<p>The final image will have all the layers from <code>diamol/base</code> as well as two additional layers - one for COPY and one for RUN command.</p>
<p>File <code>/build.txt</code> will have the following contents:</p>
<pre><code>Building...
Testing...
Done...
</code></pre>

CC BY-SA 4.0
2020-08-25T18:48:17.960Z
2020-08-25T18:48:17.960Z
Konrad Botor
<p>Below is the dockerfile that creates an image:</p>
<pre><code>FROM diamol/base AS build-stage                  
RUN echo 'Building...' &gt; /build.txt             

FROM diamol/base AS test-stage
COPY --from=build-stage /build.txt /build.txt
RUN echo 'Testing...' &gt;&gt; /build.txt              

FROM diamol/base
COPY --from=test-stage /build.txt /build.txt
RUN echo 'Done...' &gt;&gt; /build.txt               
</code></pre>
<p>and my understanding is, the final image consists layers of diamol/base and the layer created after the last RUN command as picture below shows:
<a href="https://i.sstatic.net/TE7Z5.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/TE7Z5.png" alt="enter image description here" /></a></p>
<p>Is my understanding correct?</p>

CC BY-SA 4.0
2020-09-10T07:10:22.217Z
Multiply posted at https://stackoverflow.com/q/63578999/340790 .
JdeBP
<docker>
what's the final output image in multistage build?
amjad
# what's the final output image in multistage build?

(Asked by: username_0 on 2020-08-25)

Below is the dockerfile that creates an image:
FROM diamol/base AS build-stage                  
RUN echo 'Building...' > /build.txt             

FROM diamol/base AS test-stage
COPY --from=build-stage /build.txt /build.txt
RUN echo 'Testing...' >> /build.txt              

FROM diamol/base
COPY --from=test-stage /build.txt /build.txt
RUN echo 'Done...' >> /build.txt               

and my understanding is, the final image consists layers of diamol/base and the layer created after the last RUN command as picture below shows:

Is my understanding correct?

**Tags:** docker

> **Comments:**
> **username_1**: Multiply posted at https://stackoverflow.com/q/63578999/340790 .  

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## 1 answers

### Answer by username_2 on 2020-08-25. Score: 1

The final image will have all the layers from diamol/base as well as two additional layers - one for COPY and one for RUN command.
File /build.txt will have the following contents:
Building...
Testing...
Done...


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