Using (pprof) web on a headless box

[Traun Leyden]

I'm running CentOS 6 in a Docker container, and I'm not running an X Server on it.

When I try to run the "web" command I get:

(pprof) web

Total: 6962 samples

Dropping nodes with <= 34 samples; edges with <= 6 abs(samples)

Loading web page file:////tmp/nJ2VpkjSyr.0.svg

Can't exec "/etc/alternatives/gnome-www-browser": No such file or directory at /usr/lib/go/pkg/tool/linux_amd64/pprof line 743.

Can't exec "/etc/alternatives/x-www-browser": No such file or directory at /usr/lib/go/pkg/tool/linux_amd64/pprof line 743.

Can't exec "google-chrome": No such file or directory at /usr/lib/go/pkg/tool/linux_amd64/pprof line 743.

Can't exec "firefox": No such file or directory at /usr/lib/go/pkg/tool/linux_amd64/pprof line 743.

Could not load web browser.

And unfortunately it doesn't even save the file to /tmp/EmBAQVn6Kr.0.svg -- it seems like it deletes it after it fails to find a web browser.

I tried installing firefox, and it doesn't work there either:

(pprof) web

Total: 6962 samples

Dropping nodes with <= 34 samples; edges with <= 6 abs(samples)

Loading web page file:////tmp/o7Z_W5cOVJ.0.svg

Can't exec "/etc/alternatives/gnome-www-browser": No such file or directory at /usr/lib/go/pkg/tool/linux_amd64/pprof line 743.

Can't exec "/etc/alternatives/x-www-browser": No such file or directory at /usr/lib/go/pkg/tool/linux_amd64/pprof line 743.

Can't exec "google-chrome": No such file or directory at /usr/lib/go/pkg/tool/linux_amd64/pprof line 743.

Error: no display specified

Could not load web browser.

Is there any way to just tell it to dump an svg file to the filesystem rather than trying to open a web browser?

[Caleb Spare]

Hi Traun,

$ go tool pprof -h 2>&1 | grep svg
-svg Outputs a graph in SVG format

I haven't used that, but it seems like it ought to work.

-Caleb

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[Traun Leyden]

Thanks Caleb, that's just what I'm looking for.

Unfortunately I'm profiling a binary compiled with go 1.2, and that option doesn't seem available.  Oh well, at least I know it should work once I'm on a later version of go.

[Benjamin Measures]

On Friday, 23 January 2015 01:46:57 UTC, Traun Leyden wrote:

Unfortunately I'm profiling a binary compiled with go 1.2, and that option doesn't seem available.  Oh well, at least I know it should work once I'm on a later version of go.

Until then, you can fake firefox to do what you need:

cat <<"EOF" > /usr/bin/firefox
#!/bin/sh
[[ $# -eq 1 ]] || exit
tmpdir=$(mktemp -d)
cat "$1" > "$tmpdir/$(basename "$1")"
echo "$tmpdir/$(basename "$1")" >&2
EOF
chmod +x /usr/bin/firefox

go tool pprof test.prof
(pprof) web
(pprof) /tmp/tmp.BLEjnCWQGZ/pprof001.svg

[Traun Leyden]

Sorry, I take that back.  I had been looking at the interactive help rather than "go tool pprof --help", and I do see an -svg option.