For some obscure reason, Apple blocks me from accessing my own files with the Terminal. To allow Terminal to access all files and folders, I have to give Terminal the rights for “Full Disk Access” under “Security & Privacy” in the “System Preferences“.
Unlock the file:
chflags nouchg filename.txt
-R recursively change files-v verbose
It didn’t work out. Don’t bother repeating it. It seems that with this way, the image is not of the correct architecture!
I’d like to transfer Docker images without depending on an external repository like Docker Hub.
Check the images:
docker images
Save the image to a tar file:
docker save -o myImage.tar rolfsuter/testmultiarch:latest
Copy the tar file to the Pi:
scp myImage.tar pi@[IP]:myImage.tar
Connect to the Pi:
ssh pi@[IP]
List the current Docker images on the Pi:
sudo docker images
Load the image from the tar file:
sudo docker load -i myImage.tar
Check the image. Run:
sudo docker run --rm rolfsuter/testmultiarch:latest uname
Response:
standard_init_linux.go:211: exec user process caused "exec format error"
Recently, I got a Raspberry Pi 3 Model B. Now, I’d like to figure out, if I can run an F# server in a Docker container on it. I am aware that the currently installed Raspberry Pi OS is actually a 32-bit OS while the processor of my Pi has an 64-bit architecture. This has an impact if I’d like to install .NET directly on the OS. Since I intend to use Docker, I’ll sort that out later and just try to get it going.
Try to run a container with .NET installed:
sudo docker run -it microsoft/dotnet:latest
Since I managed to spin up a .NET container, the next step is to create an F# console application and run it:
mkdir test
cd test
dotnet new console -lang "F#"
dotnet run
I am also able to run the dll file directy:
dotnet bin/Debug/netcoreapp2.1/test.dll
To exit the container and keep it running, I press [ctrl] + [p] followed by [ctrl] + [q].
First I create in the current directory a folder hostFolder containing a subfolder on the host system. I’ll mount hostFolder into the container below.
mkdir hostFolder
mkdir hostFolder/subfolder
Then I create a container from the image microsoft/dotnet:latest. Using the -v flag, I mount the hostFolder into the /targetFolder in the container. Note that the directory targetFolder is created in the root directory (/). The term "${PWD}"/hostFolder determines the path of the hostFolder to mount with ${PWD} being the current working directory. The part after the colon : with the path /targetFolder defines the mount point in the container. The -w flag determines the working directory in the container. Thus, I get directly into the /targetFolder/subFolder directory in the container.
sudo docker run -it \
-v "${PWD}"/hostFolder:/targetFolder \
-w /targetFolder/subfolder \
microsoft/dotnet:latest
For testing I create a test file within the subfolder on the container and see it on the host system.
sudo docker run -it -v "${PWD}"/Source/Repos/Lab/TestApp:/TestApp -w /TestApp microsoft/dotnet:latest
A Dockerfile describes how Docker creates an image and runs it. However, I’d like to develop on my Mac and try to setup the docker image there. Thus, I’ll setup a SAFE stack app on my Mac in another post.
Here are some notes about working with Docker. On my Raspberry Pi I need to run all commands as sudo.
First of all, do not confuse the different terms. An image is like a blueprint that serves to generate containers. The containers are then the actual instance that you can start or stop.
docker images
docker ps
docker ps -a
container command. I don’t know it it differs from the ps command above. The output seems to be the same.
docker container ls
docker start [Container ID]
e.g.
docker start 725dc751823b
If started a container with the docker run options -i and -t, you can detach from it and leave it running:
[Ctrl] + [p] followed by [Ctrl] + [q]
docker attach [Container ID]
I set up Pi-hole on a Raspberry Pi already a while ago and it is running fine. These are my notes that I took during installation. Unfortunately, the lack some details…
docker_run.sh‘ script from https://github.com/pi-hole/docker-pi-hole/blob/master/docker_run.sh
scp docker_run.sh pi@[IP]:docker_run.sh
sudo sh docker_run.sh
The script starts well but then encounters an issue after running the container:
Starting up pihole container docker_run.sh: 19: [: healthy: unexpected operator
.docker_run.sh: 19: [: healthy: unexpected operator
.docker_run.sh: 19: [: healthy: unexpected operator
.docker_run.sh: 19: [: healthy: unexpected operator
sudo docker container ls
sudo docker inspect [Container ID]
Search the log file for the password
sudo docker logs pihole
You can ignore files in git from being added to the repository by putting a .gitignore file into place. It might however happen that the .gitignore file seems not work. This is the case if you have already included the files in the git repository index.
To resolve the issue, you can perform these commands in your project directory containing the .git folder:
$ git rm -r --cached .
$ git add .
$ git commit -am "Remove ignored files"
.gitignore file controls that git does not add the files to ignore.There are several options to define the assembly information of an .NET Core app in F#:
.fsproj fileDirectory.Build.props filedotnet build or dotnet publish: -p:Version=a.b.c.dThe information of the .fsproj file seems to have priority over Directory.Build.props file. You can place the Directory.Build.props file in the project folder or the solution folder.
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>netcoreapp3.1</TargetFramework>
<Version>1.0.0.0</Version>
<FileVersion>1.0.0.0</FileVersion>
<Product>MyApp</Product>
<Copyright>Copyright © 2020 by myself</Copyright>
</PropertyGroup>
<ItemGroup>
...
<Project>
<PropertyGroup>
<Version>1.0.0.0</Version>
<FileVersion>1.0.0.0</FileVersion>
<Product>MyApp</Product>
<Copyright>Copyright © 2020 by myself</Copyright>
</PropertyGroup>
</Project>
cat MyApp.dllInstall the versioninfo tool and run it on the .dll:
dotnet tool install --global dotnet-versioninfoversioninfo MyApp.dllThe F5 button is the magic button to start debugging. However, if you start debugging the first time, you need to set up VisualStudio Code first. You need to setup a launch.json file to start debugging and a tasks.json file to first run the process.
F5.NET Core
launch.json file in the .vscode folder and opens it.
launch.json fileCtrl + Space Bar.NET: Launch .NET Core Console App.dll file in the program attribute: "${workspaceFolder}/src/MailBoxTransformer/bin/Debug/netcoreapp3.1/MailBoxTransformer.dll"src sub-folder.
F5 againbuild task defined in the preLaunchTask attribute of the launch.json fileConfigure Task
Create tasks.json file from template
.NET Core Executes .NET core build command template
tasks.json file in the .vscode folder and opens it.tasks.json file.fsproj file is not in the main folder.fsproj file as an additional argument for dotnet build."${workspaceFolder}/src/MailBoxTransformer",presentation attribute in the tasks.json file "silent" to "always"
F5 againdotnet build processlaunch.json and the tasks.json files located in the .vscode folder to your source control system (e.g. git).
You are now able to start the build process and the app itself from within VS Code. Now you can set break points and debug your app. I have included the complete launch.json and the tasks.json files below. Have fun!
.vscode folder
{
// Use IntelliSense to learn about possible attributes.
// Hover to view descriptions of existing attributes.
// For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
"version": "0.2.0",
"configurations": [
{
"name": ".NET Core Launch (console)",
"type": "coreclr",
"request": "launch",
"preLaunchTask": "build",
"program": "${workspaceFolder}/src/MailBoxTransformer/bin/Debug/netcoreapp3.1/MailBoxTransformer.dll",
"args": [],
"cwd": "${workspaceFolder}",
"stopAtEntry": false,
"console": "internalConsole"
}
]
}
.vscode folder
{
// See https://go.microsoft.com/fwlink/?LinkId=733558
// for the documentation about the tasks.json format
"version": "2.0.0",
"tasks": [
{
"label": "build",
"command": "dotnet",
"type": "shell",
"args": [
"build",
"${workspaceFolder}/src/MailBoxTransformer",
// Ask dotnet build to generate full paths for file names.
"/property:GenerateFullPaths=true",
// Do not generate summary otherwise it leads to duplicate errors in Problems panel
"/consoleloggerparameters:NoSummary"
],
"group": "build",
"presentation": {
"reveal": "always"
},
"problemMatcher": "$msCompile"
}
]
}
dotnet new console -lang "F#" -o src/MyConsoleApp
The easy way: Move first to the folder with the .fsproj file and then use dotnet run without any arguments:
cd src/MyConsoleApp
dotnet run
If you want to start the app from a location different than the one containing the .fsproj file, you need to enter the argument --project with the path to the .fsproj file.
dotnet run --project src/MyConsoleApp/MyConsoleApp.fsproj