Support Existing Agents + Purge Entries (#45)

* docs: adjust readme for new property

* build: upgrade to latest deps

* feat: support existing agent + purge

* feat: add purge entry

Author: iBotPeaches

README.md

@@ -1,18 +1,19 @@
 # SSH Socket Setup GitHub Action
-Setup an SSH socket with a private key.
+_Set up (or re-use) an SSH socket with a private key._
 
 ## Usage
 ### Inputs
 
 Following inputs can be used as `step.with` keys
 
-| Name          | Required | Type   | Description                        |
-|---------------|----------|--------|------------------------------------|
-| `host`        | Yes      | String | Remote hostname.                   |
-| `port`        | No       | Number | SSH Port (default: `22`).          |
-| `socket-path` | No       | String | Path at which to create socket.    |
-| `key`         | Yes      | String | base64 private key                 |
-| `lifetime`    | No       | Number | Seconds to keep key (default: 600) |
+| Name          | Required | Type    | Description                                        |
+|---------------|----------|---------|----------------------------------------------------|
+| `host`        | Yes      | String  | Remote hostname.                                   |
+| `port`        | No       | Number  | SSH Port (default: `22`).                          |
+| `socket-path` | No       | String  | Path at which to create socket.                    |
+| `key`         | Yes      | String  | base64 private key                                 |
+| `lifetime`    | No       | Number  | Seconds to keep key (default: 600)                 |
+| `purge-entry` | No       | Boolean | Purge `known_hosts` entry for host (default: true) |
 
 You may encode your private key in base64 via:
 

action.yml

@@ -23,6 +23,10 @@ inputs:
     description: 'how many seconds to keep socket live'
     required: false
     default: '600'
+  purge-entry:
+    description: 'Whether to purge the host entry from known_hosts prior to addition.'
+    required: false
+    default: 'true'
 outputs:
   socket-path:
     description: 'path at which socket was created'

index.js

@@ -1,54 +1,69 @@
 const core = require('@actions/core');
-
 const { execSync } = require('child_process');
 
 const host = core.getInput('host');
 const port = core.getInput('port');
 const key = core.getInput('key');
 const lifetimeInSeconds = core.getInput('lifetime');
+const shouldPurgeEntry = core.getBooleanInput('purge-entry', {required: false});
 let socketPath = core.getInput('socket-path');
 
-// Create random socket path, if none passed.
-if (!socketPath) {
-    try {
-        socketPath = execSync('mktemp -u', {encoding: 'utf-8'}).trim();
-    } catch (e) {
-        core.setFailed(e.message);
-        process.exit(1);
-    }
-}
-
-console.log(`Attempting to create ${socketPath}...`);
+// Check if we already have a pid & sock.
+const pid = process.env.SSH_AGENT_PID;
+const sock = process.env.SSH_AUTH_SOCK;
 
 // Prepare the host file.
 execSync('mkdir -p ~/.ssh');
 execSync('touch ~/.ssh/known_hosts');
-execSync(`sed -i -e '/^${host} /d' ~/.ssh/known_hosts`);
-execSync(`ssh-keyscan${port ? ` -p ${port}` : ''} "${host}" >> ~/.ssh/known_hosts`);
 
-// Start the agent (or re-use one)
-try {
-    execSync(`ssh-agent -a "${socketPath}"`)
-} catch (e) {
-    if (e.message.includes('Address already in use')) {
-        core.info('Agent already exists on sock. Skipping creation.');
-    } else {
-        core.setFailed(e.message);
-        process.exit(1);
-    }
-}
+if (pid) {
+    core.info('SSH Agent already running. Skipping spawn of ssh-agent...');
 
-// Pluck the pid and set values (if possible)
-try {
-    const pid = parseInt(execSync(`fuser ${socketPath} 2> /dev/null`, {encoding: 'utf-8'}));
+    core.exportVariable('SSH_AUTH_SOCK', sock);
+    core.setOutput('socket-path', sock);
     core.exportVariable('SSH_AGENT_PID', pid);
     core.setOutput('agent-pid', pid);
-} catch (e) {
-    core.warning('PID capture failed (fuser). Skipping...');
+} else {
+    // Create random socket path, if none passed.
+    if (!socketPath) {
+        try {
+            socketPath = execSync('mktemp -u', {encoding: 'utf-8'}).trim();
+        } catch (e) {
+            core.setFailed(e.message);
+            process.exit(1);
+        }
+    }
+
+    console.log(`Attempting to create ${socketPath}...`);
+
+    try {
+        execSync(`ssh-agent -a "${socketPath}"`)
+    } catch (e) {
+        if (e.message.includes('Address already in use')) {
+            core.info('Agent already exists on sock. Skipping creation.');
+        } else {
+            core.setFailed(e.message);
+            process.exit(1);
+        }
+    }
+
+    // Pluck the pid and set values (if possible)
+    try {
+        const pid = parseInt(execSync(`fuser ${socketPath} 2> /dev/null`, {encoding: 'utf-8'}));
+        core.exportVariable('SSH_AGENT_PID', pid);
+        core.setOutput('agent-pid', pid);
+    } catch (e) {
+        core.warning('PID capture failed (fuser). Skipping...');
+    }
+
+    core.exportVariable('SSH_AUTH_SOCK', socketPath);
+    core.setOutput('socket-path', socketPath);
 }
 
-// Add the key and set outputs
-core.exportVariable('SSH_AUTH_SOCK', socketPath);
-core.setOutput('socket-path', socketPath);
+if (shouldPurgeEntry) {
+    execSync(`sed -i -e '/^${host} /d' ~/.ssh/known_hosts`);
+}
+execSync(`ssh-keyscan${port ? ` -p ${port}` : ''} "${host}" >> ~/.ssh/known_hosts`);
+
 execSync(`echo "${key}" | base64 -d | ssh-add -t ${lifetimeInSeconds} -`);
 core.info('Done; exiting.');