::SMCumulocityMapperError, smartrest_deserializer::SmartRestJwtResponse};
+use chrono::{DateTime, Local};
 use mqtt_channel::{Connection, PubChannel, StreamExt, Topic, TopicFilter};
 use reqwest::Url;
 use std::time::Duration;
@@ -13,6 +12,8 @@ use tedge_config::{
     MqttPortSetting, TEdgeConfig,
 };
 use time::{format_description, OffsetDateTime};
+
+use serde::{Deserialize, Serialize};
 use tracing::{error, info, instrument};
 
 const RETRY_TIMEOUT_SECS: u64 = 60;
@@ -117,6 +118,13 @@ impl C8yEndPoint {
     }
 }
 
+#[derive(Debug, Deserialize, Serialize, PartialEq)]
+#[serde(rename_all = "camelCase")]
+/// used to retrieve the id of a log event
+pub struct SmartRestLogEvent {
+    pub id: String,
+}
+
 /// An HttpProxy that uses MQTT to retrieve JWT tokens and authenticate the device
 ///
 /// - Keep the connection info to c8y and the internal Id of the device
@@ -147,6 +155,7 @@ impl JwtAuthHttpProxy {
 
     pub async fn try_new(
         tedge_config: &TEdgeConfig,
+        session_name: &str,
     ) -> Result<JwtAuthHttpProxy, SMCumulocityMapperError> {
         let c8y_host = tedge_config.query_string(C8yUrlSetting)?;
         let device_id = tedge_config.query_string(DeviceIdSetting)?;
@@ -157,7 +166,7 @@ impl JwtAuthHttpProxy {
         let mqtt_config = mqtt_channel::Config::default()
             .with_port(mqtt_port)
             .with_clean_session(true)
-            .with_session_name("JWT-Requester")
+            .with_session_name(session_name)
             .with_subscriptions(topic);
         let mut mqtt_con = Connection::new(&mqtt_config).await?;
 
diff --git a/crates/core/tedge_mapper/src/sm_c8y_mapper/json_c8y.rs b/crates/core/c8y_api/src/json_c8y.rs
index 8566a84c..8566a84c 100644
--- a/crates/core/tedge_mapper/src/sm_c8y_mapper/json_c8y.rs
+++ b/crates/core/c8y_api/src/json_c8y.rs
diff --git a/crates/core/c8y_api/src/lib.rs b/crates/core/c8y_api/src/lib.rs
new file mode 100644
index 00000000..7eb6352c
--- /dev/null
+++ b/crates/core/c8y_api/src/lib.rs
@@ -0,0 +1,2 @@
+pub mod http_proxy;
+pub mod json_c8y;
diff --git a/crates/core/c8y_smartrest/Cargo.toml b/crates/core/c8y_smartrest/Cargo.toml
index 03f575bb..a25ef0da 100644
--- a/crates/core/c8y_smartrest/Cargo.toml
+++ b/crates/core/c8y_smartrest/Cargo.toml
@@ -9,14 +9,20 @@ rust-version = "1.58.1"
 agent_interface = { path = "../agent_interface" }
 csv = "1.1"
 download = { path = "../../common/download" }
+mqtt_channel = { path = "../../common/mqtt_channel" }
+reqwest = { version = "0.11", default-features = false, features = ["json", "rustls-tls"] }
 serde = { version = "1.0", features = ["derive"] }
+tedge_config = { path = "../../common/tedge_config" }
 thin_edge_json = { path = "../thin_edge_json" }
 thiserror = "1.0"
 time = { version = "0.3", features = ["formatting", "macros", "parsing", "serde"] }
+tokio = { version = "1.8", features = ["rt", "sync", "time"] }
+toml = "0.5"
 
 [dev-dependencies]
 anyhow = "1.0"
 assert_matches = "1.5"
 assert-json-diff = "2.0"
 serde_json = "1.0"
+tempfile = "3.3"
 test-case = "1.2.1"
diff --git a/crates/core/c8y_smartrest/src/error.rs b/crates/core/c8y_smartrest/src/error.rs
index ee52f984..9531f372 100644
--- a/crates/core/c8y_smartrest/src/error.rs
+++ b/crates/core/c8y_smartrest/src/error.rs
@@ -1,4 +1,5 @@
 use agent_interface::SoftwareUpdateResponse;
+use std::path::PathBuf;
 
 #[derive(thiserror::Error, Debug)]
 pub enum SmartRestSerializerError {
@@ -39,3 +40,72 @@ pub enum SmartRestDeserializerError {
     #[error("Empty request")]
     EmptyRequest,
 }
+
+#[derive(Debug, thiserror::Error)]
+pub enum OperationsError {
+    #[error(transparent)]
+    FromIo(#[from] std::io::Error),
+
+    #[error("Cannot extract the operation name from the path: {0}")]
+    InvalidOperationName(PathBuf),
+
+    #[error("Error while parsing operation file: '{0}': {1}.")]
+    TomlError(PathBuf, #[source] toml::de::Error),
+}
+
+#[derive(thiserror::Error, Debug)]
+pub enum SMCumulocityMapperError {
+    #[error("Invalid MQTT Message.")]
+    InvalidMqttMessage,
+
+    #[error(transparent)]
+    InvalidTopicError(#[from] agent_interface::TopicError),
+
+    #[error(transparent)]
+    InvalidThinEdgeJson(#[from] agent_interface::SoftwareError),
+
+    #[error(transparent)]
+    FromElapsed(#[from] tokio::time::error::Elapsed),
+
+    #[error(transparent)]
+    FromMqttClient(#[from] mqtt_channel::MqttError),
+
+    #[error(transparent)]
+    FromReqwest(#[from] reqwest::Error),
+
+    #[error(transparent)]
+    FromSmartRestSerializer(#[from] SmartRestSerializerError),
+
+    #[error(transparent)]
+    FromSmartRestDeserializer(#[from] SmartRestDeserializerError),
+
+    #[error(transparent)]
+    FromTedgeConfig(#[from] tedge_config::ConfigSettingError),
+
+    #[error(transparent)]
+    FromLoadTedgeConfigError(#[from] tedge_config::TEdgeConfigError),
+
+    #[error("Invalid date in file name: {0}")]
+    InvalidDateInFileName(String),
+
+    #[error("Invalid path. Not UTF-8.")]
+    InvalidUtf8Path,
+
+    #[error(transparent)]
+    FromIo(#[from] std::io::Error),
+
+    #[error("Request timed out")]
+    RequestTimeout,
+
+    #[error("Operation execution failed: {0}")]
+    ExecuteFailed(String),
+
+    #[error("An unknown operation template: {0}")]
+    UnknownOperation(String),
+
+    #[error(transparent)]
+    FromTimeFormat(#[from] time::error::Format),
+
+    #[error(transparent)]
+    FromTimeParse(#[from] time::error::Parse),
+}
diff --git a/crates/core/c8y_smartrest/src/lib.rs b/crates/core/c8y_smartrest/src/lib.rs
index 53976e8d..b6338b06 100644
--- a/crates/core/c8y_smartrest/src/lib.rs
+++ b/crates/core/c8y_smartrest/src/lib.rs
@@ -1,5 +1,7 @@
 pub mod alarm;
 pub mod error;
 pub mod event;
+pub mod operations;
 pub mod smartrest_deserializer;
 pub mod smartrest_serializer;
+pub mod topic;
diff --git a/crates/core/c8y_smartrest/src/operations.rs b/crates/core/c8y_smartrest/src/operations.rs
new file mode 100644
index 00000000..b3909aac
--- /dev/null
+++ b/crates/core/c8y_smartrest/src/operations.rs
@@ -0,0 +1,215 @@
+use std::{
+    collections::{HashMap, HashSet},
+    fs,
+    path::{Path, PathBuf},
+};
+
+use serde::Deserialize;
+
+use crate::error::OperationsError;
+
+/// Operations are derived by reading files subdirectories per cloud /etc/tedge/operations directory
+/// Each operation is a file name in one of the subdirectories
+/// The file name is the operation name
+
+#[derive(Debug, Clone, Deserialize, PartialEq)]
+#[serde(rename_all = "snake_case")]
+pub struct OnMessageExec {
+    command: Option<String>,
+    on_message: Option<String>,
+    topic: Option<String>,
+    user: Option<String>,
+}
+
+#[derive(Debug, Clone, Deserialize, PartialEq)]
+#[serde(rename_all = "lowercase")]
+pub struct Operation {
+    #[serde(skip)]
+    name: String,
+    exec: Option<OnMessageExec>,
+}
+
+impl Operation {
+    pub fn exec(&self) -> Option<&OnMessageExec> {
+        self.exec.as_ref()
+    }
+
+    pub fn command(&self) -> Option<String> {
+        self.exec().and_then(|exec| exec.command.clone())
+    }
+
+    pub fn topic(&self) -> Option<String> {
+        self.exec().and_then(|exec| exec.topic.clone())
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct Operations {
+    operations: Vec<Operation>,
+    operations_by_trigger: HashMap<String, usize>,
+}
+
+impl Operations {
+    pub fn new() -> Self {
+        Self {
+            operations: vec![],
+            operations_by_trigger: HashMap::new(),
+        }
+    }
+
+    pub fn add(&mut self, operation: Operation) {
+        if let Some(detail) = operation.exec() {
+            if let Some(on_message) = &detail.on_message {
+                self.operations_by_trigger
+                    .insert(on_message.clone(), self.operations.len());
+            }
+        }
+        self.operations.push(operation);
+    }
+
+    pub fn try_new(dir: impl AsRef<Path>, cloud_name: &str) -> Result<Self, OperationsError> {
+        get_operations(dir.as_ref(), cloud_name)
+    }
+
+    pub fn get_operations_list(&self) -> Vec<String> {
+        self.operations
+            .iter()
+            .map(|operation| operation.name.clone())
+            .collect::<Vec<String>>()
+    }
+
+    pub fn matching_smartrest_template(&self, operation_template: &str) -> Option<&Operation> {
+        self.operations_by_trigger
+            .get(operation_template)
+            .and_then(|index| self.operations.get(*index))
+    }
+
+    pub fn topics_for_operations(&self) -> HashSet<String> {
+        self.operations
+            .iter()
+            .filter_map(|operation| operation.topic())
+            .collect::<HashSet<String>>()
+    }
+}
+
+fn get_operations(dir: impl AsRef<Path>, cloud_name: &str) -> Result<Operations, OperationsError> {
+    let mut operations = Operations::new();
+
+    let path = dir.as_ref().join(&cloud_name);
+    let dir_entries = fs::read_dir(&path)?
+        .map(|entry| entry.map(|e| e.path()))
+        .collect::<Result<Vec<PathBuf>, _>>()?
+        .into_iter()
+        .filter(|path| path.is_file())
+        .collect::<Vec<PathBuf>>();
+
+    for path in dir_entries {
+        let mut details = match fs::read(&path) {
+            Ok(bytes) => toml::from_slice::<Operation>(bytes.as_slice())
+                .map_err(|e| OperationsError::TomlError(path.to_path_buf(), e))?,
+
+            Err(err) => return Err(OperationsError::FromIo(err)),
+        };
+
+        details.name = path
+            .file_name()
+            .and_then(|filename| filename.to_str())
+            .ok_or_else(|| OperationsError::InvalidOperationName(path.to_owned()))?
+            .to_owned();
+
+        operations.add(details);
+    }
+    Ok(operations)
+}
+
+#[cfg(test)]
+mod tests {
+    use std::io::Write;
+
+    use super::*;
+    use test_case::test_case;
+
+    // Structs for state change with the builder pattern
+    // Structs for Operations
+    struct Ops(Vec<PathBuf>);
+    struct NoOps;
+
+    struct TestOperationsBuilder<O> {
+        temp_dir: tempfile::TempDir,
+        operations: O,
+    }
+
+    impl TestOperationsBuilder<NoOps> {
+        fn new() -> Self {
+            Self {
+                temp_dir: tempfile::tempdir().unwrap(),
+                operations: NoOps,
+            }
+        }
+    }
+
+    impl TestOperationsBuilder<NoOps> {
+        fn with_operations(self, operations_count: usize) -> TestOperationsBuilder<Ops> {
+            let Self { temp_dir, .. } = self;
+
+            let mut operations = Vec::new();
+            for i in 0..operations_count {
+                let file_path = temp_dir.path().join(format!("operation{}", i));
+                let mut file = fs::File::create(&file_path).unwrap();
+                file.write_all(
+                    br#"[exec]
+                        command = "echo"
+                        on_message = "511""#,
+                )
+                .unwrap();
+                operations.push(file_path);
+            }
+
+            TestOperationsBuilder {
+                operations: Ops(operations),
+                temp_dir,
+            }
+        }
+    }
+
+    impl TestOperationsBuilder<Ops> {
+        fn build(self) -> TestOperations {
+            let Self {
+                temp_dir,
+                operations,
+            } = self;
+
+            TestOperations {
+                temp_dir,
+                operations: operations.0,
+            }
+        }
+    }
+
+    struct TestOperations {
+        temp_dir: tempfile::TempDir,
+        operations: Vec<PathBuf>,
+    }
+
+    impl TestOperations {
+        fn builder() -> TestOperationsBuilder<NoOps> {
+            TestOperationsBuilder::new()
+        }
+
+        fn temp_dir(&self) -> &tempfile::TempDir {
+            &self.temp_dir
+        }
+    }
+
+    #[test_case(0)]
+    #[test_case(1)]
+    #[test_case(5)]
+    fn get_operations_all(ops_count: usize) {
+        let test_operations = TestOperations::builder().with_operations(ops_count).build();
+
+        let operations = get_operations(test_operations.temp_dir(), "").unwrap();
+        dbg!(&operations);
+
+        assert_eq!(operations.operations.len(), ops_count);
+    }
+}
diff --git a/crates/core/c8y_smartrest/src/smartrest_deserializer.rs b/crates/core/c8y_smartrest/src/smartrest_deserializer.rs
index c995c7d1..fea01538 100644
--- a/crates/core/c8y_smartrest/src/smartrest_deserializer.rs
+++ b/crates/core/c8y_smartrest/src/smartrest_deserializer.rs
@@ -1,10 +1,11 @@
-use crate::error::SmartRestDeserializerError;
+use crate::error::{SMCumulocityMapperError, SmartRestDeserializerError};
 use agent_interface::{SoftwareModule, SoftwareModuleUpdate, SoftwareUpdateRequest};
 use csv::ReaderBuilder;
 use download::DownloadInfo;
 use serde::de::Error;
 use serde::{Deserialize, Deserializer, Serialize};
 use std::convert::{TryFrom, TryInto};
+use std::path::PathBuf;
 use time::{format_description, OffsetDateTime};
 
 #[derive(Debug)]
@@ -287,12 +288,50 @@ impl SmartRestJwtResponse {
     }
 }
 
+/// Returns a date time object from a file path or file-path-like string
+/// a typical file stem looks like this: "software-list-2021-10-27T10:29:58Z"
+///
+/// # Examples:
+/// ```
+/// use std::path::PathBuf;
+/// use crate::c8y_smartrest::smartrest_deserializer::get_datetime_from_file_path;
+///
+/// let mut path = PathBuf::new();
+/// path.push("/path/to/file/with/date/in/path-2021-10-27T10:29:58Z");
+/// let path_bufdate_time = get_datetime_from_file_path(&path).unwrap();
+/// ```
+pub fn get_datetime_from_file_path(
+    log_path: &PathBuf,
+) -> Result<OffsetDateTime, SMCumulocityMapperError> {
+    if let Some(stem_string) = log_path.file_stem().and_then(|s| s.to_str()) {
+        // a typical file stem looks like this: software-list-2021-10-27T10:29:58Z.
+        // to extract the date, rsplit string on "-" and take (last) 3
+        let mut stem_string_vec = stem_string.rsplit('-').take(3).collect::<Vec<_>>();
+        // reverse back the order (because of rsplit)
+        stem_string_vec.reverse();
+        // join on '-' to get the date string
+        let date_string = stem_string_vec.join("-");
+        let dt = OffsetDateTime::parse(&date_string, &format_description::well_known::Rfc3339)?;
+
+        return Ok(dt);
+    }
+    match log_path.to_str() {
+        Some(path) => Err(SMCumulocityMapperError::InvalidDateInFileName(
+            path.to_string(),
+        ))?,
+        None => Err(SMCumulocityMapperError::InvalidUtf8Path)?,
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
     use agent_interface::*;
     use assert_json_diff::*;
     use serde_json::json;
+    use std::fs::File;
+    use std::io::Write;
+    use std::str::FromStr;
     use test_case::test_case;
 
     // To avoid using an ID randomly generated, which is not convenient for testing.
@@ -568,4 +607,42 @@ mod tests {
         let log = SmartRestRestartRequest::from_smartrest(&smartrest);
         assert!(log.is_ok());
     }
+
+    #[test_case("/path/to/software-list-2021-10-27T10:44:44Z.log")]
+    #[test_case("/path/to/tedge/agent/software-update-2021-10-25T07:45:41Z.log")]
+    #[test_case("/path/to/another-variant-2021-10-25T07:45:41Z.log")]
+    #[test_case("/yet-another-variant-2021-10-25T07:45:41Z.log")]
+    fn test_datetime_parsing_from_path(file_path: &str) {
+        // checking that `get_date_from_file_path` unwraps a `chrono::NaiveDateTime` object.
+        // this should return an Ok Result.
+        let path_buf = PathBuf::from_str(file_path).unwrap();
+        let path_buf_datetime = get_datetime_from_file_path(&path_buf);
+        assert!(path_buf_datetime.is_ok());
+    }
+
+    #[test_case("/path/to/software-list-2021-10-27-10:44:44Z.log")]
+    #[test_case("/path/to/tedge/agent/software-update-10-25-2021T07:45:41Z.log")]
+    #[test_case("/path/to/another-variant-07:45:41Z-2021-10-25T.log")]
+    #[test_case("/yet-another-variant-2021-10-25T07:45Z.log")]
+    fn test_datetime_parsing_from_path_fail(file_path: &str) {
+        // checking that `get_date_from_file_path` unwraps a `chrono::NaiveDateTime` object.
+        // this should return an err.
+        let path_buf = PathBuf::from_str(file_path).unwrap();
+        let path_buf_datetime = get_datetime_from_file_path(&path_buf);
+        assert!(path_buf_datetime.is_err());
+    }
+
+    fn parse_file_names_from_log_content(log_content: &str) -> [&str; 5] {
+        let mut files: Vec<&str> = vec![];
+        for line in log_content.lines() {
+            if line.contains("filename: ") {
+                let