Fs path re-mapping

changelog.d/2068.added.md

@@ -0,0 +1,9 @@
+Add fs mapping, under `feature.fs.mapping` now it's possible to specify regex match and replace for paths while running mirrord exec.
+
+Example:
+
+```toml
+[feature.fs.mapping]
+"/var/app/temp" = "/tmp" # Will replace all calls to read/write/scan for "/var/app/temp/sample.txt" to "/tmp/sample.txt"
+"/var/app/.cache" = "/workspace/mirrord$0" # Will replace "/var/app/.cache/sample.txt" to "/workspace/mirrord/var/app/.cache/sample.txt" see [Regex::replace](https://docs.rs/regex/latest/regex/struct.Regex.html#method.replace)
+```

mirrord-schema.json

@@ -151,7 +151,7 @@
   "additionalProperties": false,
   "definitions": {
     "AdvancedFsUserConfig": {
-      "description": "Allows the user to specify the default behavior for file operations:\n\n1. `\"read\"` - Read from the remote file system (default) 2. `\"write\"` - Read/Write from the remote file system. 3. `\"local\"` - Read from the local file system. 4. `\"localwithoverrides\"` - perform fs operation locally, unless the path matches a pre-defined or user-specified exception.\n\n> Note: by default, some paths are read locally or remotely, regardless of the selected FS mode. > This is described in further detail below.\n\nBesides the default behavior, the user can specify behavior for specific regex patterns. Case insensitive.\n\n1. `\"read_write\"` - List of patterns that should be read/write remotely. 2. `\"read_only\"` - List of patterns that should be read only remotely. 3. `\"local\"` - List of patterns that should be read locally. 4. `\"not_found\"` - List of patters that should never be read nor written. These files should be treated as non-existent.\n\nThe logic for choosing the behavior is as follows:\n\n1. Check if one of the patterns match the file path, do the corresponding action. There's no specified order if two lists match the same path, we will use the first one (and we do not guarantee what is first).\n\n**Warning**: Specifying the same path in two lists is unsupported and can lead to undefined behaviour.\n\n2. There are pre-defined exceptions to the set FS mode. 1. Paths that match [the patterns defined here](https://github.com/metalbear-co/mirrord/tree/latest/mirrord/layer/src/file/filter/read_local_by_default.rs) are read locally by default. 2. Paths that match [the patterns defined here](https://github.com/metalbear-co/mirrord/tree/latest/mirrord/layer/src/file/filter/read_remote_by_default.rs) are read remotely by default when the mode is `localwithoverrides`. 3. Paths that match [the patterns defined here](https://github.com/metalbear-co/mirrord/tree/latest/mirrord/layer/src/file/filter/not_found_by_default.rs) under the running user's home directory will not be found by the application when the mode is not `local`.\n\nIn order to override that default setting for a path, or a pattern, include it the appropriate pattern set from above. E.g. in order to read files under `/etc/` remotely even though it is covered by [the set of patterns that are read locally by default](https://github.com/metalbear-co/mirrord/tree/latest/mirrord/layer/src/file/filter/read_local_by_default.rs), add `\"^/etc/.\"` to the `read_only` set.\n\n3. If none of the above match, use the default behavior (mode).\n\nFor more information, check the file operations [technical reference](https://mirrord.dev/docs/reference/fileops/).\n\n```json { \"feature\": { \"fs\": { \"mode\": \"write\", \"read_write\": \".+\\\\.json\" , \"read_only\": [ \".+\\\\.yaml\", \".+important-file\\\\.txt\" ], \"local\": [ \".+\\\\.js\", \".+\\\\.mjs\" ], \"not_found\": [ \"\\\\.config/gcloud\" ] } } } ```",
+      "description": "Allows the user to specify the default behavior for file operations:\n\n1. `\"read\"` - Read from the remote file system (default) 2. `\"write\"` - Read/Write from the remote file system. 3. `\"local\"` - Read from the local file system. 4. `\"localwithoverrides\"` - perform fs operation locally, unless the path matches a pre-defined or user-specified exception.\n\n> Note: by default, some paths are read locally or remotely, regardless of the selected FS mode. > This is described in further detail below.\n\nBesides the default behavior, the user can specify behavior for specific regex patterns. Case insensitive.\n\n1. `\"read_write\"` - List of patterns that should be read/write remotely. 2. `\"read_only\"` - List of patterns that should be read only remotely. 3. `\"local\"` - List of patterns that should be read locally. 4. `\"not_found\"` - List of patters that should never be read nor written. These files should be treated as non-existent. 4. `\"mapping\"` - Map of patterns and their corresponding replacers. The replacement happens before any specific behavior as defined above or mode (uses [`Regex::replace`](https://docs.rs/regex/latest/regex/struct.Regex.html#method.replace))\n\nThe logic for choosing the behavior is as follows:\n\n1. Check agains \"mapping\" if path needs to be replaced, if matched then continue to next step with new path after replacements otherwise continue as usual. 2. Check if one of the patterns match the file path, do the corresponding action. There's no specified order if two lists match the same path, we will use the first one (and we do not guarantee what is first).\n\n**Warning**: Specifying the same path in two lists is unsupported and can lead to undefined behaviour.\n\n3. There are pre-defined exceptions to the set FS mode. 1. Paths that match [the patterns defined here](https://github.com/metalbear-co/mirrord/tree/latest/mirrord/layer/src/file/filter/read_local_by_default.rs) are read locally by default. 2. Paths that match [the patterns defined here](https://github.com/metalbear-co/mirrord/tree/latest/mirrord/layer/src/file/filter/read_remote_by_default.rs) are read remotely by default when the mode is `localwithoverrides`. 3. Paths that match [the patterns defined here](https://github.com/metalbear-co/mirrord/tree/latest/mirrord/layer/src/file/filter/not_found_by_default.rs) under the running user's home directory will not be found by the application when the mode is not `local`.\n\nIn order to override that default setting for a path, or a pattern, include it the appropriate pattern set from above. E.g. in order to read files under `/etc/` remotely even though it is covered by [the set of patterns that are read locally by default](https://github.com/metalbear-co/mirrord/tree/latest/mirrord/layer/src/file/filter/read_local_by_default.rs), add `\"^/etc/.\"` to the `read_only` set.\n\n4. If none of the above match, use the default behavior (mode).\n\nFor more information, check the file operations [technical reference](https://mirrord.dev/docs/reference/fileops/).\n\n```json { \"feature\": { \"fs\": { \"mode\": \"write\", \"read_write\": \".+\\\\.json\" , \"read_only\": [ \".+\\\\.yaml\", \".+important-file\\\\.txt\" ], \"local\": [ \".+\\\\.js\", \".+\\\\.mjs\" ], \"not_found\": [ \"\\\\.config/gcloud\" ] } } } ```",
       "type": "object",
       "properties": {
         "local": {
@@ -166,6 +166,17 @@
             }
           ]
         },
+        "mapping": {
+          "title": "feature.fs.mapping {#feature-fs-mapping}",
+          "description": "Specify map of patterns that if matched will replace the path according to specification.\n\n*Capture groups are allowed.*\n\nExample: ```json { \"^/home/(?<user>\\S+)/dev/tomcat\": \"/etc/tomcat\" \"^/home/(?<user>\\S+)/dev/config/(?<app>\\S+)\": \"/mnt/configs/${user}-$app\" } ``` Will do the next replacements for any io operaton\n\n`/home/johndoe/dev/tomcat/context.xml` => `/etc/tomcat/context.xml` `/home/johndoe/dev/config/api/app.conf` => `/mnt/configs/johndoe-api/app.conf`",
+          "type": [
+            "object",
+            "null"
+          ],
+          "additionalProperties": {
+            "type": "string"
+          }
+        },
         "mode": {
           "title": "feature.fs.mode {#feature-fs-mode}",
           "anyOf": [

mirrord/config/src/feature/fs.rs

@@ -90,6 +90,7 @@ impl MirrordConfig for FsUserConfig {
                     .source_value(context)
                     .transpose()?,
                 not_found: None,
+                mapping: None,
             },
             FsUserConfig::Advanced(advanced) => advanced.generate_config(context)?,
         };
@@ -117,6 +118,7 @@ impl MirrordToggleableConfig for FsUserConfig {
             read_only,
             local,
             not_found: None,
+            mapping: None,
         })
     }
 }

mirrord/config/src/feature/fs/advanced.rs

@@ -1,3 +1,5 @@
+use std::collections::HashMap;
+
 use mirrord_analytics::{AnalyticValue, CollectAnalytics};
 use mirrord_config_derive::MirrordConfig;
 use schemars::JsonSchema;
@@ -31,17 +33,21 @@ use crate::{
 /// 3. `"local"` - List of patterns that should be read locally.
 /// 4. `"not_found"` - List of patters that should never be read nor written. These files should be
 /// treated as non-existent.
+/// 4. `"mapping"` - Map of patterns and their corresponding replacers. The replacement happens before any specific behavior as defined above or mode (uses [`Regex::replace`](https://docs.rs/regex/latest/regex/struct.Regex.html#method.replace))
 ///
 /// The logic for choosing the behavior is as follows:
 ///
-/// 1. Check if one of the patterns match the file path, do the corresponding action. There's
+///
+/// 1. Check agains "mapping" if path needs to be replaced, if matched then continue to next step
+///    with new path after replacements otherwise continue as usual.
+/// 2. Check if one of the patterns match the file path, do the corresponding action. There's
 /// no specified order if two lists match the same path, we will use the first one (and we
 /// do not guarantee what is first).
 ///
 ///     **Warning**: Specifying the same path in two lists is unsupported and can lead to undefined
 ///     behaviour.
 ///
-/// 2. There are pre-defined exceptions to the set FS mode.
+/// 3. There are pre-defined exceptions to the set FS mode.
 ///     1. Paths that match [the patterns defined here](https://github.com/metalbear-co/mirrord/tree/latest/mirrord/layer/src/file/filter/read_local_by_default.rs)
 ///        are read locally by default.
 ///     2. Paths that match [the patterns defined here](https://github.com/metalbear-co/mirrord/tree/latest/mirrord/layer/src/file/filter/read_remote_by_default.rs)
@@ -55,7 +61,7 @@ use crate::{
 ///     though it is covered by [the set of patterns that are read locally by default](https://github.com/metalbear-co/mirrord/tree/latest/mirrord/layer/src/file/filter/read_local_by_default.rs),
 ///     add `"^/etc/."` to the `read_only` set.
 ///
-/// 3. If none of the above match, use the default behavior (mode).
+/// 4. If none of the above match, use the default behavior (mode).
 ///
 /// For more information, check the file operations
 /// [technical reference](https://mirrord.dev/docs/reference/fileops/).
@@ -106,6 +112,25 @@ pub struct FsConfig {
     ///
     /// Specify file path patterns that if matched will be treated as non-existent.
     pub not_found: Option<VecOrSingle<String>>,
+
+    /// ### feature.fs.mapping {#feature-fs-mapping}
+    ///
+    /// Specify map of patterns that if matched will replace the path according to specification.
+    ///
+    /// *Capture groups are allowed.*
+    ///
+    /// Example:
+    /// ```json
+    /// {
+    ///   "^/home/(?<user>\S+)/dev/tomcat": "/etc/tomcat"
+    ///   "^/home/(?<user>\S+)/dev/config/(?<app>\S+)": "/mnt/configs/${user}-$app"
+    /// }
+    /// ```
+    /// Will do the next replacements for any io operaton
+    ///
+    /// `/home/johndoe/dev/tomcat/context.xml` => `/etc/tomcat/context.xml`
+    /// `/home/johndoe/dev/config/api/app.conf` => `/mnt/configs/johndoe-api/app.conf`
+    pub mapping: Option<HashMap<String, String>>,
 }
 
 impl MirrordToggleableConfig for AdvancedFsUserConfig {
@@ -127,6 +152,7 @@ impl MirrordToggleableConfig for AdvancedFsUserConfig {
             read_only,
             local,
             not_found: None,
+            mapping: None,
         })
     }
 }

mirrord/layer/src/detour.rs

@@ -9,7 +9,9 @@ use core::{
     convert,
     ops::{FromResidual, Residual, Try},
 };
-use std::{cell::RefCell, ops::Deref, os::unix::prelude::*, path::PathBuf, sync::OnceLock};
+use std::{
+    cell::RefCell, ffi::CString, ops::Deref, os::unix::prelude::*, path::PathBuf, sync::OnceLock,
+};
 
 #[cfg(target_os = "macos")]
 use libc::c_char;
@@ -150,10 +152,10 @@ pub(crate) enum Bypass {
     FileOperationInMirrordBinTempDir(*const c_char),
 
     /// File [`PathBuf`] should be ignored (used for tests).
-    IgnoredFile(PathBuf),
+    IgnoredFile(CString),
 
     /// Some operations only handle absolute [`PathBuf`]s.
-    RelativePath(PathBuf),
+    RelativePath(CString),
 
     /// Started mirrord with [`FsModeConfig`](mirrord_config::feature::fs::mode::FsModeConfig) set
     /// to [`FsModeConfig::Read`](mirrord_config::feature::fs::FsModeConfig::Read), but
@@ -209,6 +211,16 @@ pub(crate) enum Bypass {
     LocalDns,
 }
 
+impl Bypass {
+    pub fn relative_path(path: impl Into<Vec<u8>>) -> Self {
+        Bypass::RelativePath(CString::new(path).expect("Should be CStringable"))
+    }
+
+    pub fn ignored_file(path: impl Into<Vec<u8>>) -> Self {
+        Bypass::IgnoredFile(CString::new(path).expect("Should be CStringable"))
+    }
+}
+
 /// [`ControlFlow`](std::ops::ControlFlow)-like enum to be used by hooks.
 ///
 /// Conversion from `Result`:

mirrord/layer/src/file.rs

@@ -24,6 +24,7 @@ use mirrord_protocol::file::{GetDEnts64Request, GetDEnts64Response};
 
 pub(crate) mod filter;
 pub(crate) mod hooks;
+pub(crate) mod mapper;
 pub(crate) mod open_dirs;
 pub(crate) mod ops;
 

mirrord/layer/src/file/filter.rs

@@ -98,6 +98,7 @@ impl FileFilter {
             local,
             mode,
             not_found,
+            ..
         } = fs_config;
 
         let read_write =
@@ -399,12 +400,12 @@ mod tests {
             local,
             not_found,
             mode,
+            mapping: None,
         };
 
         let file_filter = FileFilter::new(fs_config);
 
-        let res =
-            file_filter.continue_or_bypass_with(path, write, || Bypass::IgnoredFile("".into()));
+        let res = file_filter.continue_or_bypass_with(path, write, || Bypass::ignored_file(""));
         println!("filter result: {res:?}");
         assert_eq!(res.kind(), expected);
     }
@@ -439,8 +440,7 @@ mod tests {
 
         let file_filter = FileFilter::new(fs_config);
 
-        let res =
-            file_filter.continue_or_bypass_with(path, write, || Bypass::IgnoredFile("".into()));
+        let res = file_filter.continue_or_bypass_with(path, write, || Bypass::ignored_file(""));
         println!("filter result: {res:?}");
 
         assert_eq!(res.kind(), expected);
@@ -464,7 +464,7 @@ mod tests {
     #[case("/root/.nuget/packages/microsoft.azure.amqp", DetourKind::Success)]
     fn not_found_set(#[case] path: &str, #[case] expected: DetourKind) {
         let filter = FileFilter::new(Default::default());
-        let res = filter.continue_or_bypass_with(path, false, || Bypass::IgnoredFile("".into()));
+        let res = filter.continue_or_bypass_with(path, false, || Bypass::ignored_file(""));
         println!("filter result: {res:?}");
 
         assert_eq!(res.kind(), expected);