Add MIRRORD_IMPERSONATED_CONTAINER_NAME var (#182)

* Add MIRRORD_IMPERSONATED_CONTAINER_NAME var

* Use info log, iterate to find container name

CHANGELOG.md

@@ -8,6 +8,7 @@ Check [Keep a Changelog](http://keepachangelog.com/) for recommendations on how
 ## [Unreleased]
 ### Added
 - mirrord-cli `exec` subcommand accepts `--extract-path` argument to set the directory to extract the library to. Used for tests mainly.
+- mirrord-layer provides `MIRRORD_IMPERSONATED_CONTAINER_NAME` environment variable to specify container name to impersonate. mirrord-cli accepts argument to set variable.
 
 ### Changed
 - Refactor e2e, enable only Node HTTP mirroring test.

mirrord-cli/src/config.rs

@@ -58,6 +58,10 @@ pub(super) struct ExecArgs {
     #[clap(long, value_parser)]
     pub agent_ttl: Option<u16>,
 
+    /// Select container name to impersonate. Default is first container.
+    #[clap(long, value_parser)]
+    pub impersonate_container_name: Option<String>,
+
     /// Accept/reject invalid certificates.
     #[clap(short = 'c', long, value_parser)]
     pub accept_invalid_certificates: bool,

mirrord-cli/src/main.rs

@@ -89,6 +89,13 @@ fn exec(args: &ExecArgs) -> Result<()> {
         std::env::set_var("MIRRORD_AGENT_NAMESPACE", namespace.clone());
     }
 
+    if let Some(impersonate_container_name) = &args.impersonate_container_name {
+        std::env::set_var(
+            "MIRRORD_IMPERSONATED_CONTAINER_NAME",
+            impersonate_container_name,
+        );
+    }
+
     if let Some(log_level) = &args.agent_log_level {
         std::env::set_var("MIRRORD_AGENT_RUST_LOG", log_level.clone());
     }

mirrord-layer/src/config.rs

@@ -20,6 +20,9 @@ pub struct LayerConfig {
     #[envconfig(from = "MIRRORD_AGENT_IMPERSONATED_POD_NAMESPACE", default = "default")]
     pub impersonated_pod_namespace: String,
 
+    #[envconfig(from = "MIRRORD_IMPERSONATED_CONTAINER_NAME")]
+    pub impersonated_container_name: Option<String>,
+
     #[envconfig(from = "MIRRORD_ACCEPT_INVALID_CERTIFICATES", default = "false")]
     pub accept_invalid_certificates: bool,
 

mirrord-layer/src/pod_api.rs

@@ -10,7 +10,7 @@ use kube::{
 };
 use rand::distributions::{Alphanumeric, DistString};
 use serde_json::json;
-use tracing::{error, warn};
+use tracing::{error, info, warn};
 
 use crate::config::LayerConfig;
 
@@ -22,15 +22,34 @@ struct RuntimeData {
 }
 
 impl RuntimeData {
-    async fn from_k8s(client: Client, pod_name: &str, pod_namespace: &str) -> Self {
+    async fn from_k8s(
+        client: Client,
+        pod_name: &str,
+        pod_namespace: &str,
+        container_name: &Option<String>,
+    ) -> Self {
         let pods_api: Api<Pod> = Api::namespaced(client, pod_namespace);
         let pod = pods_api.get(pod_name).await.unwrap();
         let node_name = &pod.spec.unwrap().node_name;
-        let container_statuses = pod.status.unwrap().container_statuses.unwrap();
-        let container_info = container_statuses
-            .first()
-            .unwrap()
-            .container_id
+        let container_statuses = &pod.status.unwrap().container_statuses.unwrap();
+        let container_info = if let Some(container_name) = container_name {
+            &container_statuses
+                .iter()
+                .find(|&status| &status.name == container_name)
+                .with_context(|| {
+                    format!(
+                        "no container named {} found in namespace={}, pod={}",
+                        &container_name, &pod_namespace, &pod_name
+                    )
+                })
+                .unwrap()
+                .container_id
+        } else {
+            info!("No container name specified, defaulting to first container found");
+            &container_statuses.first().unwrap().container_id
+        };
+
+        let container_info = container_info
             .as_ref()
             .unwrap()
             .split("://")
@@ -61,6 +80,7 @@ pub async fn create_agent(config: LayerConfig) -> Result<Portforwarder> {
         image_pull_policy,
         impersonated_pod_name,
         impersonated_pod_namespace,
+        impersonated_container_name,
         ..
     } = config;
 
@@ -83,6 +103,7 @@ pub async fn create_agent(config: LayerConfig) -> Result<Portforwarder> {
         client.clone(),
         &impersonated_pod_name,
         &impersonated_pod_namespace,
+        &impersonated_container_name,
     )
     .await;
 

tests/src/sanity.rs

@@ -199,6 +199,7 @@ mod tests {
         env.insert("MIRRORD_AGENT_IMAGE", "test");
         env.insert("MIRRORD_CHECK_VERSION", "false");
         env.insert("MIRRORD_AGENT_RUST_LOG", "debug");
+        env.insert("MIRRORD_IMPERSONATED_CONTAINER_NAME", "test");
         env.insert("RUST_LOG", "debug");
         let server = Command::new(path)
             .args(args.clone())