Docker Container Error on Missing Fonts

Environment

Environment	Docker Linux
Product	Progress® Telerik® Reporting

Description

When I try to render my report in a Docker container, and the report uses fonts such as Arial, which are not available on Linux by default, an exception may be thrown(look below).

Alternatively, the report may be rendered, but in rendering formats where the actual font is needed, such as PDF, the font will be replaced with the default one for the given Linux image(usually DejaVu Sans).

Error Message

error

System.NullReferenceException: Object reference not set to an instance of an object.
   at Telerik.Reporting.Drawing.FontExtensions.ToGdiFont(IFont font)
   at Telerik.Reporting.Processing.GdiFontInfoCache.CreateValue(IFont font)
   at Telerik.Reporting.Processing.GdiFontCache1.GetValue(IFont font)

Solution

Use the Dockerfile to install the missing Microsoft fonts via the ttf-mscorefonts-installer package. For example:

dockerfile

RUN apt-get update && \
    apt-get install -y debconf-utils && \
    echo "ttf-mscorefonts-installer msttcorefonts/accepted-mscorefonts-eula select true" | debconf-set-selections && \
    apt-get install -y \
        fontconfig \
        ttf-mscorefonts-installer && \
    fc-cache -f -v && \
    rm -rf /var/lib/apt/lists/*

Fonts not included in the package can be installed directly to the container using the docker container cp command to copy the font from a local directory into the container's /usr/share/fonts.

See Also

Using Container Platforms