I am trying to install erlang 25 (and elixir 1.13) on my ubuntu VM, but the default version installed by apt is erlang 24.
I've tried both :
sudo wget https://packages.erlang-solutions.com/erlang-solutions_1.0_all.deb && sudo dpkg -i erlang-solutions_1.0_all.d
sudo apt update
and
sudo wget https://packages.erlang-solutions.com/erlang-solutions_2.0_all.deb && sudo dpkg -i erlang-solutions_2.0_all.d
sudo apt update
but in both case, running apt-cache policy esl-erlang didn't show the desired version. I have recently installed erlang 25 on a identical vm, and I don't remember struggling at all, so I'm guessing there's a simple way of doing it that I just forgot ?
I hope you can help me, thank you !
From the Erlang OTP repo, you should do:
apt-get install erlang
If you decide to compile from source:
git clone https://github.com/erlang/otp.git
cd otp
git checkout maint-25 # current latest stable version
./configure
make
make install
Alternatively, you can use Kerl:
curl -O https://raw.githubusercontent.com/kerl/kerl/master/kerl
chmod a+x kerl
and place kerl in your PATH so that you can invoke it from the terminal (remember to source your .bashrc or similar if you update your PATH variable there, or open a new terminal to reload the PATH env), i.e.,
export PATH=<path-to-kerl>:$PATH
Instructions on how to use it here.
I would recommend the usage of the Erlang Version Manager, thanks to which you can compile and install any Erlang OTP version you need, regardless of what the default version is currently available for your Linux distro.
Installation of Erlang Version Manager:
$ git clone https://github.com/robisonsantos/evm /tmp/evm/
$ cd /tmp/evm/
$ /tmp/evm/install
$ echo 'source ~/.evm/scripts/evm' >> ~/.bashrc
$ bash
Installation of the specific Erlang OTP version:
$ evm install 25.1.1 -y
$ evm default 25.1.1
I am trying to set up a Docker image (my Dockerfile is available here, sorry for the french README: https://framagit.org/Gwendal/firefox-icedtea-docker) with an old version of Firefox and an old version of Java to run an old Java applet to start a VPN. My image does work and successfully allows me to start the Java applet in Firefox.
Unfortunately, the said applet then tries to run the following command in the container (I've simply removed the --config part from the command as it does not matter here):
INFO: launching '/usr/bin/pkexec sh -c /usr/sbin/openvpn --config ...'
Then the applet exits silently with an error. While investigating, I've tried running a command with pkexec with the same Docker image, and it gives me this result:
$ sudo docker-compose run firefox pkexec /firefox/firefox-sdk/bin/firefox-bin -new-instance
**
ERROR:pkexec.c:719:main: assertion failed: (polkit_unix_process_get_start_time (POLKIT_UNIX_PROCESS (subject)) > 0)
But I don't know polkit at all and cannot understand this error.
EDIT: A more minimal way to reproduce the problem is with this Dockerfile:
FROM ubuntu:16.04
RUN apt-get update \
&& apt-get install -y policykit-1
And then run:
$ sudo docker build -t pkexec-test .
$ sudo docker run pkexec-test pkexec echo Hello
Which leads here again to:
ERROR:pkexec.c:719:main: assertion failed: (polkit_unix_process_get_start_time (POLKIT_UNIX_PROCESS (subject)) > 0)
Should I conclude that pkexec cannot work in a docker container? Or is there any way to make this command work?
Sidenote: I have no control whatsoever on the Java applet that I try to run, it is a horrible and very dated proprietary black box that I am supposed to use at work, for which I have no access to the source code, and that I must use as is.
I have solved my own problem by replacing pkexec by sudo in the docker image, and by allowing passwordless sudo.
Given an ubuntu docker image where a user called developer was created and configured with a USER statement, add these lines:
# Install sudo and make 'developer' a passwordless sudoer
RUN apt-get install sudo
ADD ./developersudo /etc/sudoers.d/developersudo
# Replacing pkexec by sudo
RUN rm /usr/bin/pkexec
RUN ln -s /usr/bin/sudo /usr/bin/pkexec
with the file developersudo containing:
developer ALL=(ALL) NOPASSWD:ALL
This replaces any call to pkexec made in a process running in the container, by a call to sudo without any password prompt, which works nicely.
I have a user that has no home dir. In other words, $HOME is not defined.
It is a Jenkins user that runs a job. It does not have sudo access.
When I try to install rvm locally, it fails:
curl -sSL https://get.rvm.io > install_ruby.sh
bash install_ruby.sh stable
mkdir: cannot create directory ‘/.rvm’: Permission denied
So I try to trick it into thinking the HOME dir is the WORKSPACE dir:
export HOME=$WORKSPACE
curl -sSL https://get.rvm.io > install_ruby.sh
bash install_ruby.sh stable
It looks you are one of the happy *space* users (in home dir name),
RVM is not yet fully ready for it, use this trick to fix it:
sudo mkdir -p /ope.rvm
sudo chown -R "ope:" /ope.rvm
echo "export rvm_path=/ope.rvm" >> "/mnt/ope/ws/workspace/Hiptest Jenkins Integration Setup/.rvmrc"
and start installing again.
Unfortunately, this user does not have sudo access?
How can I install RVM for this particular job?
I ended up using rbenv. It worked out of the box.
I've got a Python Travis CI build and a Python unit test executes attempts to change the group of a file on the filesystem. The file was previously created by the unit test, so the user executing the test owns the file.
I'm able to start a sub-shell in which I can run chgrp commands (per the Travis guidelines), but unfortunately, this screws up the virtualenv set up for my specific Python version (and who knows what else).
How to replicate (in Travis CI script):
language: python
sudo: true
python:
- "3.4"
- "3.5"
before_install:
- sudo apt-get -qq update
- sudo gpasswd -a $USER fuse
script:
- touch testfile
- chgrp fuse testfile | echo 0 # this does not work - bad
- sudo -E su $USER -c "chgrp fuse testfile" # the sudo / su wrapper is required per Travis instructions, see link above - good
- python --version # reports 3.4 or 3.5 - good
- sudo -E su $USER -c "python --version" # always reports 2.7 - bad
- sudo -E su $USER -c "python --version" # always reports 3.2 - bad
As I've commented in the block above, running a command which attempts to change the group of the testfile (which is what my unit test code is doing) only works when wrapped with sudo -E su $USER -c.
Unfortunately, when I do this, I lose the ability to access python 3.4 and 3.5 in those script phases (which I've specified above) in the virtualenv that Travis has set up for me.
Any idea how I can achieve both of my goals? (allowing chgrp from the travis non-root user while simultaneously not mucking with the virtualenv or the python on the path?
When you create a new group, you have to log out and log in again to be able to use chgrp.
Using sudo is a way around this behavior. Since you're already using it for groupadd and usermod, I suggest changing the last line to sudo chgrp newtravisgroup newfile.
You can also use su to create a new login shell where newtravisgroup will be available but using sudo as mentioned above is the simplest way.
Edit:
When you use su PATH is reset. That's the reason python reverts back to the system python. You can activate the virtualenv again before running your test.
sudo -E su $USER -c "source $VIRTUAL_ENV/bin/activate; python --version"
I successfully shelled to a Docker container using:
docker exec -i -t 69f1711a205e bash
Now I need to edit file and I don't have any editors inside:
root#69f1711a205e:/# nano
bash: nano: command not found
root#69f1711a205e:/# pico
bash: pico: command not found
root#69f1711a205e:/# vi
bash: vi: command not found
root#69f1711a205e:/# vim
bash: vim: command not found
root#69f1711a205e:/# emacs
bash: emacs: command not found
root#69f1711a205e:/#
How do I edit files?
As in the comments, there's no default editor set - strange - the $EDITOR environment variable is empty. You can log in into a container with:
docker exec -it <container> bash
And run:
apt-get update
apt-get install vim
Or use the following Dockerfile:
FROM confluent/postgres-bw:0.1
RUN ["apt-get", "update"]
RUN ["apt-get", "install", "-y", "vim"]
Docker images are delivered trimmed to the bare minimum - so no editor is installed with the shipped container. That's why there's a need to install it manually.
EDIT
I also encourage you to read my post about the topic.
If you don't want to add an editor just to make a few small changes (e.g., change the Tomcat configuration), you can just use:
docker cp <container>:/path/to/file.ext .
which copies it to your local machine (to your current directory). Then edit the file locally using your favorite editor, and then do a
docker cp file.ext <container>:/path/to/file.ext
to replace the old file.
You can use cat if it's installed, which will most likely be the case if it's not a bare/raw container. It works in a pinch, and ok when copy+pasting to a proper editor locally.
cat > file
# 1. type in your content
# 2. leave a newline at end of file
# 3. ctrl-c / (better: ctrl-d)
cat file
cat will output each line on receiving a newline. Make sure to add a newline for that last line. ctrl-c sends a SIGINT for cat to exit gracefully. From the comments you see that you can also hit ctrl-d to denote end-of-file ("no more input coming").
Another option is something like infilter which injects a process into the container namespace with some ptrace magic: https://github.com/yadutaf/infilter
To keep your Docker images small, don't install unnecessary editors. You can edit the files over SSH from the Docker host to the container:
vim scp://remoteuser#containerip//path/to/document
You can use cat if installed, with the > caracter.
Here is the manipulation :
cat > file_to_edit
#1 Write or Paste you text
#2 don't forget to leave a blank line at the end of file
#3 Ctrl + C to apply configuration
Now you can see the result with the command
cat file
For common edit operations I prefer to install vi (vim-tiny), which uses only 1491 kB or nano which uses 1707 kB.
In other hand vim uses 28.9 MB.
We have to remember that in order for apt-get install to work, we have to do the update the first time, so:
apt-get update
apt-get install vim-tiny
To start the editor in CLI we need to enter vi.
You can open existing file with
cat filename.extension
and copy all the existing text on clipboard.
Then delete old file with
rm filename.extension
or rename old file with
mv old-filename.extension new-filename.extension
Create new file with
cat > new-file.extension
Then paste all text copied on clipboard, press Enter and exit with save by pressing ctrl+z. And voila no need to install any kind of editors.
Sometime you must first run the container with root:
docker exec -ti --user root <container-id> /bin/bash
Then in the container, to install Vim or something else:
apt-get install vim
I use "docker run" (not "docker exec"), and I'm in a restricted zone where we cannot install an editor. But I have an editor on the Docker host.
My workaround is: Bind mount a volume from the Docker host to the container (https://docs.docker.com/engine/reference/run/#/volume-shared-filesystems), and edit the file outside the container. It looks like this:
docker run -v /outside/dir:/container/dir
This is mostly for experimenting, and later I'd change the file when building the image.
After you shelled to the Docker container, just type:
apt-get update
apt-get install nano
You can just edit your file on host and quickly copy it into and run it inside the container. Here is my one-line shortcut to copy and run a Python file:
docker cp main.py my-container:/data/scripts/ ; docker exec -it my-container python /data/scripts/main.py
If you use Windows container and you want change any file, you can get and use Vim in Powershell console easily.
To shelled to the Windows Docker container with PowerShell:
docker exec -it <name> powershell
First install Chocolatey package manager
Invoke-WebRequest https://chocolatey.org/install.ps1 -UseBasicParsing | Invoke-Expression;
Install Vim
choco install vim
Refresh ENVIRONMENTAL VARIABLE
You can just exit and shell back to the container
Go to file location and Vim it vim file.txt
See Stack Overflow question
sed edit file in place
It would be a good option here, if:
To modify a large file, it's impossible to use cat.
Install Vim is not allowed or takes too long.
My situation is using the MySQL 5.7 image when I want to change the my.cnf file, there is no vim, vi, and Vim install takes too long (China Great Firewall). sed is provided in the image, and it's quite simple. My usage is like
sed -i /s/testtobechanged/textwanted/g filename
Use man sed or look for other tutorials for more complex usage.
It is kind of screwy, but in a pinch you can use sed or awk to make small edits or remove text. Be careful with your regex targets of course and be aware that you're likely root on your container and might have to re-adjust permissions.
For example, removing a full line that contains text matching a regex:
awk '!/targetText/' file.txt > temp && mv temp file.txt
(More)
If you can only shell into container with bin/sh (in case bin/bash doesn't work)
and apt or apt-get doesn't work in the container, check whether apk is installed by entering apk in command prompt inside the container.
If yes, you can install nano as follows:
apk add nano
then nano will work as usual
An easy way to edit a few lines would be:
echo "deb http://deb.debian.org/debian stretch main" > sources.list
You can install nano
yum install nano
You can also use a special container which will contain only the command you need: Vim. I chose python-vim. It assumes that the data you want to edit are in a data container built with the following Dockerfile:
FROM debian:jessie
ENV MY_USER_PASS my_user_pass
RUN groupadd --gid 1001 my_user
RUN useradd -ms /bin/bash --home /home/my_user \
-p $(echo "print crypt("${MY_USER_PASS:-password}", "salt")" | perl) \
--uid 1001 --gid 1001 my_user
ADD src /home/my_user/src
RUN chown -R my_user:my_user /home/my_user/src
RUN chmod u+x /home/my_user/src
CMD ["true"]
You will be able to edit your data by mounting a Docker volume (src_volume) which will be shared by your data container (src_data) and the python-vim container.
docker volume create --name src_volume
docker build -t src_data .
docker run -d -v src_volume:/home/my_user/src --name src_data_1 src_data
docker run --rm -it -v src_volume:/src fedeg/python-vim:latest
That way, you do not change your containers. You just use a special container for this work.
First login as root :
docker run -u root -ti bash
Type following commands:
apt-get update &&
apt-get install nano
docker comes up with no editors. so simply install vim, 36MB space don't kill your docker!
Make sure to update the container before trying to install the editor.
apt-get update
apt-get install nano vi