58 lines
2.1 KiB
Markdown
58 lines
2.1 KiB
Markdown
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## nsinit
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`nsinit` is a cli application which demonstrates the use of libcontainer.
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It is able to spawn new containers or join existing containers.
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### How to build?
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First to add the `libcontainer/vendor` into your GOPATH. It's because something related with this [issue](https://github.com/docker/libcontainer/issues/210).
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```
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export GOPATH=$GOPATH:/your/path/to/libcontainer/vendor
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```
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Then get into the nsinit folder and get the imported file. Use `make` command to make the nsinit binary.
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```
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cd libcontainer/nsinit
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go get
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make
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```
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We have finished compiling the nsinit package, but a root filesystem must be provided for use along with a container configuration file.
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Choose a proper place to run your container. For example we use `/busybox`.
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```
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mkdir /busybox
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curl -sSL 'https://github.com/jpetazzo/docker-busybox/raw/buildroot-2014.11/rootfs.tar' | tar -xC /busybox
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```
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Then you may need to write a configure file named `container.json` in the `/busybox` folder.
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Environment, networking, and different capabilities for the container are specified in this file.
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The configuration is used for each process executed inside the container
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See the `sample_configs` folder for examples of what the container configuration should look like.
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```
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cp libcontainer/sample_configs/minimal.json /busybox/container.json
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cd /busybox
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```
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Now the nsinit is ready to work.
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To execute `/bin/bash` in the current directory as a container just run the following **as root**:
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```bash
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nsinit exec --tty /bin/bash
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```
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If you wish to spawn another process inside the container while your
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current bash session is running, run the same command again to
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get another bash shell (or change the command). If the original
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process (PID 1) dies, all other processes spawned inside the container
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will be killed and the namespace will be removed.
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You can identify if a process is running in a container by
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looking to see if `state.json` is in the root of the directory.
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You may also specify an alternate root place where
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the `container.json` file is read and where the `state.json` file will be saved.
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