| 1234567891011121314151617181920212223242526 | FROM alpine:3.10RUN adduser -S postsrsd \    && apk add --no-cache postsrsd \    && mkdir -p /etc/postsrsd/secrets \    && chown postsrsd /etc/postsrsd/secretsUSER postsrsdVOLUME /etc/postsrsd/secrets# https://github.com/roehling/postsrsd/blob/1.6/postsrsd.c#L342ENV SRS_DOMAIN change-me.tldENV SRS_SECRET /etc/postsrsd/secrets/list# forward SRS lookupEXPOSE 10001/tcp# reverse SRS lookupEXPOSE 10002/tcp# > Cannot open file with secret: /etc/postsrsd/secrets/listCMD set -x; \    if [ ! -f "$SRS_SECRET" ]; \        then tr -dc '1-9a-zA-Z' < /dev/random | head -c 32 > "$SRS_SECRET"; \    fi \    && postsrsd -l0.0.0.0 -e
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