9715. Source Code Search with OpenGrok
OpenGrok

Use OpenGrok in docker for search source code.

1. OpenGrok

OpenGrok is a fast and usable source code search and cross reference engine, written in Java. It helps you search, cross-reference and navigate your source tree. It can understand various program file formats and version control histories of many source code management systems.

2. Docker Image for OpenGrok

You can manually setup OpenGrok from scratch, but it is much easier to use the docker image for OpenGrok. There is one image called ‘docker-opengrok’ on Docker Hub.

3. Setting up OpenGrok with Docker

3.1 Preparing Source Code

Create two directories in local disk.

$ mkdir -p /opengrok/src /opengrok/data
  • src - Contains your source files.
  • data - Used by OpenGrok. OpenGrok will generate indexes for the source files and store them here.

Download source code from GitHub to ‘src’ folder. Here, I cloned my three repositories.

$ cd /opengrok/src
$ git clone https://github.com/jojozhuang/Algorithm
$ git clone https://github.com/jojozhuang/Portfolio
$ git clone https://github.com/jojozhuang/Tutorials

Check directories/files.

Johnny@Johnny-Mac:~$ ls -all
total 0
drwxr-xr-x   5 Johnny  1694527156   160 May 03 21:34 .
drwxr-xr-x   5 Johnny  1694527156   160 May 03 21:20 ..
drwxr-xr-x  12 Johnny  1694527156   384 May 03 21:31 Algorithm
drwxr-xr-x  24 Johnny  1694527156   768 May 03 21:34 Portfolio
drwxr-xr-x  59 Johnny  1694527156  1888 May 03 21:10 Tutorials

3.2 Installing Image and Running Container

Pull the OpenGrok docker image.

$ docker pull opengrok/docker

Run a Docker container and mount these two directories: src and data; this will automatically run indexing as a part of startup.

$ docker run --name=opengrok-git -v /opengrok/src:/src -v /opengrok/data:/data -p 31030:8080 opengrok/docker

Later, you can use the following commands to start and stop the container.

$ docker start opengrok-git
$ docker stop opengrok-git

Use the following command to check logs.

$ docker logs opengrok-git

3.3 Issues

Sometimes, the opengrok indexer stops working, and you see the following message in the logs.

Indexer still locked, skipping indexing

This is because of the locker check, see here https://github.com/OpenGrok/docker/blob/master/scripts/index.sh.

#!/bin/bash

LOCKFILE=/var/run/opengrok-indexer
URI="http://localhost:8080"

if [ -f "$LOCKFILE" ]; then
	date +"%F %T Indexer still locked, skipping indexing"
	exit 1
fi
...

This issues occurs especially when indexing stops unexpectedly. The solution is to get inside the container and delete the file /var/run/opengrok-indexer.

$ docker exec -it opengrok-git bash
rm /var/run/opengrok-indexer

When the next time indexing happens, you won’t see this error, and indexer should start working again.

4. Searching Code

The OpenGrok application will now be running on http://192.168.99.100:31030/source/. Notice, we have three projects as we cloned three repositories into the ‘src’ folder. image

Search ‘trie’ in algorithm, all the questions related to trie are displayed. image Search ‘course player’ in portfolio, all my portfolios related to ‘course player’ are displayed. image Search ‘docker’ in tutorials, all my tutorials related to ‘docker’ are displayed. image

5. References